Electroweak corrections to neutralino and chargino decays into a W-boson in the (N)MSSM

We present the complete electroweak one-loop corrections to the partial widths for two-body decays of a chargino (neutralino) into a W-boson and a neutralino (chargino). We perform the calculation for the minimal and the next-to-minimal supersymmetric standard model using an on-shell renormalization scheme. Particular attention is paid to the question of gauge invariance which is achieved using the so-called pinch technique. Furthermore we show that these corrections show a strong parameter dependence and usually are in the range of 1-10 percent if the neutralino involved is a higgsino- or wino-like state. However, in case of a bino-like or a singlino-like neutralino the corrections can go up to 50% and more. Moreover we present the public program CNNDecays performing these calculations. (C) 2011 Elsevier B.V. All rights reserved.