Light Flavor Hadron Production as a Function of Multiplicity in pp Collisions at \(\sqrt{s} = 7\) TeV Measured with ALICE

  • Kishora NayakEmail author
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 203)


Excellent tracking and particle identification (PID) capabilities make ALICE a unique tool for the systematic study of light flavor hadron production over a wide transverse momentum (\(p_{\mathrm {T}}\)) range, spanning three orders of magnitude in the event charged-particle multiplicity in three collision systems, pp, p–Pb, and Pb–Pb. Here, we report recent measurements of \(p_{\mathrm {T}}\)-spectra of non-strange, single strange and multi-strange light flavor hadrons, \(\langle p_{\mathrm {T}} \rangle \), and particle ratios at midrapidity as a function of multiplicity in pp collisions at \(\sqrt{s}\) = 7 TeV. The measurements in high-multiplicity proton-proton (pp) and proton-lead (p–Pb) collisions show features which resemble those of collective effects observed in heavy-ion Pb–Pb collisions. For instance, in the \(p_{\mathrm {T}}\)-differential baryon-to-meson ratios (p/\(\pi \), \(\mathrm {\Lambda }\)/K\(^{0}_{S}\)), an enhancement of baryon production at intermediate \(p_{\mathrm {T}}\) is observed with increasing multiplicity in pp collisions, which are qualitatively similar to earlier measurements in p–Pb and Pb–Pb collisions. Moreover, in the smaller colliding systems like pp and p–Pb, the production rate of strange and multi-strange hadrons relative to pions exhibits a significant increase with multiplicity indicating a similar particle production mechanism. QCD-inspired model calculations are unable to simultaneously describe the observed trends for different particle ratios.


  1. 1.
    V. Khachatryan et al. (CMS Collaboration), JHEP 1009, 091 (2010)Google Scholar
  2. 2.
    G. Aad et al. (ATLAS Collaboration), Phys. Rev. Lett. 116, 172301 (2016)Google Scholar
  3. 3.
    B. Abelev et al. (ALICE Collaboration), Phys. Lett. B 719, 29–41 (2013)Google Scholar
  4. 4.
    G. Aad et al. (ATLAS Collaboration), Phys. Rev. Lett. 110, 182302 (2013)Google Scholar
  5. 5.
    B. Abelev et al. (ALICE Collaboration), Phys. Lett. B 728, 25 (2014)Google Scholar
  6. 6.
    Adam J et al. (ALICE Collaboration), arXiv:1606.07424 (2016)

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.National Institute of Science Education and Research, HBNIJatniIndia

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