TY - JOUR
T1 - Centrality dependence of the pseudorapidity density distribution for charged particles in Pb-Pb collisions at root s(NN)=2.76 TeV
AU - Abbas, E.
AU - Abelev, B.
AU - Adam, J.
AU - Adamova, D.
AU - Adare, A.M.
AU - Bearden, Ian
AU - Bilandzic, Ante
AU - Bøggild, Hans
AU - Christensen, Christian Holm
AU - Dalsgaard, Hans Hjersing
AU - Gulbrandsen, Kristjan Herlache
AU - Gaardhøje, Jens Jørgen
AU - Hansen, Alexander Colliander
AU - Nielsen, Børge Svane
AU - Nygaard, Casper
AU - Søgaard, Carsten
PY - 2013/11/4
Y1 - 2013/11/4
N2 - We present the first wide-range measurement of the charged-particle pseudorapidity density distribution, for different centralities (the 0-5%, 5-10%, 10-20%, and 20-30% most central events) in Pb-Pb collisions at sNN=2.76TeV at the LHC. The measurement is performed using the full coverage of the ALICE detectors, -5.0<η<5.5, and employing a special analysis technique based on collisions arising from LHC 'satellite' bunches. We present the pseudorapidity density as a function of the number of participating nucleons as well as an extrapolation to the total number of produced charged particles (Nch=17165±772 for the 0-5% most central collisions). From the measured dNch/dη distribution we derive the rapidity density distribution, dNch/dy, under simple assumptions. The rapidity density distribution is found to be significantly wider than the predictions of the Landau model. We assess the validity of longitudinal scaling by comparing to lower energy results from RHIC. Finally the mechanisms of the underlying particle production are discussed based on a comparison with various theoretical models.
AB - We present the first wide-range measurement of the charged-particle pseudorapidity density distribution, for different centralities (the 0-5%, 5-10%, 10-20%, and 20-30% most central events) in Pb-Pb collisions at sNN=2.76TeV at the LHC. The measurement is performed using the full coverage of the ALICE detectors, -5.0<η<5.5, and employing a special analysis technique based on collisions arising from LHC 'satellite' bunches. We present the pseudorapidity density as a function of the number of participating nucleons as well as an extrapolation to the total number of produced charged particles (Nch=17165±772 for the 0-5% most central collisions). From the measured dNch/dη distribution we derive the rapidity density distribution, dNch/dy, under simple assumptions. The rapidity density distribution is found to be significantly wider than the predictions of the Landau model. We assess the validity of longitudinal scaling by comparing to lower energy results from RHIC. Finally the mechanisms of the underlying particle production are discussed based on a comparison with various theoretical models.
U2 - 10.1016/j.physletb.2013.09.022
DO - 10.1016/j.physletb.2013.09.022
M3 - Journal article
SN - 0370-2693
VL - 726
SP - 610
EP - 622
JO - Physics Letters B: Particle Physics, Nuclear Physics and Cosmology
JF - Physics Letters B: Particle Physics, Nuclear Physics and Cosmology
IS - 4-5
ER -