Proposals for bottom quark/squark renormalization in the complex MSSM

We present a consistent renormalization of the topand bottom-quark/squark sector of the minimal supersymmetric standard model with complex parameters. Various renormalization schemes are defined, analyzed analytically, and tested numerically in the decays ~t2 ! ~ biHþ=Wþ (i 1⁄4 1, 2). No scheme is found that produces numerically acceptable results over all the parameter space, where problems occur in most cases already for real parameters. Two schemes are identified that show the most robust behavior. A numerical analysis of the four partial stop decay widths is performed in our ‘‘preferred’’ scheme, ‘‘mb, Ab DR.’’ The full one-loop corrections to the corresponding partial decay widths are evaluated, including hard QED and QCD radiation. We find mostly modest corrections at the one-loop level.