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PUBLIC UNDERSTANDING OF SCIENCE
W. G. SCOTTRAL/PPD 28 Nov 2007
We are encouraged to spend 1% of our research grant funding on “outreach” activities, promoting understanding, appreciation and awareness of our science to the general public: Targeting 11-16 yr olds in schools etc. can help attract more young people into a scientific career. (e.g. RAL MasterClass 12-14 Mar 2008).
Helps ensure that the UKs front line contribution in this science is recognised by opinion formers, decision-takers/politicians. Taxpayers can have an appreciation and awareness of the research being funded on their behalf.
Helps produce highly qualified researchers with advanced skills needed by academia, industry and commerce.
THE STANDARD MODEL:
422
22
||||-
|| Tr
yFL
)(V “higgs potential”
fermion kinetic term
gauge “kinetic” term
yukawaterm
higgskinetic term
],[ F
igA
where:
“covariant derivative”
field-strength tensor
vector potential
(schematic)
THE HIGGS FIELD:
GeV 2502 vv
0 2141
FG
gives masses to the pointlike particles :
L
R
L
v ym
v ym
quarks leptons
W,Z etc.
refraction?.
u=“UP” (+2/3)
PROTON
NEUTRON
d=“DOWN” (-1/3)QUARKS
…but not to the neutron/proton!
PARTICLE PHYSICS
http://www.net.rl.ac.uk/ramfiles/ppd2001-01.ram
THE ATOM
neutron
NUCLEUS
electrons (-)
proton(+)
u=“UP” (+2/3)
PROTON
NEUTRON
d=“DOWN” (-1/3)QUARKS
ELECTRICAL FORCES
e- e-
PhotonQUANTUM FIELD
THEORY
QED
e- e-
e-e-
γ
d e-
de-
γ
QED
QUARK CONFINEMENT
The “Strong” Force
Quark
Antiquark
“CHROMOSTATICS”
“CHROMOSTATICS”
THE “COLOUR” FORCE
QCD
gluons8 colours
quarks3 colours
THE WEAK FORCEBeta Decay
n p
Antineutrino
Electron
BETA DECAY(at the quark level)
d u
Antineutrino
Electron
u e-
d
W+
WEAK INTERACTION
e
THE WEAK FORCE
u e-W+
Due to W-boson exchange
The Discovery of the W+/- and Z0
UAI (1983)
MASSES:
W+/- ≈ 80GeV
Z0 ≈ 91GeV
NEUTRAL CURRENTS (1973)
ELECTRO-WEAK
e
e
0Z
THE “FORCE” PARTICLES
g1 g2 g3 g4 g5 g6 g7 g8
W- Z0 W+
γ
CERN
THE “MATTER” PARTICLES
ude
cs
tb
1
2
3
Q -1 0 -1/3 +2/3
THE DISCOVERY OF TOP(Fermilab USA 1994)
top ≈ 180 GeV
ELECTROWEAK
e- e+
z0
w+ w-
GAUGE THEORIES
MATTER PARTICLES(Fermions)
FORCE PARTICLES(Bosons)
1 + 1 = 0(Pauli exclusion principle)
1 + 1 = 4(Stimulated emission, lasers etc)
PLANCKSCALE 10 GeV
19
GUTSCALE 10 GeV
16
GRAND UNIFICATION:
strong
weak
hyper.
INV
ER
SE
CO
UP
LIN
G
ENERGY GeV
INTERACTION WITH THE HIGGS FIELD
gives masses to the “point-like” particles, quarks, leptons, W, Z etc.
LtRt
Lt
L
cv L
cv
PROF HIGGS UNIV EDINBURGH
HIGGS AT LEP HZee bbHqqZ
GeV 114 H m
TO DISCOVER THE HIGGS WE NEED: THE LHC
V
THE NEUTRINO
A VERY FRIENDLY PARTICLE
ATMOSPHERIC NEUTRINOS
SUPER-KAMIOKANDE
MINOS CHICAGO MINESSOTA (750 Km)
Solar Datadist. spect. B and . systs corr. ignoring -Salt NoSalt of
average naivemy is 03.035.0/point SNO8
NCCC
ph/9601346-hep 111 (1996) 374 PLBalso see ;ph/0202074-hep 167 (2002) 530 PLBHPS
CP-VIOLATION
THE FUNDAMENTAL FORCES
WEAK
STRONG GRAVITY
ELECTRO-MAGNETIC
UNIFIEDFORCE?
1973 “Neutral currents”
1983 w+/-, z
1996 z* → ww
RECENT DEVELOPMENTS IN PARTICLE PHYSICS
NEUTRINO MASSES ??
1) Solar
2) Atmospheric
→ v3 ≈ 85 MeV ?
THE DISCOVERY OF TOP(1994)
t → b w
ev
top ≈ 180 GeV
ATMOSPHERIC NEUTRINOS
EARTH
Cosmic ray (protons)
Neutrino
Detector
