Large Squark-Mixing Impact on H^+ Decay in the MSSM

Abstract

We study the decays of the charged Higgs boson H^+ within the Minimal Supersymmetric Standard Model. We find that the supersymetric mode 'stop + sbottom-bar' can dominate the H^+ decays in a wide range of the model parameters due to the large Yukawa couplings and mixings of stop and sbottom. Compared to the conventional modes 'tau^+ nu' and 't b-bar', this mode has very distinctive signatures. This could have a decisive impact on H^+ searches at future colliders. We find also that the QCD corrections to the 'stop + sbottom-bar' mode are significant, but that they do not invalidate our tree-level conclusion above.

4 pages, latex, 1 eps figure, uses stwol.sty; Invited talk at the 28th International Conference on High Energy Physics, Warsaw, Poland, 25-31 July 1996 (to appear in the proceedings (World Scientific))