New Revolutions in Particle Physics: Standard Model | Lecture 1

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New Revolutions in Particle Physics: Standard Model | Lecture 1
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(January 11, 2010) Leonard Susskind, discusses the origin of covalent bonds, Coulomb's Law, and the names and properties of particles.
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always talk about things are far field quanta fields the relationship between fields and particles of the relationship between fields and they want a 4 . 4 quanta dogged discrete indivisible units of energy the quantum mechanics of a implies for waves for waves and waves of course of fields fields and waves amaurosis thing we discuss the properties all in that they properties of individual particles were much but we've discussed general properties the properties of having a energy momentum the properties of having spin and the property of EU being a fermionic bows on every particle was either a Firmiana bows are from eons particles that like show together in the same state bar was on particles of galactic congregate do condensed Bergstrom state we've talked about 40 equations on occasion on the field equations of your Iike more generally various kinds of field equations we talk about how field equations can be generated from a grant from action principles quantum mechanical version of a grungy and is a kind of tool for codifying codifying the right word is codifying the interactions between particles various terms In all of grungy and things White for example product of fields represent prophecies which Armed with can call vertices where particles command and other particles go out that would for example be a terminal grungy which for How was field and so talk about these general things are we haven't talk very much about specific particles tonight while I expected to spend the 1st half hour of beating around the bush watch a little bit a few more minutes beating around the bush but then I want to come through really writing down what the particles are you other players in the drama yeah and start going through them more or less well Court 1 by 1 but in groups and try to give them some personality given some names properties also what they do and how they carry coming to work in physics through ordinary physics before I do that this kind of a triangle of concepts that we've discussed 2 legs are but not 3rd March the triangle is particles or field quanta particles fields in modern physics pretty much every elementary particle now we're Nafta think very hard in the future tonight what is an elementary particle and what is a composite particle we will come back and you might think I mean everybody it probably has some cancer of I would ask you have you distinguish a composite particle from element articles and you will always be frustrated you will always find some slippery reason that you a definition of war but for the moment but nevertheless imagined that their elementary particles and the elementary particles are the quanta of elementary fields fundamental fields theory art and war a lesson one-to-one correspondence but there's a 3rd leg of this triangle but in August question our I'm thinking so we you order was restored forces forces for and I course it is washed forces OK basically for every field is a particle for every field there's a florist electric field gives rise to to elected forces gravitational field Grise gravitational forces and may be less obvious to you follow what these with electron field electron has a field our it also gives rise forces will talk about them a little bit so others can our correspondents because this way the cars on which from this way there must also be a correspondence which goes this way always thinking about forces which is not based on field but which based on particles if this correspondence strangle really makes sense don't go but there will be many of you nor the idea of us just discussed from are 1st discuss it In the context of electrodynamics how forces come out of thinking that this is a classic electrodynamics from the complete field viewer think suppose an iPod Tour charges into space and I want another force between how I calculated while you could not although you could nor the role the forces equal product charges times her arms while are square so for will you could try calculated from where you could say what does what the 2 charges due respect what they don't based is they create electric fields I think essentially that's the thing we do it create an electric field those space and I don't write down details of what our electric fielders but let's just say this is re-elected field but to get a 2nd article and just right the electric field due to the 1st part or whatever it is the electric field to the 1st particle incidentally it's proportional could be electric charge of the 1st particle so let's
explicitly prepared him he of the 1st particle tying the electric field are provided by the electric charge electric field here are divided about electric charge maybe I should call it court EU about a factor of your charger cruel Hanover electric charge and 1 of the field energy anybody nor the formula for the field energy use an electric field field have energy store their energy as a distribution of energy in space and the field energy density of field energy is a square of electric field so we squares and we'd integrated also faced new volume and that's the energy stored In this on the electric field of the particle now this energy does not depend on where we put the a particle right where field will move promoter particle field will move with it Butterfield energy will always be the same electric field with just position of a charge of field will always give rise to exactly the same field energy in this field energy here remember equals M C squared field energy is part of the massive particles it contributes a field contributes the energy of the particle and therefore it contributes to a mass of particle is another way of thinking about a bit of renormalization some extra mass because the field surround the particle in this way look at our Malabar that I was not the 2nd particles supposing the 1st particle wasn't there but the 2nd particle was there courses energy he said not be electric field as the energy if it was only particle show the film energy would be we in the role of each tool times electric field of the 2nd particle squared method to particles are not the same Place well aware of what this this 1 were also be independent of the position of this article he worried about the energy if I have both particles if I have both particles than I have and off the field 1st before square near so we electric field if I have to particles With but will be the summer with 2 electric fields electric field not enough energy which cost energy E H Morris according to energy yet an arm the energy 1st rd electric field the electric field will be the sum of the door electric field electric field will be each EU 1 courses you want a warrant cost tool 2 where is of electric fields of particle 1 and particle through this will be the Top electric field incidentally electric fields on vectors and so we might go vector signs above the field energy you get by squaring field energy busy in the world of a space there are 3 current 1st turn he won squared you want squares gotten by squaring the 2nd terms this past week to square through square and the 3rd jersey interesting 1 as a product of EU 180 tool twice as a matter of fact pious you warned about each to factory pop-rock I was 1st earlier it's a self energy of 1 particle by itself it doesn't depend on the position of the particle it's just the number it's part of a mess of a particle let's forget it is already there part of a massive particle about this 1 also farmers self energy GRB 2nd particle what about this 1 here this 1 is not the energy of i the particle separately as proportional to the product of the
charges and is proportional to a product the field where the particles infinitely
far away so far away that they're cool Longfield's hardly overlap or 1 particles so far away that Of course long fields Our hardly overlap visibility 0 because where the EU 1 is not 0 he too will be 0 or almost 0 whether he still is nonzero new ones will be close to 0 so this would be very very small as you take the particles apart but what about when you bring them together when you bring them together the product of 122 will not be small nearby where the particles are both fields will be appreciable and you will get a contribution from there was a contribution that contribution as a function of distance for 1st almost proportional of a product of the charges it depends on the distance of course if you work at hours you might expect it's nothing but a cool watch or bar square but I like the Sabres way because it gives you will the following picture but putty in both charges far apart they don't affect our overdose simply just independent objects as you bring them together they perform distort the field it in a way that depends on the distance between them and the distortions of the field between them that field energy fast field energy which is the contribution because both of them out that's forceful so that's a purely field point of view of 4 Serbs a purely field point of view of course but if fields are nothing but collections of quanta and quite top particles must also be a way to think about forces In terms of particles sold let's talk about that before discussing electrodynamics in this way let's talk about a slightly different start up completely bill actually very completely different a set up but on molecular forces What do molecular forces come from undue 1 source of several for over a civil origins of molecular forces but he is set up I wanna think about art let's begin with a pair of protons and the shingle electron what is this proton proton soon go electron yes this proton were very far away in the ground state of electrons in the presence of a proton would just be the hydrogen atoms grounds it would be governed by some sort of throwing the wave function withdraw the throwing away function of ground state would be the grounds of a hydrogen atom and in the ground state of the proton warrant their all they're all these electronic innards ground state would certainly be found in the position nearby a proton now 1 of the Otto protons over here not want probably another Pretoria pretty far away but not faraway and it was not possible state of electron exactly the same energy where the electron was not only here but it's over here with the corresponding wave functions if pushed over a year that is exactly the same energy white because the 2 protons the same kind are and everything is completely symmetric here Sophie electron is in orbit well quantum mechanical orbit around this Proton which require mechanical orbit around this broke the ground-state energy will be exactly the same as if it was only 1 broke apart but it's not quite true why isn't it exactly true well if the protons are not infinitely faraway there a process stick it happened which could not have been a worry in infinitely way forward anybody nor the processes that can happen to electron the 2 Rich your fresh young following a threat the electron placed over here in the woods grounds they can with a small probability suddenly appear appearing asylum over here called quantum mechanical can't bring 5 passed over calm and energy barrier between here and between the would take some energy holy electron however Adam you get that energy backward drops this Adam but a half the goal of this field can go over the hill classically but quantum mechanically Connell from 1 place to another don't stand there and try to watch from what happens if you try a watch for electron going back off like anything else in quantum mechanics watching it ruins are you overheated could say Well you could stand over here and wait for the electron peer over here your watch at from here you rule from our soul we electron can hop back and forth hop back-and-forth simply means as was transition pummeling rate pummeling probability that you put will here can peer over here and it appears over anyway awhile to reappear over here for rocket this process steps are a kind of equilibrium wall terms equilibrium which the electron has up equal probability I'll be over here over here with a wave function looks which looks like the song of to wave function while the song divided by the square root of 2 for probability there are where are the 1 that's so looks like some of the wave functions which it enjoyed it well but he little over here it's slightly different you might assume I draw the exact wave functions of electrons for orbiting particle 1 as if particle toward market same thing for particle too and then in them up
well the Koran pummeling wave function the correct equilibrium wave function is not exactly the some of these 2 wave functions of a little bit different he will be March but the point is we energy off the system is not exactly where we would be here the 2 protons with infinitely far away from each other if they were instantly far away from each other you could for the proton they are our here it would have a certain energy or over here would have exactly the same energy when you put them closer together the energy of the electron is not exactly the same as it would be if we aren't if they were far apart through infinitely far apart solved if I what the plot beat energy if I a plot the energy as a function of the distance between them when they're very very far apart the energy of that electron is simply the energy of electrons with only 1 proton just about barrel at large distances the energy would just be but as you bring the protons together energy Olive back to protons plus Elektra is a little bit less friends are we are little bit West and a little bit less art is a function of the distance between start now have a situation when the system is in equilibrium with electron commonly back-and-forth equilibrium between the energy is a function Of the distance between them what's the relationship between Boston energy you would think of this as potential energy you think of this as a potential energy between the 2 broke a derivative of the energy Saul a derivative of the Energy Energy has a gradient here force always poorest pushes you toward decreased energy and so this effectively creates an attraction between the 2 proton that attraction is kind of our covalent bond to kind of force between the 2 of them which is Due to the sharing of an electron effective electron commuter superposition quantum states in the 2 wells the tool or potentials of these 2 things he now does that mean that a proton and mother Proton with an electron between them which has this attractive force will bind together not quite because another force around with a force of electrostatic force the system doesn't have 0 charge altogether and so a repulsive force repulsive force can overwhelm the attraction for us but nevertheless there it is a forest between 2 protons if there was an electron around which is door ever the jumping back and forth from electron the diminishing the of energy by the wave functions subtle adjusting a little bit a little bit better than would if you just have to wait punches together arm as a server or origin of covalent bonds sharing assuring Elektra arms In this case you could think of it you drop pictures of picture me may not do anything for you you have a proton over here at the world Lionel proton another worldwide of a proton and the electron might start out being banned this proton hop across this protons hop back across this broad time but you should take us to literally because it is still in the middle of this state you would disrupt the process but it's a description of the quantum mechanical state of electrons between protons where does this possibility of electron jumping back and forth lowers the energy relative so she just had 1 proton and just 1 electron about state that means but there is an effective force and not Yukon picture it this is this picture is very is like any analogy is often very very misleading 5 by the very presence of electrons in between the 2 protons creates an attractive for called particle exchange called particle exchange or electron exchange between the 2 were between 2 per part not a day the Beijing Electron stuff that produced no I don't think that is quite right picture it doesn't really depend on electric charges on it just depends on the fact that you could find by getting together to wave functions you could find a way function with a little bit lower energy Monday you want to know what life is like I had known he was probably talking about roses statistics are bad for par for who've like beans and idle noise theory white white white white cross man or a chance Haiti each other don't like to be in the same state photons like each other they looked to be in the same I think he was probably talking about the video the opposite of the exclusion principle for 4 Moses the of the house Derek Bell protons young that's because of electric draft right down to it before it does a little bit but I'm not very much and in fact be be of forced electronic jumping back and forth is a much shorter range force electrostatic attraction so this force would only be important but relatively small
distances whereas the cool force with for much more slowly so so-called force would be a longer range for it is there it is there a place to which shows up as if you have a neutral system and ensure a better if you have a neutral source if you'll have a tool electrons so that the public charge of this system is you're all men of course you'll have a possibility 1 electrons orbiting around this protons a 2nd electron orbiting around this proton here now little object to the court Adams hydrogen atoms neutral there is no electrostatic force between them but you still have this possibility of electrons jumping across electrons could jump across a pond or crossed and thinned it does create force which can bind barring them from buying the beer molecule the if is to blast yeah Bamberg yell at small distances of small distances it there's enough over or calm Bacorn suffer a little bit in the words what does clear 3rd Morris but it creates Our slightly nonlinear effect due to the sale of the 2 forces it's just a solution of the Schroedinger equation in the presence of the 2 forces was not an energy that would have it was just 1 of those charges but alerts what reps Raef Weaver back there is this notion of energy being lowered by the possibility of brown alternating between 2 1 Stowe asked if I had a common Bronson with quorum through a daughter Cold War diagonal elements more cars were from which 2 closely related Pangle Pangle normally unique electron your only 1 electron the Kyoto broader officers shot was aware of shark well at high temperatures at high temperatures because of the rise of temperature very very high temperatures follow happened as electron kicked Bauer her grower for and the or you remember the fact that there was a proton gets hit hard enough higher photon armed but if temperatures not that extreme what it can do is cause even if you only have a single atom it could cause electron occupy high level now higher levels have bigger wave functions so the overlap between the higher way functions could be larger and would certainly have some effect on the 4 our throw that's area special effects are we have we have a concept car that we see in the classical electrodynamics bad effect of having to charges changes the energy in between relative toward a board of Britain if you only have 1 creates a force similar kind of thing here if you have to force then there's and the possibility of a follow-on br electronic being in a superposition estates of words of the army of the equilibrium of being in the quantum superposition of the 2 states being over here over here have also lowers the energy creates a forest are Is there any way think about the Coolong force here in quantum mechanics where it is assumptions still it was jumping back and forth the electron yacht bidders on let's go back to a single proton similar proton interacting with electromagnetic field that means it's interacting with the field whose quanta off classic way we might just described it by solving the field equations electric field In the presents I'll be charged particle quantum hygienically we think about it differently particularly in quantum field theory we think about it as emission and absorption of photons that's what we a Lagrangian of choir are Elektra barracks tells us it tells us about the probability for the emitting an absorbing absorption of folk song 1 way of thinking about the electrons Mississippi actual physical electronic is a quantum mechanical superposition states in which 1st of all there are no photons superposition state with no photon a superposition of states in which a time has been made in and therefore was after Prof on target president so it's a charged particle together with a photon around through photons can be emitted photon can be reabsorb the net effect in some kind of equilibrium distribution quantum mechanical equilibrium distribution of photons surrounding Elektra Yukon measure votes for part of it a little bit different measuring free-fall upon these photons are track at the electrons emitted absorbed never have another electron over here is also a meeting and absorbing 4 so as an equilibrium but every so often there to be thought a language of fighting and diagrams every so often a photon witches emitted from here gets absorbed over
here I always think about rivers are to jugglers juggling balls and every so often if they have be close enough together the mistake will be made and Joel will grab Moser of Java linger objects really what you really wanna do is you really want to calculate energy Doolittle electromagnetic field on Doolittle quantum superposition of full present you want to calculate that energy as a function of the distance between the charged particles when they're very far apart the 2 energies just add you just get some of the energy of 1 charged particle and charged particle but as closer together the charges begin to influence each other or annoying with defined environs the emission of 1 photon by 1 particle absorption arresting 4 times by another particle creates a force creates an energy which is not exactly the sum of the tow energies and that energy is the Kwong force between Riyadh between charged particles so have till distinct languages while high from just the writing them cool for we have thought other ways of thinking about what 1 of them is classical field theory will you calculate the the fields of objects square grabbed me all the way is through the exchange of particles by particles arching back for particles can be exchanged some context or another so every kind of particle in 1 way or another produces a force in molecular physics its exchangeable electron which create forces are in electrodynamics the exchange of photons back and forth which create forces so any particle I think particle also connected with a forest were particle could be exchanged jump back and forth between 2 something else will do will describe some more examples but firm did want before we move on to just discussed the relationship between particles and forces so Nora less want a one-to-one correspondence particles field for which those particles of a quanta and forces which are associated with exchange processes where that particular kind of particle combined for job back for a port fees so what people say that rough for forces in nature now water every possible kind of article on Burma we will discuss some murders were Gore OK I think it's calms good it's time thereafter start meaning the particles listing them listing their properties and discussing what they can do what kind of process to you they can engage Iran and I could write down a bigger long list of all the elements particles and give you a test next week the with you memorize not comment would be far wrong I think it's probably better to divide them up in a small groups groups which are in some way simply related to to reach over get familiar with them a little bit them what they can do what before we try to write down the whole damn standard model of particle physics which is a monstrosity notes it's not my fault my for the standard are government particle physics is probably monstrous it's not Steve Weinberg for nobody's preferred is somebody's for persons may be in the room but there is a bit diffuse our frankly we don't understand why the particles or what they are we don't understand why there is electron Nowak and 9 were a gold particle whose name my fears of murmuring because the remained because it doesn't exist but nevertheless why some particles existed why other kinds of particles we largely by and large don't know we don't understand some relationships between particles if this 1 and that 1 and that 1 exists and has got to be a mother warned a matchup with some appropriate way by the end of the day are there on many parameters many more different types of particles in the air or relationships between them which cut down the size of the problem locate these these mathematics relationships cut back the size of a problem somewhat factor of cool factor of 3 of something like that but there are hundreds of particles so it is honestly I messed up if you want to understand what people are hoping for in the next round of experiments what you have now understand some of that mess and what proposals are about so let's begin rats named the particles will begin with the most obvious 1 Let's make a table assuming you go from Carter's for the name of a particle Owyhee yet I'll put the symbol for the particle for the particle height over he s yawning by type I simply whether property electric charge over here another quantity which characterizes particles will cause the barrier on number of very
Ruiz's we all along and there are other part of properties From moment I'm not listing their mental put the mass over here the quad the
first one of course another listing them in any particular water as it happens on Friday I am writing down more like warm 1st Bolivar swarms of course photon the standard symbol for a false promise gamma electron gamma-ray it has a field associated with that gamma particle is the quantum of a field in most cases for many cases the field carries the same symbol as the particle itself but for the me feel is called aII this really the vector potential of electromagnetic field you could use electrical magnetic fields but you could also use the vector potential which is another way of describing electromagnetic field it has some laws aren't I've been right down the speed of spin 1 unit of spin electric charges Iran barrier number whatever that is 0 the masses 0 thrust 1st particle like
particle of interest as electronic now actually is a particle which has a mail by particles that has an electric charge has elected charge most an article of the opposite charge and it is a convention where were we leaders of whether we think of the particle as the electron the impact particle as positron or whether we think of a positron as the particle and electron an article the relation between them is mutual that's all I electron I really mean electron-positron and so we could right each year plus minus standing he minuses electron need glasses the positron field of electrons usually society and maybe you compose E. downstairs to indicate that it stands for the electron made up of creation and annihilation operators for electrons electrons often eons
its charge located charge in what you well the standard particle physics quantum mechanical unit for electric charge believe it or not is the electric charge of an electron a good deal the work terms or few legal look it up and call its 10th of a mile or so of her 43 cool my 19th the core Long's order summaries more charge but our but it's not useful to think about it Call ends all particles in nature have electric charges which are integer multiples Of the electron charge could not true quirks quirks from observable particles back so the charge would just right as minus 1 electron plus warned repository so since we typically talk think of electron particle and the positron as by particle lecture score minus 1 and remember of positron has the opposite charge Barry your may act now we have the decided on units from Europe's for mass on the same as units for energy E equals M C squared so we can either described the mass of mass kilograms foreign energy and Jules although we can simply and then a new unit which is more appropriate for a microscopic physics toward In fact unit that we use condoms originally historically our commerce kicks off it is the unit which ionization energy of a electron hydrogen atom is what 13 . 5 electron volts of electron falters how much energy you get if you Pearson electron from Monique across a capacitor plate of 1 vary very small amount of energy a fraction of Joao 5 by 1 electron volts standard unit keen historically our a comic 1st theory electron what I got a want that being whose Wholey unit for us particle physics energies a larger Americana physics energies but a historical reasons we have electron volts is are you of energy and the mass electron measure the electron volts is of order a million electron volts 1 immunity in fact a half an hour trauma or not exactly abuse . 5 1 but and he indeed stands for millions of electron volts and many will be too small units from many other purposes 5 said the particle physics is the best and the masses of particles extend all over the map so we're trying to search for useful unit you're always frustrated useful you will always be too small for Mexico no worry know what exactly . 5 1 Robins rock 4 set properly 3 5 Austrian right OK now what we but quantum electrodynamics is the theory of electrons and photons and we talked about it a little bit more will I just we could also write down here table of various kilometer table would distrust pictures of basic on elementary process takes place in quantum electrodynamics photons of electrons is the emission of a faux pas by or electron electron photon and as I showed you several times you could rearrange legs of this diagram sorrow this could represent not be mission off on time but the absorption of for pardon for time comes in from the past war was sorry you Cornelius would be electrons legs around of works like this try going backward and hiding was at that really means of positron emitting before so the basic on building block for building up process even interactions users vertex with 2 electrons electron-positron whatever from 1 million when going out of photon from before going in we're out of that you both off all of the various processes for more program explained the secular the process for the year of the amount corresponds with boss between charges and in Norway would particle exchange of time bouncing back and forth between charged particles which creates bath for yet another way to describe what's going on here is in terms of available a terminal of Grosjean runs in describing this process here describes 1 electron in 1 electron and 1 vote are now a bill that out of the field operators 1 electron is sigh electron cheated creates the creation annihilation operators an electron howled sighs of electron and photon emitted is the field operated from a all time and if you plug in all the creation annihilation operated as you'll find in here buried in year terms were a photon emitted electron absorbed electron of war and this codifies the describes all of the various basic processes can happen are more prepared 6 now a parameters will grant it appears electric charge of electron and that roughly speaking is associated with peak amplitude for any electrons to we made of photon or electron UKP electron or wherever electron plows into video side of X-ray machines what's the probability that a fun time would be admitted Will the amplitude is electric charge and the probability is proportional to the square of electric charge through all of this year Is there a way of describing all Of these basic process aware that combined together they produce forces they produce process he's where photons are emitted the whole world of quantum electrodynamics flows out of this basically 1 expression here we want shudder through again now are but let's start getting a little bit more quiet course next particles of interest these of course familiar to you your 9 this were 1961 America arms 62 when I went to graduate school probably the next particles are right right now would be protons and neutrons protons and neutrons are now subsumed by quarks why do we believe there is some sense protons and neutrons are composites of quarks although we will call will remind me to come back the issue the difference so what what it means to be composted purses elementary it's a very interesting story but naively quirks a smaller than protons and neutrons and protons and neutrons which are big fat globs all our at a quarter of own mixture of quarks as a lot courts ruining get a photo of them tonight Dory holds distinction between them don't agree well Bob there's more than 1 type of quark you're apt sticks types are of or what 6 distinct particles all of which are very similar to each other in some respects very different from each other give our respect so let's was there are legal and that they had made a worldwide other called what they are the call but they are just the a historically randomly people assigned names and Noel logic what it called the logic of is 1st of all we are poor I called you assemble it is your work to which a writer of courtship quarks pressure for the symbol for quirks askew that or quarter
firmly on his will write down a charge later they have all also bounty on a number of 1 3rd no why one-third
Will the reason is very simple the barrier number is basically can't think of a number of protons and neutrons each Proton is counted is having 1 unit of barrier on each new charges can count Cameroon you bang just a word for protons and neutrons and manner some generalization approach Aung Leon was award profit protons and neutrons rather particles which will calm to which are very similar to par part of your charm also called Barry on us horribly prefix Valley means heavy and Barry on so-called Barry arms Costa a lot heavier than electrons but can take up the number of protons and neutrons will you call the number Proton was neutrons if I wake up I was way from equate ideas equal approximately equal to to the call the number of protons and neutrons and the total number of protons and neutrons in nuclear physics never changes protons can turn into neutrons neutrons can and protons crossover things are barred there a number of protons fast neutrons the changes you do us but still number protons was neutrons change on member protons could change how however how the number of protons change all we ought you do a lot about our processes with a number of protons and neutrons change put on not plus the trial protons and or neutrons change will indicate radioactivity radioactivity 1 form of radioactivity neutron became proton plus an electron neutrino or processed number of protons
changes by 1 Member no chance changes by war with the number of protons neutrons doesn't shake off as a generalization of that all of nuclear physics particle physics is quantity which firms new nuclear physics just number preposterous neutrons and that number is sometimes called the Barry on number rough to generalize a little bit beyond protons and neutrons this ballet on number of an economy in the we cool for the proton 7 of the proton high for the proton but whatever it is it has to be defined as twice as much to probe France 3 times as much for 3 so it's a convention that you say the barrier on number of protons 1 incident watch barrier and broke apart minus 1 swore Proton has barrier number plus 1 year by protons Barry latest war neutron Baron No. 1 and by neutron Baron minds wander clearly element of convention exactly what you call and law but once it was fixed the barrier of Proton was 1 of the barrier and the court was a 3rd be or 3 quarks make abroad OK so it it's just a historical glitch barrier and number of the most fundamental thing in nuclear physics is one-third and not worn what about man like what there are by Marion number is my 3rd oil right of 1st World War II a number of quarks minus the number of corpses could now whether or not that is absolute conservation law it is not believed to be an absolute conservation were by absolute conservation can proton disappear king completely disappear energy has to go some place on a processes in nature where a proton might disappear and could become something that is neither a proton or neutron or anything else that you would call a barrier Oregon for example without violating charge conservation of protons could become a positron proton could be Kanye into a positron therefore does it where you could wait out if you have a single proton sit there wait to wait a Wong Klein before that broke proton half wife decay that worry news at least 10 33 and 34 years so this is not something that happens very regularly does it happened at all the thinking is yes this is 1 of the very very interesting questions of particle physics of whether the proton can became artistic became became something that was not carry a barrier our parents were widely believed that the answer yes but has never been them a student center Hollywood heavyweight around and the 34 years for proton decay you get 34 year protons and you wait around for 1 of the 4 C 1 can do 34 Proton all out for funds you they were Norman that's not bad that's 0 barriers number biggest goes to 0 Barry Proton has barrier No. 1 by proprietors barriers minus war so that's not a barrier and we call them Barry on violating process processes which barrier numbers not concern nobody has ever witnessed such a process in a laboratory anyplace else off can they happened does not seem to be any reason why they cannot have been built into mathematics of what we know Oh we leave this is an open question but politically and released 2 of very very high precision barrier was concerned works by definition have warned reviewing one-third of EU said minus frantic work but the fill in the rest of us in particular electric charge and mass we have the label which kind of corporate talking about a lot of different kinds of quality so I put in a list of different kinds of course this is not new particles which are not quirks it's just a subheading year quirks and things are very narrow quarks down quarks slightly up down not open was nothing often about them now what direction of the battle of Manning's years gravitational field nothing or your bounty about this worst fear of strange quarks which have no stranger than on strange quarks gets more facility there are charm quarks which are
trying nice over and there are is a few or no review if you around you're squeamish a communal merit quarks on corks Bond or quirks makeup or the symbols Earl course exactly the same adjusting your writing the words bound strange charmed top same as bargain pop Botero pretentious beauty of parlor top strangers charm now remember what circumstances these things were named bird mob robbery thrusters are Rorer are due Norwood with a rumor that offer me on this OK symbols are just what I offer the 1st poems Hewitt sometimes I Q sometimes capital Q sometimes defending if you're talking about the individual types of them just use you would be as CBOT using names for the fields as used particles are and there's not completely coherent convention that everybody sticks to offer on all our friend on the Malcolm's a charges sell its useful provide them into groups of 2 these groups of 0 Barcelona repetitions of each other this group of tool in many ways is somewhat but not exactly as group of prove witches was not the same but which Our sustained pattern Harry's to Mr. Moto the power of these 2 similar alike of Sudbury Excuse me Wait a former keep hammering history from figure put down strange strange copy our right strode down system is very similar a strange John system very Samoa Provence half of choice right now with electric charges are you could see could to similarity with down our system has charged minus a 3rd and 2 thirds as the 1st example of particles in nature which have charges which are not integer multiples of electric charge of electron however quarks by themselves do not exist freely in nature there are fully is bound to other structures protons neutrons and so forth and those parcels you'll have integer Chargers OK strange exactly the the same thing minus there and Barnum top exactly the same minus theory and to scrappy red bridges repetitions of the same thing were lucky that particles of our and particles over a year they were just have exactly the same charges as particles except opera superstar Saul Mrs. simple you replication for some reason nobody understands nobody even has any idea why nature replicated itself way the Baltic area now the Byram reborn right OK amid a matters masses or not which over messes why don't we vary from Riverbend estimates for them because be precise value precise values of nurses but you could grow Bookamer Bond movie forward 1 Ave that Quark is about Kennedy solids 50 times heavier than the electorate a lot lighter than the proton recently what's brought progress they cannot 1800 times electron euros remind 140 community this is all a lot lighter than approach on the off-court about 5 and TV less than a year very Rivero for protons are made only are Gordon down quarks so it doesn't look like his newly enough man quarks rule out to be the master of performers who try to combat point is of course is an approach just road quarks OK strange in charm strangers roughly order of magnitude of 180 strange then Chavez is rural about a thousand Mary and honest that a downcourt is heavier than the other court but the strange quark which is analogous to now court is lighter than the charm quark so this pattern of inversion here the masses again nobody understands of all-white that's true young child about 12 more match you order who charge 0 fish more crypt thousand community and among co-workers enough I found that although this is called a GUT give from all the bond suing keep changing unit at about 5 GUT staff workers about 470 Jiri so how much heavier is the top quark with me off court and rebury duet calculations behind for Hutch 30 thousand or locked on price so money and these particles are extremely similar to whichever they don't say things they have the same properties and yet they have masses which 1 all over the map was antibody understand why not REA ideas yes work now we don't even have a close Nevada why bears we have 1st of all we don't even understand of course wives even while they 1 family musical family why is there 1 family law we are normal for sure if there was 1 family would be here because they would be no protons and neutrons but given that this is 1 family of our courts and I quote Swire restrained From quart or top quark bombed caught only half as if he were a use or work at the story goes to what I for the massive bastion trees I still have to go back to your list it's To tell how to assist workers to use some of Russell to you former top young but none basis contract theory about on the basis Over long how to top court would affect the rare work its way into woes shot she is water her all or part of yet they seem to know that young not not because not because there was any basic underlying reasons why the top work would you could do is use is opposing the top quark had and then calculate various diagrams evolving the top quark various ways find and diagrams involving ordinary particles not the path work which had top quarks running around fury of diet you calculate those diagrams those diagrams have effect on processes involving are the particles that you nor Burwell and say how what was the mass of the top quark after
beat in water that does the right thing and Europe from his or her right so I was not in any stands a deep understanding of why the mess of or course of what it was when observation that you needed that particular value pop caught you water that girl them be consistent with how they can plug it Carlos here that is a key out there is a broad U.S. instead on to say that you can't detect the quartet becomes as to a certain extent a matter of definition arm where means detect work you could certainly detect evidence are quarks would you can do is create an isolated quark near isolation from other things in an exam but will come with a comic who requested me I think you probably remark jet produced water or not now we can talk about Jets combined with combined with laughter really what does what's marks dropped back yet your suddenly leave yards some extent that that is not her explain now but now want telling Interfax law we can talk about how much of this is explained the amateurs much of pattern is you the right question is how much of this pattern is required for a theoretical mathematical consistency but we haven't gotten me yet some of this pattern is required some of required but not much of it very little of it as required by West it's a real lots of voted on his way the worries wars in are very very there no trial are unstable became protons or stable exist and intergalactic space and everything else the law we are the only thing that has any appreciable abundance 1st of all we only portrait of any degree of stability Hopson back the rest of these decay movies so real the real abundance of real particles in the universe or options down and now worth the relative abundance of our men's that's determined by how many quirks of each type their Rory propped on they on neutron brought salary of course from neutrons have I nuclei are so you have to know the relative abundance Our protons and neutrons to through your growth abroad but that's all it is relative abundance of protons and neutrons OK so sorely or what is a proton and warns a new trial use language and more here broke 3 quarks and on-track quarks now there are now in the business of telling you facts about these particles not at this point turning warn stand Hawaii these of effects we can't do everything awards for neutron it is stood down quarks and another court course just checked back not Quark has charged 2 thirds of the back castrato minus a 3rd of two-thirds minus a 3rd miners another 3rd this is electrically neutral charge equal 0 God tried year-old brought time from Plus is exactly the same as in the car except that would be interchange of all quarks and course toward a bad quarter a mail Of course should work a lot of except for the electric charge electric charge has to do with me interaction with photon 1st forget photons let's forget about the existence of photons for a moment and just talk about quarks and other particles Our which our portent inside the nucleus so then it would almost seem and the trauma on same thing except for an interchange of the Opel label and the downward you might is that they are their properties are almost exam exactly the same if for some reason the electric charges unimportant promote words supposing we not worry about the interaction with 4 kids just forget for dinner was seen that protons and neutrons should be I did that go because what's the difference you just replaced of course but now works but it's not quite true because of courts and down don't have exactly the same man I don't know exactly the same as that kid in easy by comparison with a mess of a proton is small it's almost negligible it is very small almost negligible in nuclear physics or in here a particle physics and total 80 just some precision the extent that you could ignore the masses of the quarks which are after all smaller by far foreign masses of protons and neutrons neutrons and protons aura good DOOR the only difference is a slight difference in mass between work from that works which 1 is gonna be heavier the neutron over broke corsets will be the 1 with more quirks because downcourt are a bit heavier than up upcourt found courts are a bit heavier quarks and was likely that neutrons have you brought on in India's neutron was a little bit heavier Proton was largely attributed to be ought to be back of the neutron has warned bank works now that's not all the risk of a difference between protons and neutrons if the downpour me up courts have exactly the same man s but Duke accounted for electromagnetism the photon TOKYO photons not completely unimportant in which would be heavier the Brookfarm neutrons wife yes because it has some electrostatic self energy because charged so the proton it would be a little bit heavier be costs of re-elected the self energy of the electromagnetic field electric field or expect a proton Kabila but have and fact the new neutron was a little bit heavier R & B reason is because we found workers will but have you or give other math that photo of a dark on a trial was our 938 a community and for apart from remind you that a lawyer or 1 . 4 0 via a review difference between them from about 1 . 4 is enough energy between them was enough energy separating them neutron can afford a little bit of a energy decays into 280 army of protons Closson electron force neutrino through a bit of excess energy neutrino which allows it became a roster particular became a with a march on OK so that's a very very rough story 4 the chance of combat tours but now it also is strange quark it's forget charmed quarks from moment as an interesting question can you replace noticed that in every respect down quarks and strange quarks are similar to each other except for the fact that the masses different fear might ask Can you construct an alarm of the proton and neutron where you pull out of downpour workers replaced by a strange quark warmth perhaps too strange quarks pull out a down quarter replaced by a
string quartet the answer is yes of course you can because every respect the Rivera Court at SoHo almost like an ice top you pull out of proton put Neutron sticks together the same way but seemed better here are so you can construct another kind of an alarm quotes strange Barry on this strange barrier to get land Is Tsai is the goal kinds of names of the Lisbon so long subsided of away from these things I can't remember the move right wrist associated with various members I don't remember which forms which now important bought for example you can create promotes name is far for bank Oregon create a strange abound what was the massive of this 1 over here amassed what a charge of this war what exactly the same as neutron because you pulled out of bounds couldn't have me as a ban on the same charge services also electrically neutral but it has a strange quark period it's called a strange barrier not stable Lake indicate where are discussed the decay processes later but not completely stable so they evaporate and this formed about war but yes they do exist likewise you compose do strange quark enough quarter was a charge that saying fact chance neutral Oregon and likewise star likewise proton Yukon replaced by strain so that all these Strange barrier arms when we needed a little became a kind of process drop last fall or roll call for a vote on the new tighter brought for firearm where there is a lot also those of us who she is now is now not it now well on the roles of what you can exchange over complicated Burkhart a moment you could always exchange 1 for a similar 1 of the same charge now are you could also always eventually these strange particles are and heavier than the protons and neutrons because of this extra 90 and of over or Romanian you can isn't much somewhat heavier then the ordinary protons and neutrons but in every respect a similar the main difference of importance as big cost a heavier bake indicate that broke par of neutrons grow so they are not found in the all those who bar there is no you do have to pick every particle and replaced by becomes a year die from nearby a question mark of a holy strange does the where they have a talk with you love OK and they become Bob tho In the bombers yeah would that yah yah yah strangers a strange new after low-cost range because you know people became familiar with protons and neutrons by 19 fifties and when they discover developing strange Romero Rohana expected fast yes yes Mass all you need is just a lump domestic works right now that's right through along so it must be summer Nelson profound which right legal warns Norinyl attempt to be dramatic but will not carry any interesting charged barrier are they carry mass will the carried energy yeah visit at a former binding energy your referred farming energy Energy Stone said not relativistically I mean masses master Rabat do not burst Sherwood Boehlert a play by shortly after years of where are serious about how they were going to yeah I go I don't know why we're part to feel your order we saw your work they say now there are still a bit of a year he also by are now I did not thinking about this particular aspect of things it's much easier to think about Bob particles the field you we could think about from your work part a toe yard reduce their eye for the 3 4 . 0 that's a big plus I don't think it's our integer causes energy North a integers usually made it right right much earlier while Yahoo move comfortably sure yes yes worked sought U.S. periods nurseries Pramod yet let's talk 1st about on as honest are simply quark by Cornell Wyatt you could raise a question why do 3 quarks my together perform something don't talk works by together In the early days of quirk ology this was a complete mystery why quarks always EU could say although it's in order to make the charge an integer multiple of electron stupid does not to be that still hippest at this stage it's a stupid but yet that is pattern that was apparent that combined together forms which is not the only role but this it is 1 of the rules of nature we do understand and we dogs their work cars from Bard he rule rule of thumb the present time is the way things buying they always buying into combinations which have integer multiple of electron charge Chris you could take that as a working ruled that her temporarily until we have a deeper understanding of right as honors also particles composite particles which also have the property where their charges integer multiple of electron charge but they have Zero Barry on number they do not have that number which means that they must be made at a quarter combination work they must be made of caught Symantec works the fact they are quirks organ backcourt Corkery APEC court so what's so what's right 1st of all the ones that you could make only our options Barrick walks up to now quirks special not in any deep stands but their special because the much lighter than the other particles they don't pick a rare decays rapidly if they do to carry on their abundant in nature and more than that doesn't take any energy and a good doesn't think much energy collisions to make them so of course they were the 1st particles to be discovered things made up of only up quirks
backcourt or the other courts amount courts are pretty light rail and and the mess on this trip agreed for right 3rd corporate Obama court and Ian Court Aramaic brickwork really could start thinking about different combinations who's of Bob Barr quark Valner Court was value of or down more for years bad him of course was down more Bora Brown Court there are a lot of work just as regime here as of me all the it while the U.S. let's work out with their electric charges electric charge up Court minus 2 Arabs in this form of minus 1 3rd of this Miners warrior right minus a might miss too that's fine charge minus 1 is like a like electronic what about this 1 is via particle but this is not just won't just be in particle August right this 1 is beast nearby particles of each other because they are related by changing particles in particles found barring the value of foreign up this discharge plus 1 of these are and particles of each other up up that's electrically neutral obviously and charge equals your mouth is fact not either 1 of these who by themselves correspond with distinct particles remember would do in quantum mechanics each 1 of these states could be thought of as a quantum think of it as a quantum state quantum state consisting of an entire up quirk and of course the quantum state consisting of an downcourt 1 other things you've been doing quite mechanics the superposed state of your have state you Canadian you could sue proposed soap opposing them means making combinations that have probability for being you have a swarm of there are 2 combinations of these tool for you if they are they are not far off plus now bogged down and work put from it make it have total probability 1 we were all square to this is a quantum state and this is not about to be orthogonal quantum state Bob Barr off minus Barham are you know what this is This is the triangle quirks not entangled who this week but entangled rule there but this is all a damned if you follow up this value Rock being similar analogous to be spin direction particle Upward Bound mess with this terminology came from there these would be tool in Pangle states and tangled not through there Spain's but truly there I still space through there populist and bound us we have used the word I saw book maybe I'll tell you what not right now our is justice analogy between the spin directions the Office of values quantum number of these 2 things individually are well-defined particles this finally here goes together with these 2 and are called the pie orange Oh they got together for a good reason for good mathematical reasons but they got together the right ones yet they got together because their man it is very close to each other is believed they would be exactly the same maps up quirk Brown Court have the same exact they were all 3 of these are virtually indistinguishable except for a small difference in their MMS and they have different charges 0 1 and minus 1 and this is called on multiple Heidi plus or minus 0 3 independent Kearns particles called upon and and as a share of elegant discussed Hawaii nature chose these particular combinations ought to be analogous to whichever but now want our new facts mathematics and until combination is simply this 1 here and this is called Re a bare feet the pie plus the 4 states here really define repine on pipe plus minus 0 and we need start reaIly design is similar to a pilot in many ways but it's heavier why is heavier that is a complicated story it this is not the elementary story it's complicated story view Oconto anew while back as a matter of fact Aerts mass OK rather masses apart on the masses of applying arms are about a 140 immunity massive apply on national priority and about 140 NTV so lurid it's not too different from questions about 440 immunity so some them as range in here not this heavy and have a massive Ada it is about 3 times heavier or something like that the massively leader is bomb 500 but remember the precise number of about right why that is widely Eva sticks out as being different was a puzzle for warmer climates not obvious robberies you may have road map abstract mathematical our fact is that if do you ought to go all there's a photo of a car they don't pay by Ron Arad caber weak and electromagnetic interactions no longer lived many of these use of the particles From a stroke we are wrong look at that L 2 to . bar from a of the civilian economy is on the other hand there are a lot of it is also more something like tree was planted in the sense that it's related to soup choir provision Bates years it's got what to do with Spain combinations of tool have spin particles are there are 2 ways you can hang your world will Comparex from the last thing we want tell you is that you can make strange are you could take any geek work and replaced by a strange quark strained bar for that makes new measures on Twitter core strange Mazon war what's your name came as arms came as on his arm as honors containing a stranger in a strange quark replacing bound for there are 4 of them Of straightened our up strange bar Baron Bosch range Barham Springs Va we still have shared 0 charges Iran and these have charged plus 1 minus 1 East or called charge came as on these 2 or call the neutral neutral came on a tour of 3 kinds of
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