High Energy Accelerators

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High Energy Accelerators

• Dennis Silverman
• Physics and Astronomy
• U. C. Irvine

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SLAC B Meson Factory

• 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.

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B Anti-B pairs formed by e e-Annihilation

• B anti-B pair created through virtual photon

b-gtanti-B
e-
virtual photon
e
anti-b-gt B
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SLAC Accelerator PEP rings
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BaBar Detector
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Typical collider detector elements
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Fermilab Tevatron

• 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.

Anti-proton
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CDF (and D0) Detectors
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LHC at CERN

• 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

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LHC Ring Layout
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LHC Tunnel and Accelerator
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Cross Section of Two Beam PathMagnets
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Atlas Detector Five Stories Tall
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Neutrino Detectors

• 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

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Super-K (Kamiokande)
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Super-K

• 11,000 20 inch phototubes
• 50 kilotons of purified water
• In a deep mine
• Dimensions 40 m diameter, 40 m high

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New Phototube layout
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SNO (Sudbury Neutrino Detector)

• 1 kiloton of Canadian
• heavy water D20
• 7 kilotons of normal
• water surrounding
• 18 m sphere
• surrounding
• 10,000 phototubes