Speaker
Description
The production of J/ψ mesons in hadron-hadron collisions occurs at the transition between the perturbative and non-perturbative regimes of quantum chromodynamics, resulting in a rich phenomenology that is yet to be fully understood.
LHCb studied the production of J/ψ mesons in jets in the forward region of proton-proton collisions at a center-of-mass energy of 13 TeV. The fraction of the jet transverse momentum carried by the J/ψ meson, z(J/ψ ) ≡ pT (J/ψ )/pT (jet), is measured using jets with pT (jet) > 20 GeV in the pseudorapidity range 2.5 < η(jet) < 4.0. The observed z(J/ψ ) distribution for
J/ψ mesons produced in b-hadron decays is consistent with expectations. However, the results for prompt J/ψ production do not agree with predictions based on fixed-order non-relativistic QCD. This is the first measurement of the pT fraction carried by prompt J/ψ mesons in jets at any experiment.
