EPS-HEP 2017

Cross section measurement of ttbargamma production in pp collision at sqrt(s) = 8 TeV with the ATLAS experiment

Not scheduled

15m

Salone Adriatico (Palazzo del Casinò)

Board: TE-14

Poster Presentation Top and Electroweak Physics Poster session

Speaker

Sara Ghasemi (University of Siegen (DE))

Description

The cross-section for top-quark pair production in association with a photon is measured in proton-proton collisions at the LHC at a center of mass energy of sqrt(s) = 8 TeV. The data with a total integrated luminosity of 20.2 fb-1 collected by the ATLAS detector in 2012 is used. The measurement is performed in the single lepton decay channel. The signal region is defined by the final state of exactly one high pT lepton, large missing transverse momentum, at least four jets where at least one is being b-tagged and exactly one photon with pT> 15 GeV. The cross-section times the branching ratio is determined in a fiducial region defined in terms of the detector acceptance. The measured ttbargamma fiducial cross-section is in good agreement with the NLO prediction. In addition, the differential cross section as a function of photon pT and eta is measured.