Exclusive decay to double at next-to-leading order in

Within the non-relativistic QCD (NRQCD) factorization framework, we calculate the exclusive decay process η_b→J/ψJ/ψ to next-to-leading order in the strong coupling constant, and, at leading order, in the charm quark relative velocity. It is found that this new contribution to the amplitude is comparable in magnitude to the previously calculated relativistic correction piece, but differs by a phase of about 90°. Including this new contribution will increase the previous prediction of substantially, thus brightening the discovery potential of this clean hadronic decay channel of η_b in the forthcoming LHC experiment.