Search for new phenomena in the WW to l nu l' nu' final state in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper reports a search for heavy particles decaying into WW pairs in proton-proton collisions at 7 TeV, setting limits on new physics models and constraining graviton masses using ATLAS data.

Contribution

The study provides the first limits on Randall-Sundrum graviton production in WW final states at 7 TeV using ATLAS data.

Findings

No significant excess observed over Standard Model predictions.

Set 95% CL lower mass limits of 1.23 TeV and 0.84 TeV for two graviton models.

Constrained parameter space for theories predicting heavy resonances decaying to WW.

Abstract

This Letter reports a search for a heavy particle that decays to WW using events produced in pp collisions at sqrt(s) = 7 TeV. The data were recorded in 2011 by the ATLAS detector and correspond to an integrated luminosity of 4.7 fb-1. WW to l nu l' nu'(l, l' = e or mu) final states are considered and the distribution of the transverse mass of the WW candidates is found to be consistent with Standard Model expectations. Upper limits on the production cross section times branching ratio into W boson pairs are set for Randall-Sundrum and bulk Randall-Sundrum gravitons, which result in observed 95% CL lower limits on the masses of the two particles of 1.23 TeV and 0.84 TeV, respectively.