Speaker
Sara Borroni
(Deutsches Elektronen-Synchrotron (DE))
Description
While in the Standard Model top quarks are predicted to be produced unpolarized at the LHC,
several models beyond the SM predict a nonzero
polarization. In particular, some of the models
predicting a larger forwardbackward
ttbar asymmetry than predicted in the SM, as measured at
the Tevatron, predict a positive top quark polarization. Using 4.7 fb1
of data collected by the ATLAS experiment at a centre of mass energy of 7 TeV, a measurement of the top quark
polarization is presented. The full ttbar system is reconstructed from final states with at least one charged lepton, and a template fit to the distribution of the angle between the charged lepton and the top quark is performed to measure the top quark polarisation.
Primary author
Sara Borroni
(Deutsches Elektronen-Synchrotron (DE))
