Is the colour-octet mechanism consistent with the double $J/\psi$ production measurement at B-factories?

TL;DR

This paper evaluates the contribution of colour-octet channels to double $J/$ production at B-factories and finds it negligible, aligning with experimental measurements.

Contribution

It provides a detailed calculation of colour-octet contributions to double $J/$ production, showing they are much smaller than colour-singlet contributions.

Findings

Colour-octet contributions are negligible compared to colour-singlet.

Predicted cross sections are consistent with Belle and BABAR measurements.

Double $J/$ production is dominated by colour-singlet mechanisms.

Abstract

Double $J/\psi$ production in $e^+e^-$ collisions involving colour-octet channels are evaluated up to order $\alpha^2\alpha_s^3$. Having implemented the variation of the parameters ($m_c$, $\mu_r$ and long-distance matrix elements), we found that the cross sections for producing double $J/\psi$ at B-factories range from $-0.016$fb to $0.245$fb, which are even much smaller than that via the colour-siglet mechanism. Accordingly, this result is consistent with the measurement by the Belle and BABAR Collaborations.