What are Quarks? ( Quark Color | Flavor | Quark Confinement)

[Music] you hi welcome to my channel so ordinary matter all the stuff that makes up the world is made up of atoms atoms are made up of what electrons protons neutrons electrons are elementary particles point mass particles they are not made up of further fundamental particles but neutrons and protons as it turns out are not elementary they are made up of further fundamental entities which are known as quarks so works are these fundamental entities that make up a class of particles known as hadrons of which neutrons and protons are a part of so in this video I'm going to talk about what works are I'm also going to talk about quark color hypothesis what is flavor and then what is quark confinement but before I talk about all of these topics let us first do a little bit of a revision from my previous video in my previous video I talked about the Eightfold way now let's do a little bit of a revision because it will give us flow in the entire discussion so in my previous video I talked about the Eightfold way which is an organizational scheme of organizing or grouping together different kinds of hadron particles you see there are a large number of these had drawn particles out there so I had drones are a class of particles that experience the strong interaction now there is a huge diversity of hadron particles out there and one very natural question that comes to mind is are all of these particles elementary or are they made up of further elementary particles and this question led to the idea of Eightfold way which was basically arranging these Hadron particles into charts or groups or geometrical patterns based on same spin but different charge and different strangeness so for example one group II is the baryon after so this consists of eight lightest baryon particles having spin 1/2 now hadrons as I said are particles subatomic particles that experience a strong interaction but hadrons can be subdivided into two groups bosons and fermions so the bosons which have integral spin they do not follow the exclusion principle are known as mean zones and the forming on say follow the exclusion principle are known as in parry ons so eight of the lightest baryons can be formed in this kind of an octet structure all of them having spin 1/2 and different strangeness and different charges similarly we can also arrange nine meson particles they all have spin 0 but they have different strangeness and different charges there are further similar structures like the baryon decoupler which is basically ten baryon particles all having spent three by two but different strangeness and different charges so this is a basically known as the Eightfold way which is a way of organizing these different hadron particles into groups having same spin each group having same spin but different charges so the Burien octet the Me's all known at the baryon d-- couplet are a few of the examples of these groupings now this kind of a classification scheme naturally leads to the question that are these particles made up of something more fundamental or are they fundamental on their own so at this point I want to bring to your memory the idea of the periodic table now if you remember the periodic table which consists of more than 100 different elements or atoms but they are all essentially made up of electrons protons and neutrons in different combinations so in the same way that this huge diversity of atoms can be created by recombining electrons protons and neutrons in different combinations can these hadron particles be generated by recombining certain more fundamental entities there led to the idea of the orc model so this was an idea which was independently proposed by Murray gell-mann and Zweig who said that we can perform certain mathematical calculations and say that there are certain fundamental entities having certain properties which when they organize in certain proportions can lead to the creation of all of these particles so he proposed that there are three fundamental entities so these three fundamental entities having different strangeness and different charges so these fundamental entities are what is known as quirks so these works are these supposed fundamental particles that when they combine in different proportion ends up creating those hedron particles in the first place now if you look at the characterization of the properties of these quarks provided by Murray gell-mann then you will see that there are right now three quarks up there you have the down quark the up quark and the strange wall the down and the up quark has strangeness of zero the strange quark has a strangeness of minus 1 while the down and the strange quark has a charge of minus 1 by 3 and the up quark has a charge of plus 2 by 3 electronic charge so because most of these particles have integral charges either neutral or plus a material electronic charge or minus integral electronic charge so the quarks which make them up need to have fractional charges and based on this proposition of three or entities and similarly the antiparticle version of three anti quark entities we can recreate the Hadron particles and explain the properties of each one of them so essentially the quark model says this that each baryon particle consists of three works similarly each anti baryon particle consists of three anti quarks while a meson particle is made up of a fourth antique or pierre so based on this idea we can recreate let's suppose the baryon obtained as being composed of particles which are made up of three quarks and the combination of up down and strange can be in different proportion we can recreate the meson non aid as being composed of a quark antiquark pair as well as the baryon d couplet has been composed of particles which are made up of three different works in this manner we can recreate all the Hadron particles as being created by a combination of three quarks or a quark antiquark pair and by looking at the properties of the quarks we can explain the properties of the hadron particles themselves for example if you look at the neutron which consists of one up and two down work now I told you the up quark has plus 2 by 3 electronic charge and the down quark has minus 1 by 3 electronic charge so because the neutron has a one up and two down work it charge should be plus 2 by 3 minus 1 by 3 minus 1 by 3 which is equal to 0 so the neutron is the neutral particle it can have spin half the quarks have half Spill they organize themselves in such a manner that the neutron is also a half spin particle and because up and down are not strange particles their strangeness is zero you end up getting a zero strangeness similarly you can look at the proton which has two up and one down quark so its charge comes out to be plus 2 by 3 plus 2 by 3 minus 1 by 3 which comes out to be 1 so proton is positively charged it's spin is 1/2 as well as strangeness is 0 similarly you can also explain let's suppose a positive PI meson having charge plus 1 and strangeness of zero and the Omega particle having charge of minus 1 and strangeness of minus 3 so in a way this idea of these fundamental entities called quarks that make up all these hetero particles is able to explain how all the diversity of hadron particles can be recreated by simply rearranging these quarks and antiquarks in different numbers now even though this kind of an idea is associated historically with the development of its own mathematical representations but for the sake of the discussion we do not need to go into the mathematics I am simply telling you about the particles that constitute all these hadron particles so as it turns out these quarks are essentially these fundamental entities that create the Hadron particles like neutrons and protons now one serious problem that arose as a result of the kind of organization of hadrons in terms of quarks is that many Hadron particles consisted of more than two similar kind of quarks for example you have a neutron that consists of two downwards a proton that consists of two up quarks and more other particles that consist of more than two similar kind of works now if it is that these quarks are spin 1/2 particles then how is it that two of the same kind of quarks can exist in this inside the same particle now this goes to what is known as the exclusion principle now you must have heard of what the exclusion principle is it simply states - or fermion particles or four particles having 1/2 integral spin no more than one similar particle can exist in the same quantum state right so if that is true then how is this possible that - same kind of quarks exist inside the same particle to get around this kind of a problem it was suggested that maybe maybe apart from works being divided into up down and strange there is some additional property associated with these quarks which when they come together to form a hydrant particle is in different proportions and this additional property is known as color so the or color hypothesis basically is or was originally given to get around this idea of violating the exclusion principle of how the same kind of corpse can come together to create the head-on particles it simply suggest that in the same way that let's suppose you have electronic charges okay right charge is a property of particles and this property can manifest into two different ways you can have positive charge you can have negative charge and when a positive and a negative charge come together then they create an electrically neutral hole right so in electromagnetism charge is a property that can manifest in two different ways of positive and negative so in terms of quarks this color is a property that can manifest in six different ways you can have red green blue and for the antique works you can have anterior antique green and NT blue so this is called the or color hypothesis and it simply states that quarks which come in three different forms apart from that there is an additional property which we call as color but this has nothing to do with visual color even here I am representing using the visual color of red green and blue but the actual property has nothing to do with ordinary visual color it's just a naming convention you can say now why you have used this naming convention I am going to come to that in a moment but essentially this is some kind of a quantum property that can be used to distinguish the quarks from one another now you could have easily named these properties as let's suppose X Y Z or something like that but the reason they have been named as a red green and blue is because it can help us in understanding how these different colors come together to create Hadron particle so for example the analogy here is that when you talk about primary colors when you talk about white light it basically come is composed of three primary colors right when the primary colors come together you create white light now the analogy with respect to works and Hadron particles is that all hand-drawn particles are supposed to be colorless so when works come together to create a Hadron particle they come together in such a manner that their color properties will be either an equal proportion or will cancel each other out so that the final Hadron particle is colorless so if you have a baryon particle it will consist of three quarks which have each red green and blue property so that the final baryon particle is a colorless Hadron particle can you see that now similarly if you look at let's suppose a meson particle which consists of a quark antiquark pair then in that case the we'll have a particular color let's suppose red and the antiquark will have an T red so that ultimately the meson itself is colorless in fact all naturally occurring hadron particles are what you can say as color less because they do not exhibit this property this is a property which is intrinsic to the nature of works only and only when works come together to combine then this property is irrelevant but beyond quarks this property is not relevant in the sense that hadrons are colorless so they are either composed of an equal proportion of these three properties or they are composed of one color and one ant occur in fact this color hypothesis also explains why certain kinds of hadron particles having certain number of quarks are not found for example let's propose a Hadron particle consisting of two quarks okay not a meson which consists of a quark antiquark but rather a Hadron particle consists of two works now we cannot have ahead on particle consists of two parts because in that case whatever the color of these two quarks up they will not create a colorless Hadron particle so to quote a combination of hadron particles are not found in nature or rather for quark combinations you do not have for or combination of hadron particles because even in that case the hadrons would not be colorless so all the hadrons were the baryons army zones they are all colorless in the sense that when these works come together then they cancel out you can say in that term the property of color so as to create a colorless Hadron particle so using this idea of color hypothesis let's suppose if you look at the neutron which I said consists of one up and two down for now these three quarks the up down down have different colors so now there is this additional property of color which differentiates both the down quark you see that similarly you have a proton just two up and one down quark but now all these three different quarks have different color similarly if you look at a baryon octet and the baryon the couplet they all consist of hadrons having three quarks but all three in each particle have the color property of red green and blue ultimately all of them are colorless in that sense and similarly the meson which consists of a quark antiquark pair is consisting of work having a color and an antiquark having the anti color so this idea of core color is something which is very much inherent to the peculiarity of works themselves that do not manifest beyond the Hadron particles to macroscopic objects let's suppose and in fact this peculiar property of color is very much intrinsically linked to the idea of the strong force itself you see the quarks are attracted to each other because of a strong force and the strong force you can say is very much dependent on this color property in the same way that let's suppose electromagnetic force is dependent on the charge property so electromagnetic force has this property of charge based on which you can have extractive and repulsive forces right so in that same way the strong force is intrinsic to this property of color that quarks have in fact the strong force is also known as the color for sometimes now this is all about the property of our color but apart from the quad color as I said that there are different kinds of quirks like up down and strange but as it turns out today we know that there are further more kinds of quirks now what is this property call this property is called flavor in a flavor you something taste sweet something tastes sour something tastes salty I have no idea how that name came into this differentiation of quarks but that's how its name the flavor of quarks as it turns out is what tells us whether the quark is up down Oh strange and then you have these additional quarks the charm top and bottom which are basically quarks that were discovered later on that were found in particles heavy particles that were formed in very high energetic nuclear reactions that were extremely unstable so today at this particular point in time we know of six different kinds of quarks you can say or six different flavor of quarks because is what is known as the manifestation of the property of flavor so you have the upward the down quark the strange quark the charm quark the top and the bottom quark now of course there is a lot of mathematics and theoretical formulation behind these ideas we cannot go there I'm just introducing the topic here so the worth flavor manifests in six different ways as six distinct quark particles now keeping aside all these theoretical ideas of these fundamental entities constituting hadrons in different proportions coming together experimentally none of the quarks have been actually isolated in the half a century of discussion on quarks we have not yet been experimentally able to isolate and detect these forks as individual particles and this brings me to the topic of orc confinement so what is quark confinement I told you that inside a Hadron particle let's suppose a barrier I only have three quarks that are very much attracted to each other because of the strong interaction so the strong interaction is a force which exists between these works due to their color property so there is an exchange of particles going on between these quarks which is known as gluons so based on the exchange of gluons between these quarks it leads to the creation of a very strong a very powerful in fact the strongest of all forces in these distances the strong interaction and it is a strong interaction that holds these quarks together inside and Hadron particle now the nature of this force is such that you can imagine that they are being as a result of the exchange of new own particles but you can also let suppose imagine that there is a bond or a attractive force which can be replicated by a spring let's suppose so if you have three quarks that are attached to each other in Springs in the sense that what I want to say is that so if you pull the spring then with increasing extension the force increases right so the more you try to pull the spring apart the more the force to bring it back increases now of course in real life at some point the spring will break apart but what happens here what happens when experimentally you try to break apart the court by giving some kind of an external energy by some sort of a high energetic nuclear reaction where you are bombarding these hedron particles with smaller particles like electrons or some other particles so you're essentially trying to break apart this combination but when you provide energy to it when you try to separate these quarks instead of the quarks being isolated you end up creating a or canticle pair now let me explain to you with an example let's suppose that you have a neutron particle right the neutron has a one up and two down course if I provide huge amounts of energy to this neutron by let's suppose some kind of an external gamma photon and I expect the gamma photon to come and break apart the neutron into its constituent quarks what actually ends up happening is that the gamma photon instead of breaking apart the neutron into individual quarks the energy is used for the creation of a quark antiquark pair so now these combination of works will reshuffle so you end up getting two up and one down quark which will become a proton and then you will get a one ante up and one down quark which will become a PI meson so essentially instead of the external energy breaking apart the had drawn into its individual quarks you end up getting these new particles so the extra energy instead of breaking apart the quarks lead to the creation of a quark antiquark pair which rearrange inside the Hadron to create new particles so when a neutron is bombarded with a gamma photon it essentially becomes a proton and the PI meson so this is what happens with all the hadron particles whenever you try to bombard them with very high energetic particles instead of the energy breaking apart the Hadron you end up creating a quark antiquark pair which then reorganized to create two new particles in the first place so this is known as the idea of or confinement this is why we have not yet been experimentally able to isolate the quarks into individual particles you can think of this like the idea of magnets so if you have a magnet which has an odd pollen a South Pole you cut the magnet in half you don't get a North Pole and South Pole separately but rather you get two parts having north and south right the 1/2 will have both North and South the other half will also have both North and South the same thing with quarks when you try to break apart the Hadron particle instead of breaking apart the quarks you end up creating new particles from that excess energy that you have provided this is known as poor confinement so there is all for today's video I hope that you have got a little bit of an idea of what quarks are these are the fundamental entities that make up all the Hedgehog particles so along with electrons and we which belong to the class of particles called leptons these quarks now constitute the fundamental particles in our universe and apart from discussing quads we also talked about quad color red green blue coming together for flavor and worth can find mine in my next video I will talk about the standard D model in particle physics till then see you thank you very much have a nice day [Music] you

Channel: For the Love of Physics

Views: 86,661

Keywords: quark confinement, quark model, quark color, quark (idea), confinement of quarks, quark color confinement, quark flavors, quark color charge, quark color force, quark, quark confinement in particle physics, quarks explained, what are quarks, what is quark, quarks, quarks and leptons, color force, hadrons, hadron, for the love of physics, eightfold way, physics, education, particle physics, strong force, nuclear physics, strong interaction, Standard model of particle physics

Id: fWPvhFcDjEs

Length: 24min 1sec (1441 seconds)

Published: Wed Jun 03 2020