PARTICLE PHYSICS

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W. G. SCOTT RAL/PPD 28 Nov 2007
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THE STANDARD MODEL
(schematic)
higgs kinetic term
yukawa term
fermion kinetic term
gauge kinetic term
where
higgs potential
field-strength tensor
covariant derivative
vector potential
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THE HIGGS FIELD
quarks leptons W,Z etc.
gives masses to the pointlike particles
refraction?.
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but not to the neutron/proton!
PROTON
NEUTRON
uUP (2/3)
QUARKS
dDOWN (-1/3)
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PARTICLE PHYSICS

• http//www.net.rl.ac.uk/ramfiles/ppd2001-01.ram

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THE ATOM
electrons (-)
NUCLEUS
proton()
neutron
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PROTON
NEUTRON
uUP (2/3)
QUARKS
dDOWN (-1/3)
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ELECTRICAL FORCES
e-
e-
Photon
QUANTUM FIELD THEORY
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QED
e-
e-
?
e-
e-
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QED
d
e-
?
e-
d
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QUARK CONFINEMENT
The Strong Force
Quark
Antiquark
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CHROMOSTATICS
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CHROMOSTATICS
THE COLOUR FORCE
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QCD
gluons 8 colours
quarks 3 colours
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THE WEAK FORCEBeta Decay
n
p
Antineutrino
Electron
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BETA DECAY(at the quark level)
d
u
Antineutrino
Electron
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WEAK INTERACTION
u
e-
W
d
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THE WEAK FORCE
Due to W-boson exchange
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The Discovery of the W/- and Z0UAI
(1983)MASSES W/- 80GeVZ0 91GeV
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NEUTRAL CURRENTS (1973)
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ELECTRO-WEAK
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THE FORCE PARTICLES
g1 g2 g3 g4 g5 g6 g7 g8W- Z0 W?
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CERN
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THE MATTER PARTICLES
Q -1 0
-1/3 2/3
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THE DISCOVERY OF TOP(Fermilab USA 1994)
top 180 GeV
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ELECTROWEAK
w
w-
z0
e
e-
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GAUGE THEORIES
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MATTER PARTICLES(Fermions)
1 1 0(Pauli exclusion principle)
FORCE PARTICLES(Bosons)
1 1 4(Stimulated emission, lasers etc)
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PLANCK SCALE 10 GeV
GRAND UNIFICATION
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GUT SCALE 10 GeV
hyper.
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weak
INVERSE COUPLING
strong
ENERGY GeV
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INTERACTION WITH THE HIGGS FIELD
gives masses to the point-like particles,
quarks, leptons, W, Z etc.
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PROF HIGGS UNIV EDINBURGH
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HIGGS AT LEP
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TO DISCOVER THE HIGGS WE NEED THE LHC
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THE NEUTRINO
V
A VERY FRIENDLY PARTICLE
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ATMOSPHERIC NEUTRINOS
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SUPER-KAMIOKANDE
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MINOS
CHICAGO
MINESSOTA (750 Km)
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CP-VIOLATION
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THE FUNDAMENTAL FORCES
ELECTRO- MAGNETIC
UNIFIED FORCE?
STRONG
GRAVITY
WEAK
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RECENT DEVELOPMENTS IN PARTICLE PHYSICS
1973 Neutral currents 1983 w/-,
z 1996 z ? ww
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NEUTRINO MASSES ??
1) Solar2) Atmospheric? v3 85 MeV ?
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THE DISCOVERY OF TOP(1994)
t ? b w evtop 180 GeV
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ATMOSPHERIC NEUTRINOS
EARTH
Neutrino
Cosmic ray (protons)
Detector