The fraction of χc1 and χc2 decays in the prompt J/ψ yield, F_{χc→J/ψ} = σ_{χc→J/ψ}/σ_{J/ψ}, is measured by the LHCb detector in p Pb collisions at √s_NN = 8.16 TeV. The study covers the forward (1.5 < y* < 4.0) and backward (−5.0 < y* < −2.5) rapidity regions, where y* is the J/ψ rapidity in the nucleon-nucleon center-of-mass system. Forward and backward rapidity samples correspond to integrated luminosities of 13.6 ± 0.3 nb^−1 and 20.8 ± 0.5 nb^−1, respectively. The result is presented as a function of the J/ψ transverse momentum p_{T,J/ψ} in the range 1 < p_{T,J/ψ} < 20 GeV/c. The F_{χc→J/ψ} fraction at forward rapidity is compatible with the LHCb measurement performed in pp collisions at √s = 7 TeV, whereas the result at backward rapidity is 2.4 σ larger than in the forward region for 1 < p_{T,J/ψ} < 3 GeV/c. The increase of F_{χc→J/ψ} at low p_{T,J/ψ} at backward rapidity is compatible with the suppression of the ψ(2S) contribution to the prompt J/ψ yield. The lack of in-medium dissociation of χc states observed in this study sets an upper limit of 180 MeV on the free energy available in these p Pb collisions to dissociate or inhibit charmonium state formation.

Aaij, R., Abdelmotteleb, A. S. W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2024). Fraction of χc Decays in Prompt J/ψ Production Measured in p Pb Collisions at √s_NN = 8.16 TeV. PHYSICAL REVIEW LETTERS, 132(10), 1-12 [10.1103/physrevlett.132.102302].

Fraction of χc Decays in Prompt J/ψ Production Measured in p Pb Collisions at √s_NN = 8.16 TeV

Carbone, A.;Ferrari, F.;Galli, D.;Patrignani, C.;Spedicato, E.;Villa, A.;
2024

Abstract

The fraction of χc1 and χc2 decays in the prompt J/ψ yield, F_{χc→J/ψ} = σ_{χc→J/ψ}/σ_{J/ψ}, is measured by the LHCb detector in p Pb collisions at √s_NN = 8.16 TeV. The study covers the forward (1.5 < y* < 4.0) and backward (−5.0 < y* < −2.5) rapidity regions, where y* is the J/ψ rapidity in the nucleon-nucleon center-of-mass system. Forward and backward rapidity samples correspond to integrated luminosities of 13.6 ± 0.3 nb^−1 and 20.8 ± 0.5 nb^−1, respectively. The result is presented as a function of the J/ψ transverse momentum p_{T,J/ψ} in the range 1 < p_{T,J/ψ} < 20 GeV/c. The F_{χc→J/ψ} fraction at forward rapidity is compatible with the LHCb measurement performed in pp collisions at √s = 7 TeV, whereas the result at backward rapidity is 2.4 σ larger than in the forward region for 1 < p_{T,J/ψ} < 3 GeV/c. The increase of F_{χc→J/ψ} at low p_{T,J/ψ} at backward rapidity is compatible with the suppression of the ψ(2S) contribution to the prompt J/ψ yield. The lack of in-medium dissociation of χc states observed in this study sets an upper limit of 180 MeV on the free energy available in these p Pb collisions to dissociate or inhibit charmonium state formation.
2024
Aaij, R., Abdelmotteleb, A. S. W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2024). Fraction of χc Decays in Prompt J/ψ Production Measured in p Pb Collisions at √s_NN = 8.16 TeV. PHYSICAL REVIEW LETTERS, 132(10), 1-12 [10.1103/physrevlett.132.102302].
Aaij, R.; Abdelmotteleb, A.  S.  W.; Abellan Beteta, C.; Abudinén, F.; Ackernley, T.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Agapopoulou, C.; Aidala, ...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1002013
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