Factorization and NLO QCD correction in e+ e- → J/ψ(ψ(2S))+ χc₀ at B Factories

الأصل · EN

In nonrelativistic QCD (NRQCD), we study e+ e- → J/ψ(ψ(2S)) +χc₀ at B factories, where the P-wave state χc₀ is associated with an S-wave state J/ψ or ψ(2S). In contrast to the failure of factorization in most cases involving P-wave states, e.g. in B decays, we find that factorization holds in this process at next to leading order (NLO) in αₛ and leading order (LO) in v, where the associated S-wave state plays a crucial rule in canceling the infrared (IR) divergences. We also give some general analyses for factorization in various double charmonium production. The NLO corrections in e+ e- → J/ψ(ψ(2S)) +χc₀ at √s=10.6 GeV are found to substantially enhance the cross sections by a factor of about 2.8; hence crucially reduce the large discrepancy between theory and experiment. With mc=1.5 GeV and μ=2mc, the NLO cross sections are estimated to be 17.9(11.3) fb for e+ e- → J/ψ(ψ(2S))+ χc₀, which reach the lower bounds of experiment.