A study of relativistic corrections to $ J/\psi\rightarrow p\bar{p}$ decay

TL;DR

This paper investigates relativistic effects in the decay of $J/ar{J}$ into proton-antiproton pairs, revealing significant corrections that influence decay amplitude calculations beyond leading order.

Contribution

It introduces a calculation of relativistic corrections in charmonium decay using NRQCD and light-cone distribution amplitudes, demonstrating the validity of collinear factorisation beyond leading order.

Findings

Relativistic corrections of order $v^2$ have a large numerical impact.

Collinear factorisation remains valid beyond leading order in this context.

NRQCD corrections depend solely on nucleon twist-3 light-cone distribution amplitudes.

Abstract

We study relativistic corrections in exclusive $S$-wave charmonium decays into proton-antiproton final state. We calculate the NRQCD corrections to the dominant decay amplitude, which depend on the nucleon twist-3 light-cone distribution amplitudes only. It is shown that in this case the collinear factorisation is also valid beyond the leading-order approximation. Our numerical estimates show that relativistic correction of relative order $v^2$ provides large numerical impact.