$J / \psi$ electromagnetic production associated with light hadrons at $B$ factories

TL;DR

This paper calculates electromagnetic production cross sections of J/ψ with light hadrons and leptonic pairs at B factories, comparing theoretical predictions with experimental data to understand production mechanisms.

Contribution

It provides the first detailed calculation of electromagnetic production cross sections of J/ψ associated with light hadrons and leptonic pairs at B factories, including decay contributions.

Findings

Cross sections for J/ψ with light hadrons are about 0.10 pb.

Cross sections for J/ψ with μ+μ− are about 0.056 pb.

The prompt cross section for J/ψ with μ+μ− is about 0.068 pb, covering 16% of Belle data.

Abstract

The electromagnetic productions of $J \psi$ associated with light hadrons(LH) and leptonic pairs($\mu^+\mu^-$, $\tau^+\tau^-$) at $B$ factories are studied. We find that the direct electromagnetic production cross sections of $J / \psi$($\psi(2S)$) associated with light hadrons is about $0.10(0.04)$ pb. The direct production cross sections of $J / \psi$($\psi(2S)$) associated with $\mu^+\mu^-$ is about $0.056(0.020)$ pb. If we include the contributions from $\psi(2S)$ decay, we can get the prompt cross section $\sigma[e^+e^- \to J/\psi +\mu^+\mu^-]=(0.068 \pm 0.002)$ pb, about $(16 \pm 5) %$ of the Belle data $\sigma[e^+e^- \to J/\psi +X_{non-c\bar c}]=(0.43\pm 0.09\pm 0.09)$ pb, meanwhile the $e^+e^- \to J/\psi +\tau^+\tau^-$ process only contributes $2 %$. The prompt cross section $\sigma[e^+e^- \to J/\psi +Light Hadrons]=(0.121 \pm 0.005)$ pb is about $(28 \pm 8) %$ of the Belle data.