Production of charmed baryons in $\bar{p}p$ collisions close to their thresholds

Abstract

Cross sections for the charm-production reactions $\bar{p}p\to {\bar{\Lambda }}_c^{-}{\Sigma }_c^{+}$, ${\bar{\Sigma }}_c{\Sigma }_c$, ${\bar{\Xi }}_c{\Xi }_c$, and ${\bar{\Xi }}_c^{\prime }{\Xi }_c^{\prime }$ are presented, for energies near their respective thresholds. The results are based on a calculation performed in the meson-exchange framework in close analogy to earlier studies of the Jülich group on the strangeness-production reactions $\bar{p}p\to \bar{\Lambda }\Sigma$, $\bar{\Sigma }\Sigma$, $\bar{\Xi }\Xi$ by connecting the two sectors via SU(4) flavor symmetry. The cross sections are found to be in the order of $0.1-1$ $\mu b$ at energies of $100$ MeV above the respective thresholds, for all considered channels. Complementary to meson-exchange, where the charmed baryons are produced by the exchange of $D$ and $D^{\ast }$ mesons, a charm-production potential derived in a quark model is employed for assessing uncertainties. The cross sections predicted within that picture turned out to be significantly smaller.

Comments: 17 pages, 7 figures