Search for High-Mass Resonances in the Dilepton Final State with the CMS Detector

TL;DR

This paper reports a search for high-mass dilepton resonances using CMS data at 7 TeV, setting limits on new heavy gauge bosons and gravitons, and excluding certain models below specific mass thresholds.

Contribution

The study provides the first experimental limits on Z' and Kaluza-Klein gravitons at 7 TeV, constraining theoretical models predicting such particles.

Findings

Excluded Z' with SM-like couplings below 1940 GeV

Excluded Z_{psi} below 1620 GeV

Excluded Kaluza-Klein gravitons below 1450-1780 GeV depending on coupling

Abstract

A search for narrow resonances at high mass in the dimuon and dielectron channels has been performed by the CMS experiment at the CERN LHC, using pp collision data recorded at sqrt{s}=7 TeV. The event samples correspond to an integrated luminosity of 1.1 fb^{-1}. Heavy dilepton resonances are predicted in theoretical models with extra gauge bosons (Z') or as Kaluza-Klein graviton excitations (G_{KK}) in the Randall-Sundrum model. Upper limits on the inclusive cross section of Z'(G_{KK}) to l+l- relative to Z to l+l- are presented. These limits exclude at 95 % confidence level a Z' with standard-model-like couplings below 1940 GeV, the superstring-inspired Z_{psi} below 1620 GeV, and, for values of the coupling parameter k/M_{Pl} of 0.05 (0.1), Kaluza--Klein gravitons below 1450 (1780)GeV.