QCD corrections to J/psi plus eta_c production in e+e- annihilation at sqrt{s}=10.6 GeV

TL;DR

This work computes the NLO QCD corrections to e+e- -> J/psi + eta_c at sqrt(s) = 10.6 GeV within the NRQCD framework, presenting an independent analytic result obtained with FDC and confirming a K-factor near 2 as reported by previous studies. It carefully handles ultraviolet, infrared, and Coulomb singularities through dimensional regularization and renormalization (OS for charm mass/field and MSbar for αs), isolating Coulomb effects into the bound-state wave function. The study finds that NLO substantially enhances the cross section, reducing part of the discrepancy with Belle/BaBar measurements, but notes that the remaining scale dependence and the need for resummation of ln(s/m_c^2) terms at higher energies call for further refinements, including potential relativistic corrections and log resummation. Overall, the results reinforce NRQCD’s applicability to double charmonium production while highlighting areas for methodological improvement at larger center-of-mass energies.

Abstract

Next-to-Leading-Order(NLO) QCD corrections to J/jpsi plus eta_c production in e+e- annihilation at sqrt{s}=10.6 GeV is calculated in this paper, and an analytic result is obtained. By choosing proper physical parameters, a K factor (ratio of NLO to LO) of about 2, which is in agreement with the result in Ref.\cite{Zhang:2005ch}, is obtained. Our results show that the Next-Next-to-Leading-Order(NNLO) corrections might be quite large. The plot of the K-factor vs the center-of-mass energy sqrt{s} shows that it is more difficult to obtain a convergent result from the perturbative QCD without resummation of ln(s/m_c) terms as the sqrt{s} becomes larger.