The production of χc1(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 χc1(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 χc1(3872) structure as a compact tetraquark. Comparisons with model calculations and implications for the binding energy of the χc1(3872) state are discussed. © 2021 CERN.

Observation of Multiplicity Dependent Prompt χc1 (3872) and ψ (2S) Production in pp Collisions

De Serio, M.;Pappagallo, M.;Simone, S.;
2021-01-01

Abstract

The production of χc1(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 χc1(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 χc1(3872) structure as a compact tetraquark. Comparisons with model calculations and implications for the binding energy of the χc1(3872) state are discussed. © 2021 CERN.
File in questo prodotto:
File Dimensione Formato  
PhysRevLett.126.092001.pdf

accesso aperto

Tipologia: Documento in Versione Editoriale
Licenza: Creative commons
Dimensione 544.53 kB
Formato Adobe PDF
544.53 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11586/379221
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 44
  • ???jsp.display-item.citation.isi??? 35
social impact