Search for high-mass dilepton resonances in pp collisions at sqrt(s) = 8 TeV with the ATLAS detector

TL;DR

This paper reports a search for high-mass dilepton resonances at 8 TeV using the ATLAS detector, setting exclusion limits up to around 2.9 TeV for various theoretical models.

Contribution

It provides the first comprehensive search for multiple high-mass resonance models in dilepton channels at 8 TeV with detailed exclusion limits.

Findings

Excluded narrow resonance masses below 2.79 TeV in dielectron channel

Excluded resonance masses below 2.53 TeV in dimuon channel

Set limits on various beyond Standard Model theories

Abstract

The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying to dielectron or dimuon final states. Results are presented from an analysis of proton-proton (pp) collisions at a center-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb-1 in the dielectron channel and 20.5 fb-1 in the dimuon channel. A narrow resonance with Standard Model Z couplings to fermions is excluded at 95% confidence level for masses less than 2.79 TeV in the dielectron channel, 2.53 TeV in the dimuon channel, and 2.90 TeV in the two channels combined. Limits on other model interpretations are also presented, including a grand-unification model based on the E6 gauge group, Z* bosons, Minimal Z' Models, a spin-2 graviton excitation from Randall-Sundrum models, quantum black holes and a Minimal Walking Technicolor model with a composite Higgs boson.