Charged-particle spectra obtained in Pb+Pb interactions at (Formula presented.) and pp interactions at (Formula presented.) with the ATLAS detector at the LHC are presented, using data with integrated luminosities of 0.15 nb<sup>−1</sup> and 4.2 pb<sup>−1</sup>, respectively, in a wide transverse momentum (0.5 < p<inf>T</inf>< 150 GeV) and pseudorapidity (|η| < 2) range. For Pb+Pb collisions, the spectra are presented as a function of collision centrality, which is determined by the response of the forward calorimeters located on both sides of the interaction point. The nuclear modification factors R<inf>AA</inf> and R<inf>CP</inf> are presented in detail as a function of centrality, p<inf>T</inf> and η. They show a distinct p<inf>T</inf>-dependence with a pronounced minimum at about 7 GeV. Above 60 GeV, R<inf>AA</inf> is consistent with a plateau at a centrality-dependent value, within the uncertainties. The value is 0.55 ± 0.01(stat.) ± 0.04(syst.) in the most central collisions. The R<inf>AA</inf> distribution is consistent with flat |η| dependence over the whole transverse momentum range in all centrality classes.
Measurement of charged-particle spectra in Pb+Pb collisions at (Formula presented.) = 2.76 TeV with the ATLAS detector at the LHC
CONVENTI, Francesco Alessandro;DI DONATO, CAMILLA;ROSSI, Elvira;
2015-01-01
Abstract
Charged-particle spectra obtained in Pb+Pb interactions at (Formula presented.) and pp interactions at (Formula presented.) with the ATLAS detector at the LHC are presented, using data with integrated luminosities of 0.15 nb−1 and 4.2 pb−1, respectively, in a wide transverse momentum (0.5 < pI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.