Production of charmed baryons in (p)over-barp collisions close to their thresholds

Abstract

Cross sections for the charm-production reactions (p) over barp -> (Lambda) over bar (-)(c)Sigma(+)(c),(Sigma) over bar (c)Sigma(c), (Xi) over tilde (c)Xi(c,)and (Xi) over tilde (c)'Xi(c)' 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 Julich group on the strangeness-production reactions (p) over barp -> (Lambda) over bar Sigma, (Sigma) over bar Sigma, (Xi) over tilde 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* mesons, a charm-production potential derived in a quark model is employed for assessing uncertainties. The cross sections predicted within that picture turn out to be significantly smaller.