QCD Corrections to Scalar Quark Decays

Abstract

In supersymmetric theories, the main decay modes of scalar quarks are decays into quarks plus charginos or neutralinos, if the gluinos are heavy enough. We calculate the O(${\alpha }_s$) QCD corrections to these decay modes in the minimal supersymmetric extension of the Standard Model. In the case of scalar top and bottom quarks, where mixing effects can be important, these corrections can reach values of the order of a few ten percent. They can be either positive or negative and increase logarithmically with the gluino mass. For the scalar partners of light quarks, the corrections do not exceed in general the level of ten percent for gluino masses less than 1 TeV.

Comments: A few typos corrected and some additional explanations given. The figures are slightly changed due to a bug in the Fortran code. The qualitative discussion is unchanged. Version to appear in Phys. Rev. D. PS file also at: http://itpaxp1.physik.uni-karlsruhe.de/prep/prep.html