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

Abstract

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.

Comments: 7 pages LaTeX with english text revised, 3 eps-figures, talk given at the Annual Session of Nucl.Phys.Department of RAN (Moscow, Russia, November 16-20,1998)