The nuclear modification factors of J/ψ and ψ(2S) mesons are measured in PbPb collisions at a centre-of-mass energy per nucleon pair of √s_NN = 5.02 TeV. The analysis is based on PbPb and pp data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464 μb-1 and 28 pb-1, respectively. The measurements are performed in the dimuon rapidity range of | y| < 2.4 as a function of centrality, rapidity, and transverse momentum (p_T) from p_T= 3 GeV/c in the most forward region and up to 50 GeV/c. Both prompt and nonprompt (coming from b hadron decays) J/ψ mesons are observed to be increasingly suppressed with centrality, with a magnitude similar to the one observed at √s_NN = 2.76 TeV for the two J/ψ meson components. No dependence on rapidity is observed for either prompt or nonprompt J/ψ mesons. An indication of a lower prompt J/ψ meson suppression at p_T> 25 GeV/c is seen with respect to that observed at intermediate p_T. The prompt ψ(2S) meson yield is found to be more suppressed than that of the prompt J/ψ mesons in the entire p_T range.

Measurement of prompt and nonprompt charmonium suppression in PbPb collisions at 5.02 TeV

Meridiani P.;Amapane N.;Argiro' S.;Bellan R.;Costa M.;Covarelli R.;Kiani B.;Migliore E.;Monaco V.;Monteil E.;Obertino M. M.;Pacher L.;Pinna Angioni G. L.;Romero A.;Sacchi R.;Sola V.;Solano A.;
2018-01-01

Abstract

The nuclear modification factors of J/ψ and ψ(2S) mesons are measured in PbPb collisions at a centre-of-mass energy per nucleon pair of √s_NN = 5.02 TeV. The analysis is based on PbPb and pp data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464 μb-1 and 28 pb-1, respectively. The measurements are performed in the dimuon rapidity range of | y| < 2.4 as a function of centrality, rapidity, and transverse momentum (p_T) from p_T= 3 GeV/c in the most forward region and up to 50 GeV/c. Both prompt and nonprompt (coming from b hadron decays) J/ψ mesons are observed to be increasingly suppressed with centrality, with a magnitude similar to the one observed at √s_NN = 2.76 TeV for the two J/ψ meson components. No dependence on rapidity is observed for either prompt or nonprompt J/ψ mesons. An indication of a lower prompt J/ψ meson suppression at p_T> 25 GeV/c is seen with respect to that observed at intermediate p_T. The prompt ψ(2S) meson yield is found to be more suppressed than that of the prompt J/ψ mesons in the entire p_T range.
2018
78
509
1
27
http://dx.doi.org/10.1140/epjc/s10052-018-5950-6
LHC, CMS, PbPb collisions, Charmonium suppression
Sirunyan A.M.; Tumasyan A.; Adam W.; Ambrogi F.; Asilar E.; Bergauer T.; Brandstetter J.; Brondolin E.; Dragicevic M.; Ero J.; Del Valle A.E.; Flechl ...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1768647
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