Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure inppcollisions at √s=7 TeV with the ATLAS detector

This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all- hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of =s 7 TeV and correspond to an integrated luminosity of 4.6 fb^− 1. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of- mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum pT> 320 GeV and pseudorapidity η < | 1.9 |, is measured to be σ(W+Z) = 8.5 +-1.7 pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques.