Search for supersymmetry in all-hadronic events with MT2

A search for supersymmetry or similar new physics was carried out using a $\sqrt{s} = 7$ TeV $pp$ collisions data sample corresponding to 1.1 $\mathrm{fb}^{-1}$ of integrated luminosity collected by the CMS experiment at the LHC. Fully hadronic final states were selected based on the stransverse mass variable $M_{T2}$. Two complementary analyses were performed. A first one targets the region of parameter space with medium to high squark and gluino masses, in which the signal can be separated from the Standard Model backgrounds by a strong cut on $M_{T2}$. A second analysis has been optimized to look for events with a light gluino but heavy squarks. In this case, the $M_{T2}$ cut was relaxed, but higher jet multiplicity and an additional $b$-tag was required. The dominant backgrounds in both analyses are different. All backgrounds were estimated using both simulation and data-driven methods. As no excess of events over the expected background was observed, exclusion limits were derived.