Form Factors and Strong Couplings of Heavy Baryons from QCD Light-Cone Sum Rules

TL;DR

This paper derives QCD light-cone sum rules to calculate form factors and strong couplings of heavy baryons, providing predictions for decay widths and couplings relevant for charm production models.

Contribution

It introduces a method to reduce sensitivity to interpolating current choices and derives new sum rules for heavy baryon transitions and couplings.

Findings

Predicted the $ ext{Λ}_b o p$ form factor.

Calculated decay widths for $ ext{Λ}_b o p ext{l} u_l$ and $ ext{Λ}_b o p ext{π}$.

Derived sum rules for $ ext{Λ}_c ND^{(*)}$ and $ ext{Σ}_c ND^{(*)}$ strong couplings.

Abstract

We derive QCD light-cone sum rules for the hadronic matrix elements of the heavy baryon transitions to nucleon. In the correlation functions the $\Lambda_c,\Sigma_c$ and $\Lambda_b$ -baryons are interpolated by three-quark currents and the nucleon distribution amplitudes are used. To eliminate the contributions of negative parity heavy baryons, we combine the sum rules obtained from different kinematical structures. The results are then less sensitive to the choice of the interpolating current. We predict the $\Lambda_{b}\to p$ form factor and calculate the widths of the $\Lambda_{b}\to p\ell\nu_l$ and $\Lambda_{b}\to p \pi$ decays. Furthermore, we consider double dispersion relations for the same correlation functions and derive the light-cone sum rules for the $\Lambda_cND^{(*)}$ and $\Sigma_cND^{(*)}$ strong couplings. Their predicted values can be used in the models of charm production in $p\bar{p}$ collisions.