  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.
