The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sNN=5.02 TeV per nucleon pair, using the decay chain X(3872)→J/ψπ+π-→μ+μ-π+π-. The data were recorded with the CMS detector in 2018 and correspond to an integrated luminosity of 1.7 nb-1. The measurement is performed in the rapidity and transverse momentum ranges |y|<1.6 and 15<50 GeV/c. The significance of the inclusive X(3872) signal is 4.2 standard deviations. The prompt X(3872) to ψ2S yield ratio is found to be ρPb-Pb=1.08±0.49(stat)±0.52(syst), to be compared with typical values of 0.1 for pp collisions. This result provides a unique experimental input to theoretical models of the X(3872) production mechanism, and of the nature of this exotic state.

Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Dragicevic, M., et al. (2022). Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at √sNN =5.02 TeV. PHYSICAL REVIEW LETTERS, 128(3) [10.1103/PhysRevLett.128.032001].

Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at √sNN =5.02 TeV

Ciocci M. A.;Messineo A.;
2022-01-01

Abstract

The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sNN=5.02 TeV per nucleon pair, using the decay chain X(3872)→J/ψπ+π-→μ+μ-π+π-. The data were recorded with the CMS detector in 2018 and correspond to an integrated luminosity of 1.7 nb-1. The measurement is performed in the rapidity and transverse momentum ranges |y|<1.6 and 15<50 GeV/c. The significance of the inclusive X(3872) signal is 4.2 standard deviations. The prompt X(3872) to ψ2S yield ratio is found to be ρPb-Pb=1.08±0.49(stat)±0.52(syst), to be compared with typical values of 0.1 for pp collisions. This result provides a unique experimental input to theoretical models of the X(3872) production mechanism, and of the nature of this exotic state.
2022
Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Dragicevic, M., et al. (2022). Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at √sNN =5.02 TeV. PHYSICAL REVIEW LETTERS, 128(3) [10.1103/PhysRevLett.128.032001].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1327095