Çakır, OrhanÇiftçi, Abbas KenanÇiftçi, RenaYıldız (Duran), HaticeKuday, Sinan2020-03-152020-03-152013022301https://doi.org/10.1103/PhysRevLett.110.022301http://hdl.handle.net/20.500.12575/70578The ATLAS experiment has observed 1995 Z boson candidates in data corresponding to 0:15 nb-1 of integrated luminosity obtained in the 2011 LHC Pb + Pb run at √SNN = 2.76 TeV. The Z bosons are reconstructed via dielectron and dimuon decay channels, with a background contamination of less than 3%. Results from the two channels are consistent and are combined. Within the statistical and systematic uncertainties, the per-event Z boson yield is proportional to the number of binary collisions estimated by the Glauber model. The elliptic anisotropy of the azimuthal distribution of the Z boson with respect to the event plane is found to be consistent with zero. © 2013 CERN.enArticle1102022301-1022301-180031-90071079-7114