, 72:2211,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 20 Nov 2012

Measurement of event shapes at large momentum transfer with the ATLAS detector in pp collisions at \(\sqrt{\mathbf{s}}=7\ \mathrm{TeV}\)

Abstract

A measurement of event shape variables is presented for large momentum transfer proton-proton collisions using the ATLAS detector at the Large Hadron Collider. Six event shape variables calculated using hadronic jets are studied in inclusive multi-jet events in 35 pb−1 of integrated luminosity at a center-of-mass energy of \(\sqrt{s} = 7~\mathrm{TeV}\) . These measurements are compared to predictions by three Monte Carlo event generators containing leading-logarithmic parton showers matched to leading order matrix elements for 2→2 and 2→n (n=2,…,6) scattering. Measurements of the third-jet resolution parameter, aplanarity, thrust, sphericity, and transverse sphericity are generally well described. The mean value of each event shape variable is evaluated as a function of the average momentum of the two leading jets p T,1 and p T,2, with a mean p T approaching 1 TeV.