Exclusive $eta_b$ decay to double $J/\psi$ at next-to-leading order in $alpha_s$

TL;DR

This paper calculates the exclusive decay of ta_b to double J/ at next-to-leading order in lpha_s within the NRQCD framework, significantly enhancing the predicted branching ratio and aiding future experimental detection.

Contribution

It introduces the next-to-leading order calculation of ta_b d7 J/ J/ decay, revealing a substantial increase in predicted decay rate.

Findings

Next-to-leading order contribution is comparable to relativistic correction.

New amplitude contribution differs by about 90b0 in phase.

Predicted branching ratio for ta_b d7 J/ J/ decay is substantially increased.

Abstract

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