From neutrinos to cosmic sources

From neutrinos to cosmic sources

From neutrinos to cosmic sources Neutrinos in Standard Model A brief history of neutrinos Sources of neutrinos Detectors Neutrino oscillations - fundamentals Atmospheric neutrinos Solar neutrinos Neutrinos from supernovae and other cosmic sources Neutrinos from accelerators Direct mass measurement Neutrinos in Universe Summary of experimental results Future neutrino studiesProf. dr hab. D. Kiełczewska, prof. UWProf. dr hab. E. Rondio, IPJFrom neutrinos to cosmicsources, DK&ER1

Textbooks and references Current Aspects of Neutrino Physics, ed: D. Caldwell, 2001 Particle Physics, B.R. Martin & G. Shaw, 1997 Introduction to High Energy Physics, 4th edition,D.H.Perkins, 2000 Spaceship Neutrino, author: C. Sutton, 1992 www pages: neutrinos to cosmicsources, DK&ER2

ExamsA list of subjects will be presented at the end of the course;The student will be asked to report on a subject of the list.For those who attended the course(not more than 3 skipped lectures):The student chooses one subject of the list before the examand reports on it during the exam.For others:The student chooses 3 subjects of the list before the examand will be asked to report on one of them during the exam.From neutrinos to cosmicsources, DK&ER3

Wykład 1Neutrinos in Standard ModelFrom neutrinos to cosmicsources, DK&ER4

The neutrino: what is it?F. Reines: „....the most tiny quantity ofreality ever imagined by a humanbeing”and yet:Our sun emits 2x10 38 ν/secEarth receives > 4x10 10 ν/sec/cm 2Universe: 330 ν/cm 3(3 times less than photons10 9 times more than nucleons)From neutrinos to cosmicsources, DK&ER5

Ubiquitous NeutrinosThey must have played someimportant role in the universe!From neutrinos to cosmicsources, DK&ER6

How small is it?neutrinoFrom neutrinos to cosmicsources, DK&ER7

Baryons:The hadronic particlesProton Lambda AntiprotonMesons:From neutrinos to cosmicsources, DK&ER8

Standard Model– elementary particlesChargequarksChargeantiquarksleptonsantileptonsFrom neutrinos to cosmicsources, DK&ER9

SpinAngular momentum:fermions: ½bosons: 0, 1Left-handed statesRight-handed statesFrom neutrinos to cosmicsources, DK&ER10

Standard Model - interactionsWe know from experiments:Strong interactionsElectro-magnetic interactionsWeak interactionsElectro-weakinteractionsFrom neutrinos to cosmicsources, DK&ER11

Carriers of InteractionsStrongFermionss=1/2quarkBozonsgluons - gFermionss=1/2quarkElectromagnet.photons e - e -Weakinteractive bosons From neutrinos to cosmicsources, DK&ERquarkFeynmandiagrams12

Weak interactionsW - W +W -W +From neutrinos to cosmicsources, DK&ER13

Weak Interactions: CC and NCprocesses• “Charged Current” reaction:exchange of W boson• Proposed by Fermi (1934)• Responsible for neutron β decayCC• ‘Neutral Current’ reaction:exchange of Z boson• Proposed by Weinberg-Salam• Discovered with neutrinosNCFrom neutrinos to cosmicsources, DK&ER14

Some Weak Reactions InvolvingNeutrinos‘Inverse betadecay’ElectroncaptureFrom neutrinos to cosmicsources, DK&ER15

Some Weak Decaysneutron decaymuon decayW - W +From neutrinos to cosmicsources, DK&ERW bosons transformleptons INSIDE families16

Lepton number conservationIncluded in Standard Model on the basis of observations!Eg. tau lepton decay:tau lepton number: +1 0 0 +1muon lepton number: 0 +1 -1 0tau lepton number : -1 0 0 -1electron lepton number: 0 -1 +1 0From neutrinos to cosmicsources, DK&ER17

Lepton number conservationleptons antileptonsTotal L +1 -1L initial =L finalΔL=0L e =1: e - ν e ΔL e =0L =1: µ - ν ΔL =0L τ =1: τ - ν τ ΔL =0flavor lepton numbersare also conservedin Standard Model NC (neutral current) interactions can occur for all flavors For a CC (charged current) interaction a neutrino has to produce acharged lepton and thus needs enough energy to produce its massFrom neutrinos to cosmicsources, DK&ER18

Baryon number conservationObservation: proton is stable! Why?Why e.g: ??Proton lifetime:Standard Model describes this fact introducinga conserved quantum number:quarks antiquarksBaryon number B: +1/3 -1/3ΔB=0A question: what about neutron?From neutrinos to cosmicsources, DK&ER19

weakquarksQuarks in colorAntiquarksuuuupddddownc strong c c charmsssstrangettttopbbbbottomFrom neutrinos to cosmicsources, DK&ER20

Standard Model with colorsGeneration I Generation II Generation IIILeptonsQuarksGaugeBosonsFrom neutrinos to cosmicsources, DK&ERgluons21>>>

Success of Standard ModelThose are all(known today)elementaryparticlesThey are governedby the sameUNIVERSALlaws of physicsHowever ...........From neutrinos to cosmicsources, DK&ERsudcsbtbeuucst22bddct

Standard Model is incomplete There are 26 constants of Nature – too many!( among others 15 masses); we would like to understandrelations between them and unify all the interactions We don’t understand the origin of masses - a searchfor Higgs (which may be responsible for providingelementary particles with their masses) will becarried in LHC We already know from studies of neutrinos thatStandard Model has to be extendedFrom neutrinos to cosmicsources, DK&ER23

MassesBut at least one neutrinomass is >40 meVFrom neutrinos to cosmicsources, DK&ERBozon masses:25

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