Study of J/ψ meson production inside jets in pp collisions at s=8TeV

Abstract A study of the production of prompt J / ψ mesons contained in jets in proton-proton collisions at s = 8 TeV is presented. The analysis is based on data corresponding to an integrated luminosity of 19.1 fb−1 collected with the CMS detector at the LHC. For events with at least one observed jet, the angular separation between the J / ψ meson and the jet is used to test whether the J / ψ meson is part of the jet. The analysis shows that most prompt J / ψ mesons having energy above 15 GeV and rapidity | y | 1 are contained in jets with pseudorapidity | η jet | 1 . The differential distributions of the probability to have a J / ψ meson contained in a jet as a function of jet energy for a fixed J / ψ energy fraction are compared to a theoretical model using the fragmenting jet function approach. The data agree best with fragmenting jet function calculations that use a long-distance matrix element parameter set in which prompt J / ψ mesons are predicted to be unpolarized. This technique demonstrates a new way to test predictions for prompt J / ψ production using nonrelativistic quantum chromodynamics.