Λ+ c production in pp collisions at √s = 7 TeV and in p-Pb collisions at √sNN = 5.02 TeV

Acharya, S. and Antičić, Tome and Erhardt, Filip and Gotovac, Sven and Jerčić, Marko and Lončar, Petra and Mudnić, Eugen and Planinić, Mirko and Poljak, Nikola and Utrobičić, Antonija and Vicković, Linda and Zou, S. (ALICE Collaboration) (2018) Λ+ c production in pp collisions at √s = 7 TeV and in p-Pb collisions at √sNN = 5.02 TeV. Journal of High Energy Physics, 2018 (4). pp. 108-48. ISSN 1029-8479

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Abstract

The pT-differential production cross section of prompt Λ+ c charmed baryons was measured with the ALICE detector at the Large Hadron Collider (LHC) in pp collisions at √ s = 7 TeV and in p-Pb collisions at √ sNN = 5.02 TeV at midrapidity. The Λ+ c and Λ– c were reconstructed in the hadronic decay modes Λ+ c → pK−π +, Λ+ c → pK0 S and in the semileptonic channel Λ+ c → e +νeΛ (and charge conjugates). The measured values of the Λ + c /D0 ratio, which is sensitive to the c-quark hadronisation mechanism, and in particular to the production of baryons, are presented and are larger than those measured previously in different colliding systems, centre-of-mass energies, rapidity and pT intervals, where the Λ+ c production process may differ. The results are compared with the expectations obtained from perturbative Quantum Chromodynamics calculations and Monte Carlo event generators. Neither perturbative QCD calculations nor Monte Carlo models reproduce the data, indicating that the fragmentation of heavy-flavour baryons is not well understood. The first measurement at the LHC of the Λ+ c nuclear modification factor, RpPb, is also presented. The RpPb is found to be consistent with unity and with that of D mesons within the uncertainties, and consistent with a theoretical calculation that includes cold nuclear matter effects and a calculation that includes charm quark interactions with a deconfined medium.

Item Type: Article
Keywords: Heavy Ion Experiments, Quark gluon plasma
Date: 2018
Subjects: NATURAL SCIENCES > Physics
Additional Information: Open Access, Copyright CERN, for the benefit of the ALICE Collaboration. Article funded by SCOAP3. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0 https://creativecommons.org/licenses/by/4.0/), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. Received: January 11, 2018. Accepted: February 6, 2018. Published: April 18, 2018.
Divisions: Faculty of Science > Department of Physics
Publisher: Springer
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 11 Sep 2018 10:37
Last Modified: 11 Sep 2018 10:37
URI: http://digre.pmf.unizg.hr/id/eprint/5847

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