A search for supersymmetric particle production in a photon, b-jet and ETmiss final state is conducted using 20.3 fb-1 of proton-proton collision data collected by the ATLAS detector at a
center-of-mass energy of
√ s
= 8 TeV at the LHC in 2012.
Two signal regions are defined, with one geared toward high-mass gluino production decaying to a moderate-to-high-mass neutralino and the other geared toward direct gaugino production.
Several variables are optimized for sensitivity to the targeted scenario, including photon pT, ETmiss, Njets, and Nb-jets, among others.
The Standard Model contribution is estimated using data-driven methods, and no significant excess above Standard Model expectations is observed in either of the signal regions.
In one signal region, a total of 12 candidate events are observed while 18.8 ± 5.3 events are expected from Standard Model backgrounds.
In the other signal region, a total of 2 candidate events are observed while 3.63 ± 1.25 events are expected from Standard Model backgrounds.
The result of this analysis is interpreted in a general gauge mediation framework with a lightest neutralino that is a mixture of bino and higgsino.
Limits are set in a 2D plane of gluino mass vs neutralino mass.
Neutralino masses between 150 GeV and 450 GeV are excluded at 95% CL for all gluino masses,
and gluino masses up to at least 1200 GeV (and up to 1350 GeV in some cases) are excluded at 95% CL for neutralino masses between 450 GeV and 50 GeV less than the gluino mass.