Multiplicity dependence of light-flavor hadron production in pp collisions at √s = 7 TeV

Scientific paper - Original scientific paper

• Author: S. Acharya
• Author: ...
• Author: Tome Antičić; MBZ: 218816
• Author: ...
• Author: Filip Erhardt; MBZ: 345132
• Author: ...
• Author: Sven Gotovac; MBZ: 108173
• Author: ...
• Author: Marko Jerčić; MBZ: 358125
• Author: ...
• Author: Petra Lončar; MBZ: 350591
• Author: ...
• Author: Eugen Mudnić; MBZ: 248856
• Author: ...
• Author: Mirko Planinić; MBZ: 213776
• Author: ...
• Author: Nikola Poljak; MBZ: 283732
• Author: ...
• Author: Goran Simatović; MBZ: 329845
• Author: ...
• Author: Antonija Utrobičić; MBZ: 342963
• Author: ...
• Author: Linda Vicković; MBZ: 242565
• Author: ...
• Author: J. Zmeskal
• Collaboration: ALICE Collaboration
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Comprehensive results on the production of unidentified charged particles, π±, K±, KS0, K* (892)0, p, p¯, ϕ(1020), Λ, Λ¯, Ξ−, Ξ¯+, Ω−, and Ω¯+ hadrons in proton-proton (pp) collisions at s=7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid autocorrelation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle-to-pion ratios are shown to depend solely on charged- particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at Large Hadron Collider energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions.

• Keywords (english): multiplicity: dependence; hadron: production; pp: scattering; charged particle: multiplicity; charged particle: density; model: hydrodynamics; rapidity: difference; particle: spectrum; heavy ion: scattering; strangeness: parton; transverse momentum; CERN LHC Coll; Monte Carlo; collective; 7000 GeV-cms/nucleon
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C
• Numbering: vol. 99, no. 2, 024906
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/physrevc.99.024906
• URN:NBN: urn:nbn:hr:217:001484
• Publication: 2019
• Document URL: https://link.aps.org/doi/10.1103/PhysRevC.99.024906
• Type of resource: Text
• Access conditions: Open access
• Public note: Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Received 2 August 2018; published 8 February 2019.
• Created on: 2020-08-21 16:42:22