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. . ., 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. . ., 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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