FYS 3510 Particles and
fundamental
interactions
Spring2016
18.01-30.05
Monday1415-1600,Aud.Ø467
Tuesday1415-1600,Aud.Ø394
Website2016Additionalmaterial
FaridOuld-Saada
18/01/16
F. Ould-Saada
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Website2016
§  Coursecontent&goals
§  Practical:teaching,lecturesvsexercises,
evaluation
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2016
-
§  Time,pensumotherrecommended
-
material
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Additionalmaterial
§  Notecolourcoding:
▪  Red=importantinformation;Yellow=working
onit;Green=readyfor“printing”
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-  Particles and Fundamental
interactions, 2012, Braibant et al
-  Additional material covering
introduction to heavy ion physics
CERNvisit2015
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-
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Modern Particle Physics, 2013, Thomson,
for information
Nuclear and Particle Physics, Amsler 2015,
for information
CERNsummerstudentlectures
Reviewofparticleproperties
NobelLecturesinPhysics
HyperPhysics
§  2016:March29–April1
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InternationalMasterClasses
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Thebook
§  ”ParticlesandFundamentalinteractions”aimstoprovidethebasisoftheoretical
foundationandphenomenologicalknowledgeofthestructureofmatteratthe
subatomiclevel.Itstartsbypresentingthegeneralconceptsatthesimplestleveland
doesnotrequirepreviousknowledgeofthefield,exceptforthebasicquantum
mechanics.Thereadersaregraduallyintroducedtotheincreasinglymoreadvanced
topics,sothatthistextcanaccompanystudentsallthewaytotheirgraduateand
doctoralstudiesinexperimentalhigh-energyphysics.Specialemphasisisplacedon
experimentalandphenomenologicalaspectsofthefieldandhowmeasurementsand
theoryinterplayinthedevelopmentofparticlephysics(andnuclearphysics,added).
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Feature:OnlinematerialavailablethroughUiOlogging.
BraibantSylvie,GiacomelliGiorgio,SpurioMaurizio,
ParticleandFundamentalInteractions-ADeeperinsightintoParticlePhysics,2012,ISBN
978-94-007-2464-8.
§  ParticlesandFundamentalInteractions:Supplements,ProblemsandSolutions-ADeeper
InsightintoParticlePhysics,2012,ISBN978-94-007-4135-5
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Exercisesessions
§  “Pensum”bookhassetsofproblemswith“solutions”
§  Solveasmanyasyoucan
§  Exercisesessionswillbeorganisedwhenneeded
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Compulsory“projects”andfinalexam
§  3-4compulsory“projects”andfinaloralexam(writtenifmanycandidates)
§  FinalexamJune6-7
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NuclearPhysicscourse–inparallelwithFYS3510
§  FYS3520–Nuclearphysics,structureandspectroscopy
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Somerelated(future)courses:
§  FYS4170–RelativisticQuantumFieldTheory
§  FYS4550–ExperimentalHighEnergyPhysics
§  FYS4560–ElementaryParticlePhysics
§  FYS4530–Subatomicmany-bodytheory
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Aboutyourselves
§  FollowingNuclearPhysicsCourse(FYS3520)?
§  Quantummechanicsintroduction?
§  Specialrelativityintroduction?Including4-vectors,…?
§  Masterclasses?Heardof?Participated?
§  VisitedCERN?
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Whatdoyouexpectfromthecourse?
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Aboutmyself
§  FaridOuld-SaadaorFaridOuld-Saada
¡
Feedbackmostwelcome
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Feedbackisneededinordertoplansometrip
§  29March–1April2016
§  Shortdiscussion
§  Institutecontributeswith30kNOK(intotal)…
▪  Sosome“owncontribution”isexpected
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CERNStudentprogram
§  http://jobs.web.cern.ch/join-us/students
§  SummerstudentDeadline27.1.2016
§  TechnicalstudentDeadline26.4.2016
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Studentcontacts
§  Oneor2candidate(s)
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Courseevaluation
§  Mid-termevaluation
▪  Youwillhavethechancetogivefeedbackinordertoimprove
teaching“onthefly”
§  Finalevaluation
▪  Studentcontactscollectinputfromallremainingstudents
▪  Meeting
▪  Report
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1.HistoricalNotesandFundamentalConcepts.
2.ParticleInteractionswithMatterandDetectors.
3.ParticleAcceleratorsandParticleDetection.
§  A2.Thenaturalunitsinsub-nuclearphysics
§  A3.BasicconceptsofrelativityandclassicalEM.
4.TheParadigmofInteractions:theElectromagneticCase.
§  A4.Dirac’sequationandformalism.
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5.FirstDiscussionoftheOtherFundamentalInteractions.
6.InvarianceandConservationPrinciples.
7.HadronInteractionsatLowEnergiesandtheStaticQuarkModel.
8.WeakInteractionsandNeutrinos.
9.DiscoveriesinElectron-PositronCollisions.
10.HighEnergyInteractionsandtheDynamicQuarkModel.
11.TheStandardModeloftheMicrocosm.
12.CP-ViolationandParticleOscillations.
13.MicrocosmandMacrocosm.
14.FundamentalaspectsofNucleonInteractions.
15.HeavyIonCollisions
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1.1Introduction 1.2TheDiscoveryofParticles 1.3TheConceptoftheAtomandIndivisibility
§  Read5-9inbook
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1.4TheStandardModelofMicrocosm–Fundamental
FermionsandBosons
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Elementaryparticlephysicsdealswith
§  thesearchandthestudyoftheultimateconstituentsofmatter
§  aswellasoftheirinteractions
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Atom–Nucleus,nucleons(proton,neutron),electron–quarks,…
§  BacktoearlyUniverse
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QuarksandLeptons,ultimateconstituentsofMatter…currently
§  Fermions–half-integerspin,matterparticles,obeyFermi-Diracstatistics.
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Forcesregulatetheinteractionsamongstmatterparticles
§  Strong,Weak,ElectromagneticandGravitational
§  Eachinteractionhasitsownquantumfield,namely,theforceparticlesthatrelaythe
interaction
§  ForceparticlesareBosons–integerspin–obeyBose–Einsteinstatistics.
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Scalar(spin0)Higgsboson
§  Mainingredientinthemechanismthatattributesmasstoparticles
§  MechanismofSpontaneousSymmetryBreaking
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1stfermionfamily
§  Allordinarymatter
belongstothisgroup
§  Neutrinosneededin
mostmatter
transformations
▪
¡
Betadecay,fusionin
stars
2ndand3rdfamilies
§  Existedjustafterthe
Big-Bang
§  Nowfoundonlyin
Cosmicraysor
producedathigh
energyAccelerators
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Eachparticlealsohasanantimatter
counterpart...sortofmirrorimage.
Stableparticles
§  Photon,neutrinosandantineutrinos,
electron,positron,proton,antiproton
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Leptonsarefreeparticles
Quarksandgluonsareconfinedin
hadrons
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Quarksarenotfree,theycomein3colorsandareconfinedin
Hadrons
Onlycolorlesscombinationsofquarksexistinnature
§  Mesons=quark-antiquark(π+,π0,π-)
§  Baryons=qqq(p,n)
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Freequarksunobservedinnature
§  Hadronsmadeofquarks
§  Quarkpropertiesdeducedfromstudiesofhadronproperties
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Analogytodeducingpropertiesofnucleonsbystudying
nuclei…
§  Nucleiareboundstatesofnucleons…
§  Nucleonsareboundstatesofquarks
§  ArepropertiesofNucleideduciblefrompropertiesofquarksandtheir
interaction?
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Inpractice,itisbeyondpresentcalculationtechniques
§  NuclearPhysicsandParticlePhysicshavebeentreatedas2almost
separatesubjects
§  Howevertherearemanyconnectionsbetweenthefields
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NuclearPhysicsdistinctfromAtomicPhysics
§  1896-Becquerel:somenucleiunstableanddecayspontaneously
§  Radioactivity:α(4He++), β (e-,e+),γ(photons)
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§
§
J.J.Thomson–1897:cathoderaysareelectronse-
Rutherford1911:largeanglescatteringofparticlesbythingoldfoils
§  verysmall,electricallychargedcentralnucleus
§  Planetaryatom
Chadwick1932:neutron,n,neutralradiationemittedinα-Be
Bohr–1913:“Bohrmodel”usingQuantumMechanics(QM)
§  Avoidsatomcollapseinplanetaryversionbasedonclassicalmechanics
§  PhenomenaofatomicphysicsexplainedbyDiracequation–relativisticanalogue
ofSchrödingerequation
§  Heisenbergetal.:applicationofQMtoNucleusmadeofnucleons(p,n)
§  Forcebindingnucleusisnotelectromagnetismholdingelectronsintheirorbits,
butashort-range,charge-independent,StrongNuclearforce
§
DifferentmodelsareusedtointerpretvariousclassesofphenomenainNuclearPhysics
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Electrone--(Thomson1897),protonp(Rutherford1919),neutronn(Chadwick1932),
positrone+(Anderson1932,predictedbyDirac1927)
Photonγ-Planck1900:quantizationofEMradiationtoexplainblack-bodyradiation
Cosmicradiation(V.Hess1912:aerostaticballoons)
§  Primarycosmicrays–fromextraterrestrialspace:p(85%),α(10%),heavynuclei(1%),e(2%),…
§  SecondaryCRsfrominteractionofprimaryCRswithterrestrialatmosphere
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Neutrinoν
§  Pauli1930:postulatedneutralspin1/2particletoexplainapparentnon-conservationofenergy
andangularmomentuminβ-decays,3-body(insteadof2-bodydecaytoe-+p)
§  Reines-Cohen-1956:detectionofantineutrinoatnuclearreactor
§
§
Muon(Neddermyer1937),Pion(Lattesetal.1947)discoveredincosmicrays
1950s:Highenergybeamsofparticlesinlaboratories,Antiproton1955++
Controlledscatteringexperiments,greateruseofcomputers,sophisticatedanalysistechniques
§  1960s:largenumberofunstableparticleswithveryshortlifetimesà“ParticleZoo”
▪  Quarkmodel:Gell-Mann&Zweigà3familiesofmorefundamentalparticles–Quarks,q
confirmedindeepinelasticscatteringeNandνN
▪
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¡
¡
¡
Allhadrons
aremadeofa
smaller
numberofyet
more
fundamental
particles–
quarks
Confirmedin
experiments
byshooting
highenergy
electronson
nucleons(p,n)
Protonsand
Neutronsare
madeof
quarksbound
bygluons.
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Modelpredictsparticleslikethe
Ω-Particle(1963)!
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¡
¡
Explainsnearlyallparticlephysicsphenomena,exceptGravity
Interactionofasmallnumberofelementary(fundamental)particles
§  SingletheorytointerpretallHEdata,contrarytonuclearphysics
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Elementaryparticlecharacterizedbyquantumnumbers:massm,
electricchargeq,spins=0,1/2,1,3/2,…
§  Spin:permanentintrinsicangularmomentuminQM–noclassical
analogue
§  Fermions:half-integerspin(electron,quark:s=1/2)
§  Bosons:integerspin(photon:s=1,Higgs:s=0,“Graviton”:s=2)
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3familiesofparticlesinSM
§  2spin-1/2familiesoffermions:Leptons(electron,neutrino)andQuarks
(u,d)
§  1familyofspin-1bosons
§  (atleast)onespin-0Higgsbosontoexplainoriginofmass(CERN2012)
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¡
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Leptonsand
quarks(spin1/2
fermions)
Quantum
Numbers
(conservedinSM)
§  ElectricchargeQ
§  LeptonnumberL
(Le,Lµ ,Lτ)
§  BaryonNumberB
§  …
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s:1963,νµ:1963
c:1974
b:1976
t:1995
ντ:2000
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Electromagnetic
§  Allelectricallychargedparticles:electron,quarks,W-bosons
§  Masslessγàlongrangeinteraction
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Weak
§  allparticles(butgluonsandphotons),includingneutrinosandHiggs
§  HeavyW+,W-,Z0m=80-90GeV(CERN1983)àshortrangeinteraction
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Stronginteraction
§  Onlyquarks(andgluons)boundinnucleons
§  Masslessgaugebosons(gluon,DESY1979)butshortrangedueto
confinement
§  Strongnuclearforces(NP)areaconsequenceofthismore
fundamentalstronginteraction
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Thefourfundamentalforcesare
carriedbyvectorfieldparticles-
bosons
Ifyouchangethestrengthofany
interaction,youwouldarrivetoa
totallydifferentworld…
Isthe
relative
strength
always
Likethat?
-No,it
depends
whereyou
live!
?
JustaftertheBig-Bangitisbelievedthatall4forceshadthesamestrength…
¡
¡
Readtext1.3pp5-9
Scaleofdimensions
inmetersforvarious
typesof“atoms”
andscaleof
“ionization”
energies,
§  necessaryenergies
toextracta
constituentfromthe
considered“atom.”
¡
¡
Temperatures
correspondingto
theconsidered
energies
Cosmictimewhen
theUniversehad
thattemperature
startingfromthe
BigBang
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¡
(N2)gas(10-8cm)
inaroomatNTP
(293oK,1Atm)
M=28.1,66.10-27
kg;k=1,38.10-23J
K-1;1eV=1,602.
10-19J
F. Ould-Saada
1
2
m〈v 2 〉 = 23 kT ≈ 0.038 eV
⇒ 〈v 2 〉 = 510m s −1
Ek ≅ 1, 3⋅10 −4 T [ K ] ; 1eV = 7740K
t [ s ] ≅ 2, 25⋅10 20 T −2 $%K −2 &'
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Our current
understanding
leads to a
coherent
picture of the
Universe:
Astronomy:
Statistics:
v=Hd
E=kT
Relativity:
Quantum mechanics
E=hν=hc/λ
…and a series of
phase transitions
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Very hot
Very Cold
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¡
Travelbackintime
TeVscaleè1ps
¡  –13.7Myears
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startingtotallysymmetric
withBigBangsome13.7M
yearsago
coolingtowardscurrent
2.7ºKwhileexpanding,
wentthroughsuccessive
phasetransitionswith
associatedSymmetry
Breakings,
ledtoadiversityoffields
responsiblefor4
``fundamental''forces
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Current
experimental limits
?
27
AppendixA2
¡
S.I.units
§  [kg,m,s]everydayobjects,macroscopicphenomena,but
▪  Mass:me=9.1x10-31kg
▪  Distance:1fm=10-15m
▪  Cross-section(area):1barn=10-28m2,1pb=10-12b,1|=10-15b
¡
Naturalunits
¡
!=c=1
§  [h,c,GeV]
▪  UnitofactioninQM:!=h/2π=1.055x10–34J.s=6.58x10–16eV.s
▪  Speedoflight(relativity):c=2.998x108m/s=2.998x1023fm/s
▪  Protonrestmassenergy:mp~1GeV/c2=109eV/c2=1.602x10-10J
▪  !c =0.197GeV.fm
▪  E2=p2c2+m2c4àE2=p2+m2
▪  Momenta:eV/c;MeV/c;GeV/c;TeV/c
▪  Masses:eV/c2:Me=0.51MeV/c2;Mp=0.94GeV/c2
▪  !=c=1à[M]=[E]=[P]=[L–1]=[T–1]àGeV
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Quantity
[kg, m, s] [!, c, GeV ]
! = c =1
Energy
kg m 2 s −2
GeV
GeV
Momentum kg m s −1
GeV / c
GeV
Mass
kg
GeV / c 2
GeV
Time
s
(GeV / !)
Length
m
(GeV / !c)
−1
GeV −1
Area
m2
(GeV / !c)
−2
GeV −2
¡
−1
GeV −1
1MeV=1.53×1021s–1
1MeV–1=197fm
1s=3×1023fm
1s–1=6.5×10-16eV
1ps–1=0.65meV
1m=5.07×106eV–1
1m–1=1.97×10–7eV–1
Example
§  Root-mean-squarecharge
radiusofproton
§  NUàSI(Dimensions!)
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r2
1/2
= 4.1GeV −1 → ×!c [GeV fm ]
= 4.1GeV −1 ( 0.197GeV fm ) = 0.8 fm
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§  Distances:1fm=10-15m
▪  ProtonRadius:~0.8fm
▪  RangeofStrongnuclearfore:~1-2fm
▪  Rangeofweakforce:~10-3fm
▪  Radiusofatom:~105fm
§  Crosssections–unitforarea.Barn:1b=10-28m2
▪  ππscattering(strongprocess):few10mb,asppscattering(previousfigure)
▪  νpscattering(weakprocess):few10|(1|=10-15b)
§  Energies:1eV=1.6X10-19joules
▪  1keV=103eV;1MeV=106eV;1GeV=109eV;1TeV=1012eV;
▪  Atomicionisation:feweV
▪  Bindingofnucleonsinheavynuclei:7-8MeVperparticle
§  Momenta:eV/c;MeV/c;GeV/c;TeV/c
§  Masses:eV/c2:Me=0.51MeV/c2;Mp=0.94GeV/c2;
▪  MW=80.4GeV/c2;MZ=91.2GeV/c2
▪  SIunits:1MeV/c2=1.78X10-30kg
▪  Atomicmassunit:1u=mC/12=1.661X10-27kg=931.5MeV/c2
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¡
Strengthof
Quantum
Electrodynamics
§  finestructure
constantα
§  αdimensionless:
samenumerical
valueregardless
ofunitsystem
used
!
#
"
#
! = c = ε 0 = µ 0 = 1$
e2
α=
4πε 0 !c
e2
1
⇒α =
≈
4π 137
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