Stochastic acceleration in accreting black holes

We present an extension of the BELM code (Belmont et al 2008) to investigate the microphysics of particle acceleration in black holes accretion disc corona. The updated version of the code accounts for the dynamics of resonant slab waves as well as their interaction with both leptons or protons. It is found that the proton temperature is an important regulating effect of the stochastic particle acceleration process in accretion disk corona. We present a preliminary fit of the high soft spectral state of Cygnus X-1.