VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
Introduction to Particle Physics
Thomas GajdosikFizikos Institutas
Vilnius Universitetas, Teorinės Fizikos Katedra
The Particle Zoo Symmetries The Standard Model
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
The Particle Zoo
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the electrone-
ThomsonThomson
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the photon
1900-1924
γ
PlanckPlanck EinsteinEinstein
ComptonCompton
e-
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the proton
e-
1900-1924
γ
1914
RutherfordRutherford
p
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the neutron
e-
1900-1924
γ
1914
n
p
1932
ChadwickChadwick
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the muon
e-
1900-1924
γ
1914
µ
p
1932
n
1937
Whoorderedthat one?
• Hess• Anderson,
Neddermeyer
• Street, Stevenson
spark chamber
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the pion
e-
1900-1924
γ
1914
π
p
1932
n
1937
µ
1947
PowellPowellYukawaYukawa
prediction discovery
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the positron (anti-matter)
e-
1900-1924
γ
1914
e+
p
1932
n
1937
µ
1947
π
AndersonAnderson
DiracDirac
prediction
discovery
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
the neutrino
e-
1900-1924
γ
1914
ν
p
1932
n
1937
µ
1947
π
e+
FermiFermiPauliPauli
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
strange particlese-
1900-1924
γ
1914
KK
p
1932
n
1937
µ
1947
π
e+
Rochester,Butler,...
1947-...
ν
ΣΣ
ΛΛ
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
„I have heard it said that the finderof a new elementary particle usedto be rewarded by a Nobel Prize,but such a discovery now ought tobe punished by a $10,000 fine.“
e-
1900-1924
γ
1914K
p
1932
n
1937
µ
1947
π
e+
1947-...
ν
Σ
Λ
Willis Lamb, in his Nobel prize acceptancespeech 1955, expressed the mood of thetime:
LambLamb
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
mean life time (s)
n
µ
πc
KL
D
Kc
KS
π0
η
τ
B
φ
J/ψϒ1s ϒ2s
ϒ3s
ϒ4sω
ρ
D*
Σc
Σ0
Ω−
mass (GeV/c2)
1s
1 ms
1 µs
10-15s
10-20s
10-25s
100000 e- p
1 ns
The Particle Zoo
W±
Zo
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
• electron accelerators: very short-waved particleprobes, shot directly at the „target“ probe; most widely-known example: electron microscopes
• at even higher energies of the probes, new particlescan be produced – short-lived particles, which existedshortly after big bang, can be „revived“: a „mini bigbang“ in the lab!
• to get even closer to big bang:build colliders, whereaccelerated particles collidehead-on
Particle accelerators
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
• in the early times: electro-static accelerators(cascade generator, Van-de-Graff generator)
• in parallel, high-frequency linear accelerators havebeen developed:
Particle accelerators
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
• the betatron, a „free-flighttransformator“: a magnet field (whichholds particles in an orbit) is increasedwith time, thus producing a circularelectric induction field whichaccelerates the particles
Particle accelerators
• the cyclotron, peak of development of accelerator physics in the 1920ies: a charged particle circulates in a magnetic field, and is accelerated byswitched electro-static fields. At non-relativistic energies, the rotationalfrequency is independent of the momentum (or energy) of the particle, onlythe orbit radius increases with time spiral path
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
Particle acceleratorsthe synchrotron is the advancement of thecyclotron to relativistic energies. It consistsof several modules which take over different tasks:
• bending magnets force particles on theircircular path• high-frequency cavities take care of theacceleration• focussing magnets keep the particle beamstogether
The world‘s largest electron-positron collideris the LEP, built in the 1980ies and used until2000 at CERN, Geneva reaching ~200 GeVof energy. It is now replaced by the LHC, which collides protons at energies of 14 TeV SPS tunnel
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
J/Ψ196645 GeVe+ e-SLAC
gluon19782 x 20 GeVe+ e-PETRA
antiproton19546 GeVpBevatron
discoverystartedEbeamparticlesaccelerator
J/Ψ1959/1960
29 / 33 GeVp, p, e±PS/AGS
first artificial mesons
19533,3 GeVpCosmotron
Particle accelerators
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
15199226 + 820 GeVp e±HERA
>10 00020092 x 7000 GeVp pLHC
5000199910,5 GeVe+ e-PEP II
luminosity[ 10-30 cm-2 s-1]startedEbeamparticlesaccelerator
13 000199910,5 GeVe+ e-KEK B
2519872 x 900 GeVp pTEVATRON
Particle accelerators
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
antiproton
e-
1900-1924
γ
1914
p
1932
n
1937
µ
1947
π
e+
cosmic rays,Bevatron,PS (CERN)
ν
p_
1955
also antiprotons!
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
1897
antineutrino
e-
1900-1924
γ
1914
p
1932
n
1937
µ
1956
π
e+
reactors:Clyde Cowan, Frederick Reines
ν
_
1955
1947
ν
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
partons / parton model
e-
γp
nµ
π
e+
ν
Richard Feynman1969
1900-1924
1897 1914 19471932
1937 1955
1947
1969
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
charm quark: J/Ψ
e-
γp
nµ
π
e+
Burt Richter (SLAC), Samuel Ting (BNL)1974
ν
c
1900-1924
1897 1914 19471932
1937 1955
1947
1969
1974
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
tau lepton: τ
e-
γp
nµ
π
e+
Martin Perl (SLAC-LBL)1975
ν
τ
19751900-1924
1897 1914 19471932
1937 1955
1947
1969
1974
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
bottom quark
e-
γp
nµ
π
e+
E288 (Fermilab)1977
ν
b
19751900-1924
1897 1914 19471932
1937 1955
1947
1969
1974 1977
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
Gluon
e-
γp
nµ
π
e+PETRA (DESY)1979
ν
g
19751900-1924
1897 1914 19471932
1937 1955
1947
1969
1974 1977
1979
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
W- and Z-boson
e-
γp
nµ
π
e+
discovery: UA1, UA2 (CERN)1983
ν
W,Z evidence: 1973 Gargamelle bubblechamber (CERN)
1900-1924
1897 1914 19471932
1937 1955
1947
19831969 `73
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
top quark
e-
γp
nµ
π
e+
ν
tCDF, D0 (Fermilab)1995
19751900-1924
1897 1914 19471932
1937 1955
19951947
19831969
1974 1977
1979
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
tau neutrino: ντ
e-
γp
nµ
π
e+
DONUT (Fermilab)2000
ν
ντ
19751900-1924
1897 1914 19471932
1937 1955
19951947
19831969
1974 1977
20001979
VU lecture – Introduction to Particle Physics Thomas Gajdosik, FI & VU
19751900-1924
1897 1914 19471932
1937 1955
?1947
19831969
1974 1977
2000`73 1979
Higgs particleH
ATLAS, CMS (CERN)
201x
CDF, D0 (Fermilab)
2009 ? ?
?1995
?
?