Decay H+→W+γ in a nonlinear Rξ gauge -: art. no. 095008

A new evaluation of the charged Higgs boson decay H+-->W(+)gamma is presented in the context of the general two-Higgs doublet model. A nonlinear R-xi gauge which considerably simplifies the calculation is introduced and simple expressions are obtained for the fermionic and bosonic contributions. The H+-->W(+)gamma branching ratio is analyzed for several values of the parameters of the model. Although this decay can have a branching fraction as large as 10(-4) in a certain region of the parameter space, it is found that such a region is disfavored by the most recent constraints on b-->sgamma, g-2 of the muon, Z-->b(b) over bar, and the rho parameter, along with the exclusions from direct searches at the CERN e(-)e(+) LEP collider. The possibility of detecting this decay at future colliders is discussed.