CMS-PAS-BPH-15-003

CMS-PAS-BPH-15-003
Measurements of correlations between J/ $\psi$ mesons and jets produced in $\sqrt{s}=$ 8 TeV pp collisions
CMS Collaboration
May 2019

Abstract: A study of the production of J/ $\psi$ mesons in conjunction with jets in pp collisions at $\sqrt{s} =$ 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/ $\psi$ meson and the jet is used to test whether the J/ $\psi$ meson is a jet fragment. The differential distributions of jet fragmentation probability as a function of jet energy for a fixed J/ $\psi$ energy fraction $z$ are presented. The experimental results are compared to a theoretical model using the fragmenting jet function (FJF) approach. The J/ $\psi$ jet fragmentation data agree with the predictions of the FJF calculations that use specific long-distance matrix element parameters. This agreement shows that the combination of data on jet fragmentation to J/ $\psi$ mesons and FJF analysis is a new way to test predictions for charmonium production from nonrelativistic quantum chromodynamics and to evaluate long-distance matrix element parameter sets. The analysis also shows that most J/ $\psi$ mesons with energy above 15 GeV and rapidity $\|y\| <$ 1.0 are fragments of jets with pseudorapidity $\|\eta_{\mathrm{jet}}\| <$ 1.
Links: CDS record (PDF) ; inSPIRE record ; HepData record ; CADI line (restricted) ; These preliminary results are superseded in this paper, PLB 804 (2020) 135409. The superseded preliminary plots can be found here.

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