Search for direct chargino production in anomaly-mediated supersymmetry breaking models based on a disappearing-track signature in pp collisions at sqrt(s)=7 TeV with the ATLAS detector

TL;DR

This paper searches for long-lived charginos predicted by anomaly-mediated supersymmetry breaking models using disappearing-track signatures in 7 TeV proton-proton collisions at the LHC, finding no excess over Standard Model expectations.

Contribution

It presents the first search for direct chargino production with disappearing tracks in ATLAS data at 7 TeV, setting constraints on chargino properties in these models.

Findings

No significant excess observed over background

Constraints placed on chargino mass and lifetime

Method demonstrates sensitivity to long-lived charged particles

Abstract

A search for direct chargino production in anomaly-mediated supersymmetry breaking scenarios is performed in pp collisions at sqrt(s) = 7 TeV using 4.7 fb^-1 of data collected with the ATLAS experiment at the LHC. In these models, the lightest chargino is predicted to have a lifetime long enough to be detected in the tracking detectors of collider experiments. This analysis explores such models by searching for chargino decays that result in tracks with few associated hits in the outer region of the tracking system. The transverse-momentum spectrum of candidate tracks is found to be consistent with the expectation from the Standard Model background processes and constraints on chargino properties are obtained.