UC Santa Cruz

A search for supersymmetric particle production in a photon, b-jet and E_T^miss 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 p_T, E_T^miss, N_jets, and N_b-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.