Further studies on the exclusive productions of J/psi +chi _{cJ} (J=0,1,2) via e^+e^- annihilation at the B factories

Abstract

By including the interference effect between the QCD and the QED diagrams, we carry out a complete analysis on the exclusive productions of e^+e^- rightarrow J/psi +chi _{cJ} (J=0,1,2) at the B factories with sqrt{s}=10.6 GeV at the next-to-leading-order (NLO) level in alpha _s, within the nonrelativistic QCD framework. It is found that the {mathcal {O}} (alpha ^3alpha _s)-order terms that represent the tree-level interference are comparable with the usual NLO QCD corrections, especially for the chi _{c1} and chi _{c2} cases. To explore the effect of the higher-order terms, namely {mathcal {O}} (alpha ^3alpha _s^2), we perform the QCD corrections to these {mathcal {O}} (alpha ^3alpha _s)-order terms for the first time, which are found to be able to significantly influence the {mathcal {O}} (alpha ^3alpha _s)-order results. In particular, in the case of chi _{c1} and chi _{c2}, the newly calculated {mathcal {O}} (alpha ^3alpha _s^2)-order terms can to a large extent counteract the {mathcal {O}} (alpha ^3alpha _s) contributions, evidently indicating the indispensability of the corrections. In addition, we find that, as the collision energy rises, the percentage of the interference effect in the total cross section will increase rapidly, especially for the chi _{c1} case.