Next-to-next-to-leading-order QCD corrections to J/ψ plus ηc production at the B factories

Abstract

In this paper, we calculate the next-to-next-to-leading-order (NNLO) QCD corrections to e+e− → J/ψ + ηc at the B factories. After including the NNLO corrections, the cross section of e+e−→ J/ψ +ηc is enhanced by about 17%, and the perturbative series of the prediction shows the convergent behavior. It is also found that the contributions from bottom quark starts at the {alpha}_s^3 -order, which is about 2.4% of the total prediction. The renormalization scale μR dependence of the cross section is reduced at the NNLO level, but the prediction is sensitive to the charm quark mass mc. By considering the uncertainties caused by renormalization scale μR, charm quark mass mc and the NRQCD factorization scale μΛ, our prediction shows agreement with the BABAR and BELLE measurements within errors.