Skip to Main content Skip to Navigation
Journal articles

Measurement of Leptonic Asymmetries and Top Quark Polarization in ttbar Production

Abstract : We present measurements of lepton (l) angular distributions in ttbar -> W+ b W- b -> l+ nu b l- nubar bbar decays produced in ppbar collisions at a center-of-mass energy of sqrt(s)=1.96TeV, where l is an electron or muon. Using data corresponding to an integrated luminosity of 5.4fb^-1, collected with the D0 detector at the Fermilab Collider, we find that the angular distributions of l- relative to anti-protons and l+ relative to protons are in agreement with each other. Combining the two distributions and correcting for detector acceptance we obtain the forward-backward asymmetry A^l_FB = (5.8 +- 5.1(stat) +- 1.3(syst))%, compared to the standard model prediction of A^l_FB (predicted) = (4.7 +- 0.1)%. This result is further combined with the measurement based on the analysis of the l+jets final state to obtain A^l_FB = (11.8 +- 3.2)%. Furthermore, we present a first study of the top-quark polarization.
Document type :
Journal articles
Complete list of metadatas
Contributor : Emmanuelle Vernay <>
Submitted on : Tuesday, July 3, 2012 - 8:35:06 AM
Last modification on : Wednesday, September 16, 2020 - 4:19:14 PM

Links full text



V.M. Abazov, H. Li, G. Sajot, J. Stark, S. Greder, et al.. Measurement of Leptonic Asymmetries and Top Quark Polarization in ttbar Production. Physical Review D, American Physical Society, 2013, 87, pp.011103(R). ⟨10.1103/PhysRevD.87.011103⟩. ⟨in2p3-00713888⟩



Record views