MSSM Higgs bosons at the LHC

The recent results on Higgs boson searches from LHC experiments provide significant guidance in exploring the minimal supersymmetric (SUSY) standard model (MSSM) Higgs sector. If we accept the existence of a SM-like Higgs boson in the mass window of 123 GeV-127 GeV as indicated by the observed γγ events, there are two distinct mass regions (in m _A) left in the MSSM Higgs sector: (a) the lighter CP-even Higgs boson being SM-like and the non-SM-like Higgs bosons all heavy and nearly degenerate above 300 GeV (an extended decoupling region); (b) the heavier CP-even Higgs boson being SM-like and the neutral non-SM-like Higgs bosons all nearly degenerate around 100 GeV (a small non-decoupling region). On the other hand, due to the strong correlation between the Higgs decays to W ⁺W ^- and to γγ predicted in the MSSM, the apparent absence of a W ⁺W ^- final state signal is in direct conflict with the γγ peak. If we consider the W ⁺W ^- channel on its own, the absence of the W ⁺W ^- signal would imply that the SM-like Higgs boson has reduced coupling to W ^±, and that the other non-SM-like Higgs bosons should not be too heavy and do not decouple. If both the γγ excess and the absence of a W ⁺W ^- signal continue, new physics beyond the MSSM will be required. A similar correlation exists between the W ⁺W ^- and τ ⁺τ ^- channels: a reduced W ⁺W ^- channel would force the τ ⁺τ ^- channel to be larger. Future searches for the SM-like Higgs boson at the LHC will provide critical tests for the MSSM prediction. We also study the signals predicted for the non-SM-like Higgs bosons and emphasize the potential importance of the electroweak processes pp→H ⁺H ^-, H ^±A0, which are independent of the SUSY parameters except for their masses. In addition, there may be sizable contributions from pp→H ^±h0, A0h0 and W ^±H0, ZH0 in the low-mass non-decoupling region, which may serve to discriminate the model parameters. We allow variations of the relevant SUSY parameters in a broad range and demonstrate the correlations and constraints on these parameters and associated SUSY particles.