Leading/nonleading charm production asymmetry in $\Sigma^-p$ interactions

The asymmetries between the spectra of leading and nonleading charmed mesons measured in $\Sigma^-A$ interactions at $p_L$= 340 GeV/c in the WA89 experiment are described in the framework of Quark-Gluon String Model. There are two versions of the model under consideration: one of them includes the sea charm quark-antiquark pairs and the other one does not. It's shown that the asymmetries between $D^-$ and $D^+$-meson spectra and between $D_s^-$ and $D^+_s$- meson spectra can be fitted by QGSM curves obtained with the same parameters as charm asymmetry in $\pi^-A$ experiments described in previous studies. The QGSM results are compared with the calculations in the next-to-leading approximation of perturbative QCD approach carried out by the other authors.