Multiplicity dependence of light-flavor hadron production in pp collisions at s =7 TeV

ALICE Collaboration

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Comprehensive results on the production of unidentified charged particles, π±, K±, KS0, K∗(892)0, p, p, φ(1020), Λ, Λ, Ξ-, Ξ+, Ω-, and Ω+ hadrons in proton-proton (pp) collisions at s=7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid autocorrelation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle-to-pion ratios are shown to depend solely on charged-particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at Large Hadron Collider energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions.

Original languageEnglish (US)
Article number024906
JournalPhysical Review C
Volume99
Issue number2
DOIs
StatePublished - Feb 8 2019

Fingerprint

collisions
protons
charged particles
pions
hadrons
strangeness
inelastic collisions
transverse momentum
autocorrelation
generators
quantum chromodynamics
hydrodynamics
energy
augmentation
predictions

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics

Cite this

Multiplicity dependence of light-flavor hadron production in pp collisions at s =7 TeV. / ALICE Collaboration.

In: Physical Review C, Vol. 99, No. 2, 024906, 08.02.2019.

Research output: Contribution to journalArticle

@article{6fe4b5f3a60d45198c9f286213cecd1b,
title = "Multiplicity dependence of light-flavor hadron production in pp collisions at s =7 TeV",
abstract = "Comprehensive results on the production of unidentified charged particles, π±, K±, KS0, K∗(892)0, p, p, φ(1020), Λ, Λ, Ξ-, Ξ+, Ω-, and Ω+ hadrons in proton-proton (pp) collisions at s=7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid autocorrelation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle-to-pion ratios are shown to depend solely on charged-particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at Large Hadron Collider energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions.",
author = "{ALICE Collaboration} and S. Acharya and Acosta, {F. T.} and D. Adamov{\'a} and A. Adler and J. Adolfsson and Aggarwal, {M. M.} and {Aglieri Rinella}, G. and M. Agnello and N. Agrawal and Z. Ahammed and Ahn, {S. U.} and S. Aiola and A. Akindinov and M. Al-Turany and Alam, {S. N.} and Albuquerque, {D. S.D.} and D. Aleksandrov and B. Alessandro and Alfanda, {H. M.} and {Alfaro Molina}, R. and Y. Ali and A. Alici and A. Alkin and J. Alme and T. Alt and L. Altenkamper and I. Altsybeev and Anaam, {M. N.} and C. Andrei and D. Andreou and Andrews, {H. A.} and A. Andronic and M. Angeletti and V. Anguelov and C. Anson and T. Antičić and F. Antinori and P. Antonioli and R. Anwar and N. Apadula and L. Aphecetche and H. Appelsh{\"a}user and S. Arcelli and R. Arnaldi and Arsene, {I. C.} and M. Arslandok and A. Augustinus and R. Averbeck and Azmi, {M. D.} and Seger, {Janet E.}",
year = "2019",
month = "2",
day = "8",
doi = "10.1103/PhysRevC.99.024906",
language = "English (US)",
volume = "99",
journal = "Physical Review C",
issn = "2469-9985",
publisher = "American Physical Society",
number = "2",

}

TY - JOUR

T1 - Multiplicity dependence of light-flavor hadron production in pp collisions at s =7 TeV

AU - ALICE Collaboration

AU - Acharya, S.

AU - Acosta, F. T.

AU - Adamová, D.

AU - Adler, A.

AU - Adolfsson, J.

AU - Aggarwal, M. M.

AU - Aglieri Rinella, G.

AU - Agnello, M.

AU - Agrawal, N.

AU - Ahammed, Z.

AU - Ahn, S. U.

AU - Aiola, S.

AU - Akindinov, A.

AU - Al-Turany, M.

AU - Alam, S. N.

AU - Albuquerque, D. S.D.

AU - Aleksandrov, D.

AU - Alessandro, B.

AU - Alfanda, H. M.

AU - Alfaro Molina, R.

AU - Ali, Y.

AU - Alici, A.

AU - Alkin, A.

AU - Alme, J.

AU - Alt, T.

AU - Altenkamper, L.

AU - Altsybeev, I.

AU - Anaam, M. N.

AU - Andrei, C.

AU - Andreou, D.

AU - Andrews, H. A.

AU - Andronic, A.

AU - Angeletti, M.

AU - Anguelov, V.

AU - Anson, C.

AU - Antičić, T.

AU - Antinori, F.

AU - Antonioli, P.

AU - Anwar, R.

AU - Apadula, N.

AU - Aphecetche, L.

AU - Appelshäuser, H.

AU - Arcelli, S.

AU - Arnaldi, R.

AU - Arsene, I. C.

AU - Arslandok, M.

AU - Augustinus, A.

AU - Averbeck, R.

AU - Azmi, M. D.

AU - Seger, Janet E.

PY - 2019/2/8

Y1 - 2019/2/8

N2 - Comprehensive results on the production of unidentified charged particles, π±, K±, KS0, K∗(892)0, p, p, φ(1020), Λ, Λ, Ξ-, Ξ+, Ω-, and Ω+ hadrons in proton-proton (pp) collisions at s=7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid autocorrelation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle-to-pion ratios are shown to depend solely on charged-particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at Large Hadron Collider energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions.

AB - Comprehensive results on the production of unidentified charged particles, π±, K±, KS0, K∗(892)0, p, p, φ(1020), Λ, Λ, Ξ-, Ξ+, Ω-, and Ω+ hadrons in proton-proton (pp) collisions at s=7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid autocorrelation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle-to-pion ratios are shown to depend solely on charged-particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at Large Hadron Collider energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions.

UR - http://www.scopus.com/inward/record.url?scp=85061298690&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85061298690&partnerID=8YFLogxK

U2 - 10.1103/PhysRevC.99.024906

DO - 10.1103/PhysRevC.99.024906

M3 - Article

AN - SCOPUS:85061298690

VL - 99

JO - Physical Review C

JF - Physical Review C

SN - 2469-9985

IS - 2

M1 - 024906

ER -