Heavy-Quark Spin Symmetry Violation effects in Charmed Baryon Production

TL;DR

This paper explores how violations of heavy-quark spin symmetry affect interactions and production rates of charmed baryons, providing theoretical insights crucial for upcoming high-energy experiments.

Contribution

It constructs effective Lagrangians including HQSS violations and computes differential cross-sections for charmed baryon production, enhancing predictive accuracy for experiments.

Findings

Invariant Lagrangian under HQSS couples pseudoscalar D mesons to nucleons and Lambda_c baryons.

Nucleons and Sigma_c baryons couple with vector D mesons, showing symmetry breaking effects.

VHQSS influences the differential cross-sections of charmed baryon production in proton-antiproton collisions.

Abstract

In this work, we investigate the Heavy-Quark Spin Symmetry (HQSS) exhibited in the effective Lagrangians governing the three-point interactions of $D$ mesons, charmed baryons, and nucleons. We first construct the effective Lagrangians, and there are 12 distinct terms. As a result, we observe that the invariant Lagrangian under HQSS manifests exclusively in the pseudoscalar $D$ mesons coupling to nucleons and $\Lambda_c$ baryons, whereas nucleons and $\Sigma_c$ ($\Sigma_c^*$) baryons only couple with vector $D$ mesons. By taking into account the violated heavy-quark spin transformation, one can recover all interactions from the effective Lagrangians. Furthermore, we compute the differential cross-sections of the $p\bar p \to Y_c\bar{Y}_c'$ scatterings, where $Y_c,\bar{Y_c}' = \Lambda_c,~\Sigma_c,~\Sigma_c^*$, to reveal the residue of the violating HQSS (VHQSS) on charmed baryon production. Ultimately, by accounting for VHQSS, we aim for precise predictions of production rates, which are essential for the High-Energy Storage Ring (HESR) experiments at the Facility for Antiproton and Ion Research (FAIR).