pT spectra in pp and AA collisions at RHIC and LHC energies using the Tsallis-Weibull approach

  • Sadhana Dash
  • D. P. Mahapatra
Regular Article - Theoretical Physics


The Tsallis q -statistics have been incorporated in the Weibull model of particle production, in the form of q-Weibull distribution, to describe the transverse momentum (\(p_{T}\)) distribution of charged hadrons at mid-rapidity, measured at RHIC and LHC energies. The q-Weibull distribution is found to describe the observed \( p_{T}\) distributions over all ranges of measured \( p_{T}\). Below 2.2 GeV/c, while going from peripheral to central collisions, the parameter q is found to decrease systematically towards unity, indicating an evolution from a non-equilibrated system in peripheral collisions, towards a more thermalized system in central collisions. However, the trend is reversed in the all inclusive \( p_{T}\) regime. This can be attributed to an increase in relative contribution of hard pQCD processes in central collisions. The \( \lambda\)-parameter is found to be associated with the mean \( p_{T}\) or the collective expansion velocity of the produced hadrons, which shows an expected increase with centrality of collisions. The k parameter is observed to increase with the onset of hard QCD scatterings, initial fluctuations, and other processes leading to non-equilibrium conditions.


  1. 1.
    STAR Collaboration (J. Adams et al.), Nucl. Phys. A 757, 102 (2005)ADSCrossRefGoogle Scholar
  2. 2.
    PHENIX Collaboration (K. Adcox et al.), Nucl. Phys. A 757, 184 (2005)ADSCrossRefGoogle Scholar
  3. 3.
    E. Schnedermann, J. Sollfrank, U.W. Heinz, Phys. Rev. C 48, 2462 (1993)ADSCrossRefGoogle Scholar
  4. 4.
    G. Wilk, Z. Wlodarczyk, Phys. Rev. Lett. 84, 2770 (2000)ADSCrossRefGoogle Scholar
  5. 5.
    A. Dumitru, F. Gelis, L. McLerran, R. Venugopalan, Nucl. Phys. A 810, 91 (2008)ADSCrossRefGoogle Scholar
  6. 6.
    S. Gavin, L. McLerran, G. Moschelli, Phys. Rev. C 79, 051902 (2009)ADSCrossRefGoogle Scholar
  7. 7.
    Liang He, Terrence Edmonds, Zi-Wei Lin, Feng Liu, Denes Molnar, Fuqiang Wang, Phys. Lett. B 753, 506 (2016)ADSCrossRefGoogle Scholar
  8. 8.
    Hanlin Li, Liang He, Zi-Wei Lin, Denes Molnar, Fuqiang Wang, Wei Xi, Phys. Rev. C 93, 051901(R) (2016)ADSCrossRefGoogle Scholar
  9. 9.
    C. Tsallis, J. Stat. Phys. 52, 479 (1988)ADSCrossRefGoogle Scholar
  10. 10.
    T. Osada, G. Wilk, Phys. Rev. C 77, 044903 (2008)ADSCrossRefGoogle Scholar
  11. 11.
    Zebo Tang, Yichun Xu, Lijuan Ruan, Gene van Buren, Fuqiang Wang, Zhangbu Xu, Phys. Rev. C 79, 051901(R) (2009)ADSCrossRefGoogle Scholar
  12. 12.
    Kun Jiang, Yinying Zhu, Weitao Liu, Hongfang Chen, Cheng Li, Lijuan Ruan, Zebo Tang, Zhangbu Xu, Phys. Rev. C 91, 024910 (2015)ADSCrossRefGoogle Scholar
  13. 13.
    P.K. Khandai, P. Sett, P. Shukla, V. Singh, J. Phys. G 41, 025105 (2014)ADSCrossRefGoogle Scholar
  14. 14.
    W.K. Brown, K.H. Wohletz, J. Appl. Phys. 78, 2758 (1995)ADSCrossRefGoogle Scholar
  15. 15.
    W.K. Brown, J. Astrophys. Astron. 10, 89 (1989)ADSCrossRefGoogle Scholar
  16. 16.
    S. Dash, B.K. Nandi, P. Sett, Phys. Rev. D 93, 114022 (2016)ADSCrossRefGoogle Scholar
  17. 17.
    S. Dash, B.K. Nandi, P. Sett, Phys. Rev. D 94, 074044 (2016)ADSCrossRefGoogle Scholar
  18. 18.
    Nirbhay K. Behera, S. Dash, B. Naik, Basanta K. Nandi, Tanmay Pani, arXiv:1610.02419v1 (2016)Google Scholar
  19. 19.
    S. Picoli jr., R.S. Mendes, L.C. Malacarne, Physica A 324, 678 (2003)ADSMathSciNetCrossRefGoogle Scholar
  20. 20.
    S. Picoli jr., R.S. Mendes, L.C. Malacarne, R.P.B Santos, Braz. J. Phys. 39, 468 (2009)ADSCrossRefGoogle Scholar
  21. 21.
    M.D. Azmi, J. Cleymans, J. Phys. G 41, 065001 (2014)ADSCrossRefGoogle Scholar
  22. 22.
    J. Cleymans, G.I. Lykasov, A.S. Parvan, A.S. Sorin, O.V. Teryaev, D. Worku, Phys. Lett. B 723, 351 (2013)ADSCrossRefGoogle Scholar
  23. 23.
    UA1 Collaboration (C. Albajar et al.), Nucl. Phys. B 335, 261 (1990)ADSCrossRefGoogle Scholar
  24. 24.
    ALICE Collaboration (B. Abelev et al.), Eur. Phys. J. C 73, 2662 (2013)ADSCrossRefGoogle Scholar
  25. 25.
    ALICE Collaboration (B. Abelev et al.), Phys. Rev. Lett. 110, 082302 (2013)ADSCrossRefGoogle Scholar
  26. 26.
    ALICE Collaboration (B. Abelev et al.), Phys. Lett. B 720, 52 (2013)ADSCrossRefGoogle Scholar
  27. 27.
    PHENIX Collaboration (S.S. Adler et al.), Phys. Rev. C 69, 034910 (2004)CrossRefGoogle Scholar

Copyright information

© SIF, Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Indian Institute of Technology BombayMumbaiIndia
  2. 2.Utkal University, Department of PhysicsBhubaneswarIndia

Personalised recommendations