A description of charmonia decays $J/\psi \rightarrow B\bar B$ within the QCD factorisation framework

TL;DR

This paper analyzes $J/\psi$ decays into baryon-antibaryon pairs using QCD factorisation, including next-to-leading power corrections and electromagnetic interference, achieving about 20% accuracy in branching fractions and angular coefficients.

Contribution

First calculation of next-to-leading power corrections in $J/\psi \to B\bar B$ decays within the QCD factorisation framework, demonstrating its effectiveness.

Findings

Branching fractions and angular coefficients are described with ~20% accuracy.

QCD factorisation provides a dominant contribution to decay amplitudes.

Inclusion of electromagnetic interference improves phenomenological description.

Abstract

Decays $J/\psi\to B\bar B$ into octet baryon-antibaryons pairs are studied within the QCD factorisation framework. The next-to-leading power correction to the leading-order decay amplitude is calculated for the first time. The phenomenological analysis also includes the interference with the electromagnetic decay $J/\psi\to \gamma^*\to B\bar B$. The branching fractions and the angular coefficients $\alpha_B$ are described with an accuracy of about $20\%$. The obtained results allow us to conclude that the calculated amplitudes provide a dominant contribution and therefore QCD factorisation provides a suitable basis for understanding of these decays.