New Physics at a TeV and the LHC – II & IIIHiggs and New Physics Searches at the LHC

Sreerup Raychaudhuri

Tata Institute of Fundamental Research, Mumbai, India

IPM String School (ISS 2009), Tehran, IranApril 17, 2009

Significance of the TeV energy scale:

• top-down approach : • GUT or stringy unification must have low energy

consequences; high scale SUSY will have low energy manifestations, extra dimensions will become accessible at high enough energies

• bottom-up approach : • hierarchy problem, neutrino masses, GUT evolution

• aesthetic approach :• 18 free parameters in the SM• no QCD-EW unification• desert scenarios

Capabilities of the LHC

Cannot do a blind search…

All important final states require a trigger

• Huge QCD backgrounds… especially if looking for hadronic final states

• Cannot see very soft pT jets/leptons/photons

LHC has severe limitations….

Can find the Higgs boson of the SM (if it exists)Can find a SUSY signal if kinematics permitsCan find a resonant new state

Sure shots :

Less sure :

Can measure Higgs boson couplings

Can determine t quark properties to precision

Can measure SUSY parametersCan discover exotics, e.g. gravitons, monopoles…

How are we so sure?

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11 RG evolution of mSUGRA spectrum

12 Present status of MSSM parameter space

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MSSM Higgs parameter space – 3 yr LHC MSSM Higgs parameter space – high lumi

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Charged Higgs boson can fill up the hole

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