Search for an excess of events with an identical flavour lepton pair and significant missing transverse momentum in sqrt{s} = 7 TeV proton-proton collisions with the ATLAS detector

TL;DR

This paper reports a search for supersymmetric particles in proton-proton collisions at 7 TeV, focusing on events with two identical flavor leptons and missing transverse momentum, but finds no evidence of new physics.

Contribution

It introduces a novel search strategy for supersymmetric particles using flavor correlation and missing energy in 7 TeV collision data, setting new exclusion limits.

Findings

No excess beyond Standard Model expectations was observed.

Model-independent limits were established on new physics contributions.

Excluded regions of supersymmetric parameter space based on the data.

Abstract

Results are presented of a search for supersymmetric particles decaying into final states with significant missing transverse momentum and exactly two identical flavour leptons (e or mu) of opposite charge in sqrt{s}=7 TeV collisions at the Large Hadron Collider. This channel is particularly sensitive to supersymmetric particle cascade decays producing flavour correlated lepton pairs. Flavour uncorrelated backgrounds are subtracted using a sample of opposite flavour lepton pair events. Observation of an excess beyond Standard Model expectations following this subtraction procedure would offer one of the best routes to measuring the masses of supersymmetric particles. In a data sample corresponding to an integrated luminosity of 35 pb-1 no such excess is observed. Model-independent limits are set on the contribution to these final states from new physics and are used to exclude regions of a phenomenological supersymmetric parameter space.