Searches for New Physics with Jets in ATLAS

Various new physics models predict jets in their final states, making events with jets a potentially fruitful channel for searches at the LHC. Using data taken by the ATLAS detector at a center-of-mass energy of 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 χ distributions were obtained from a dataset which corresponded to an integrated luminosity of 3.1 pb-1. Analysis of the χ distributions excludes quark contact interactions at a 95% confidence level up to a compositeness scale of 3.4 TeV. Using multi-body final states, a search was done for evidence of a fundamental scale of gravity, MD, of order 1 TeV. Events with ∑pT>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 Standard Model 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. References: [1] arXiv:1009.5069v1 [hep-ex] [2] ATLAS-CONF-2010-088