Charged particle production in p+Pb collisions with the ATLAS detector

Martin Spousta

doi:10.1016/j.nuclphysa.2014.09.015

Abstract

Abstract We report on the measurements of centrality dependence of the charged particle pseudorapidity distribution and transverse momentum distributions in proton–lead collisions with the ATLAS detector at LHC. The data were collected in 2012 run providing proton–nucleus collisions at s NN = 5.02 TeV . These measurements are expected to contribute to understanding the initial state of the nuclear wave function. The presented results also point to the importance of understanding the fluctuating nature of the nucleon–nucleon collisions.

Highlights

Nuclear modification factors in p+Pb collisions – measured for pT = 0.1– 22 GeV, η = -2.5 –2.5, y* = -2– 2.5 – trends: increase between 0.1–2 GeV, decrease up to 8 GeV, plateau – magnitude of the peak increases with centrality and from p-going to Pb-going direction – magnitude of the peak strongly depends on the choice of geometric model
Charged particle multiplicity in p+Pb collisions – measured for |η| highly asymmetric shape in central – central to peripheral ratio linear with a slope strongly dependent on centrality – multiplicity per participant pair strongly depends on the geometric model
Multiplicity for different modelsE.g. allows for possible variation in effective acceptance of FCal due to Npartdependent backward shift