/ hep-ex CERN-PH-EP-2015-160

Measurement of the centrality dependence of the charged-particle pseudorapidity distribution in proton--lead collisions at $\sqrt{s_{_{\rm{NN}}}} = 5.02$ TeV with the ATLAS detector

Pages: 28

Abstract: The centrality dependence of the mean charged-particle multiplicity as a function of pseudorapidity is measured in approximately 1 $\mu$b$^{-1}$ of proton--lead collisions at a nucleon--nucleon centre-of-mass energy of $\sqrt{s_{_{\rm{NN}}}} = 5.02$ TeV using the ATLAS detector at the Large Hadron Collider. Charged particles with absolute pseudorapidity less than 2.7 are reconstructed using the ATLAS pixel detector. The $p$+Pb collision centrality is characterised by the total transverse energy measured in the Pb-going direction of the forward calorimeter. The charged-particle pseudorapidity distributions are found to vary strongly with centrality, with an increasing asymmetry between the proton-going and Pb-going directions as the collisions become more central. Three different estimations of the number of nucleons participating in the $p$+Pb collision have been carried out using the Glauber model as well as two Glauber--Gribov inspired extensions to the Glauber model. Charged-particle multiplicities per participant pair are found to vary differently for these three models, highlighting the importance of including colour fluctuations in nucleon--nucleon collisions in the modelling of the initial state of $p$+Pb collisions.

Note: 28 pages plus author list + cover pages (46 pages total), 14 figures, 4 tables, submitted to EPJC, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2012-15/

Total numbers of views: 457
Numbers of unique views: 273
Запись создана 2015-08-31, последняя модификация 2015-08-31

Внешняя ссылка:

Полный текст
Оценить этот документ:

1
2
3

(Еще не рецензированная)