Constraining type II 2HDM in light of LHC Higgs searches

We study the implication of the LHC Higgs search results on the Type II Two Higgs-Doublet Model. In particular, we explore the scenarios in which the observed 126 GeV Higgs signal is interpreted as either the light CP-even Higgs h ⁰ or the heavy CP-even Higgs H ⁰. Imposing both theoretical and experimental constraints, we analyze the surviving parameter regions in m _H (m _h ), m _A, m _H ±, tan β and sin(β - α). We further identify the regions that could accommodate a 126 GeV Higgs with cross sections consistent with the observed Higgs signal. We find that in the h ⁰-126 case, we are restricted to narrow regions of sin(β - α) ≈ ±1 with tan β up to 4, or an extended region with 0.55 < sin(β - α) < 0.9 and 1.5 < tan β < 4. The values of m _H, m _A and m _H ±, however, are relatively unconstrained. In the H ⁰-126 case, we are restricted to a narrow region of sin(β - α) ~ 0 with tan β up to about 8, or an extended region of sin(β - α) between -0.8 to -0.05, with tan β extended to 30 or higher. m _A and m _H ± are nearly degenerate due to Δρ constraints. Imposing flavor constraints shrinks the surviving parameter space significantly for the H ⁰-126 case, limiting tan β ≠10, but has little effect in the h ⁰-126 case. We also investigate the correlation between γγ, V V and bb/ττ channels. γγ and V V channels are most likely to be highly correlated with γγ: V V ~ 1 for the normalized cross sections.