Vector meson production associated with a lepton pair in $e^+$ $e^-$ annihilation

TL;DR

This paper explores a new QED-based mechanism for producing vector mesons alongside lepton pairs in electron-positron annihilation, predicting observable rates at current collider experiments.

Contribution

It introduces a novel production channel for vector mesons in $e^+e^-$ annihilation, with detailed calculations showing significant rates for experimental detection.

Findings

Production rates are dominated by diagrams with vector meson emission from leptons.

Rates exhibit a $ ext{ln}^2 m_l^2$ enhancement due to collinear lepton emission.

Predicted rates are sufficient for observation at BESIII and Belle II.

Abstract

In this work, we investigate a novel production mechanism of vector mesons, exemplified by the production of a neutral vector meson associated with a lepton pair in $e^+e^-$ annihilation, i.e., $e^+e^-\to V l^+l^-$ ($V=J/\psi, \rho^0, \omega, \phi$, and $l=\mu, \tau$). These vector meson production channels can be precisely accounted within QED. The production rates of these processes are dominated by those diagrams where the vector meson is emitted from either the incident electron or positron, which exhibit a $\ln^2 m_l^2$ enhancement stemming from the triple collinear limit of leptons. Our numerical analysis indicates that the corresponding production rates are substantial enough to warrant the observation of these novel vector meson production channels at BESIII and Belle II experiments in near future.