Observation of Multiplicity Dependent Prompt <i>χ</i><sub>c1</sub> (3872) and ψ (2<i>S</i>) Production in pp Collisions

Aaij, R, Beteta, C Abellan, Ackernley, T, Adeva, B, Adinolfi, M, Afsharnia, H, Aidala, CA, Aiola, S, Ajaltouni, Z, Akar, S
et al (show 967 more authors) (2021) Observation of Multiplicity Dependent Prompt <i>χ</i><sub>c1</sub> (3872) and ψ (2<i>S</i>) Production in pp Collisions. PHYSICAL REVIEW LETTERS, 126 (9). 092001-.

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The production of χ_{c1}(3872) and ψ(2S) hadrons is studied as a function of charged particle multiplicity in pp collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 2  fb^{-1}. For both states, the fraction that is produced promptly at the collision vertex is found to decrease as charged particle multiplicity increases. The ratio of χ_{c1}(3872) to ψ(2S) cross sections for promptly produced particles is also found to decrease with multiplicity, while no significant dependence on multiplicity is observed for the equivalent ratio of particles produced away from the collision vertex in b-hadron decays. This behavior is consistent with a calculation that models the χ_{c1}(3872) structure as a compact tetraquark. Comparisons with model calculations and implications for the binding energy of the χ_{c1}(3872) state are discussed.

Item Type: Article
Additional Information: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-023.html (LHCb public pages)
Uncontrolled Keywords: LHCb Collaboration
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 21 Apr 2021 10:17
Last Modified: 16 Oct 2023 18:02
DOI: 10.1103/PhysRevLett.126.092001
Open Access URL: https://journals.aps.org/prl/pdf/10.1103/PhysRevLe...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3120039