Search for long-lived charginos in anomaly-mediated supersymmetry breaking scenarios with the ATLAS detector using 4.7 fb-1 data of pp collisions at sort(s) = 7 TeV

In anomaly-mediated supersymmetry breaking (AMSB) scenarios, a lightest chargino is predicted to have a lifetime long enough to be detected in collider experiments. This note presents an updated search for disappearing tracks resulting from decaying charginos in pp collisions at sqrt(s) = 7 TeV. The search is based on data corresponding to an integrated luminosity of 4.71 fb-1 collected with the ATLAS detector in 2011. The pT spectrum of candidate tracks is found to be consistent with the expectation from background processes and constraints on the lifetime and the production cross section are obtained. In the minimal AMSB framework with m3/2 < 32 TeV, m0 < 1.5 TeV, tan(beta) = 5 and mu > 0, a chargino having a mass below 90 GeV and a lifetime between 0.2 ns and 90 ns is excluded at 95% confidence level. The result also gives a new constraint for a chargino having a mass up to 118 GeV.