Measurement of Top Quark Polarization in Top-Antitop Events from Proton-Proton Collisions at root s=7 TeV Using the ATLAS Detector
2013 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 111, no 23, 232002- p.Article in journal (Refereed) Published
This Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4: 7 fb(-1) of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at root s = 7 TeV. Final states containing one or two isolated leptons ( electrons or muons) and jets are considered. Two measurements of alpha P-l, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving or a maximally CP violating production process. The measurements obtained, alpha P-l(CPC) = -0: 035 +/- 0: 014(stat) +/- 0: 037(syst) and alpha P-l(CPV) = 0: 020 +/- 0: 016(stat)(-0.017)(+0.013)(syst), are in good agreement with the standard model prediction of negligible top quarkpolarization.
Place, publisher, year, edition, pages
2013. Vol. 111, no 23, 232002- p.
IdentifiersURN: urn:nbn:se:uu:diva-216785DOI: 10.1103/PhysRevLett.111.232002ISI: 000328616300013OAI: oai:DiVA.org:uu-216785DiVA: diva2:690766
ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.111.232002.2014-01-242014-01-242014-01-24Bibliographically approved