Gluino two-body decays at full one-loop level in the MSSM with quark-flavour violation

Abstract

We study the two-body decays of the gluino at full one-loop level in the Minimal Supersymmetric Standard Model with quark-flavour violation (QFV) in the squark sector. The renormalization is done in the DRbar scheme and hard gluon and photon radiations are included by adding the corresponding three-body decay widths. In the numerics the dependence of the gluino decay widths on the QFV parameters is discussed with special emphasis put on the separation of the electroweak and the SUSY QCD corrections. The main dependence stems from the $\tilde c_R - \tilde t_R$ mixing in the decays to up-type squarks because there hold strong constraints from B-physics on the other quark-flavour mixing parameters. Including the full one-loop corrections, the changes of the gluino decay widths are mostly negative and of the order of about -10\%. The QFV part stays small in the total width but can vary up to -8\% for the decay width into the lightest squark. For the corresponding branching ratio, however, the effect is smaller by at least a factor of two. The electroweak corrections can become 35\% of the SUSY QCD corrections.