Some recent progress in understanding exclusive double charmonium production at $B$ factories

Abstract

We review some recent progress in understanding various exclusive double charmonium production processes at $B$ factories, within the nonrelativistic QCD factorization framework. First we investigate the impact of the joint perturbative and relativistic correction on the process that has attracted a great amount of attention in the past decade, $e^{+}{e}^{-}\to J/\psi +{\eta }_c$. We then briefly discuss the phenomenological implication of the next-to-leading order perturbative correction to the processes $e^{+}{e}^{-}\to J/\psi +{\chi }_{c0,1,2}({\eta }_{c2})$. We further emphasize a novel theoretical challenge, which is recently discovered by applying the NRQCD factorization approach to the helicity-suppressed hard exclusive reactions involving heavy quarkonium.

Comments: 9 pages, 2 figures, 1 table. Talk given by Y. J. at the Xth Quark Confinement and the Hadron Spectrum, 8-12 October 2012, TUM Campus Garching, Munich, Germany