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Advances in High Energy Physics
Volume 2019, Article ID 4604608, 7 pages
Research Article

Out-Of-Equilibrium Transverse Momentum Spectra of Pions at LHC Energies

1Nile University, Egyptian Center for Theoretical Physics, Juhayna Square of 26th-July-Corridor, 12588 Giza, Egypt
2World Laboratory for Cosmology And Particle Physics (WLCAPP), 11571 Cairo, Egypt

Correspondence should be addressed to Abdel Nasser Tawfik; ge.ude.un@kifwata

Received 9 March 2019; Revised 10 May 2019; Accepted 20 May 2019; Published 2 June 2019

Guest Editor: Sakina Fakhraddin

Copyright © 2019 Abdel Nasser Tawfik. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In order to characterize the transverse momentum spectra () of positive pions measured in the ALICE experiment, two thermal approaches are utilized; one is based on degeneracy of nonperfect Bose-Einstein gas and the other imposes an ad hoc finite pion chemical potential. The inclusion of missing hadron states and the out-of-equilibrium contribute greatly to the excellent characterization of pion production. An excellent reproduction of these -spectra is achieved at GeV and this covers the entire range of . The excellent agreement with the experimental results can be understood as a manifestation of not-yet-regarded anomalous pion production, which likely contributes to the long-standing debate on “anomalous” proton-to-pion ratios at top RHIC and LHC energies.