Charged-particle pseudorapidity density at mid-rapidity in p-Pb collisions at root S-NN=8.16 TeV

0504296 - ÚJF 2020 RIV US eng J - Journal Article
Acharya, S. - Acosta, F. T. - Adamová, Dagmar - Bielčík, J. - Bielčíková, Jana - Broz, M. - Contreras, J. G. - Křížková Gajdošová, K. - Horák, D. - Křížek, Filip - Kučera, Vít - Kushpil, Svetlana - Lavička, R. - Mareš, Jiří A. - Petráček, V. - Šafařík, K. - Šumbera, Michal - Závada, Petr … Total 1009 authors
Charged-particle pseudorapidity density at mid-rapidity in p-Pb collisions at root S-NN=8.16 TeV.
European Physical Journal C. Roč. 79, č. 4 (2019), č. článku 307. ISSN 1434-6044. E-ISSN 1434-6052
R&D Projects: GA MŠMT(CZ) LTT17018
Research Infrastructure: CERN-CZ - 90058
Institutional support: RVO:68378271 ; RVO:61389005
Keywords : ALICE collaboration * heavy ion collisions * nucleon-nucleon
OECD category: Nuclear physics; Particles and field physics (FZU-D)
Impact factor: 4.389, year: 2019
Method of publishing: Open access
https://doi.org/10.1140/epjc/s10052-019-6801-9

The pseudorapidity density of charged particles, dN(ch)/d eta, in p-Pb collisions has been measured at a centre of-mass energy per nucleon-nucleon pair of root S-NN = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, vertical bar eta vertical bar < 1.8. The dN(ch)/d eta value is 19.1 +/- 0.7 at vertical bar eta vertical bar < 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 root S-NN = 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 dN(ch)/d eta distribution. Saturation-based models reproduce the distributions well for eta > -1.3. The dN(ch)/d eta 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.
Permanent Link: http://hdl.handle.net/11104/0295963