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Transcript
Particle Physics at
the LHC Era
Tianjun Li
ITP, CAS
ICTS, USTC, March 22, 2013
Outline
• Introduction to the Standard Model (SM)
• Theoretical Overiew for New Physics (NP)
• LHC Higgs Searches
• LHC Supersymmetry Searches
• Implications for Supersymmetric SMs
• Summary
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I. Introduction to the SM
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Physicists
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Higgs Mechanism
3 Goldstone bosons are eaten by gauge bosons
what left is a Higgs boson.
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Gauge Hierarchy Problem
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II. Theoretical Overview for NP
• New Particles
• New Gauge Symmetries
• Global Symmetry Breaking
• Supersymmetry
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New Particles
• Vector-Like Fermions
• Singlet Boson or Higgs Fields
• Doublet Boson or Higgs Fields
• Triplet Higgs Fields
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New Gauge Symmetries
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(1) U(1)’ Models:
(2) SU(2)’ Models:
(3) Top Color Models
(4) Top SU(5) Models
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B or L Symmetry Breaking
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Supersymmetry
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Particle Spectrum
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Gauge Coupling Unification
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III. LHC Higgs Searches
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8cm length & 16*10-4 cm radius
Event rate:
N = L x (pp) 109 interactions/s
Mostly soft (low pT) events
Interesting hard (high-pT) events are rare
very powerful detectors needed
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ATLAS in Brief
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NJU
SDU
IHEP, USTC
CMS similarities
General purpose CMS designed with equivalent performance
as ATLAS while independent cross check is essential 43