This paper reports the measurement of J/psi meson production in proton–proton (pp) and proton–lead (pPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV by the CMS experiment at the LHC. The data samples used in the analysis correspond to integrated luminosities of 28 pb−1 and 35 nb−1 for pp and pPb collisions, respectively. Prompt and nonprompt J/psi mesons, the latter produced in the decay of B hadrons, are measured in their dimuon decay channels. Differential cross sections are measured in the transverse momentum range of 2 < pT < 30 GeV/c, and center-of-mass rapidity ranges of |yCM| < 2.4 (pp) and −2.87 < yCM < 1.93 (pPb). The nuclear modification factor, RpPb, is measured as a function of both pT and yCM. Small modifications to the J/psi cross sections are observed in pPb relative to pp collisions. The ratio of J/ψ production cross sections in p-going and Pb-going directions, RFB, studied as functions of pT and yCM, shows a significant decrease for increasing transverse energy deposited at large pseudorapidities. These results, which cover a wide kinematic range, provide new insight on the role of cold nuclear matter effects on prompt and nonprompt J/psi production.
Measurement of prompt and nonprompt J/psi production in pp and p Pb collisions at sqrt(s_NN)=5.02TeV
Amapane, N.;Argiro, S.;Bellan, R.;Costa, M.;Covarelli, R.;Kiani, B.;Migliore, E.;Monaco, V.;Monteil, E.;Obertino, M. M.;Pacher, L.;Ravera, F.;Romero, A.;Sacchi, R.;Sola, V.;Solano, A.;
2017-01-01
Abstract
This paper reports the measurement of J/psi meson production in proton–proton (pp) and proton–lead (pPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV by the CMS experiment at the LHC. The data samples used in the analysis correspond to integrated luminosities of 28 pb−1 and 35 nb−1 for pp and pPb collisions, respectively. Prompt and nonprompt J/psi mesons, the latter produced in the decay of B hadrons, are measured in their dimuon decay channels. Differential cross sections are measured in the transverse momentum range of 2 < pT < 30 GeV/c, and center-of-mass rapidity ranges of |yCM| < 2.4 (pp) and −2.87 < yCM < 1.93 (pPb). The nuclear modification factor, RpPb, is measured as a function of both pT and yCM. Small modifications to the J/psi cross sections are observed in pPb relative to pp collisions. The ratio of J/ψ production cross sections in p-going and Pb-going directions, RFB, studied as functions of pT and yCM, shows a significant decrease for increasing transverse energy deposited at large pseudorapidities. These results, which cover a wide kinematic range, provide new insight on the role of cold nuclear matter effects on prompt and nonprompt J/psi production.File | Dimensione | Formato | |
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