Prompt double J/psi production in proton-proton collisions at the LHC

Abstract

We provide a detailed study of prompt double J/psi production within the nonrelativistic QCD (NRQCD) framework in proton-proton collisions at the LHC. We confront the recent LHC data with the results obtained at leading order (LO) in the NRQCD framework within two approaches of the collinear factorization and the k(T)-factorization. We show that the LHCb data are consistent with the k(T)-factorized LO NRQCD results. We show that the full LO NRQCD formalism cannot describe the recent CMS data, with about one order of magnitude discrepancy. If the CMS data are confirmed, this indicates rather large higher-order corrections for prompt double J/psi production. We provide various predictions which can further test the NRQCD-based approach at the LHC in a kinematic region that LO contributions dominate. We also investigate long-range in rapidity double J/psi correlations. We found no evidence of a ridge-like structure for double J/psi production in proton-proton collisions at the LHC up to subleading alpha(6)(s) accuracy.