Factorization and NLO QCD correction in e^+ e^- \to J/\psi (\psi(2S))+ \chi_{c0} at B Factories}

Understand

In nonrelativistic QCD (NRQCD), we study $e^+ e^- \to J/\psi(\psi(2S)) +\chi_{c0}$ at $B$ factories, where the P-wave state $\chi_{c0}$ is associated with an S-wave state $J/\psi$ or $\psi(2S)$.

• 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 $\alpha_s$ 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.