Search for long-lived, heavy particles in final states with a muon and multi-track displaced vertex in proton-proton collisions at √s = 7 TeV with the ATLAS detector

ATLAS COLLABORATION, G. AAD, F. MONTICELLI, ET AL

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2013 vol. 110 p. 1 - 18

0031-9007

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 √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.