Charge asymmetries for D, ${\rm D_s}$ and $\Lambda_{\rm c}$ production in $\sigma^-$-nucleus interactions at 340 GeV/c

Abstract.

CERN experiment WA89 has studied charmed particles produced by a $\Sigma^-$ beam at 340 GeV/c on nuclear targets. Production of particles which have light quarks in common with the beam is compared to production of those which do not. Considerable production asymmetries between $\mathrm{D}^-$ and $\mathrm{D}^+$, $\mathrm{D}_\mathrm{s}^-$ and $\mathrm{D}_\mathrm{s}^+$ and $\Lambda_\mathrm c$ and $\bar{\Lambda_\mathrm c}$ are observed. The results are compared with pion beam data and with theoretical calculations.