Next-to-next-to-leading-order QCD corrections to e+e− → J/ψηc at B factories

Abstract

Within the nonrelativistic QCD (NRQCD) factorization framework, we compute the long-awaited O(αs2) corrections for the exclusive double charmonium production process at B factories, i.e., e+e−→J/ψ+ηc at s=10.58 GeV. We confirm that NRQCD factorization does hold at next-to-next-to-leading-order (NNLO) for exclusive double charmonium production. It is found that including the NNLO QCD correction considerably reduces the renormalization scale dependence, and also implies the reasonable perturbative convergence behavior for this process. We also include both O(v2) and O(αsv2) corrections for this process. With all the available corrections lumped together, our most comprehensive prediction is consistent with both the BaBar and Belle measurement within errors.