Perturbative QCD Analysis of Exclusive Processes $e^+e^-\rightarrow VP$ and $e^+e^-\rightarrow TP$

TL;DR

This paper uses perturbative QCD with $k_T$ factorization to analyze exclusive $e^+e^-$ annihilation into meson pairs, predicting cross sections and invariant mass dependence, with results aligning with experimental data and testable at BESIII and Belle-II.

Contribution

It provides a detailed perturbative QCD analysis of $e^+e^- o VP$ and $TP$ processes, including allowed channels and cross section predictions at specific energies.

Findings

Cross sections follow a $1/s^4$ power law with invariant mass.

Most theoretical results agree with existing experimental data.

Predictions can be tested at BESIII and Belle-II.

Abstract

We study the $e^+e^-\to VP$ and $e^+e^-\to TP$ processes in the perturbative QCD approach based on $k_T$ factorization, where the $P,V$ and $T$ denotes a light pseudo-scalar, vector and tensor meson, respectively. We point out in the case of $e^+e^-\to TP$ transition due to charge conjugation invariance, only three channels are allowed: $e^+e^-\to a_2^{\pm} \pi^\mp$, $e^+e^-\to K_2^{*\pm} K^\mp$ and the V-spin suppressed $e^+e^-\to K_2^{*0} \bar K^0+\overline K_2^{*0} K^0 $. Cross sections of $e^+e^-\to VP$ and $e^+e^-\to TP$ at $\sqrt{s}=3.67$ GeV and $\sqrt{s}=10.58$ GeV are calculated and the invariant mass dependence is found to favor the $1/s^4$ power law. Most of our theoretical results are consistent with the available experimental data and other predictions can be tested at the ongoing BESIII and forthcoming Belle-II experiments.