Probing the CP-violating light neutral higgs in the charged higgs decay at the LHC

Abstract

The CP-violating MSSM allows existence of a light neutral Higgs boson (M_H150 GeV) in the CPX scenario in the low tan β (5)region, which could have escaped the LEP searches due to a strongly suppressed H₁ZZ coupling. This parameter space corresponds to a relatively light H⁺ (M_H+<M_t), which is predicted to decay dominantly into the WH₁ channel. Thus one expects to see a striking tt^- signal at the LHC, where one of the top quarks decays into the bbb^-W channel, via t→bH^±, H^±→WH₁ and H₁→bb^-. The characteristic correlation between the bb^-,bb^-W and bbb^-W invariant mass peaks is expected to make this signal practically free of the SM background. Our parton level Monte Carlo simulation yields upto 5000 events, for L=30 fb^-1, over the parameter space of interest, after taking into account the b-tagging efficiency for three or more b-tagged jets.