Leading Effects in the Spectra of Λc\Lambda_c and Λˉc\bar{\Lambda}_c Produced in Σ−p\Sigma^-p, pppp and π−p\pi^-p Interactions

The spectra of leading and nonleading charmed baryons ($\Lambda_c$ and $\bar{\Lambda}_c$) as well as the asymmetries between these spectra measured in $\Sigma^-A$, $\pi^-A$ and pA collisions at $p_L= 600 GeV/c$ in the E781 experiment are simultaneously described within the framework of Quark-Gluon String Model (QGSM). It is shown that the charmed baryon spectra can be fitted by QGSM curves calculated with the parameter of diquark fragmentation, $a_f^{\Lambda_c}$=0.006. It was obtained in this experiment that the asymmetry between the spectra of $\Lambda_c$ and $\bar{\Lambda}_c$ in $\pi^-A$ collisions is of nonzero value. It might be described in our model only assuming that the string junction is transfered from target proton into the kinematical region of pion projectile fragmentation.Comment: LaTeX, 12 pages, 2 epsfigures, replaced with the minor corrections in language and in references, submitted to Phys.At.Nucl. 200

Asymmetry in Charmed Particles Production in Σ−\Sigma^{-} beam

We present the calculation of the inclusive $x_F$-distributions of charmed hadrons, produced in high-energy $\Sigma^-$-beam. The calculation is based on the modified mechanism of charmed quarks fragmentation as well as on the mechanism of $c$-quark recombination with the valence quarks from initial hadrons. We predict the additional asymmetry in the production of charmed hadrons due to the different distributions of the valence s and d quarks in $\Sigma^-$-beam.Comment: 19 pages, Latex, 6 figure