Search for supersymmetry in di-jet events with novel data-driven background estimation

We present a search for supersymmetry (SUSY) in di-jet events with the CMS detector at the LHC. Our study is focused on a SUSY parameter space where squarks are pair produced and both directly decay to a quark and neutralino with the latter escaping the detector, thus leaving a missing energy signature. Although the background from QCD di-jet events is overwhelming, the particular kinematics of the SUSY events allow to define powerful discriminating variables which enable a clear separation of signal and QCD events. Therefore, the only important SM background left for this search is the invisible decay of the Z boson accompanied with two jets in the final state. This background can be estimated by utilizing a novel approach using gamma+jet events thus enabling a possible discovery of SUSY in the di-jet system with the early physics data