QCD and SUSY QCD corrections to the three-body decay of the charged Higgs boson - art. no. 015002

The O(alpha(s)) QCD corrections to the three-body decay width of the charge d Higgs boson Gamma(H+--> W+<b over dot (b)over bar>) are discussed in the MSSM. Our calculations indicate that the standard QCD corrections to the th ree-body decay mode raise the width by about 12% and the supersymmetric QCD corrections (due to (g) over tilde, (t) over tilde, (b) over tilde exchang es) can be comparable to or even larger than the standard QCD corrections i n some regions of the supersymmetric parameter space. This is mainly due to the effect of large left-right mixing of the top squark ((t) over tilde). It could significantly affect the phenomenology of the H+ search.