A Search for New Physics in the Dilepton Channel with the ATLAS Detector at the LHC

This thesis presents a search for a new, neutral heavy gauge boson decaying to lepton pairs using data from the ATLAS detector at the LHC. This search is performed in two channels, using both electron-pair and muon-pair final states. The results use the full 2012 ATLAS data set from $pp$ated luminosity of 21 fb−1. No statistically significant signal is found, and limits are placed on a variety of Z′ models. A Sequential Standard Model Z′, with identical couplings to fermions as the Standard Model Z0 boson, is excluded at the 95% confidence level for masses lower than 2.79 TeV in the electron channel, 2.53 TeV in the muon channels, and 2.90 TeV with the channels combined. Limits are placed on additional Z′ models based on the grand unification group E6, with lower masses ranging from 2.43 to 2.58 TeV.