What Can Wobbling Muons Tell Us About the Particles in our Universe?

Ok good evening everyone and welcome it's been  an exciting two weeks here at Fermilab as we've   watched the rest of the world uh wonder what g  minus 2 is all about so you happen to have picked   a good night to come to a public lecture uh it's  my pleasure to introduce our speaker this evening   tell us Dr Adam Lyon he's an experimental  particle physicist here at Fermilab he   received his undergraduate degree from  north carolina state university in 1991   and his phd from the university of maryland  in 1997. he did his thesis work here on the d0   experiment which many of you know and search for  supersymmetric particles and he did not find any   after that he went to the university of  rochester and studied heavy quarks at the cornell   accelerator and then he came back to fermilab  and joined the scientific computing division   as an associate scientist he's been heavily  involved in particle physics here at the   lab including data management high performance  computing and he's now an associate division head   and leads the scientific computing divisions  82 scientists so it's a big job there   he joined g minus two on 2011 even before the  big magnet arrives so he's been on it since the   beginning here at fermilab and in recent times  he's been working on quantum computing so adam   really does a lot of very interesting things in  his life and i look forward to hearing what you   have to say tonight adam so welcome over to you  wow thank you so much nigel i really appreciate   the introduction let me uh get things going here  hopefully you can see me and he hear me okay   so great i'm gonna do that okay okay you should  be able to see my screen so let me start yeah   okay great okay so thank you welcome everyone  it is such a pleasure and honor to uh to be   telling you about uh the first result from uh our  muon g minus two experiment here at fermilab or   what can wobbly muons tell us about the particles  in our universe uh so i'm speaking on behalf of   the muon g minus two collaboration and let  me say first for a second what that means so   um the work that i'll be showing is really a  work of of many many people so uh there are   a little over 200 people working on this  experiment uh from 35 institutions and   seven countries from all over the world you  can see on our map you know if we want to   have a meeting where everyone shows up awake and  that's not an easy thing to do um and actually   i should point out this is a small collaboration  uh there are collaborations and particle physics   experiments that have thousands of people so  we're we're actually a very small collaboration   and as as uh as nigel said this is a really  exciting time for me on t-2 in fermilab about   two weeks ago uh one of our spokespersons chris  paulie presented the first result from our muon g   minus 2 experiment and that's what i'll be talking  about tonight um and hopefully some of you got to   see that science seminar so i'll give you some  of the background behind this and as nigel said   we're just amazed by all the excitement from our  our little experiment so i have to start at the   beginning uh and and tell you a little bit about  what particle physics is and and how it works   so the question questions we're really trying to  answer are you know what are the building blocks   of matter what's the universe made out of at the  smallest scale scale and how do those building   blocks interact what are the forces that that  go between them so you know we start with kind   of the standard picture of something you know  like a dew drop of water uh that contains water   molecules the water molecules have atoms right  and the atoms have electrons and protons and and   also neutrons uh and and for a long time that we  thought that was the story until in the late 60s   it was discovered that protons and neutrons  have internal structure they actually have   quarks inside of them they have three quarks the  proton has two ups and a down quark and we kind of   imagine that there's gluons these particles that  carry the strong force that bind these particles   together inside the proton and also bind the  protons and the neutrons into the nucleus   so so this zone now sort of build up the standard  model which is sort of our periodic table of   of uh subatomic physics uh and now i've already  told you about three particles uh the up quark the   down quark that make protons and neutrons and the  electron and what's really amazing is that with   these three particles that pretty much describes  matter in our everyday world everything uh you   me the planet uh cars dogs everything uh that  is made up of up down and electrons uh there's   also i mentioned the gluons that's the force  particle for the strong force there's photons   you probably have heard of those they carry the  electromagnetic force in fact there's photons   hitting from sent out by your screen hitting  your eyes so photons are very important um   so what's really interesting in particle physics  is that as we've done experiments and looked for   more particles we found more so the electron has  some heavier cousins it has a particle called the   muon we'll talk about this one a lot and even  heavier cousin call called the tau um and then   there are other particles that are associated with  each of the electron muon and tau collectively   these are called leptons and these other particles  are the neutrinos and these are really fascinating   interesting particles fermilab has become the  world's premier particle physics laboratory and   studying neutrinos we have many neutrinos neutrino  experiments and we're building new ones uh we're   building a big experiment in a mine in south  dakota called dune uh you've probably heard talks   about that if you pay attention to the fermi lab  on youtube and things like that i won't talk about   neutrinos very much for we'll concentrate instead  on the muons but neutrinos are very interesting   and along with the with the additional electrons  we've discovered additional quarks um so in fact   i was at the d0 experiment when the top quark was  discovered in 1995 that was another very exciting   time and so you see this where are these three  families three columns of of uh of fundamental   particles um and then to round out the force  carrying particles we have the photon the gluon   that i talked about and then there's the weak  force which is involved in radioactive decay and   that has two force carrying particles a heavy w  particle and a heavy z particle the w and z boson   and then there's one more particle that was  predicted for quite a while uh it was finally   discovered at the large experiments on the large  hadron collider at cern and this particle is the   higgs boson so this made you know all the  news in 2012 and this completes the picture   of the stair model uh and we think that well  higgs boson is involved in giving mass to to   particles in this terror model uh and this is the  the picture of what we have of the stereo model   and this has been tested with literally thousands  of analyses and uh and all these particles exist   and we study them uh but we have this notion that  you know we want to ask is this the whole picture   um is there more to the story and we  think that this is not the whole picture   uh that that there must be more to this story  um and so we look uh beyond the steering model   uh to try to look for look for things that that  the stereo model doesn't explain and find other   theories that can encompass the theorem model  and explain these things so for example when i   went through the forces you might have noticed  that one force was missing that was gravity of   course gravity is very important for us um so the  standard model does not describe gravity at all   and that's a that's a feature we would like to  have um you probably if you follow a lot of uh   advances in science recently you probably  know that our everyday world is really only   five percent of the universe the matter in  our everyday world uh we know that there are   there's matter uh that gravitationally but not  with the electromagnetic force so for example   when we look at galaxies and we look at stars  at the edges of galaxies we can calculate   by how much mass there is in the galaxy how fast  those stars should be going and we find them to be   going much faster than they ought to be going and  we also actually astronomers find these structures   called gravitational lenses where there's a  background galaxy that's the picture is distorted   uh by a foreground galaxy and there's not enough  mass in the foreground galaxy to do that so we   think there's extra matter that we can't see  called dark matter uh we know the universe has   been expanding for quite a while as we know for  quite a while the universe has been expanding   and recently in the year 2000 or so we just  discovered that the expansion is accelerating   so there's some energy that's fueling that and  we don't know what that is that's called dark   energy we have uh several experiments of  formula looking for dark matter and then a   galaxy survey trying to understand uh dark energy  so fermilab is involved in that too uh we also   want to answer ask questions like you know why is  the electron so light and the top quark so heavy   uh i mentioned the three particles that basically  make up our everyday world what are the other   particles for the second and third families those  other columns in that table um we're all made of   matter uh anti-matter is not really found in our  everyday everyday world why is that where did the   any matter go and maybe there are more surprises  that will that that there are all there so   theorists um try to develop extensions to the  standard model to try to answer these questions   um so so pretend you're a theorist and you're  coming up with with your model to try to explain   some of these things so you know your model has  to have us have certain things so for example   you have to you know whatever the center  model predicts that we've that we've tested   your model had better do that too you know what's  right is right and your model has to predict the   same things hopefully your model predicts new  and testable phenomena like maybe new particles   they're not in the standard models we can build  experiments look for those here's an example this   is a extension called supersymmetry that predicts  many many new particles and we've searched for   these at the tempertron at fermilab and now at  the lhc um you can also predict the particles   that we know about but maybe behaving somewhat  differently than what the standard model predicts   um so so those are things we can test many of  these models have kind of cool sounding names   like super symmetry super gravity extra dimensions  things like that to get people interested um   and um so really there's there's two ways that  uh experimentalists go about testing the theorem   model itself and also looking for for this new  for these extensions to this theorem model and   what we do is we try to make one way to do it is  to try to make these particles uh in high energy   collisions so the lhc now is trying to do that and  so look for particles we haven't seen before and   also trying to look very closely at the at the  particles we do know about studying them very   precisely to try to catch them doing something  that maybe the standard model does not predict and   so for that you need lots and lots of particles  and so we typically call that high intensity there we go okay so uh you haven't heard  about any new particles being discovered uh   beyond the stair model uh even though the lhc  has looked really really really hard all those   experiments have many many analyses looking for  particles from supersymmetry and other models   they are still looking uh in fact at the end we'll  sort of talk a little bit about where that's going   so what else can we do while they're doing that  so as i mentioned we can study some pr particle   properties very precisely it compared to the  standard model uh and this experiment muon   g minus two is one of those types of experiments  that does that uh and actually uh this experiment   is very special the latest the one before ours  uh that the the result that came from brookhaven   about 20 years ago brookhaven national laboratory  they did this experiment and they measured a   slight discrepancy with the steering model not  enough to to claim a discovery but enough to be   really really interesting so we're going to talk  about this tonight and what fermilab has done uh   in our experiments um and our result okay so i  said i would talk about muons a lot so muons are   in fact a really nice laboratory for for studying  fundamental physics so here's where the muon is   on our our table of standard model particles was  discovered uh 1936 by these two gentlemen from   caltech the first one carl anderson actually got  the nobel prize for for discovering anti-electrons   or positrons or anti-matter basically they took  this device called a cloud chamber up to a really   high peak so they could see particles coming down  from the sky they're called cosmic ray particles   and they saw uh tracks in this cloud chamber uh  and there was a magnetic field to bend the tracks   and they saw a particle here that didn't bend  like the particles that that they knew about   not like how electrons or protons bend uh and so  eventually this this became uh known as the muon   um and muons are are are like electrons uh  they're in sort of the same row here in the   stereo model picture they have the same charge  as an electron oh and the lights just turned off   can people still see me okay or do i need  to go turn on the lights again the lights   are on timer here on this floor so uh i'm just  gonna keep going hopefully hopefully that's okay   um it might be a good idea to turn the lights on  if you can okay give me one second great thank you okay sorry about that i was actually fiddling with  the lights hoping they wouldn't do that but uh but   they did anyway okay so let's see so muons are  like electrons um they're also fundamental so uh   we think they have they don't have any internal  structure but muons are unlike electrons in that   they're they're quite a bit heavier than  electrons they're unstable they don't live   very long they live for about two microseconds at  rest then they decay to electrons and neutrinos   and one thing that's that's interesting about  muons is that they can penetrate a lot of material   so here's a picture of a cosmic ray hitting the  atmosphere and makes lots and lots of particles   some of those particles eventually are muons and  muons can can penetrate buildings and things like   that there's new ones going through us right now  they don't really do very much to us but if you're   running a very sensitive experiment and a muon  goes through your experiment that might confuse   what you see so a lot of neutrino experiments that  are incredibly sensitive have to go underground   to avoid being affected by cosmic ray muon  so this particle that we study very intently   is an annoyance for other other experiments which  is kind of funny i think okay so we're going to   study a property of the muon very very closely and  that property is spin so leptons and quarks have   this internal property called spin and it's we  could say it's an intrinsic angular momentum and   we sort of imagine that it's spinning like a top  um we don't know if that's what that would that's   what it's really doing but this this analogy  seems to work from in many ways and so if you've   all played with gyroscopes and i hope you have you  know you spin up this gyroscope this disc starts   spinning really fast and this thing can kind of  stand up all by itself because of its angular   momentum and so we're going to use this analogy a  lot and we're going to say the spin direction is   the axis of the gyroscope so the disc is spinning  in a certain direction and that generates a spin   along its axis so when i say the spin direction  you know picture this little gyroscope and where   this arrow is pointing we'll see this again uh  spin and charge make for a little bar magnet uh   and when we place a bar magnet into another magnet  um then that bar magnet will move a little bit   so if you put say a muon in a magnetic field from  an external magnet so here's our muon spinning   and here's our magnetic field with strength b  then this little magnet feels a torque and the   spin will precess so the spin vector and the other  axis of this thing will move around sort of like   it's shown here and it moves with a frequency that  we can measure and that frequency is related to   uh the strength of the magnetic field some  constants like the charge and the mass of the muon   and this really interesting number here  called called or this this quantity called   g uh which is we call the g factor um and the  g factor is actually a property of the particle   and for that basically says how much that particle  interacts within it with the magnetic field   um so if g is really small then the procession  will be really slow and you can say well the   particle is not really feeling the magnetic  field if g is really big and so then the spin   the precession frequency will be really fast then  the particle's really feeling that magnetic field   right so this sort of measures the strength of  how well a particle feels a magnetic field um   so so if we can measure some of these  things we can measure the precession   frequency and physicists can measure frequencies  really well and if we know the strength of the   magnetic field whether it's a refrigerator  magnet or an mri magnet we can measure that   or determine that then we can measure what this  g factor is uh and that's in fact what we've done   so the g factor is really important it's a it's  a quantum mechanical effect and quantum mechanics   actually predicts that g is equal to two for a  point like particle and this was actually derived   by paul iraq a very famous physicist in 1928 and  this was confirmed with uh with electrons in the   20s and 30s that g was not equal to interestingly  a little bit later when some when people measured   g for the proton it wasn't they didn't get two  they got a kind of a strange number uh and that   was one of the first indications that protons  and neutrons two have an internal structure that   they're beta quarks they're not they're not point  like particles this of course was figured out much   later but this was kind of the hint of that uh and  then in the late 40s uh as there was a surprise   this g factor for the electron which  had been close to two for quite a while   foley and kutch did an experiment where they  found g to be a little bit greater than two   uh not much greater but a little bit greater and  their uncertainties you know could not account for   for this discrepancy their certainties were quite  good uh so this plus or minus point zero zero one   zero that's you know how their their their degree  of what how much they believe this number is right   so it's uh so the three could be a a two or  a four uh and actually this the way this is   written is kind of a pain all these zeros  what we actually like to do is say the last   two digits here is the error in the last two  digits that's the same as what you saw before   so huh what's going on here so g for the electron  is now measured to be a little bit greater than   two why is that uh does the electron have some  internal structure and the answer is in fact no so   here again is the result g is a little bit greater  than two and actually uh the two is kind of a pain   so physicists like to get rid of things that are a  pain and so we actually have a new quantity called   the anomalous uh factor and for that we actually  subtract off the two and then divide it by two so   it's the fractional part over two and this is what  we call the anomalous part of the magnetic moment   and so basically all you have to remember is if  a is greater than zero then g is greater than two   and we'll kind of go back and forth i have these  in green to sort of say that you know these are   all related so what's going on here is that if you  uh study quantum mechanics uh quantum mechanics   actually says that and this is the the the theory  that describes how subatomic particles work   and their world quantum mechanics says  that empty space is not actually empty   and that any particle any particle can  quickly and randomly appear and disappear   by quickly borrowing its energy this is uh  related to the heisenberg uncertainty principle   and so let's just have a little a little  animation here so say you have a muon spin   around and a photon appears this could be a muon  or an electron it doesn't matter they do the same   or you have you know a photon up here and that  then goes into a electron positron pair and   then you get a photon again uh or maybe uh two uh  particles with quarks appear or uh z boson appears   or interestingly maybe something we don't know  is appearing and disappearing um and so these are   called virtual particles uh and actually we can  see we can see them in see their effects inside   protons and neutrons and things like that so we  know this this picture actually works and so if   g being a little bit more than two accounts for  these effects from all these virtual particles   and you can actually and so uh so remember here  we have this result a little bit more than two   uh and this a little bit more than two was first  predicted uh by this gentleman julian schwinger   who got the nobel prize for this this was in  uh i guess the late 40s early 50s um and uh so   the way this works is that we imagine sort of  the the uh the the g factor being built up by   the basic thing that's happening the two part  which is the the electron interacting with the   magnetic field that's the photon and the x that's  the magnetic field the electron sort of says high   to the magnetic field and then goes on goes on  again so in and out uh and then this little extra   part here is where the photon sort of appears  uh and so the electron uh gives gives a little   energy to this photon and gets it back later  on and schwinger actually calculated how much   this uh interaction adds to g and so he got  this which almost exactly we're very closely   matches what uh what foley and kutch got so this  is the start of what we call quantum corrections   uh to these diagrams uh actually the same thing  happens for the muon this was uh confirmed in the   in the 50s and 60s and actually leon letterman who  became the who was the second director of premier   lab he was was led one of these experiments uh  in the 50s for g minus two of the muon okay so   i showed you that that one picture of the quantum  correction here here that is involving involving   the photon you can have other pictures as well  you can have the z boson that one i mentioned   you can have photons that go to quarks that go  back to photons again and then you can have a very   very complicated funny looking diagrams like  this one again involving clarks that sort of blue   the blue ball there um and you can sort of  go wild there is really an infinite number   of diagrams involving you know lots and lots  of these little loops you can imagine you know   two loops three loops 100 loops and really  interesting looking things you can make them   look like space invaders if you want it's kind  of neat uh but there is a fortunate role there's   a good thing that happens even though there's  there's an infinite number of diagrams the more   complicated the diagram the less it contributes  to the g factor so the more stuff going on   the less it contributes and so this one the most  basic one that's the one that contributes the most   and the more complicated ones contribute less  so at some point you don't have to calculate   anymore because it just doesn't  you know they don't add very much   however as our experiment precision improves then  you have to start worrying about these more some   of these more complicated diagrams because these  sensitive experiments you can see there's effects   can see their effects and so to um to account for  the the precision that our experiments are and now   the theorists have to calculate over 13 000 of  these diagrams uh to to calculate what the what   the standard model prediction is for the g factor  and some of these are very difficult to calculate   uh um and there's sort of an industry behind doing  this in fact the fear the theorists themselves   have their own collaboration now this is only  a couple years old uh there have been a lot   of groups uh theory groups uh calculating parts  of g minus two uh and so uh they form their own   collaboration to come to a consensus uh to to put  together all their different ways of doing things   uh and come with one uh one number for the  standard model prediction that they can all agree   on and this is what now the formula experiment  our experiment we will compare to their value   so we no longer choose which theorists to follow  uh the theorists themselves get together and give   us the best value that they think is right  okay so i showed you also in that animation   that there could be question marks there could  be particles that we don't know about that are   in the mix of virtual particles and could be  affecting the g factor and that's what's really   exciting right uh that we could be sensitive  to particles that are not in the stern model   and then we can ask the question is the standard  model complete um so here here's the game plan um   so the theorists will calculate um g the g factor  or a the anomalous part with all these diagrams   from all these corrections from the particles that  we know about that the stair model has and that's   the standard model prediction uh experimentalists  like myself uh make an experiment and measure   the anomalous uh part of the g factor with great  precision right precision that matches their their   calculation and then we look to see do we agree is  there a discrepancy and if there is a discrepancy   well then that's really interesting maybe there's  a hint that there's something else going on   outside this terror model that's affecting our  muons and if we agree well that's also you know   that's interesting too um maybe you would agree  not quite as interesting as finding something new   uh but that's okay uh it's all interesting all  right so how do we actually uh do this experiment   um so we need a couple of things first of all  we need muons we need something that that gives   us muons a source of muons using muons from the  sky from cosmic rays they're not enough of them   at any in any one place to really use them for  for this sort of experiment although there are   other experiments that study those cosmic rays  but we need a lot more muons on that uh we   need a magnetic field uh to make the muon spin  process right i showed you that that gyroscope   that's processing and we need to put them  somewhere where we can watch them for a while   right we have to give time for that procession to  happen and time for the muon to decay and so we   have to actually watch them uh so there's a device  called a storage ring and that's what this picture   is here this is the storage ring of brookhaven  this was an experiment done 20 years ago   and storage rigs are really nice for for this sort  of thing because it checks off two of these boxes   uh storage ring uh keeps the muons going in  a circle that's what the magnet this is a   magnetic storage ring so the magnet does keeps  the the muons going in a circle so we can keep   them there for a while and it provides the  magnetic field to make the spins process   um and so this was uh the ring of arcademan and  that's uh that's what we're going to use actually   brookhaven has this really really nice diagram  here to show how the experiments work uh so i'll   use it too and and the fermi lab experiment is is  almost the same uh so you have a source of protons   uh brookhaven has their accelerator we have our  accelerator complex that takes protons we always   start with protons because that comes from from  a hydrogen model and then those go through our   accelerators and we accelerate them to high energy  and then we smash those protons into a target   and because energy and mass are interchangeable  that's e equals mz squared uh a lot of the energy   that those protons are carrying by like this are  going very fast can be converted to new matter   and and we can make a lot of different types of  particles a lot of stuff comes out but particles   called pions are the ones we're interested in  they're made of two quarks and those pions will   decay to muons and neutrinos and these muons will  have a very special property so let's look at that   for a second so here's our here's protons  hitting a target we've got lots of stuff   a lot some of what comes out are pions uh and a  pion will decay after a short period of time to   a muon and a neutrino we actually have used  pi pluses because protons are positively   charged and they like to make pi pluses and  so we're actually going to use uh mu pluses or   anti-muon so actually our our experiment uses  anti-matter which is kind of cool so the pi pluses   uh decay to muons and a nutrient and a neutrino  and actually we use this to also make neutrinos   uh we don't care about the neutrinos you need a  very different beam to if you're going to study   neutrinos so we make the muons and the neutrinos  just just go on their merry way and we never see   them they can go through everything so it doesn't  matter and what's a neat thing is remember how the   spin works that we have the spin axis when the  muons are produced their spin is uh is always in   the opposite direction that the muon is traveling  that is a property of the weak force which is how   this thing decays and we get this for free this  is physics so the the muon spin is always in the   opposite direction of the whip of the direction  the muon is going and so we can make a beam where   all the muon spins are all pointing the same  way uh and this is called a polarized beam and   this is really key if uh if we had randomized uh  spins directions that wouldn't work we need all   the spins pointing in the same direction and  we get that in fact it's hard not to get that   with pions okay so the muons are going to go into  the storage ring uh so here uh and they go around   and and their spins process as they go around the  storage ring so let's look at that so remember   here's our our little formula for relating  the the spin per session frequency how fast   the spin is processing around how many times  around a second uh it's related to the g factor   and the magnetic field this is when a muon is at  rest uh but these are muons are moving they're   going around the storage ring here's sort of  a top-down view of the storage ring our little   race track and this this formula is a lot more  complicated i won't i won't scare you with it   but there's a really neat thing that does  happen that if you take this formula for the   spin frequency and subtract off what we call the  cyclotron frequency then we get this frequency   called omega a which is directly related to the  anomalous part of the g factor so all we need   is to measure to know the magnetic field really  well some constants and this frequency and then   we can measure what this anomalous part of the  g-factor is or how much of it is greater than two   and so what this cyclotron frequency is is  just how just the rate at which the muons go   around the ring uh and so we imagine this has  a vector called the momentum and this method   vector spins uh just in the direction that the  new one's going around so it just goes around in   a circle and so if you look at the vector itself  this is what it's doing oh i was able to fix that   um so it goes around it's just pointing in the in  the direction of the muon that's all that it does   so nothing nothing nothing interesting there so  let's play some games so if g is exactly equal to   two that means that a is zero right and the spin  processor frequency is the cyclotron frequency   and if that were the case then i'll show you  here then the spin vector which is in red   is in lock step with the momentum vector so as the  muon goes around the ring and the its direction   points in a different direction it goes around the  spin direction follows that in lock step um okay   so now let's say g is a little greater than two  which of course we know that it is so that means   that a mu is a little bit more than zero and so  that means that the spin precession frequency is   a little bit greater than the cyclotron frequency  and so that means the spin vector will advance   a little faster and that's what's shown here  notice that the spin is now getting out of sync   with the direction i don't i don't rotate  the middle ones because that that will make   you nauseous uh and you can see sometimes it's  forward sometimes it's backwards and in between   it's actually exaggerated here for the value of  g minus two for the muon it takes 29 times around   the ring for the spin vector to go all the way  around once um let's let's try to hit this home   a little bit more i'm going to uh get two friends  to help us these are our two doggies riley and   rini we adopted them about seven months ago and  so so if g is equal to zero actually we're gonna   do this we're gonna rename them spin and momentum  just for this talk uh and so if g is equal to zero   spin and momentum should rotate around the same  rate and hey they they did and if g is a little   greater than two spin spins go a little faster  uh okay we're still working on it uh hopefully   maybe by the next result from g minus two  we'll have all that figured out um so anyway   so these mu ones are the spin is processing  if g is great greater than two it's processing   at a faster rate than the muons are going  around the ring and then the mu1 is decay   the muons we have positive muons so they decay  to positrons or or positively charged electrons   and then we can catch those electrons in a  detector called a calorimeter or those positrons   in a calorimeter and measure their energy so let's  see how that works and there's another really neat   thing that happens uh because of the weak force so  imagine i'll use i'll first start out with muons   at rest and so muons will decay to a positron  and more neutrinos uh lots of neutrinos are being   produced here that we don't care about they just  go on their merry way and we've never seen them   we care about the positron and the really neat  thing is that the way the weak force works is that   the positron when it is emitted from the muon  the highest energy positrons are emitted along   the direction of the muon spin so here is our  little gyroscope here's the direction that the   spin is pointing if this muon were to decay  to a positron the positron will come out in   the direction of that spin so here's another one  comes out in the direction of that spin one more   comes out in the direction of that spin right so  that's really neat that means that this positron   uh is carrying information about the spin of  the original muon right so by looking at these   positrons we can get information about the spin  of the mu of the muon that it came from right so   we can actually see this then procession of the  muon spin through these positrons so i hope that   made sense um we're gonna actually go a little  bit further because that was for a muon at rest   and our muons on the storage ring are moving and  they are moving fast they're going you know almost   the speed of light uh and so what happens then is  that basically the direction that the mule that   the positron is emitted is always along the same  direction as the muon the new one is going so fast   that basically it's like throwing a ball from  a fast-moving train right if you're on top of a   train and you throw a ball that ball is going the  speed of the train because the speed of the train   is overwhelmed however fast you throw the ball  but that the ball or in this case the positron   will get a little boost of energy either a boost  or kind of an anti-boost depending on if it's   thrown off along the direction of the  muon or in a different direction so   so we have these these detectors are called  calorimeters which i represent as a catcher's mitt   so the catcher's mitt will catch the positron and  it'll measure how much energy that positron has   by sort of how hard it hits that catcher's mitt  so if the spin is pointing in the same direction   as the mule momentum so the spin is pointing  along the direction the muon is traveling in   that positron will hit the calorimeter and  the calorimeter will register really high   energy that that that positron is  getting a boost from the the muon's   motion and muon's direction if the positron  is emitted in the backwards direction   uh so backwards from from the direction the  muon is traveling in it'll get a boost too uh   because the muon is still moving uh from left to  right but it'll get a little bit less of a boost   and so the energy that is registered by the  calorimeter will be a little bit less um than what   it was in the forward direction and if it's in  in between uh still the positron always comes out   you know in the direction of the muon because it's  overwhelmed by that but now is but the energy that   the calorimeter uh registers will be in between  uh the lowest and the highest so from this you can   sort of see this picture of you know how we can  maybe measure use these calorimeters to measure   the pesticide energy to get information about  where that muon spin vector was when it decayed   um and so the way this actually works here here's  a piece of our storage ring uh this dash line here   is where the muons actually go so they're going  around the ring the muons will decay to a positron   uh the positrons actually are lighter uh and a  little slower than the muon so they curl inward   out of the the sort of the the point  out of where they should be and then   and then the next storage ring because the surgery  is not set up for positrons it's set up for muons   so it'll curl inward and it'll eventually hit  our catcher's mitts or our our calorimeters   and sometimes they can go really far into the  catcher spin sometimes they don't go very far   at all that depends on you know where the  spin vector was uh when the muon decayed   so more comp in a more complicated  picture uh i showed you sort of   one positron at a time it's actually not what we  get we get lots of positrons and they all have an   energy distribution uh so this sort of shows what  the energy energy distribution is uh here i should   kind of show a threshold energy where we're going  to look at how many how many positrons come in   above this energy uh and so when the spin and the  the spin vector and the momentum are aligned then   this spectrum is pushed really high because  right because the positrons get a nice boost   and i'm gonna see if i can control this here  a little bit and so as the spin projector   turns around so here i'm going to stop it and go  oops and do that there we go there we go so it's   backwards notice that the energy spectrum is lower  above the threshold and it's pushed to the left   and it gets higher and higher and higher  and when it's aligned it's the highest   i'm looking at the left picture here and then  when it's anti-aligned it's the lowest and uh and   so this oscillates right so now on the right-hand  picture i'm going to go back to the beginning and   stop it on the right hand picture uh we're now  counting these positrons over this threshold of   energy and i'm going to plot how many of these we  see uh and so when the spin and the momentum are   aligned uh we see a lot it's that's like 30 it's  really high in the upper right inset plot and then   as it gets anti-aligned it gets low and then it  gets higher again as it comes align and then lower   when it gets anti-aligned and then higher again  when it's aligned so hopefully that makes sense   let's let this run and so we build up what's  called the wiggle plot uh as these muons are going   around the ring their spins are processing they're  shooting out positrons uh and that positron energy   depends on where the spin vector is uh and we can  tell where that is by basically measuring how many   how many positrons we see over this this  threshold and we see this oscillation   and remember this oscillation the frequency of  this oscillation is omega a and that's directly   related to the anomalous part of the g factor  so we can measure g minus two uh by looking at   this the frequency of these oscillations and  that's basically how this experiment works   okay so if that wasn't clear i could  talk about it more more at the end   um and you can ask me questions about it  so uh so brookhaven did this experiment   and and collected billions of of positrons and  made their wiggle plot i'll show them one from   friendly lab a little bit later and so they came  up with a result for the anomalous part of the g   factor and it's lots of digits here with a of  the error and the last two digits uh which is   really really far out compare that to the kitchen  foley number from 1948 uh you know and to see how   much how much more precision we have compared  to what they had uh we have the standard model   value and then we can compare we take the  difference and that makes this this gap here   here's where the brookhaven result is but their  error bar that's the error here and we call this   a 540 parts per billion uh measurement that's the  precision and i'll talk about that in a second   uh and that makes for this gap and we can  characterize the sort of the significance of this   gap in standard deviations or sigma and it's 3.7  sigma if the error bars were smaller if this error   were improved then this would get better this  would get larger um and so that's what actually   formula i was going to try to do but this is 3.7  the gold standard for our discovery is five sigma   um and so so it doesn't quite meet the level of  a discovery but certainly very very interesting   um actually just to give you a sorry hint of what  a part per billion is you know what a percent is   that's a part of a hundred and a part per billion  is a part out of a billion uh so basically the way   we calculated it is very simple you take the  uncertainty which is in these last two digits   you divide that by the the measured value  and that's the and that's the result and you   multiply it by a billion and you get the parts per  million so how how precise is this so if you pick   a nice round number like 100 parts per billion  that's equivalent to measuring the length of a   football field to about 10 microns or less than  the width of a human hair so so that's really   really really uh very precise so that gives you  some picture of the precision of these experiments   okay so uh so from so brookhaven got their  result they got a 3.7 sigma discrepancy so   not a discovery but also very interesting uh and  actually this is generating an enormous amount of   interest this plot shows the number of citations  to the the papers from brookhaven over the years   and that really has been sustained for a long time  uh but for brookhaven to make big improvements to   this would have been very difficult uh and  so bricky evans does a lot of other things   so they stopped working on g minus two and the  ring sat for quite a long time uh at brookhaven   uh and then around 10 years ago or so a little  more at fermilab uh some people started to   get the idea that you know this is this is so  interesting that maybe fermilab should should   do the experiment with a lot of improvements to  first check to see if the brookhaven result was   right would we get the same result too or we get  something different and aim for this five sigma   discovery level uh you know so if we do see the  same deviation that brookhaven did by the time we   would be done uh we would have an undeniable  signal of new physics if in fact that that   really happens uh so the goal is to really do this  experiment here again at fremulab with a factor   of four in a better precision and that involves  delivering 20 times the muons that brookhaven saw   here at femi lab so we need 20 times more muons  we have a a very powerful accelerator complex   that can actually do that and also make many  improvements uh to basically do the experiment   three times better in terms of what uncertainties  of how well we do things and things that can   that maybe you know we have to be very careful  about do those things three times better to   really improve this error this uncertainty  uh and also to try to reduce our cost   by reusing as uh the sort of the the big parts  and expensive parts of the experiment from   brookhaven and also other components that were  freed up when the temperature on collider shut   down in premier lab in 2011. so we've actually  recycled a lot of stuff from from the temperature   okay so moving the ring from brookhaven to  fermilab that was a an amazing thing uh so first   of all the ring is made up of coil so here's two  coils uh here top and bottom and there's a coil   on the back those are continuously wound wires  of niobium wire that they're super conducting   so that makes the magnetic field and they go all  the way around and we can't break them uh if we   break them we got to make a new magnet and that's  really expensive we also can't flex these things   more than about three millimeters uh and these  rings themselves are big they're 50 feet in   diameter so if you stick that on a highway that  takes about four lanes of a highway so they're   not easy to drive around uh fortunately there's  there's nothing hazardous about them so so that   sense it's easy uh but they're big uh and they're  very fragile so we contracted with a company   called emmer to move the ring from from brookhaven  to fermi lab and so they built this giant gigantic   frame uh that the coils sit in you kind of barely  see them here the next slide will be better   um to really rigidly hold these coils so  that they would be very very very protected   uh and then we put the put the ring on a barge  we slid it out of the building a brookhaven put   it on a barge and basically drove it uh on the  barge down the eastern seaboard around florida   uh up the up the gulf of mexico to  mobile alabama alabama where the   tennessee tom bigby waterway where  that entrance is and then up there   eventually hit the mississippi and then on to  illinois and so this was an amazing you know   water or journey for three thousand miles it took  three months we got some really neat pictures   here's where the ring is being handed off from  the ocean tug to the river tug uh and here it is   going by the st louis arch and uh and then here  it is arriving in lamont which is about 30 miles   from fremulab which is the closest point on the  illinois river where the the magnet could be could   be offloaded uh from the barge uh so then the  magnet was still 30 miles away from from the lab   down here in lamont and so we had to drive  it across the chicago tollways the the the   highways in the suburbs from lamont to fermi lab  we did that over three nights uh so here it is   actually on interstate 88 uh with all with support  traffic i was actually i was very lucky i was in a   car following the ring it was really really cool  uh and then behind us the traffic was stopped i'm   sure they were not very happy but you know all in  the name of science uh and actually during the day   uh in between these moves the magnet would sit  and so it actually sat across the street from a   costco and a bunch of us brought some brochures  and talked to lots of people it was really neat   uh and then it arrived at the lab and we  had a big celebration we opened the lab   so that people could see it and actually we had  no idea how many people we would get uh and it   turns out uh thousands of people came in fact so  many people came that we had to eventually start   turning people away we ran out of parking uh so it  was an amazing thing and here's you know my family   and a photo op in front of the ring a lot of  people did so eventually uh we built our building   that the ring goes into and we call this area  the muon campus uh so this is this will support   our experiment g minus two and another experiment  that's under construction called new to e and this   part down here is where is part of the delivery  ring where we deliver muons to this campus and   that's actually recycled from the tamatron this  is the old tematron anti-proton source and here's   here's our two buildings uh and so here's just  a couple slides putting the ring back together   um so you know we have this base of iron this  actually this comes in pieces and so we truck that   from brookhaven here's the ring itself now sitting  on top of it we can slide it into the building the   front of the building comes off and we slide it  in and then we lower it uh onto this platform   and then we build up more iron that also  got shipped by truck from brookhaven   and this actually forms the magnetic field uh here  are the here are the two inner coils and the muons   kind of go in this inset region in between  the two coils so that's what that looks like   i i talked briefly about how muons are created so  we do something sort of similar to what brookhaven   does we have rings and accelerators that  accelerate protons they're very high energy   so protons from our accelerator complex eventually  make it into this ring called the recycler ring   that kind of reorganizes the bunches of protons   and sends them to a target station so that's our  big block of metal we have a cylinder of nickel   nickel alloy that the protons hit about a trillion  protons uh at a time hit this target and there are   16 bunches of protons in about 1.4 seconds so each  bunch has about a trillion protons they hit this   target a whole lot of other stuff comes out the  other side as i mentioned before including pions   uh and these pions remember they decay the muons  there's a beam line here where these pines will   decay remember all these muon spins are pointing  in the same direction it's a polarized beam   uh so that's that's that's what makes this  experiment work and eventually these muons go   around this delivery ring that was sort of those  three bunker buildings that i showed you before   and they go around this ring a couple times four  times typically and that's because there are other   particles that are coming along with muons and  we don't want those particles we don't want them   hitting our ring because they'll they'll make it  they'll make a mess and so actually we use this   delivery ring to separate out those particles from  the muons and then we throw those particles away   and let the muons continue on into our ring so  out of a trillion protons that strike the target   about 250 000 muons make it to this point  down here right before they enter the building   for the for the g minus two ring and so here  here is the g minus two ring uh it's the same   brookhaven ring uh the magnet itself is the same  but everything else is new uh inside this magnet   although some things are recycled uh these beam  line components here these magnets this is where   the beam comes in muons come in this way from  from the building outside the building into here   they go into the g minus two ring these these  magnets are recycled from other parts of the   lab so about 250 thousand thousand muons enter the  ring there's sort of a torturous route they have   to follow to get stored to go to continue going  around only about two percent make it through that   so we actually only store about 5 000 muons at a  time these new ones are going really really fast   uh you know 0.9994 the speed of times the speed  of light and so if you remember special relativity   uh when you have uh something going really fast  it's clocked to us looks like it's going slower   and so a two point a muon that would at rest live  for 2.2 seconds on average live 64 microseconds by   2.2 microseconds live 64 microseconds uh and this  is great because the neurons will live quite a   long time they'll go around lots of times actually  this is on this is the average so some muons live   shorter some of you wants to live a lot longer  and so we actually allow these muons uh to to go   around for 10 muon lifetimes so after about 700  microseconds they're all gone they multiplicate   and we fill the ring uh 16 times every  1.4 seconds uh and the ring is at a very   high vacuum so the muons don't hit anything the  magnet itself is super conducting as i mentioned   we have to put high current in this magnet uh  to get the magnetic field we want and so we have   liquid helium going around those coils at five  degrees kelvin or negative 450 degrees fahrenheit   uh the magnet strength itself is about the same  as a standard mri magnet uh in a medical office so   pretty so strong not super strong but but strong  but you know quite strong uh and we've done a lot   of work it took us a year of adding little bits  and pieces little bits of metal here and there and   turning knobs to make the magnetic field itself  as uniform as we could all the way around the ring   that really helps us with the analysis and then  we had to measure the magnetic field remember we   have there's the b part of our formula we have to  know what the magnetic field is and so we measure   that we have embedded probes hundreds of embedded  probes inside the ring itself and then we actually   have a little trolley it's a little railroad car  that goes around the ring the little rails here   and the trolley itself has 17 uh probes on it and  it measures the magnetic field as it goes around   in 9000 stations as it goes around the ring we  can't run we can't have muons in the ring while   the trolley's going around because we'll try and  we'll block them all uh but that's okay so and we   we take a break every three days uh running muons  and we stop the muons and then we run the trolley   and measure the magnetic field so that's really  kind of neat um so again back to the muons and   you want to enter from the back they have to enter  this magnet so there's actually a hole in the coil   where the muons can enter uh and this actually  is a neat picture looking down these magnets here   but the muons go go into the ring there's  actually a special magnet called the inflector   that cancels out the magnetic field of the ring  where the muons are entering because the muons   wouldn't like seeing a very big magnetic field all  of a sudden and so we have to cancel the magnetic   field with this strange looking magnet um and  when we do that uh unfortunately there's a problem   and that the muons don't quite enter at the  right orbit so if we didn't do anything if   we just let them keep going they would all kind  of hit the wall here and we will lose them all   so we actually have to kick the muons onto the  right orbit and so as the murders are going around   their first time their first time around the ring  when they hit about a quarter of the way around   there are these plates that we  charge up to very very high voltage   uh and they fire within about 100 nanoseconds so  100 billionths of a second and as the new ones   are going by they are kicked about 10 milliradians  so not very much but just enough uh so that they   will will keep going around the ring um uh and  so we won't lose them so uh so the stickers are   very important uh and actually these kickers you  know they're we need them they're essential but   they also cause us a little bit of headaches  which uh maybe i'll get to and explain that um   we have another complication and that the magnetic  field itself of the ring keeps the muons focused   but only in kind of the horizontal direction so  here's there's kind of a cross section of what   the the beam looks like the the vacuum region so  the muons are in this region here they're going   uh into uh the screen at some level uh so  imagine the muons going by into the screen   uh and so they live in this in this in this circle  here about it's a nine centimeter diameter uh spot   where the muons go and so they are focused in  a horizontal direction so they'll stay in the   ring but if we didn't do anything they would  they're unfocused in their vertical direction   so they would basically get more diffused they get  taller and tall the beam would get more and more   spread out vertically and eventually we would just  lose them all after a couple of turns so we have   electrostatic plates these quadrupole plates that  act as a lens to this forum here one on each side   and we charge these up and these keep the the beam  vertically focused uh so that's really important   if we didn't do that we would lose the beam so we  need these things to keep the muons in the ring uh   and then we have uh the detectors the calorimeters  the catcher's mitts right so we have 24 of these   things i've pointed out a few of them um and uh  and so these these are little boxes that are inset   sort of into the ring where the positrons go  remember the plastic strands curl inward so we   have these boxes that's to catch them um and they  sort of at the end of these carts to have all the   services for for these calorimeters there's  like i said 24 of them all the way around and   these calorimeters are actually uh lead fluoride  crystals uh so when a positron enters a crystal   it kind of rattles around inside the crystal  and makes lots of other particles and things   and the crystal reacts by giving off a tiny tiny  bit of light it gives off gives off photons and we   can we can capture those photons and measure how  many photons there are uh with a device at the end   called a septum and basically the more light that  gets produced the more energy the positron has   and the more signal we'll see on these systems so  that's how we do that energy measurement that's   how we measure that spectrum the oscillating  spectrum that's what these calorimeters does what   they do these catchers mix okay and um and then  we also have devices called trackers um that these   weird straw looking things uh so actually inside  these straws this is where the positrons go so the   parts positrons go through these straws they're  very thin so they don't really block the positrons   inside these straws there's a wire and there's a  gas and when the muon i'm sorry when the positron   goes through the straw it ionizes the gas and uh  the wire senses that and so it's a little hard   to see here's sort of where these trackers are if  you look carefully these little black dots where   the the positrons hit the wire uh and so we can  we can sort of connect the dots and extrapolate   back somewhere around here and see where the  muon was when it decayed so we can get a picture   of we can deduce where that muon was when when  it decayed to the positron and that's a really   important thing we need to do uh just very  quickly i'll show you a little movie i gotta   turn off the laser pointer uh of you know if you  were a muon this is kind of what you would see   it's not stopping starting that this is on a  trolley here's here's the tracker the trolley   has to move along there's the calorimeters behind  here and here are the quadrup the quadrupole   plates so of course you're going around it takes  about 140 nanoseconds 140 billionths of a second   for a new on to go around the ring so you'd be  going around a lot faster i'm getting close to   the end so uh let me just go through this uh sort  of briefly so i mentioned the kicker causes some   some some complications and so the beam itself you  imagine where the beam of muons are in the ring   they kind of slosh around and so we we say the  muon beam swims back and forth this is the serve   as what the muon beam looks like as it's going  around the ring so we kind of you know in this   box this nine centimeter diameter box or a circle  uh the ring the the mu1's kind of slosh around uh   so it swims and the width of this gets gets bigger  and smaller and so we say it swims and it breathes   so the muons are not always you know in the center  which is which is uh which causes some problems   but we have to figure that out and deal with that  we have other interesting things like uh we have   two low energy positrons from decays that enter  the calorimeter at the same time or a calorimeter   at the same time the calorimeter might not be able  to time apart if they're so close in time so it'll   actually add the two together and it'll look like  a really high energy positron from a muon out here   so this is called pile up and we have to  actually figure this out and subtract that off   uh because that's actually a mistake uh you know  it's an unavoidable mistake so we can figure that   out by different mean simulation and from data  and we can uh subtract that off we can have muons   on the edge of the beam uh that hits things and  then curl inward and maybe hit and maybe hit a   a calorimeter so mu1 is doing that would confuse  us a little bit we can actually figure that out   but looking at data and figuring out how often  that happens the temperature in the hall this was   our first run so we were learning things for the  first time the temperature of the hall was um was   was not well controlled and so that changed the  magnetic field or the magnet a little bit so we   had to deal with that uh these kicker plates are  very high voltage and so sometimes we would get   sparks so we had actually run the lower voltage  than we wanted uh and we also the quadrupoles have   high voltage resistors uh and the company that  made them for us couldn't quite make enough of   them so we tried to make a few of them ourselves  uh and two of we didn't make didn't make very many   i think we made like four or five of them but two  of them uh didn't work so well um and so that uh   that created some problems but anyway we have  to figure all that out that's part of what we do   um and so here is our wiggle pots remember i  showed you the wiggle building up the wiggle plot   uh and so this is what ours looks like from  our experiment it looks sort of like what you   saw there uh building it up and so in this and  one thing note this wiggle plot wraps around so   if i showed you you have a one long thin wiggle  plot that'd be really hard to see so this point   here wraps around at this point here uh so overall  it's about 700 microseconds um it's actually you   can see it's kind of slopes downward and that's  because we're actually measuring the number of   positrons and as muons decay over time there's  fewer and fewer positrons because there's fewer   and fewer muons for them to come from and so this  so you're seeing the number of muons decrease over   time uh and this is the result of 18 million fills  18 million fresh batches of muons and 8.2 billion   positrons total which is a little more than what  brookhaven saw and this was a little more than   a month of running so what took brookhaven about  three years to do in terms of data we can produce   about the same amount of data in a little more  than a month right and so this is you know shows   the power of the fermilab complex that we can make  a lot more muons one thing to note is that i have   weird units here i said this was 700 microseconds  so this point here should be about 102 and a half   microseconds but it's not it's about that but we  don't actually know what this point is and that's   because we've blinded this experiment uh we've  actually shifted the time here by a secret amount   we don't know on the experiment we didn't know  what this was so we could extract omega a we could   figure out what this frequency is which would  be omega a which would lead to the anomalous   part of the g factor which is what we want but  we would actually get an answer shifted by a   secret amount so we couldn't actually figure  out the answer we could do everything else   but we couldn't actually know the answer and  that was something really important for us to do   um because you know there's sort of an answer  that everyone's hoping for right you know we're   we're all hoping that maybe you know we'll  we'll will confirm the brookhaven experiment   uh and when you have something you're hoping for  you know and you and you sort of know how things   are going you can unconsciously uh make decisions  that kind of reinforce the result you want   right and we don't want to do that right we're  scientists you know we have to keep our cool   uh we don't want to be tempted into uh into sort  of driving the result into something that we want   and so we actually make it so we can't figure out  the result until the very end so we have no idea   are we matching this error model are we confirming  brookhaven we have no idea until we're done   and so there's a secret blinding factor we  actually detune uh one of the the clocks   that feeds into the experiment which would  which changes what omega a we would get uh   that secret value is kept in two sealed envelopes  one at fermi lab and one in seattle where we have   a lot of people who work on the experiment and  it's in two places for safekeeping um and as i   mentioned we blind the results to present you know  to prevent biases from human nature um and so we   don't imply until all the analyses are done uh and  we have a rule that once we do unblind we're not   allowed to change anything what we get is what we  get and so we make public whatever answer we get   uh and that is a rule that we have to follow  it's actually in our bylaws for our for our   collaboration and so i won't spend too much time  on this don't worry about the numbers it just   shows a lot of the uncertainties and corrections  we figured out this was an enormous amount of   work it took us three years after collecting  the data to to do all the analyses we had 11   groups doing the analyses each with a different  technique uh they all had to agree in the end   and we had many many checks and we solved many  problems and estimated uncertainties for many   problems we had checks and cross checks so it  took us three years to do all this and once all   this was done and we all checked each other's work  and saw presentations about how all this was done   then we could consider we could consider  on blinding remember once we unblind   we're not allowed to change anything so  whatever it is we is but whatever it is   it is so whatever we take mistakes we made you  know we better figure this out before we unblind   so about february 25th a little more than a  month ago uh we all got together uh so we had   about 170 people uh for uh that was the authors  of the run one paper which is a fraction of our   data we all got together and we all had to vote  uh and the vote had to be unanimous in favor of   unblinding to proceed uh and if we didn't  vote unanimously then we wouldn't i'm blind   uh we'd have to look harder and maybe understand  you know what was the concern from that particular   person that wasn't the case we were satisfied  that we've done everything we could we could   and so we voted unanimous unanimously to  unblind so before i show you the answer you   probably already know the answer but let's  look to see what we could have gotten so   very quickly so here's uh sort of the the answer  plot here's what brick even got uh with their on   uncertainty bars and here's where this general  model is right here's this gap this 3.7 sigma gap   so what could fermilab get well we could get uh  we could get a result that confirms brookhaven you   know if our result overlaps the brickhaven result  uh then essentially we're confirming brookhaven   and and we also would have a discrepancy with  the standard model and as we said as i said   you know this is sort of what we're kind of  all hoping for right that would be the best   thing although you know we got to keep our cool  you know that might not be what we get and of   course we blinded so we're not influenced by this  you know we don't make decisions based on that   we could confirm the stair model right that would  be interesting um that would so that would be the   question as to why uh the brookhaven result is so  different uh maybe they just got unlucky and saw   what we call a statistical fluctuation but that  would have to be investigated so this would have   to be explained why we got why we got to start  model value and they didn't that's a possibility   we could get something in between um so you know  that's that's sort of the most unsatisfying answer   because we can't really say what's going  on here if we get something in between   we would have to analyze more data which is what  we're doing and hope that this this will either   move around maybe we're seeing a fluctuation  uh or maybe this is the right answer and then   our error bars would get smaller in the same  position so we would have to look at more data   uh before we could really say anything and then  there's sort of the nightmare scenario where you   know we put in our calculations we get the we get  the the point on the plot it doesn't show up on   the plot it goes somewhere else right something  weird is going on uh you know we were pretty sure   this wasn't going to happen we had done so many  checks and so many cross-checks and and we were   confident you know we would not have been blinded  we wouldn't have decided to remind it to a blind   if we thought there was something that we missed  so we really were confident that we wouldn't get   you know some weird answer but you know you don't  know until you look all right and and once we've   unblinded it whatever it is you know that we have  to make public right so i'll just go through it so we open up the envelopes here steve  herzog from the university of washington   opening up his envelope with the the  the secret factor it's the bottom number   directly two clocks that we've landed for various  reasons so it's a bomb number that matters   here's chris paulie our spokesperson at fremulab  he opens his envelope gets the same answer   the same number so that's good  so we have the same unblinding   secret unblinding number that we put into our  our notebook and we get the answer so here i'll   let this play so you can hear what our reaction  was this is pretty cool and this is what we get wow so we confirm the brookhaven result here is our  result here so you have to realize for us this   is like landing on mars right i mean this is the  largest man the mars lander successfully reaching   the surface of mars this is our mars lander  moment uh and so we did in fact get a result   very close to the brickhammer result uh here's the  number then we'll go through the numbers of course   lots of numbers but basically on the graph here is  our formula result and yes we're a little bit to   the left of brookhaven but we substantially  overlap uh and so we confirm their result   and again this is why we come blinded right  because uh because if we didn't if we did   this if we did this you know with while knowing  the answer we would have to prove to people that   we weren't influenced to get this and but  because we blinded we couldn't figure out   what this was until the very end and we have in  our roles that once we unblind this is you know   we have to publish whatever we get and this is  what we got so uh we can actually average these   two together uh to combine our the power of our  two data sets and actually we can get a a value   with a smaller uncertainty by combining these  two independent experiments uh and because of the   error bars get a little smaller that increases the  significance of the discrepancy with a fair model   so instead of 3.7 sigma we're now at 4.2 sigma so  we we strengthen the discrepancy with the terror   model still not five sigma so we still can't claim  a discovery but you know maybe we're on the way   on the way to that so that's so that's very  exciting that's this is why this is so exciting   uh so in the end uh my second and last slide so  we confirmed uh the brookhaven result uh and so   so what brookhaven did was was confirmed by us so  so that means that's correct we strengthened the   tension with the stern model it's a 4.2 sigma not  five sigma yet uh but maybe we're getting there   still can claim a discovery but we have a lot more  data to look at uh run one our first result was on   six percent of the total amount of data that we  hope to collect uh so we have actually two more   years worth of data in the can run two and run  three and now we're actually in the process of   taking run four and we'll have a run five and  maybe we'll have a run six uh so we're actually   at ten times brookhaven now uh and and we hope  to get it eventually to 20 times per game right   that would be our our false full statistics so  in about a year a little more than a year from   now we plan on releasing the results from run  two and run three so these are blinded still we   have different blinding secret blinding factors  uh so these are still blinded so we'll you know   look at run two and run three do those analyses  and checks and cross checks and then you know   maybe in summer or 2022 we'll decide to unblind  again and we'll see what we get uh and then as i   mentioned we're taking a run for now actually next  week i have to go on shift we babysit we all take   turns babysitting the experiment uh 24 hours a day  so i'm on evening shift uh from four to midnight   for four days next week so i'm looking for it's  actually a lot of fun i'm looking forward to doing   that um and so we have a lot more data so so what  does this all mean so you've heard there's been a   lot of reports in the news you know we've broken  physics you know you don't have to listen to your   physical professors anymore uh you know so what  does this mean if this is this really were a sign   of new physics and again not a discovery but but  again we have hints uh you know what could this   be physics be uh and the issue here is that this  experiment by ourselves we can't determine that   alone uh we have there are there are models uh  that are compatible with our value for g minus two   and are also compatible with not seeing anything  at the lhc yet uh and we can't tell which of   those models are right um the lhc is doing a big  upgrade and they will we will be able to look at a   lot more data a lot faster than they could before  uh and so you know there's hope that they can see   rarer and rarer stuff because they're going to  be making a lot more data a lot more collisions   so maybe they'll have a hint of something as well  and so to really pin this down uh we need another   experiment to have to have a hint there are some  other hints out there nothing above five sigma um   and so you know it's still wait and see uh but you  know it's still very exciting to see these hints   and especially the hint from us uh come out so  um so don't throw away your physics books uh the   stereo model still works you know where it works  it works well uh and we'll have to see where where   these hints will go and and it's very exciting  um if you want some some reading material if you   can't sleep one night uh you can find our papers  uh there's a website called the archive if you   search for this person's name you'll find our four  papers it's they're very technical but they're but   they're neat that describe the experiment and if  you actually actually want something more basic   um actually sort of along the lines of what i've  talked about if you google g minus two explain   comics uh the american physical society uh has  a comic that they've um they've asked uh uh   this person who makes the phd comics he's really  good uh and he has a comic strip about the g minus   two result okay that is all that i have so uh  hopefully i left you with a sense of how the   experiment worked uh kind of the history of it  where we where we've gone and what we've done   and where we're going and uh some some idea of  why this is so exciting so thank you very much   thank you so much adam this was an  incredible talk um we have as you   can imagine quite a few questions from the  audience um both here and youtube live um   so i'm going to ask you a bunch of  questions from our audience um that's great   so first question could there be something  systemic in the magnet producing the results as   it's the same magnet in both experiments um would  it have been better to build a new storage ring or   um is that a possibility right so that's a great  question and we've asked that question ourselves   and and that basically at every seminar we  give someone asked this question so it's a   good question um so yes the the magnet itself  is the same um but everything else is new so   the detectors are new uh the beam is new right the  the uh the inflector the different parts of the of   the magnet the inflector magnet the kickers the  quadrupoles those are all new um and we actually   we've improved upon the magnet uh from brookhaven  quite a bit i mentioned that we made the magnet   very very uniform we actually did that better  than brookhaven did about three times better   than brookhaven um and so so we we really believe  that there's there's there's really no correlation   between our experiment and in the brookhaven  experiment even though we use the same magnet   you know the magnet itself really just supplies  the magnetic field uh and it has uh the so the   strength and mimic feel of course is important but  that doesn't necessarily tie the two exp you know   our experiment their experiment together  um and basically to build a new storage   storage ring would have been cost prohibitive  we probably would not have done the experiment   you had had the the the ring fallen off the barge  and sunk or something horrible like that you know   we probably would not have done the experiment  because it would have been too expensive to   build a new magnet uh but like i said we're very  confident that there's no correlation from the   magnet itself between between the two experiments  thanks awesome a lot of questions about the five   five sigma um how long until uh what do you think  is going to happen next um there's you know more   runs coming up what do you what right right so  actually i think uh i'm not i'm not sure if so   run two and run three we think we'll get so that  should be a factor of two better in uncertainty um   you know will that will be a lot closer to five  sigma uh will we actually reach five sigma uh   maybe maybe maybe we'll be right on the edge of  it uh certainly you know once we get run four and   run five then then we should be well you know if  the result stays the same of course uh uh if we   keep getting the the answer where it is then yeah  i think certainly by the time we're done we'll be   you know the plan was to be well over five sigma  and so we should hit five sigma um somewhere along   the way i don't i don't know if we'll get there  uh when we analyze run two and run three but   hopefully shortly thereafter awesome um so from  youtube live um can this kind of experiment be   done with the tau particle oh that's an excellent  question i'm so glad you asked that question so   kinda in fact um if we could do it with the  tau it would be kind of a lot better because   um i didn't really explain this very much but the  electron so this experiment has been done with   the electron actually too exquisite precision uh  to part first to sub part per trillion precision   but the problem is that because the electron is  so light let me see if i can get back to that   to that slide well that's not working  i don't want to do that a second do okay there it is okay let me do that  okay so because the electron is so light   it is only really sensitive to  certain types of these diagrams   because the muon is heavier it's actually more  sensitive so it's sensitive to these diagrams with   quarks and the diagrams with the z and w boson  the electron is much less sensitive to those   a tau would be even more sensitive to stuff uh the  problem with towels is that they're very hard to   make um well actually that's not true we can make  tiles uh we don't they're not made as copiously   as muons uh so so they are hard to make and they  live for an incredibly short period of time they   live for something like 10 to the minus 13 seconds  uh and so when you have a particle that lives for   microseconds or hundreds of microseconds you  know we that's easy for electronics to deal   with electronics can can deal with things at the  microsecond scale very very easily but when you're   talking about you know sub femtosecond which  is you know 10 to the minus 12 is a femtosecond   we're talking you know faster than that then  that's very very difficult to do uh so no so   so no one really knows how to do this with pals in  a way that's that that would work if we could that   would be great but um but that's that would  be an incredibly difficult experiment to do   so we had one question about uh the data  um how is this experiments data stored how   much data is gathered free and how much  data is gathered for each of the runs   okay so i'm trying to remember so i said it was  about 8.2 billion positrons uh for run one uh and   run two and run three have a little more than that  um so it's probably i don't know i don't know what   the actual number is i'll guess it's around 10  billion each maybe a little more uh for each of   those runs and get to that plot again that's what  i'm trying to do here oh just missed it there it   is yeah so run two and three are probably quite  a bit longer and have a lot more data so they'll   probably i don't know the answer i'll stop in my  head but they'll have you know hopefully 30 or so   billion positrons so runs one two and three if you  want to know about how how much data this takes   about sometimes i think four or five petabytes of  data maybe more maybe um they actually know that's   about eight petabytes of data um so uh so that's  a lot of data that we that we store on on tape   uh at fermilab for this experiment hopefully that  answers the question yes um so uh another question   uh what is your current favorite explanation of  the difference between theory and measurement   all right so so i'm not going to give you uh a fun  answer you know as an experimentalist uh you know   um you know we see actually it's very interesting  um you know the the theorists themselves are   trying to figure out you know which bottles um  uh could be compatible and there are many uh   yeah i don't i don't have a personal favorite um  i mean that super symmetry would be fun uh because   i've been i was involved in a super symmetric  super symmetry search when i was a grad student   uh and and there's just a lot of a lot of  experiments i've been looking for super symmetry   uh and so far it's been it's eluded the lhc if it  does exist and so that's sort of been a puzzle um   so so it would be great if it were super symmetry  but it'll be great it would be anything else   so i think it's it's not it's not that i would  prefer one or another uh it would be great to know   right that's that's really what we're hoping for  um and once we do know uh you know once we get to   the point where maybe the lhc has seen something  or and or you know we have we have a much bigger   discrepancy and other experiments are starting to  see hints and we get a better picture of what the   theory is that that's beyond the stereo model you  know that doesn't necessarily mean the steering   model is wrong uh it just means that it's a piece  of a bigger picture and we will have learned more   right so so that's what sort of that's what we  want to do we want to learn more we know this   general model is an incredible theory it predicts  so many things i don't have actually here i will   since you asked the question i can so in making  this talk and actually my talk came out to be   twice as long as i wanted so i had to get rid of  a lot of slides so i can actually show you one now   okay i think you can see this one so this  is a plot from the cms experiment there   are many formula people who work on cms this  is uh at the lhc at cern in europe um and so   this is you know many many many many analyses  looking for standard moderate particles or the   screen of the dots are are the rate that these  particles are produced in the lhc or in the   experiment the stereo model can predict this and  so the gray bars are the prediction and the dots   are what what this experiment measures and a  lot of times you can't even see the gray bars   because the dots are right on top sometimes the  dots are going within the error bars sometimes   the gray bar is below this weird thing here and  this is actually a limit this is a so triple   z so looking for three bosons that's that's  something the lhc hasn't seen yet or that or   cms hasn't seen yet because the the value of  the the rate that that it's predicted is too   too low too rare for what the llc can produce  right now right so they set a limit uh but   this this this whole plot here is nine orders of  magnitude here this is an incredible plot because   basically it shows how strong the stereo model  is that all these predictions uh are basically   correct so this is an amazing thing and this is  why it's so hard to look beyond the stair model   because the stereo model works so well and even  though we have these ideas we have these these   things we wish the stereo model would do that  it doesn't you know what it does do it does   incredibly well and there are very very small  number of experiments like ours like g minus two   that has a hint of something weird going on right  and no one has a hint about five sigma so um   so yeah so so thank you for letting me show  one of my backup slides i appreciate that   um so a follow-up question to that um how do  we know that the anomalous frequency indicates   something beyond the standard model and not just  a need for some fine-tuning um to the thousands of   diagrams from the standard model contributions ah  that is a great question right so could there be   a mistake in uh or something else going on in the  stair model prediction um i don't have it in this   talk unfortunately um so this this um this uh muon  g minus two theory initiative let me find their   picture again here they are right so there's  there's there's over a hundred theorists here   some of them work alone some  of them work in small groups   and they they've all produced pieces of the  standard model prediction so so calculating   what these diagrams contribute to g minus two as  i mentioned some of them are very difficult to uh   to calculate and so they kind of sometimes they  calculate them different ways uh and they put all   that together and if you look carefully you notice  that the theory value had an uncertainty as well   so they evaluate all these different ways of  coming up with these calculations and they look   to see you know how they're slightly different if  they agree if they don't agree you know and they   assign uncertainties what's called a systematic  uncertainty based on the level of agreement um   and they come up with a very small uncertainty  uh so so this is the error bar that they put on   on this value and that takes into account  sort of all the different ways of doing this   these calculations now to be fair um there are  some new very new calculations that are being done   with a technique called lattice qcd uh so some  of these diagrams can be calculated in a new way   um with this with this technique the the  technique itself is not that new at all   but it's being applied uh to g minus two in a way  that kind of pushes this technique to its limit uh   and so they they're producing i don't have  the plot here but they're producing results   that are more pushed out to the right but a lot of  them have very large error bars uh they could you   know basically they overlap you know everything  uh so you can't really say uh what they're saying   they're not included um in this in this average uh  because they're they're very new and they need to   be evaluated there is a new result from lattice  tcd from from one group which is more over here   toward the experimental value uh and um that's  very interesting uh they are claiming that they   understand how their calculation works uh to a  very high level of accuracy uh but that has to   be scrutinized and it's very it's very new and  so actually it was so new that the that it came   out after this value was determined and this was  a few this was determined a few months ago so this   this thing is so new that it hasn't been looked at  very closely yet by the muon g minus 2 initiative   so i think they're going to be very busy over  the next year uh lattice qcd does involve a   lot of assumptions and there are some places  there's some regimes where it works really well   and there's some regimes where it doesn't work  very well and so you know if groups are claiming   it works very well in lots of regions you know  that's something that has to be looked at and   this is how know this is how science works right  uh you know someone pushes pushes things to the   edge and gets a result uh and then it has to be  scrutinized by the community and uh and over time   you know the community will either believe it and  and maybe you know that'll push the sarah model   value over to the right or maybe they'll find uh  something that's that uh that was overlooked or   a reason to doubt the new result the new these  new uh calculations and it'll stay down here so   let's have to see i think you know as we're as  we're busy doing you know analyzing run two and   run three and taking run four uh the the the stamp  the community my two initiative will be very busy   evaluating uh these these new last qct real  results because they are in conflict with   techniques that have they've been doing for 20  years and so even if it turns out that these last   qc results are more correct then then they have  to explain why these long established results are   wrong what's wrong with them because now there's  a tension within the stern model that has to be   that has to be uh understood so so no matter  what happens we'll learn something new   um so that's what i want to say in the end so what  are your thoughts about the possible relationship   to dark matter as the news has talked about this  um is it just wild speculation or is it justified   um so i i think i think there's something  in between justified and wild speculation   right so so as i said um there are  lots of models that are compatible   with uh with muon g minus with our value  for mu1 g minus two endless discrepancy   uh dark matter models some of them are compatible  so it could be dark matter uh it could be   other particles called leptoques it could be  supersymmetric particles and we just don't   know you know like i said we we really won't we  can't determine that from our experiment alone   uh we need hints from hopefully you know if  hopefully the lhc will start seeing some hints uh   uh or other experiments will start need  showing some hints or we'll need to to have   new experiments that are even more sensitive uh  and and maybe that'll point us along the way so   so so guiding to an answer like that is difficult  at this time uh but you know we're starting to   sort of shine light on things and right now the  spotlight is very broad uh but maybe with other   experiments it can be narrowed in the future  um so we have a few practical questions um   as the magnetic field is measured every three  days how much variation is seen over time that's a great question uh i can show you  this uh where'd it go here it is so that's   a great question so so we actually care about the  magnetic field where the muons are and to do that   uh we have to run this trolley around the ring and  actually we have a little camera we can see the   trolley go by it's really cool um but but yeah  so the magnetic field between those three days   does change and that's mostly because for run one  uh we had a hard time controlling the temperature   of the hall so this sort of shows the changing  magnetic field over those three days that we can   measure with these embedded probes in the ring  and that's really what they're for so we have i   think 300 and some probes around the ring they're  fixed in the ring and they're measuring how the   magnetic field changes in between the trolley runs  so the trolley runs are kind of the very precise   measurement uh and that's every three days  and then we use these fixed probes to get from   one three-day measurement to the next three-day  measurement so we can determine what what the   ring was doing in that intervening time so these  fixed probes really make it so that we can do that   awesome um so when you kick the muons so they  won't crash into the ring wall does this affect   their spin um and uh how do we know things in  place to focus and kick the muons into a focused   beam are not affecting the results that's a  great that's another great question uh the   the kick is incredibly short so if it does  change the spin it doesn't change it very much   um the uh i'll have it in this talk but there  is actually something neat that happens so yes   the the quadrupoles do change the spin um but we  can actually minimize that effect by choosing a   very particular momentum or energy for our muons  so it turns out there's something called the magic   momentum and if you if the muons are going around  the ring at 3.09 gev that's the magic momentum   then that minimizes the effect of the of the field  from the quadrupoles it doesn't so it actually   can actually if you choose this exact right  momentum then the muons really don't feel the um   they're not affected by the quadrupoles now the  problem we have is that you know most of the muons   are going a lot of the mirrors are going around  3.09 but a lot of them are not exactly 3.09 some   of them are a little off uh so there's always  a range of momentum they're very close they're   within i think point one five percent of 3.09 but  that's enough that we have to worry about it so   we actually have a correction we can calculate  we can look at where the mu ones are in the ring   and that gives us that tells us what the momentum  distribution is of the muons and from that we can   calculate a correction for this effect um  there's actually another correction because the   quadrupoles you'll focus vertically that does set  up a little vertical oscillation of the beam and   so the muons might not uh decay the positrons  in the horizontal plane they might be tilted   up a little bit or tilt it down a little bit  and that's called the pitch and there actually   is a pitch correction that we make uh we can  figure that out uh and we can correct for that   and uh and assign uncertainties to that as well  so those are actually long-standing corrections   brookhaven did them too uh and so they're they're  they're so we know how to do them and we know how   to how to estimate their uncertainties and so  and so we do all that so yeah so that's a good   question and we know how to deal we know how to  deal with the effects of parts of the ring that   that could potentially change the spin um so  does the ring make much sound when it's working well that is a good so not really so so you  can't be inside the hall when the ring when   the ring has muot uh because there is there is  a radio there is potential for radiation and so   we have a we have a kind of a uh elaborate  safety system an interlocking system so no   one can be inside the hall so you can't be in this  picture when we actually have beam uh in the ring   um we do it's sort of funny uh like i mentioned  sparks uh so sometimes some of the kicker plates   and some of the quad plates can spark uh  that's actually not so good we don't want   that to happen uh and for the kicker we actually  uh sometimes those can be heard and so we actually   have a baby monitor uh next to the kickers uh  that's tied into computers in the control room   uh and so we can actually if the kicker  spark which fortunately is very rare   we can actually hear them spark on these  baby monitors it's really kind of funny   um but we have other ways of detecting the sparks  as well it's sort of a backup last resort way   of detecting these sparks uh but really  on the whole i mean there's fans running   uh for all these electronics there's fans in the  hall so you just kind of hear a home of stuff   you don't really hear things whistling around in  the ring but but the baby monitor is kind of fun   um so is it possible that the five sigma  requirement is too high a threshold giving the   given the intrinsic uncertainty of what you're  trying to measure um as suggested by the standard   model a good question interesting question so  no um so so five segment is really the standard   for experimental particle physics i think it's  also for other areas of physics as well uh it's   a long established um uh standard and and really  you know you you strive for that result so so   you're trying to take enough data and maybe it  takes years to get there uh but you do and let   me i have a slide actually well maybe i won't  show that slide but to try to explain what that   means so basically what you're worried about  is um you know could could the actual value   let me get there could the true value really be  the standard model value uh and what you're seeing   is a is a an unlucky statistical fluctuation  so it's like you know if you're i don't know   if you're playing back admin if those of you who  play backgammon uh you know each player when they   turn they roll two dice right and if you roll  double sixes you're really happy because that's   like the best move you can get and sometimes when  you're playing backhand and you're playing against   someone and they're doing really well and they get  like you know two double sixes in a row and you're   like oh this is terrible you're going to lose  you know and and that's really unlikely it's very   unlikely to get something like two double sixes  in a row but it can happen um you know unlikely   things can happen um and so you know the the  but the the less likely it is for that to happen   then the more robust your answer is right so  basically a 3.7 so actually here 5.26 uh 4.2 sigma   uh means that if in fact the the true answer is  a standard model then uh the odds are 140 000   that a statistical fluctuation could could make  your result be pushed out all the way to here   so that's that's becoming you know that's a light  that's quite unlikely and the odds of two double   sixes are like one and i think 1200 or something  like yeah i think 1200 or 1300 or something like   that so a lot less likely than than the odds of  getting two double sixes in backgammon um but if   if this were five sigma then the odds would be 1  and 1.7 million and at that point we say you know   that really that's so unlikely that that then this  this this result is very very robust so the closer   closer you get the five sigma the more robust  you get so we're we're getting you know we're   better than 3.7 so we're getting more robust uh  but that five sigma really is that gold standard   that that we want to meet uh and that's when  that's when everyone takes takes this seriously   uh as a discovery uh and so the higgs had to  be above five sigma the top quark when that was   discovered that had to be above five sigma um and  and we we we're we're keeping with that tradition   because that works because because one one out  of one point seven million that's really rare   very very unlikely that that would happen i'm  sorry thanks so time for one last question um   so thinking decades ahead um where could  this new discovery lead decades ahead   okay um so so hopefully uh in the next three or  four years uh g minus our experiment will be done   and we will you know if things go the way they're  going this is a prediction right we don't know   this is going to happen but you know we will  probably get a result which is much greater   than five sigma you know assuming this thera model  stays where it is maybe moves around a little bit   because this lattice these lattice results we'll  have to see what happens but uh but maybe we get a   a result that that's greater than  five sigma and that would be great   and as i said you know even with that uh you know  we alone can't really say what the new physics is   but hopefully decades from now um you know the lhc  will have run you know we you know there they will   be in a position to hopefully see something new  uh if if it was if it's within their reach right   there there are things within their maybe within  the reach or maybe not and so we have to see what   they see uh we're doing another experiment here  called mu to e which will be turning on probably   in a few years uh and they're going to look for  a very very very very rare decay of the muon   something like at a rate of of 10 to the minus  50 uh and so if they see something that's a big   discrepancy with the standard model uh if  they measure something above that and so   that again would when that would narrow down  the spotlight right as to what uh what we   see uh what part what models there could be and  you know we have these big neutrino experiments   uh that are going on uh and they're you know  they're looking for things like what's called   cp violation and understanding uh how  neutrinos work to even greater detail   uh and so you know this is all you know this all  gets put together right so so you know we we try   to create with all these experiments uh try to  create a picture a hope hopefully consistent   picture and it might not be for a while this is  how science goes right it takes a while to uh   for things to sort of merge into into an answer uh  you know and it might take decades to do that but   we're putting together we have pieces that we're  putting together and hopefully we can do more   powerful experiments in the future you know based  on what previous experiments see or don't see   uh that will guide us you know along this  journey to understanding you know more about   about nature and the universe that that's really  ultimately what we want to do and maybe along   the direction of what this bigger theory is  that the steering model we think lives inside awesome thank you so so much um and for those of  you that did not have your questions answered or   those that are interested in learning more  um we'll have a g minus two focused ask a   physicist or ask a scientist on april 25th  and our um physics slam on april 30th will   feature a talk by another g minus 2 physicist in  a very different format so thank you again adam   so much this was wonderful and i look forward to  seeing um everyone here again at one of our other   events and congratulations what an amazing amazing  amazing accomplishment from all about the g minus   t thank you so much and uh and this is really  a lot of fun and everyone have a good evening

Channel: Fermilab

Views: 98,489

Keywords: Fermilab, Physics

Id: PpZo6ZZ-PBI

Length: 101min 43sec (6103 seconds)

Published: Mon May 03 2021