The Status of GMSB After 1/fb at the LHC

Abstract

We thoroughly investigate the current status of supersymmetry in light of the latest searches at the LHC, using General Gauge Mediation (GGM) as a well-motivated signature generator that leads to many different simplified models. We consider all possible promptly-decaying NLSPs in GGM, and by carefully reinterpreting the existing LHC searches, we derive limits on both colored and electroweak SUSY production. Overall, the coverage of GGM parameter space is quite good, but much discovery potential still remains even at 7 TeV. We identify several regions of parameter space where the current searches are the weakest, typically in models with electroweak production, third generation sfermions or squeezed spectra, and we suggest how ATLAS and CMS might modify their search strategies given the understanding of GMSB at 1/fb. In particular, we propose the use of leptonic $M_{T2}$ to suppress $t{\bar t}$ backgrounds. Because we express our results in terms of simplified models, they have broader applicability beyond the GGM framework, and give a global view of the current LHC reach. Our results on 3rd generation squark NLSPs in particular can be viewed as setting direct limits on naturalness.

Figures (19)

• Figure 1: Schematic Feynman diagram for a GMSB event. The typical production will be of colored superpartners, e.g., gluinos. Their cascade decays will produce jets and possibly other particles (depicted here as green wedges), and will end in the NLSP. The NLSP will always decay to its SM partner plus an invisible gravitino.
• Figure 2: NLO production cross sections for wino pairs (left) and gluino pairs (right). The dashed lines indicate 10 fb, 1 fb and 0.1 fb, while the blue, red and green curves correspond to Tevatron, 7 TeV LHC, and 14 TeV LHC. The 10 fb rate roughly corresponds to the kinematic reach of the current 1/fb LHC searches. The 1 fb rate corresponds to the kinematic limit for the Tevatron and the 7 TeV LHC, both of which will collect ${\mathcal{O}}(10\,\,{\rm fb}^{-1})$ of data in their complete runs. Finally, the 0.1 fb rate corresponds to the kinematic limit for the 14 TeV LHC, which is expected to collect ${\mathcal{O}}(100\,\,{\rm fb}^{-1})$ in total.
• Figure 3: Current best limits on the simplified parameter space for bino NLSP described in Table \ref{['tab-bino']}, together with the Tevatron limit estimated in Ruderman:2011vv. Left: squark masses are decoupled. Right: NLSP mass is fixed at 375 GeV.
• Figure 4: Current best limits on the simplified parameter space for wino production and bino NLSP described in Table \ref{['tab-wino-bino']}.
• Figure 5: Current best limits on the simplified parameter space for wino co-NLSPs described in Table \ref{['tab-wino']}, together with the Tevatron limit estimated in Ruderman:2011vv. Left: squark masses are decoupled. Right: NLSP mass is fixed at 375 GeV.