Measurement of event shapes at large momentum transfer with the ATLAS detector in pp collisions at root s=7 TeV


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Aad G., Abbott B., Abdallah J., Khalek S. A., Abdelalim A. A., Abdinov O., ...More

EUROPEAN PHYSICAL JOURNAL C, vol.72, no.11, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 72 Issue: 11
  • Publication Date: 2012
  • Doi Number: 10.1140/epjc/s10052-012-2211-y
  • Journal Name: EUROPEAN PHYSICAL JOURNAL C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: Yes

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 root s = 7 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.