Revisiting the production of J /ψ + ηc via the e+ e- annihilation within the QCD light-cone sum rules

We make a detailed study on the typical production channel of double charmoniums, e(+)e(-) -> J / psi + eta(c), at the center-of-mass collision energy root s = 10.58 GeV. The key component of the process is the form factor F (VP)(q(2)), which has been calculated within the QCD light-cone sum rules (LCSR). To improve the accuracy of the derived LCSR, we keep the J / psi light-cone distribution amplitude up to twist-4 accuracy. Total cross sections for e(+)e(-) -> J / psi + eta(c) at three typical factorization scales are sigma vertical bar(mu s) = 22.53(-3.49)(+3.46) fb, sigma vertical bar(mu k) = 21.98(-3.38)(+3.35)( )fb, and sigma vertical bar(mu 0) = 21.74(-3.33)(+3.29) fb, respectively. The factorization scale dependence is small, and those predictions are consistent with the BABAR and Belle measurements within errors.

Automated summary

A detailed study was conducted on the production channel of double charmoniums, with calculations of form factor and total cross sections showing consistency with experimental measurements. The factorization scale dependence was found to be small, indicating the accuracy of the predictions.