Exclusive ηb decay to double J/ψ at next-to-leading order in αs

Within the non-relativistic QCD (NRQCD) factorization framework, we calculate the exclusive decay process ηb→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 B(ηb→J/ψJ/ψ) substantially, thus brightening the discovery potential of this clean hadronic decay channel of ηb in the forthcoming LHC experiment.