High Energy Accelerators
Dennis Silverman
Physics and Astronomy
U. C. Irvine
SLAC B Meson Factory
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Neutral B0 mesons are composed of a u quark and a b
antiquark.
They live long enough to go some distance in the
detector, called BaBar.
They oscillate to their anti- B0 through annihilating to a
W+ and W- pair.
In this oscillation there is a discrepancy between particle
and antiparticle rates.
This allows us to learn about such a discrepancy that
allowed the universe to remain one part in a billion
matter after matter and antimatter annihilated in the big
bang.
A similar B factory called Belle is producing similar
results in Japan.
B – Anti-B pairs formed by e+ eAnnihilation
B – anti-B pair created through virtual photon
e-
virtual photon
b->anti-B
e+
anti-b-> B
SLAC Accelerator – PEP rings
BaBar Detector
Typical collider detector elements
Fermilab Tevatron
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Rings allow collisions of protons and anti-protons in their
center of mass, each of 1TeV energy.
Included quarks and anti-quarks colliding at a typical 1/3
of a TeV each.
proton
Anti-proton
CDF (and D0) Detectors
LHC at CERN
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Large Hadron Collider at CERN Geneva
7 TeV protons on 7 TeV protons in their center of
mass, 27 km long ring tunnel
Cost of $2.5 billion to international collaboration,
U.S. about $0.5 billion share, including much
manpower
Atlas and CMS detectors
Capable of producing Higgs and SUSY particles
Starting in 2007
LHC Ring Layout
LHC Tunnel and Accelerator
Cross Section of Two Beam Path
Magnets
Atlas Detector – Five Stories Tall
Neutrino Detectors
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Large water detectors
Charged particles produce Cherenkov light cones
Detect atmospheric produced neutrinos from
cosmic rays, and their oscillations
Detect solar neutrinos and their oscillations
Detect supernova produced neutrinos
Search for proton decay
Talk in the Fall from Hank Sobel
Super-K (Kamiokande)
Super-K
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11,000 20 inch phototubes
50 kilotons of purified water
In a deep mine
Dimensions: 40 m diameter, 40 m high
New Phototube layout
SNO (Sudbury Neutrino Detector)
1 kiloton of Canadian
heavy water D20
 7 kilotons of normal
water surrounding
 18 m sphere
surrounding
 10,000 phototubes
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