Angular distributions in $J/\psi\to p\bar{p}\pi^{0}(\eta)$ decays

TL;DR

This paper calculates angular distributions in specific $J/ar{J}$ decays near the $par{p}$ threshold using an optical potential model, predicting observable anisotropies due to tensor forces.

Contribution

It introduces a model-based calculation of angular distributions in $J/ar{J}$ decays, highlighting the impact of tensor forces on anisotropy near the $par{p}$ threshold.

Findings

The $par{p}$ invariant mass spectra agree with experimental data.

Predicted large anisotropy in angular distributions due to tensor forces.

Model provides a testable prediction for future experiments.

Abstract

The differential decay rates of the processes $J/\psi\to p\bar{p}\pi^{0}$ and $J/\psi\to p\bar{p}\eta$ close to the $p\bar{p}$ threshold are calculated with the help of the $N\bar{N}$ optical potential. The same calculations are made for the decays of $\psi(2S)$. We use the potential which has been suggested to fit the cross sections of $N\bar{N}$ scattering together with $N\bar{N}$ and six pion production in $e^{+}e^{-}$ annihilation close to the $p\bar{p}$ threshold. The $p\bar{p}$ invariant mass spectra is in agreement with the available experimental data. The anisotropy of the angular distributions, which appears due to the tensor forces in the $N\bar{N}$ interaction, is predicted close to the $p\bar{p}$ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of $N\bar{N}$ interaction.