"The 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 root s(NN) = 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. DOI: 10.1103\/PhysRevLett.110.022301"
Aad, G., Abajyan, T., Abbott, B., Abdallah, J., Khalek, S.a., Abdelalim, A.a., et al. (2013). Measurement of Z Boson Production in Pb-Pb Collisions at root s(NN)=2.76 TeV with the ATLAS Detector. PHYSICAL REVIEW LETTERS, 110(2), 1-18 [10.1103/PhysRevLett.110.022301].