Master class II with Boris Kayser

Video in TIB AV-Portal: Master class II with Boris Kayser

Formal Metadata

Master class II with Boris Kayser
Neutrino Physics: present and future
Alternative Title
Kayser, Boris
Title of Series
CC Attribution - NonCommercial - NoDerivatives 3.0 Germany:
You are free to use, copy, distribute and transmit the work or content in unchanged form for any legal and non-commercial purpose as long as the work is attributed to the author in the manner specified by the author or licensor.
Release Date

Content Metadata

Subject Area
We will review the physics of neutrino oscillation, and summarize what has been learned from oscillation and other data during the last dozen years. We will discuss recent surprises that may point to new interactions and new particles. Then we will turn to the future: What are the open questions, why are they interesting, and how can we answer them through future experiments?
Keywords Neutrino Physics
Theory of relativity Power inverter Hot working Neutrino oscillation Visible spectrum Optischer Schalter Force Negativer Widerstand Mixing (process engineering) Basis (linear algebra) Phase (matter) Turning Roll forming Colorfulness Matrix (printing) Alcohol proof Bahnelement Neutrino Color charge Nanotechnology Quark Boiler (power generation) Angeregter Zustand Flavour (particle physics) H-alpha Electron Transmission tower Combined cycle Stellar atmosphere Ground station Year Bending (metalworking) Presspassung Weinberg-Winkel FACTS (newspaper) Mixing (process engineering) Kopfstütze Angle of attack Sizing Matrix (printing) Rotation Neutrino
Energiesparmodus Lint (software) Nuclear reactor Magnetic core Visible spectrum Optischer Schalter Negativer Widerstand Printing Mixing (process engineering) Casting defect Flavour (particle physics) Particle Roll forming Gentleman Limiter Solar energy Measuring cup Atmosphere of Earth Interplanetary magnetic field Flavour (particle physics) Electron Sensor Rain Source (album) FACTS (newspaper) Mixing (process engineering) Distortion Current density Superconducting magnetic energy storage Nuclear magnetic resonance Homogeneous isotropic turbulence Cosmic distance ladder Will-o'-the-wisp Sunlight Measurement Nuclear reaction Band gap Gear Alcohol proof Inertial navigation system Friction Commodore MAX Machine Institut für Raumfahrtsysteme Spare part Forging Neutrino Hose coupling Firearm Material Angeregter Zustand Pelzware DIN 72552 Tool Transmission tower Stellar atmosphere Nuclear reactor Weinberg-Winkel Kopfstütze Positron Cogeneration Angle of attack Matrix (printing) Tanning Neutrino
Brillouin zone Drehmasse Visible spectrum Scale (map) Electric arc Order and disorder (physics) Universe Elektrisches Dipolmoment Alcohol proof Neutrino Mass Antiparticle Neutrino Key (engineering) Stellar atmosphere Weinberg-Winkel Dipol Hilt Scale (map) Kopfstütze Angle of attack Universe Hour Antiparticle Water vapor Magnetism Neutrino Neutrino
Prozessleittechnik Energiesparmodus Analog signal Roman calendar Woodturning Neutron Effects unit Magnetic core Amplitude AM-Herculis-Stern Mixing (process engineering) Ladungstrennung Particle Rigging Gentleman Limiter Color charge Cork (material) Boson Radioactive decay Neutrino Voyager program Flavour (particle physics) Charge density Reaction (physics) Musical development Electric power distribution Electron Minute Polarisierbarkeit Ladungstrennung FACTS (newspaper) Mixing (process engineering) Direct current Current density Universe Cartridge (firearms) Beta particle Mint-made errors Mass Angeregter Zustand Antiparticle Morning Large Hadron Collider Dampfbügeleisen Radioactive decay Neutrino Hot working Grey Bomb Electric power distribution Atomhülle Lepton Energy level Cell (biology) Field-effect transistor Rack railway Black box Neutrino Spaceport Negation Contrast (vision) Mass Hose coupling Mail (armour) Angeregter Zustand Tin can Energiesparmodus Tool Ballpoint pen Captain's gig Effects unit Weak interaction Positron Collar (clothing) Quark Gentleman Spin (physics) Doppelter Betazerfall Fermion Electricity Miner Neutrino Restkern Quantum number
Potenzialströmung Rear-view mirror Prozessleittechnik Acceleration Analog signal Negativer Widerstand Annulus (mycology) Thursday Particle Separation process Matrix (printing) Color charge Boson Radioactive decay Neutrino Photodissoziation Model building Speckle imaging Mechanic Rear-view mirror Electron Light FACTS (newspaper) Universe Mass Antiparticle Radioactive decay Hose coupling Neutrino Nucleosynthesis Bottle Hot working Mechanismus <Maschinendynamik> Neutrino oscillation Day Lapping Measurement Universe Lepton Cardboard (paper product) Überschallstaustrahltriebwerk Standard cell Spare part Neutrino Video Hose coupling Big Bang Prozessleittechnik Mechanical fan Particle Drehmasse Positron Quark Game Spin (physics) Doppelter Betazerfall Matrix (printing) Bow (ship) Baryon Neutrino Firearm
Prozessleittechnik Prozessleittechnik Hull (watercraft) Particle Universe Lepton Energy level Phase (matter) Standard cell Universe Matrix (printing) Photonics Neutrino Baryon Hose coupling Neutrino Model building
Prozessleittechnik Rear-view mirror Electron Universe Lepton FACTS (newspaper) Positron Standard cell Matrix (printing) Neutrino Baryon Radioactive decay Hose coupling Neutrino Model building
Prozessleittechnik Order and disorder (physics) Source (album) AM-Herculis-Stern Particle Colorfulness Matrix (printing) Leather Gentleman Gun Color charge Radioactive decay Neutrino Model building Weight Mechanic Ground station Polarisierbarkeit Cocktail party effect Season Light FACTS (newspaper) Basis (linear algebra) Universe Cartridge (firearms) Mass Plane (tool) Large Hadron Collider Radioactive decay Hose coupling Neutrino Measurement Differential (mechanical device) Universe Lepton Field-effect transistor Surface acoustic wave Standard cell Alcohol proof Spare part Neutrino Temperature Mail (armour) CPA Prozessleittechnik Superheterodyne receiver Particle Elektronentheorie Finger protocol Saw Baryon Neutrino Quantum number
Theory of relativity Grey Neutrino oscillation Source (album) Negativer Widerstand Lepton Mixing (process engineering) Light Kette <Zugmittel> Basis (linear algebra) Phase (matter) Turning Matrix (printing) Bahnelement Rutschung Dimmer Neutrino Video Mass Hose coupling Angeregter Zustand Neutrino Typesetting Electron Vakuumphysik Light Source (album) FACTS (newspaper) Basis (linear algebra) Mixing (process engineering) Phase (matter) Universe Cartridge (firearms) Matrix (printing) Camcorder Mass Steering wheel Digging stick Neutrino Hose coupling
Year Neutrino Minute Neutrino Angeregter Zustand
Thermocouple Effects unit Woodturning Optischer Schalter Negativer Widerstand Light Particle Roll forming Signal (electrical engineering) Rapid transit Linear motor Neutrino Model building Flavour (particle physics) H-alpha MOS-FET Reaction (physics) Combined cycle Sensor Year Source (album) Bulletin board Mixing (process engineering) Fermi National Accelerator Laboratory Signal (electrical engineering) Cartridge (firearms) Mass Mint-made errors Potentiometer Neutrino Sensor Gaussian beam Neutrino oscillation Measurement Summer (George Winston album) Crystal structure Force Camera lens Field-effect transistor Standard cell Game Optical illusion Direct current Orbital period Neutrino Month Teilchenrapidität Mass Hose coupling Angeregter Zustand Transmission tower Presspassung Cockpit Scintillator Remotely operated underwater vehicle Water vapor Synthesizer Contrast (vision) Neutrino Star Last Ground (electricity)
welcome we spoke at 3rd the beginning about the fact the LAT tonic mixing means that each neutrino definite flavors of superposition of Masai now of course 1 convert that relation to express each I state as a superposition of the flavors and as you see the flavor of a fraction of Miss Oregon State and why it's just square view Welfel high what that means is that when new I interacts and produces a charge laptop the probability that that produce charged electrons in particular of the flavor Alpha is just you helpful squares so I showed you before the squared spectrum it's normal inverted form here it is again but this time showing by color coding the flavor content of the various Mexican states to the degree that we know it experimentally the newly fraction that is to say you I squared of a Ms stating green the new new fraction in red the new tower fraction in blue and once again With these fractions mean is if this mess citing state interacts and makes a charge leptin the probability that that charge let on is in particular In an electron Is the green fraction of this neutrino attractions being normalized to 1 now you see the scholars around widely distributed 1 thing we actually don't know is how big the newly fraction of the isolated neutrino is regardless of whether it's at the top or the bottom we know only that had stood to sing but this fraction which is parameterize in terms of a mixing angle local played a 1 3 is no bigger than about 3 per cent of that neutrinos now these fractions tell you the sizes of the various elements of the mixing matrix but if you want to talk about the signs are the faces of those elements we have to go to the Matrix itself assuming that its 3 by 3 and Unitarian the mixing matrix can be written as a product of 4 factors like this 1 of them involves nothing but faces which recalled Meyer on a CP violating faces they do not affect isolation the rest is just like the way you write a rotation in terms of a product of 3 boiler rotations each of which depends on 1 while know you can do the same thing here the 1st factor depends on the course on that sign of a mixing angle fated to 3 which dominates the behavior of atmospheric neutrinos so it is measured in the atmospheric oscillation experiments and the best fit is actually maximal mixing which means "quotation mark very "quotation mark theater in other words that equals 45 degrees but at 90 % there's still a considerable uncertainty 1 factor involves a mixing angle fated to the thing 1 to which dominates with the solar neutrinos do that's also very large not 45 degrees but it's 34 closer something like 1 1 after Greece finally there is this crust mixing 1 3 three-course 1 3 mixing factor in the middle it involves this mixing angle I called fatal 1 3 about which we know only that that number is less than . 0 3 were correspondingly fatal 1 3 useless and something like 11 degrees this final factor can also involve ACP violating phase Delta and if it does that will produce a CP violating difference between the probabilities for corresponding neutrino into neutrino oscillation these factors do not affect oscillation but that 1 would cause the CPU violation notice however that Delta enters into the mixing matrix enhanced enters into physics only in combination with the sign of fatal 1 3 consequently the size of any such CP violation is going to depend among other things on the side of the A 1 3 so that number is very important there have been some hints From existing experiments but they won 3 is not 0 but the sincere not very strong yet so I decided not to mention you look at this you may be wondering about the following question what is so special about the 1 3 Why is it that the CP violating phase occurs next State A 1 3 why doesn't it occur next the fatal 1 too for the year to 3 for all of that that's a good question on onward U.S. state there is actually nothing special about their 1 3 if you multiply out all of these factors and then you plug that matrix into this master formula and you work out for example the difference between new muted newly waterway bar this is what you're going to find notice that this CP violating their friend vanishes if any of the mixing angles a 0 they want 3 or if they want to or the 3 but of course advantages of the CP violating phases in the now the fact that it depends on all 3 of these angles should not be a surprise Kobayashi in scholar who won a Nobel Prize for showing that the quark mixing matrix could violate but they discovered that it could do that only if there are at least 3 Work family and they didn't say so explicitly but obviously those 3 court families have all been mixed because for example of 2 of them expert but the 3rd doesn't mix with the 1st the 1st Eagle noted that the family is there and so there isn't enough physics to violate the it's the same thing here if any 1 of these mixing angles vanishes that I can find some basis in which I have to interacting states and a 3rd 1 which is the coupled entirely from the 2 interacting states and is not enough physics to violate city so all the angles have to be non-zero however this sign to their 1 3 is approximately 1 experimental there are 2 theories about 45 degrees this signed 231 2 is a big number also this angle this 34 degrees the only thing we don't know is signed 2 fatal 1 3 so to emphasize that the size of any CP violation is vulnerable to this not only unknown angle we have chosen as a choice to put this face factor next the fatal 1 3 we could have put it makes the fatal 1 2 instead the physics consequences would
have been exactly the same no finally here it goes the spectrum I'll take it to be in its normal form just so we can talk about it and I'll try to summarize for you where the various pieces of this picture what we know experimentally came from let's start at the top left reactor at experiments have been done some of them With the detector about 1 kilometer from the reactor now the energy of neutrinos coming out of a reactor is about 3 and that results in L. over EU which makes the experiment sensitive To this big gap .period insensitive to this little 1 so it thinks these 2 neutrinos are 1 neutrino In an experiment like that a formula this form holds and this affected mixing angle measures the flavor content of the neutrino that's at 1 end of the Delta and square that the experiment concede With these experiments looked for is the disappearance of neutrinos coming out of a reactor as they travel a kilometer now those neutrinos are electron neutrinos because reactors involve nuclear reactions which involve electrons or positron they happen to be new Boras not but that's irrelevant the electorate tree these experiments and do not see any disappearance at 1 kilometer so they put an upper limit on the degree to which this neutrino cobblestone electron the degree to which a couple stood electron is just what we call its newly fractions so that's what gets Ltd then it is limited to about 3 per cent the food right now apart from his possible 3 per cent or less the rest of the neutrino His new new on town the atmospheric experiments spot with me on neutrinos and they see that they oscillate big-time In fact the oscillation this is because it can be 45 degree isolation what that means Is that 1 of these pieces which is "quotation mark of some angle thing and the other these pieces which a sign of it's a mental thing I so apart from this 3 cent 3 is just a 50 50 mixture of new going downhill what's observed is that when atmospheric neutrinos travel through the entire diameter of the Earth to detector they also weighed they disappear half of them gold or but when neutrinos come down from above the detector so the only about 1 kilometer the thickness of the the atmosphere away they don't playing that into this formula bounds said this Delta and squirted from a above from and course the experiments do want better than that and that's how this gets the value that it gets which I quoted before it's about 2 . 4 times 10 to the minus 3 electoral votes moving to the closely spaced solar pair the matter in the sun and through which solar neutrinos travel on the way out from the solar core where they're made to the outer edge of sun influences therefore I would change very much and the flavor changes described the what's called the large mixing angle Mikhail Smirnov from and that has the consequence but what comes out of the sun once the neutrinos get to the IRS 90 per cent of them part of the SMEs I can stay 9 Louisiana New United tout tools so the sun is a source of flocks of amassed and of course unless I can state is an ordinary particle like approach it doesn't oscillating anything nearsighted states don't oscillate if they did that would violate an energy conservation so this comes out of the sun propagates all the way to the air still isn't tuna gets here it's where is that I don't know which way is West but the sun is down there somewhere they're coming right now need to upwards from before the probability that this neutrino from the sun is gonna make an electron in that sector that's looking for it to do that this is just the electrons the new III fraction of this neutrino the green fracture that's measured to be about the probability of making electron by solar neutrino was measured to be about a 3rd consequently the newly fraction of this material has been determined from solar experiments To be 1 3rd now Unitarian mixing matrix says that the sum of all the 3 newly fractions of the 3 neutrino says that up to 1 neutrinos work this 1 is small this 1 is a 3rd of a neutrino therefore this 1 has to be two-thirds of a neutrino the rest of these 2 neutrinos pardon for the same reason that this is a 50 50 new new new down mixture if that mixing angles really 45 degrees and not 51 degrees but it's approximately something like this for the same reason adds this way here these 2 neutrinos together must be the orthogonal fifty-fifty nature new minus New Town Hall Square at 2 that doesn't tell you that new new new tower current equal proportion in these 2 neutrino separately but that is also true and it's very easy to show finally the splitting between the 2 closely spaced neutrinos can be measured by solar and by reactor experiments this is best measured by a reactor experiment which has it's detected not 1 kilometer but on written 80 kilometers all the way from all Bonjour reactors so it is much bigger L and hence it is sensitive to a much smaller Delta Times Square and is sensitive to the scarf that has given us a very nice the Patriot measurement of that gap the way they measure it they're looking for a new barred disappearance the distance to the reactors is fixed but the energy use and they're looking at a spectrum of reactors neutrinos and consequently they can study that spectrum as a function of the and that's going to determine what this coefficient of consolidated that's how we learned what we know now what we know has raised some question 1st of all what is the absolute
scale dream how far above 0 is all but we don't know Our neutrinos unlike the courts and charged that times their only antiparticles Water the dipole moments of neutrinos what is this angle 1 3 on which CP violation Is that atmospheric mixing angle really 45 degrees if it is that's very interesting because when something like that happens Maxwell mixing there's usually a reason a symmetry or something Is is the neutrino spectrum quirk like foreign do neutrino interactions while its CPU that is delayed the neutrinos neutrinos differently we said neutrinos are abundant what can neutrinos in the universe tell us about each other In particular is seeking a violation involving the neutrinos the key to understanding the matter antimatter symmetry in the universe I'm going to skip stuff of I need to in order to be sure to get to the what physics is behind tree nowhere and while we have our eyes fixed on these questions what Chad you may be surprised now what I'd like to do it the rest of the time talk about Huron stuff you these questions like guards 24 hours after just a few what's the question why is it interesting how can you go about answering it through future experiments are being a realistic in skip this 1 so I'm going to do what I threatened to do on the zone of ensuring its of stonewalling to having a harmony to skip take catcher it is the
antineutrino beside the neutrino 1st of all what the question was agreed the
question is for each mass state for each physical neutrino particles map which in Inouye but for each Ms and forgiven eliciting age Is the antineutrino the same as the neutrino In which case we call the neutrinos Myron particles or is the antineutrino different from the neutrino In which case we call them direct article an equivalent question is do neutrinos have Myron amasses because if they do then the mere sight in states are like this viral particles so what some irony an example is a monster like this which absorbs a right-handed antineutrino and makes a left-handed neutrino as this illustrates what any Meyer man's dollars is the turn antineutrino interlude in a neutrino or the other way around so the next new new bar and consequently they don't conserve the leptin number all that distinguishes electrons neutral and charged on the 1 hand From intellect on neutral and charged this is not left on flavor and slept on this versus intellect sits the it's electronic equivalent of the barrier number the distinguishes a neutron from an empty neutron that's what this quantum number is if there are terms like this which makes new new bar a new a war have opposite values of this quantum number then obviously this quantum number is not conserved so Maryland estimate explicitly violate Elkins now why does the presence of a Myron How the result that neutrinos are the only antiparticles rather than going through the mathematics or give you the hand-waving answer you know that you took a lunch right as a result of K 0 K 0 bomb mixing the neutral came inside states are not K 0 Abkhazia a bar a rather the states which recalled K shorting table neglecting CP violation these adjust the sum of the difference of K so what you see is that apart from other than overall sign which is of relevance either of K Shura work a long goes into itself under particle anti particle interchange so OK shorting longer what you might call my Arana bows on in a similar way the Myron Ostrom induces a new new Bob mixing which is analogous to this cake as a result of this new bomb mixing the neutrino mass items they will not be no on the bar it's going to be their son and when I make a new into a new bar and a new bar into a new this sum of course doesn't change so the neutrinos its own antiparticles and that's why Myron investors are like this make body called but perhaps the search for any firm EON would mix that fermion on with either it's only in the firm were closely related and Euphemia this mixing if the firmly on his electrically charged would reverse the sign of the electric charge turn electron positive well I would violate electric charge conservation that's a very big no-no so an electrically charged particle could not have a Myron arrested neutrinos are electrically neutral so they could have Myron minister and if they do that's going to make them very different from the courts and the charge electrons because a Myron a neutrino mass necessarily has a different origins than the quirk in the charge but promises in the Standard Model the cork amateurs but ministers come from EU collar coupling all the quirks of the charge To the Higgs field a Yukawa coupling although neutrino 2 The Lakes field would generate what is called a Dirac neutrino the analog of the court this term is not a own minister it is not mix neutrino antineutrino if there are Myron masses that Mesa neutrinos very different because the origin of the masses at least the Meyer on a piece of it as a origin that nobody else that we know of no other particles shares now I know that direct neutrinos my running neutrinos are a little bit unfamiliar particularly the Myron tree so what's a direct entry 1 what some ironic really in the context on the Standard Model interaction 1st the directory Dirac may ask I can state plus it's anti particle is a collection of 4 states with a common man although not the momentum by the long narrow the spin by a short 1 so we have a left-handed we polarized between all a right-handed antineutrino over right-handed neutrino lieutenant introductory when this left-handed neutrino interacts and makes a charge let the natural selection will be negative and with this right-handed antineutrino interacts when it makes will be positive In the director picture we understand that in terms of leptin number of conservation the direct picture there is a cancer of lacked number that's the difference between you and new bar New has L equals plus new has equals miners and is conservative and all my like an electron also as eloquence plus and helpless like a positron also has a legal minds so that's where this particle makes film and there were the standard model also has a feature that its currents are left-handed that means that when there is a difference between firmly on an energy me on between neutrino an antineutrino it's only the left-handed neutrino that interacts and only the right-handed in the so the right-handed neutrino the left and then antineutrino do not interact at least they don't in the limit that these particles are highly relativistic which they always are in the experiments to do the states are there but they don't interact so you might as well don't interact idea make them that's a very good question alleviate puzzle over there will be acquitted now in contrast that From ironic adrenal is just tool states of a common areas elected won the right in that 1 as before this left-handed 1 when it interacts makes a negative charge where is this right 1 makes a positive charge left In the Meyer a picture we do not understand that in terms of leptin number conservation there is no conserved wept on number now if there were this particle that 1 would be different but in the Myra case they're not in fact there is no difference between this particle and that 1 other than the opposite polarization so you can just a race that ball the only difference between these 2 particles is there handedness the polarization but we know that the weak interactions all of the standard model violate parity that is to stay they distinguish the left and the particle from writing the article is whether these cells in here as a result of that distinction and you can bear it out by staring carefully about what brung the incoming left-handed neutral act on is going to make an minors while incoming writing in the neutral uptown is gonna make Canal Plus and that's how these 2 particles get to make different final states all they needed to have was different polarisations they don't need to have a concerted worked on number polarization is sufficient because the weak interaction errors about the polarization now of course the neutrino Myron award rack is totally electrically neutral but you might ask can and have an electric charge distribution inside 18 up 2 0
for instance could there be they positive core surrounded by an equal and opposite compensating negative shell well this cannot be their efforts of on a neutrino because the anti particle to this system is obviously since charges reversed on the particle into particle conjugation a negative core surrounded by a positive shelf well this thing is obviously different from that fate but the antineutrino in the ironic case is the same as the neutrino so on a neutrino can look like that there is a more mathematical way of proving the same thing but this is essentially the point I'm ironic neutrino not only is overall electrically neutral is very electrically neutral it hasn't got any charge distribution inside suppose you have no Meyer on a massive just a directness and the corresponding Dirac neutrino for state In you turn on a Meyer on mail what it will do this way this direct neutrino With 4 states into 2 Myron industry knows each of which has just 2 states a left-handed 1 Orion 1 and there is no antineutrino distinct from the so you can remember this behavior by simply recalling that 2 plus 2 is 4 the hacking in determined experimentally whether there are my Myron the promising approaches to look for neutrinos double beta 0 neutrino Baden-Baden decays at school that's a process in which 1 nucleus decays to another by emitting 2 majors and nothing else if you see this reaction which has not been confirmed so far at any 9 0 level you will demonstrate that there is a nature of neutrino minister because the court level the trend was double beta decays to doubt works turning it into a port into lecturer if you see the reaction you know the amplitude for this is is non-zero whatever's in the black box and you know also that the W boson connects cost collective so the evidence for this is 0 so is the amplitude for that but this process converts a right-handed antineutrino into a left-handed neutrino that is exactly what the Myron investor might give you as an example dollars so if neutrinos double beta decay is none 0 nature does contain an amplitude which has the effect of Elmira arrested this is Irureta it may be a very tiny Myron minister minutes of life history and because of that case 0 K 0 bar article that argument if there a Myron amasses the neutrinos from the audience .period there's a lot of interest in doing this experiment various experiments under development throughout the world now the final question I wanted to get neutrino interactions violates I hope to convince you is a very closely related question are we you and I descended from heavy neutrinos no Nomura say more about this tomorrow morning when I want to go through sort of morning waiting level here the universe confronts us with a
big challenge a cosmically broken symmetry because it contains barrier islands the nuclear arms of which we are made but essentially no knowing the barrier the barrier number of the universe defined as the number of Barron's minus the number of anti barrier or what's the same thing 3 times the number of works minus the number of intercourse the 3 of these 4 barrier is observed to be 9 0 yet Standard cosmology tells us that if this number had been non-zero right at the beginning at the moment the being back in its own 0 barrier number would have been raised by several different physical process so shortly after the Big Bang b was 0 and yet today is not How does 0 turned into not 0 Sakharov told us long ago that this cannot happen without a violation of CP that sort of obvious CP violation just means that matter and antimatter behave differently now if you start would be equal 0 that means you have equal numbers of variance in energy barrier and if the 2 behave the same then what everyone does the other does too so you're going to continue to have equal numbers the barrels into various but that's not what we see today To CP must be violated the CPA is observed to be violated in the court mixing matrix by a court analog of that thing Michael Dell however that CPU violation is much it's not that it's too small it is of a character that would lead to much too small a barrier and the much smaller than the various members of the sea well if the quirks can't do it an obvious question is can the lap times doing you know it's a barrier and we're trying to exploit and let me parenthetically explain to you why it's a barrier number were trying to explain left on the universe may have a 9 0 leptin number 2 but part of the electronic content of the universe is all bows neutrinos I talked about at the beginning of which were made in the Big Bang nobody knows how to detect those neutrinos much less measures their wept on Nov what we can measure Is the barrier number in several different ways big-bang nucleosynthesis for example so this we now and this is what we like to explain and there it is in fact a let tonic scenario known as let the Genesis which can explain it and I like to go through that with you let the genesis is a consequence of the most popular theory of why neutrinos tho they have non-zero masses why so that theory is called the seesaw mechanism and associates with the familiar like neutrinos very heavy neutrino Cecil partners called on the way the arithmetic works the heavier the ends are the lighter than neutrinos are hence the name seesaw it's this game where a child's itself the chairman of a board which goes up and down now when we say very heavy neutrinos I'm talking about tendered at 10 10 of the 15 not about to make his neutrinos at the LHC or any other accelerator however just after the Big Bang it was hot very hot hot enough that the average energy per bottle was enough To make these masses so these neutrinos would have been there if the is seesaws right just after the Big Bang no it is a signature feature of the seesaw that both these heavy neutrinos and the light ones which we see today are the only antiparticles so that's another motivation for looking for neutrino was double beta decay if the heavy neutrinos it's only anti particle that means it doesn't know whether it's select honorary left on a candy cane to give 1 pick indicate for example into an electron or into a positron however they have neutrino oscillation violates if the antineutrino oscillation probability is different than the neutrino oscillation probability then quite likely those heavy and decays in the early universe violated CPC also the cause in the sea these 2 CP violations come from the same place they come from the matrix of so-called Yukawa coupling constants y which couple these heavy neutrinos To the Higgs double that of the Standard Model and the Standard Model leptin goblets each of which contains a neutrino and they charge slept on and the 3 of them 1 for each family now if these heavy neutrino decay in the early universe violated CPC then that means that for CP mirror image decays like this the CP mirror image of is end itself because it's it's only anti particle the CP mirror image of an electron is a positron and CPU murder in images of which causes H minus rates percentage minors are the charge exist In the Standard Model his Dublin now that may be confusing all that somebody probably told you that there is no charge for use in the Standard Model and what they mean by that is that the charge has been absorbed by the W Plus To make a longitudinal spin stated the W plus but that day that's not in the early universe before the year-to-year before the universe cooled the through about 100 GB where the pigs vacuum expectation value turn-on this bottle was just a member of the Higgs doublet In W boson didn't have any mass at all so at the time I'm talking about that's an ordinary particles and it's available for this game and the CBE is violated the rates for these 2 CP mirror-image decays for different it's like a CBE violated his violated here new new bar oscillate different many of these 2 rates for different than after the decays have occurred there's more electrons and positrons or the other way the universe has only equal numbers of electrons in now of course what we're trying to explain is that the universe as an equal numbers of Barry and indeed step 1 gets as far as the left then there is a step too In Step 2 the
Standard Model process predicted by the very well confirmed standard model that shows line 1 the Standard Model process called the sailor process which is not perjury which does not concern the variant when he distinguishes it from preventing or the leptin number which distinguishes electoral from but does conservative different acts and the nature of this Milliron processes that such that if you start With the sort of universe which would have resulted from CP violation indicate which has a non-zero lectern number because it has an equal numbers of electrons and positrons and similarly
meal pluses in new minuses and neutrinos and antineutrinos if you have this on 0 leptin numbers
still no barriers a new input back into this process the outcome the universe which still has a non-zero number and now also a non-zero barrier number approximately minus a 3rd of the original left off such that the final self final His minus L initial which is equal to a initial minus initial so the Monticello has been conserved but now there is a non-zero barrier and that's what we were trying to explain and it's observed that this works quantitative for very reasonable values of the parameters not only do you get a non-zero barrier number but you get the abjure non-zero Ulibarri a number of the observed number of barrier islands come C. C relative to the number of photons per se se in the universe so this is a very very are tempting hypothesis it depends on the sea we don't know this is so is right but if the seesaw is right then left the Genesis falls out of it's unavoidable at some level provided that there are CPU are leading phases in this maker and if indeed the
matter which we are made came from those heavy neutrinos then we all come long ago from loans having tree knows we are their children yes the statement like all also In the last what you mean by that point the I think maybe the best time to answer that question is after we've gone on just a little bit but if I fail to answer it harassed me so I will ensue the company was in the other so think little we don't know all right navigate as all right right the lectern number there were talking about concerned will be defined but it is not conserved and the fact that it is not conserved is essential come back that before these decays occurred we might have had electrons and positrons but we would have had them very likely in equal numbers for the same reason we would have had burials annuity barriers in equal numbers after these decays occur if there is a CP violating difference between the rights we have on equal numbers of electrons in comes so manifestly leptin number has not been conserved and we are using that crucial so I'm just using leptin numbers a framework in which to talk but it's not a conserved 1 of them that's crucial and when you get here I'm sorry and
you get here the barrier numbers and Serbia that's how we get
from the non-zero on number 2 9 0 barrier what would you like to because of this to what was in the now you also have for all of which that right gun so in addition to these decays their decays in which heavy and goes to neutrino procedures 0 or antineutrino postage plus H 0 that's right then we have these neutrinos and antineutrinos and I by this point the temperature of the universe has come down to the to the degree that degree what a choice if it the damages come down to the degree that at least some of those primordial neutrinos from the big banks are not relativistic they may all be non relativistic but only some of that is the temperature is below the mass of the heaviest of the now but so long as the neutrinos relativistic I told you that when a new interact it makes no myosin anew and the new bar makes an plus and in Newburgh New Order saying that apart from polarization of the polarization is enough that the left and the guy makes no minors the right and the gun Excel but once neutrino become known relativistic those soliciting quantum numbers are not defined anymore and I just have a thing there if it should make a charge that done it can be a view the persuasion so I deliberately didn't want to go there but when I answered an earlier question but since you ask it it's not only that we can't measure the left a number of the universe because of the fact that the neutrinos there it is also as you correctly call attention to it that the leptin a number of the universe is not the following that because we have all these neutrinos and we have a police neutrinos and other neutrinos as a leather spends lovers out there that Israeli that and so long as they were relativistic I could have used their polarisations as a kind of a proxy for leptin number no let number but the polarization also results in a differentiation of what they do once in honor of the visit there is always more and you're quite right but we can still talk about on we just have to understand a bunch of things about it is not conserved we can't measure it is not what well-defined police still talk about my clear for these purposes we can talk about it but the yes and all of the and with the Cecil Group and the yes bothering you tough bunch tough points to fix it well you have put your finger on what is the most challenging aspects of both the seesaw mechanism and let the Genesis I think they're both very appealing but they're both very challenging to try to figure out a way to actually confirm experimentally it is a signature of the salt that Myron misses presence the Myra messes and is a key ingredient of the season that means you want neutrinos that will dedicate to occur if you if you have experiments very very very much more sensitive than the present ones and they still don't see anything I for 1 would become skeptical of the sea salt on the other hand if you do Woosie see neutrinos elevating carry while that increases the possibility of the saw it doesn't prove there could be others let time violating processes than menaces the or there could be Myron amasses would not this is yes but now and 1 in the world who I mean with my back there is a minimum ironic for a reasonable seesaw it's like at the question this Tropic come in colors other than Brown to which the answer is do you have a reasonable question about chocolate with the the reasonable men who look like they're on a mail and I would say there bigger then the Dirac masses of the quirks in the charge so a the top workers there you can talk about ministers smaller than that you can have Myron there are around 10 to the minus 5 electoral votes but you don't have a seesaw mechanism with the kind of environment the Cecil depends on the Myron amassed being bigger than the other me as much of it move right along with with that no we come the other part of the question How are you get evidence for this thing we just spoke about the seasonality talk about left agendas but the genesis is based on the seesaw idea that bodies is very heavy particles that would have existed in the early universe too heavy to be made in the laboratory today so happy test let the Genesis there are variations that people are working on I'm working on 1 myself where the heavy neutrinos are actually within range of the LHC so potentially you might actually be able to create them and then you could study the decays in you would see that they have the CP violating the case that would be be
extremely however in plane Vanallen
Cecil pictures that's not the way it is they're very heavy so you have to do something else and that's something else depends on this link and I spoke about before between CP violation in heavy neutrino the case in the early universe and CP violation in neutrino oscillation and here I hope to explain what I mean by likely In a convenient basis in which the mass matrix for the heavy neutrinos has been diagonal lines and in which the Miss matrix for the charged electrons has been diagonal lines the Yukawa coupling matrix that I called Why which couples the heavy neutrinos to digs in the light let on is the only source of CP violation among the left on the matter what experiment you and the case in the early universe neutrino oscillation today new goes the GAM anything this electronic the only place that CP violating phases can occur Is this matrix nothing else is complex no this set of couplings is responsible for Handy came into being in the light leptin but it has another role as the universe calls through roughly 100 200 g the neutral Higgs field picks up its famous vacuum expectation value in the standard model now particles have mass other than those heavy neutrinos which had misses from outside the standard model right from the get-go once that happens the neutral Higgs piece not I haven't ridden out the neutral charged pieces separately the neutral Higgs field here developed a vacuum expectation value it's about 175 g has get here which is why multiplied by the advent of which I call the that's just the constant in what I have a Fermi uncoupling like this times are constant that is the same sort of mass and that the courts have is called direct minister so once the of kicks in you get a Meyer owner sorry they direct mailers us for the neutrino it is just rare times this coupling matrix In terms of this direct the diagonal mass matrix for the heavy neutrinos whose diagonal elements are just the masses of those heavy neutrinos nasa's so the real number and this mixing matrix which we have been talking about it which we claim is Unitarian here is the seesaw relations this is the matrix which has been diagonal eyes and was diagonal elements are the masters of the light neutrinos notice and is is inversely proportional to heaven and that's the see-saw the bigger and end is the smaller and new now let's look at the faces this is a matrix of masses it's a real nature if leopard Genesis took place it came From phases in y hence why must be complex enhance indeed which is just wide times a number must also be complex but then again it is real Effendi is complex unless something really unexpected happens what's in this parenthesis has to be complex but this is also a matrix of real masses it has to be real if this inside the parenthesis is complex and that his real dumb mixing matrix had better be complex to absorb the phases inside here and make a new but if the mixing matrix is complex and then because of that formula Reppard used here through this imaginary part is going to be a CP violating difference between neutrino an antineutrino oscillation brother so to say it again if elected genesis occurred why and hence the unnecessarily complex hands unless something unexpected happens this parenthesis is complex to which requires that you also be complex to make new wheels now it is possible for what is in this parenthesis to be real even tho Andy is not real and then you can be real and we don't get an imaginary part however I submit to you but that is not the natural state of affairs if this is to be real despite the fact that Andy is it and despite the fact that the physics of Md Is the physics of this interaction and the fixes of is some ironic masses that have nothing to do with the direction and so these 2 matrices have nothing to do with 1 another if that's to be complex and yet what's in this parameter what's in his practices to be real I consider that quite unlikely and that's what I meant what I said it's not likely that that has not happened can it happen yes the affordability and we want to do it on purpose we know just how to do mathematics but I don't think that's very likely consequently you expect if elected genesis occurred that neutrino oscillation does violate and consequently people are gearing up to walk for that CP violation this is the question and people want to
answer experimentally and I am going to skip the next slide because I want to
conclude and come on you the House I've described
what we would like to do In terms of the physics of neutrinos as we currently understand it but there may be surprises and to illustrate that there may be surprises I'd like to tell you about some surprises we off already experience within the last year 1 of them bears and sterile neutrino the question is are there more than 3 minutes I states and what you'll see is related father sterilant Reno what the Allison the
experiment reported years ago is a rapid New Mudavadi newly bar neutrino oscillation and I'm using this 2 neutrino approximations they found that their neutrinos already isolated when l reuse of water in these units which means that the Delta swear that they require is also water 1 in those units 1 Eagle Square but 1 the square is much larger then the atmospheric and the solid dealt words which together describe successfully wall other isolation experiment if Ellison the has really seen in oscillation so that there is a 3rd at Delta and squared then there must be at least for me excited states 1 2 3 this can be 1 of these but then there's a force so there at least for me excited states since they are orthogonal idea in states although I Hambletonian I can form for orthogonal flavor states as linear combinations of them now from measurements of the invisible with a busy bows on that we know that when this decays to neutrino appears in only 2 cases to 3 different neutrino flavors made up lot of lightness items but the invisible with has been measured and it has been translated into the turn of the different numbers of neutrinos that disease decays into and the answer is something like 2 . 9 8 poster minus 0 . 0 2 which sounds suspiciously like free so only 3 flavors coupled to the hence if there are more than 3 months this idea states and hence more than 3 flavors the additional flavors adult coupled with that's an experimental observer and that was In a meeting these particles are not likely to have twice this year would you say is true but that doesn't mean that wouldn't fit with Ellis and they're going promises around 1 wall all of course could be 1 evil square the masses of three-quarters Museum has become 1 of the hectic and the Standard Model flavor neutrinos the don't couple to busy don't couple to the WE that comes from the weak I suspend structure the eye with people's they have structured the double its and Michael's 1 structure disease and such neutrinos that don't have standard model interactions coupling neither to the Xena the W are what we call the tree so what else in the handset is the existence of sterile Atorino the question is is the Austin the signal genuine neutrino oscillation the Minnewil experiment at Fermilab is trying to confirm or refute Allison the ballot many bones both Alinghi are about 17 times larger than they were in Ellison the Bunnell over here ratio still about the same as Ellis and the only 1 and many bulletin last summer just released its 1st new new body newly bar results this is the same reaction analysts and the look that and here are the results the mini-boom results are red the corresponding Ellison the results are black plotted versus Al overeat and the this with body years the probability for a new body to Reebok as seen by medieval overseen by Ellis the which is speed Allison the source some effect many will also see some effect non-zero oscillation probability moreover although the error bars are beginning need to be shrunk through further data taking and that's what many believe is doing qualitatively the many Bloomdale look like they do the same thing as the Allison the data well I think approximately nobody expected the medieval native to look like that most everybody including the members of the expected when they take a look at the data no see flat at 0 nothing surprise so do Ellison the mini-boom see a genuine oscillation in the same oscillations is each other now the all right the with they're pretty big errors so what you get is a region Delta and squared and signs were into the inner space and the 2 works the interesting thing is that the 2 experiments are consistent with a non-zero oscillation and consistent with each other In that in those terms it's not a unique .period in that space but 2 regions the system the 3 a 2nd surprise this 1 has to do with the possibility that neutrinos interact with matter In a way that's outside the standard model this is an experiment called me which sends
a beam of of neutrinos from Fermi Lab about 735 kilometers to a distant detector they look at a number of things 1 of the things they look for is disappearance the new 1 neutrinos or what is equivalent to the probability that they don't disappear that's what referred to hear the probability that a new new was still in new when it reaches the detector and within the last year the antineutrino analyze now I everybody expected that these 2 probabilities would be the same as each other but experimentally maybe that In those 2 parameters that I was just referring to In blue here is the allowed region for the neutrino data the allowed region Indiana Delta and squared and in signs were to these are the parameters without I hope the actors is clear this is signs were to fail after this is felt squared this assigns were debated In movie allowed region From neutrinos In red the corresponding allowed region for the antineutrino now the solid curve is the 90 per cent confidence level curve I think that's the 1 you should look at and 90 per cent confidence level there is a say over of overlaps with the 2 results are consistent but there's obviously some tension now within the standard model you cannot explain that if you can neglect all of the interactions of neutrinos and antineutrinos will matter then these 2 things have to be equal to 1 another and less CPT in variances violated and I for 1 I'm very reluctant to give up Cpt on the other hand these neutrinos do interact with matter they do that when they're being produced they do that in the detector obviously as they make something in the detector when they do that as they passed through earth matter on the way from from you have to the detector these people have shown that non-standard neutrino interactions can explain this disparity and the non-standard interaction that they have used to explain it is 1 in which the new town when it reaches the detector makes contrary to what I said at the beginning not a town but you want that does not happen in the Standard Model when you go back in you write this In the Prix mixing form L for couples only 2 new Alpha the new new makes only on the new tower makes only attack they have the Newtown making you want so it outside the standard model but if you will allow this kind of interaction then they can explain this I don't know where either the surprises is going I don't know if these effects are going to hold up but there they are and I described them to you just to underline the point that as you do neutrino physics you may think you can anticipate the general nature of what you're going to see you may be in for a very big surprise In summary good luck to all of you


  700 ms - page object


AV-Portal 3.20.2 (36f6df173ce4850b467c9cb7af359cf1cdaed247)