Searches for new physics with jets at ATLAS

Using data taken by the ATLAS detector at sqrt(s) = 7 TeV, two types of events with jets were analyzed for evidence of new physics—di-jet and multi-jet events. The di-jet events were used to set a constraint on quark compositeness, while the multi-jets were used to probe for low-scale gravity and weakly-coupled string theory. For the di-jet analysis, di-jet chi distributions were obtained from a dataset which corresponded to an integrated luminosity of 3.1 pb−1. Analysis of the chi distributions excludes quark contact interactions at a 95% confidence level up to a compositeness scale of 3.4 TeV. Through multi-body final states, a search was done for evidence of a fundamental scale of gravity, M_D, of order 1 TeV. Events with SumPT > 700 GeV and invariant mass > 800 GeV were selected from a sample with integrated luminosity of (295±32) nb−1, yielding 193 events—all of which were multi-jet events. The number of events was in agreement with the QCD prediction of 254±18±83, and an upper limit of 0.34 nb at the 95% confidence level was set for new physics models with these final states.