Implications of Yukawa textures in the decay H+ → W+γ within the 2HDM-III

Abstract

We discuss the implications of assuming a four-zero Yukawa texture for the charged Higgs decay H+ → W+γ at the one-loop level, within the context of the general two-Higgs doublet model of type III. We begin by presenting a detailed analysis of the charged Higgs boson couplings with heavy quarks and the resulting effects on their decays. In particular, we present the possible enhancement of the decay H+ → W+γ, whose branching ratio could be of the order 10−2, for charged Higgs mass of the order 180 GeV. These parameters can still avoid the B → Xsγ constraint, the perturbativity and ρ0 bound. We show that BR(H+ → W+γ) ∼ 10−2 is favored by the constraints of mixing and of the radiative corrections to the vertex in the regime small tan β. In a scenario favored by all the above restrictions, we study the production of charged Higgs bosons, which is also sensitive to the modifications of its couplings, and we evaluate the events rates at the LHC, including the ‘direct’ and ‘indirect’ production channels. We get an event rate of order 60 (120) for ‘direct’ (‘indirect’) production reaction and including the decay H+ → W+γ in the final state, with an integrated luminosity of 105 pb−1.