Branching Ratio and direct CP Asymmetry for B to K^(*) γ Decay in MSSM

The present paper deals with a next-to-leading order analysis of the radiative $B \to K^* \gamma$ decay. Working in the PQCD approach developed by Szczepaniak {\it et al.}, we compute the correction, coming from a single gluon exchange with the spectator, to the essential form factor. Since the branching ratio gets much above the experimental data, although in agreement with other theoretical models predictions, we take into consideration the effects of complex flavour couplings in the squark sector. Finally, we discuss these SUSY implications on the branching ratio and direct CP asymmetry values and impose bounds on the squark mixing parameter $(\delta_{23}^d)_{LR}$.