Exclusive charm production in pbar p collisions at s^1/2 <15 GeV

TL;DR

This paper investigates open charm production in proton-antiproton collisions at energies below 15 GeV, using a topological approach to estimate cross sections and spin asymmetries relevant for FAIR experiments.

Contribution

It introduces a topological decomposition method to estimate meson and baryon exchange trajectories and predicts polarization observables for open charm production at FAIR energies.

Findings

Predicted cross sections for exclusive charm production reactions.

Calculated longitudinal double-spin asymmetries with non-trivial t and s dependence.

Provided estimates consistent with SU(4) symmetry and existing strangeness production data.

Abstract

We discuss the open charm production in peripheral reactions $\bar pp\to \bar Y_cY_c$ and $\bar pp\to M_c\bar M_c$, where $Y_c$ and $M_c$ stand for $\Lambda_c^+,\Sigma_c^+$ and $D,D^*$, respectively, at $\sqrt{s}\lesssim 15$ GeV, which corresponds to the energy range of FAIR. Our consideration is based on the topological decomposition of the planar quark and diquark diagrams which allows to estimate consistently meson and baryon exchange trajectories and energy scale parameters as well. The spin dependence is determined by the effective interaction of lowest exchanged resonance. Unknown parameters are fixed by an independent analysis of open strangeness production in $\bar pp\to \bar YY$ and $\bar pp\to \bar KK$ reactions and of SU(4) symmetry. We present the corresponding cross sections and longitudinal double-spin asymmetries for exclusive binary reactions with open charm mesons and baryons in the final state. The polarization observables have a non-trivial $t$ and $s$ dependence which is sensitive to details of the open charm production mechanism.