학술논문

Measurement of the centrality dependence of the charged-particle pseudorapidity distribution in proton–lead collisions at sNN=5.02 TeV with the ATLAS detector
Document Type
article
Source
European Physical Journal C. 76(4)
Subject
Nuclear and Plasma Physics
Particle and High Energy Physics
Synchrotrons and Accelerators
Physical Sciences
ATLAS Collaboration
hep-ex
nucl-ex
Atomic
Molecular
Nuclear
Particle and Plasma Physics
Quantum Physics
Nuclear & Particles Physics
Astronomical sciences
Atomic
molecular and optical physics
Particle and high energy physics
Language
Abstract
The centrality dependence of the mean charged-particle multiplicity as a function of pseudorapidity is measured in approximately 1 [Formula: see text]b[Formula: see text] of proton-lead collisions at a nucleon-nucleon centre-of-mass energy of [Formula: see text] [Formula: see text] 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 [Formula: see text] 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 [Formula: see text] 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 [Formula: see text] collisions.