1207.6915 (ATLAS Collaboration)

Measurement of charged-particle event shape variables in sqrt(s) = 7 TeV
proton-proton interactions with the ATLAS detector    [PDF]

ATLAS Collaboration

The measurement of several event shape variables is presented in minimum bias pp collisions at a center-of-mass energy of 7 TeV using the ATLAS detector at the LHC. The observables studied are the transverse thrust, thrust minor and transverse sphericity, each defined using the momenta perpendicular to the beam direction of the final state charged particles. Events with at least six charged particles are selected. In addition to the differential distributions, the evolution of each event shape variable as a function of the leading charged particle transverse momentum, charged particle multiplicity and summed transverse momentum is presented. Predictions from several Monte Carlo models have been compared with data and they show significant deviations from data.

View original: http://arxiv.org/abs/1207.6915