Charm-quark fragmentation fractions and production cross section at midrapidity in pp collisions at the LHC

Scientific paper - Letter

• Author: S. Acharya
• Author: ...
• Author: Filip Erhardt
• Author: ...
• Author: Sven Gotovac
• Author: ...
• Author: Marko Jerčić
• Author: ...
• Author: David Karatović
• Author: ...
• Author: Petra Lončar
• Author: ...
• Author: Eugen Mudnić
• Author: ...
• Author: Mirko Planinić
• Author: ...
• Author: Nikola Poljak
• Author: ...
• Author: Linda Vicković
• Author: ...
• Author: N. Zurlo
• 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)

Recent pT-integrated cross-section measurements of the ground-state charm mesons and baryons, D0, D+, Ds+, Λc+, and Ξc0, are used to evaluate the charm fragmentation fractions and production cross section per unit of rapidity at midrapidity (|y|<0.5), in pp collisions at s=5.02 TeV at the LHC. The latter is dσcc¯/dy||y|<0.5=1165±44(stat)-101+134(syst) μb. These measurements were obtained for the first time in hadronic collisions at the LHC, including the charm baryon states, recently measured by ALICE at midrapidity. The charm fragmentation fractions differ significantly from the values measured in e+e- and ep collisions, providing evidence of the dependence of the parton-to-hadron fragmentation fractions on the collision system, indicating that the assumption of their universality is not supported by the measured cross sections. An increase of a factor of about 3.3 for the fragmentation fraction for the Λc+ with a significance of 5σ between the values obtained in pp collisions and those obtained in e+e- (ep) collisions is reported. The fragmentation fraction for the Ξc0 was obtained for the first time in any collision system. The measured fragmentation fractions were used to update the cc¯ cross sections per unit of rapidity at |y|<0.5 at √s=2.76 and 7 TeV, which are about 40% higher than the previously published results. The data were compared with perturbative-QCD calculations and lie at the upper edge of the theoretical bands.

• Keywords (english): charm: fragmentation; p p: scattering; electron p: interaction; charm: ground state; quantum chromodynamics: perturbation theory; cross section: measured; hadron hadron: interaction; CERN LHC Coll; rapidity; ALICE; experimental results; 2760 GeV-cms/nucleon; 5020 GeV-cms/nucleon; 7000 GeV-cms/nucleon
• Language: english
• Publication type: Scientific paper - Letter
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review D
• Numbering: vol. 105, no. 1, L011103
• p-ISSN: 2470-0010
• e-ISSN: 2470-0029
• DOI: https://doi.org/10.1103/PhysRevD.105.L011103
• URN:NBN: urn:nbn:hr:217:902268
• Publication: 2022
• Document URL: https://link.aps.org/doi/10.1103/PhysRevD.105.L011103
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2022 CERN, for the ALICE Collaboration. 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 2021; accepted 16 December 2021; published 12 January 2022.
• Created on: 2024-09-01 12:26:06