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Charged-particle pseudorapidity density at mid-rapidity in p–Pb collisions at √sNN = 8.16 TeV

Acharya, S ; Adolfsson, Jonatan LU ; Christiansen, Peter LU ; Ljunggren, Martin LU ; Nassirpour, Adrian LU orcid ; Oskarsson, Anders LU ; Richert, Tuva LU ; Silvermyr, David LU orcid ; Stenlund, Evert LU and Zurlo, N (2019) In European Physical Journal C 79(4).
Abstract
The pseudorapidity density of charged particles, d N ch / d η, in p–Pb collisions has been measured at a centre-of-mass energy per nucleon–nucleon pair of sNN = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, | η| < 1.8. The d N ch / d η value is 19.1 ± 0.7 at | η| < 0.5. This quantity divided by ⟨ N part ⟩ / 2 is 4.73 ± 0.20 , where ⟨ N part ⟩ is the average number of participating nucleons, is 9.5% higher than the corresponding value for p–Pb collisions at sNN = 5.02 TeV. Measurements are compared with models based on different mechanisms for particle production. All models agree within uncertainties with data in the Pb-going side, while HIJING overestimates, showing... (More)
The pseudorapidity density of charged particles, d N ch / d η, in p–Pb collisions has been measured at a centre-of-mass energy per nucleon–nucleon pair of sNN = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, | η| < 1.8. The d N ch / d η value is 19.1 ± 0.7 at | η| < 0.5. This quantity divided by ⟨ N part ⟩ / 2 is 4.73 ± 0.20 , where ⟨ N part ⟩ is the average number of participating nucleons, is 9.5% higher than the corresponding value for p–Pb collisions at sNN = 5.02 TeV. Measurements are compared with models based on different mechanisms for particle production. All models agree within uncertainties with data in the Pb-going side, while HIJING overestimates, showing a symmetric behaviour, and EPOS underestimates the p-going side of the d N ch / d η distribution. Saturation-based models reproduce the distributions well for η> - 1.3. The d N ch / d η is also measured for different centrality estimators, based both on the charged-particle multiplicity and on the energy deposited in the Zero-Degree Calorimeters. A study of the implications of the large multiplicity fluctuations due to the small number of participants for systems like p–Pb in the centrality calculation for multiplicity-based estimators is discussed, demonstrating the advantages of determining the centrality with energy deposited near beam rapidity. © 2019, CERN for the benefit of the ALICE collaboration. (Less)
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author
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author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
European Physical Journal C
volume
79
issue
4
article number
307
publisher
Springer
external identifiers
  • scopus:85064051779
ISSN
1434-6044
DOI
10.1140/epjc/s10052-019-6801-9
language
English
LU publication?
yes
additional info
Export Date: 26 April 2019
id
5fa04b10-3a22-455f-9e6c-2c9f8734488d
date added to LUP
2019-04-26 12:49:12
date last changed
2023-04-09 08:44:01
@article{5fa04b10-3a22-455f-9e6c-2c9f8734488d,
  abstract     = {{The pseudorapidity density of charged particles, d N ch / d η, in p–Pb collisions has been measured at a centre-of-mass energy per nucleon–nucleon pair of sNN = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, | η| &lt; 1.8. The d N ch / d η value is 19.1 ± 0.7 at | η| &lt; 0.5. This quantity divided by ⟨ N part ⟩ / 2 is 4.73 ± 0.20 , where ⟨ N part ⟩ is the average number of participating nucleons, is 9.5% higher than the corresponding value for p–Pb collisions at sNN = 5.02 TeV. Measurements are compared with models based on different mechanisms for particle production. All models agree within uncertainties with data in the Pb-going side, while HIJING overestimates, showing a symmetric behaviour, and EPOS underestimates the p-going side of the d N ch / d η distribution. Saturation-based models reproduce the distributions well for η&gt; - 1.3. The d N ch / d η is also measured for different centrality estimators, based both on the charged-particle multiplicity and on the energy deposited in the Zero-Degree Calorimeters. A study of the implications of the large multiplicity fluctuations due to the small number of participants for systems like p–Pb in the centrality calculation for multiplicity-based estimators is discussed, demonstrating the advantages of determining the centrality with energy deposited near beam rapidity. © 2019, CERN for the benefit of the ALICE collaboration.}},
  author       = {{Acharya, S and Adolfsson, Jonatan and Christiansen, Peter and Ljunggren, Martin and Nassirpour, Adrian and Oskarsson, Anders and Richert, Tuva and Silvermyr, David and Stenlund, Evert and Zurlo, N}},
  issn         = {{1434-6044}},
  language     = {{eng}},
  number       = {{4}},
  publisher    = {{Springer}},
  series       = {{European Physical Journal C}},
  title        = {{Charged-particle pseudorapidity density at mid-rapidity in p–Pb collisions at √sNN = 8.16 TeV}},
  url          = {{http://dx.doi.org/10.1140/epjc/s10052-019-6801-9}},
  doi          = {{10.1140/epjc/s10052-019-6801-9}},
  volume       = {{79}},
  year         = {{2019}},
}