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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Simultaneous measurement of forward-backward asymmetry and top polarization in dilepton final states from tt¯ production at the Tevatron
AU - Abazov, V. M.
AU - Abbott, B.
AU - Acharya, B. S.
AU - Adams, M.
AU - Adams, T.
AU - Agnew, J. P.
AU - Alexeev, G. D.
AU - Alkhazov, G.
AU - Alton, A.
AU - Askew, A.
AU - Atkins, S.
AU - Augsten, K.
AU - Avila, C.
AU - Badaud, F.
AU - Bagby, L.
AU - Baldin, B.
AU - Bandurin, D. V.
AU - Banerjee, S.
AU - Barberis, E.
AU - Baringer, P.
AU - Bartlett, J. F.
AU - Bassler, U.
AU - Bazterra, V.
AU - Bean, A.
AU - Begalli, M.
AU - Bellantoni, L.
AU - Beri, S. B.
AU - Bernardi, G.
AU - Bernhard, R.
AU - Bertram, I.
AU - Besanifmmode çelse çon, M.
AU - Beuselinck, R.
AU - Bhat, P. C.
AU - Bhatia, S.
AU - Bhatnagar, V.
AU - Blazey, G.
AU - Blessing, S.
AU - Bloom, K.
AU - Boehnlein, A.
AU - Boline, D.
AU - Boos, E. E.
AU - Borissov, G.
AU - Borysova, M.
AU - Brandt, A.
AU - Brandt, O.
AU - Fox, H.
AU - Price, D.
AU - Ratoff, P. N.
AU - Ross, A.
AU - Williams, M. R. J.
AU - D0 Collaboration
N1 - © 2015 American Physical Society Published: 22/9/2015, Received 22/7/2015 Evidence of Acceptance not available
PY - 2015/9/22
Y1 - 2015/9/22
N2 - We present a simultaneous measurement of the forward-backward asymmetry and the top-quark polarization in tt¯ production in dilepton final states using 9.7 fb−1 of proton-antiproton collisions at s√=1.96 TeV with the D0 detector. To reconstruct the distributions of kinematic observables we employ a matrix element technique that calculates the likelihood of the possible tt¯ kinematic configurations. After accounting for the presence of background events and for calibration effects, we obtain a forward-backward asymmetry of Att¯=(15.0±6.4(stat)±4.9(syst))% and a top-quark polarization times spin analyzing power in the beam basis of κP=(7.2±10.5(stat)±4.2(syst))%, with a correlation of −56% between the measurements. If we constrain the forward-backward asymmetry to its expected standard model value, we obtain a measurement of the top polarization of κP=(11.3±9.1(stat)±1.9(syst))%. If we constrain the top polarization to its expected standard model value, we measure a forward-backward asymmetry of Att¯=(17.5±5.6(stat)±3.1(syst))%. A combination with the D0 Att¯ measurement in the lepton+jets final state yields an asymmetry of Att¯=(11.8±2.5(stat)±1.3(syst))%. Within their respective uncertainties, all these results are consistent with the standard model
AB - We present a simultaneous measurement of the forward-backward asymmetry and the top-quark polarization in tt¯ production in dilepton final states using 9.7 fb−1 of proton-antiproton collisions at s√=1.96 TeV with the D0 detector. To reconstruct the distributions of kinematic observables we employ a matrix element technique that calculates the likelihood of the possible tt¯ kinematic configurations. After accounting for the presence of background events and for calibration effects, we obtain a forward-backward asymmetry of Att¯=(15.0±6.4(stat)±4.9(syst))% and a top-quark polarization times spin analyzing power in the beam basis of κP=(7.2±10.5(stat)±4.2(syst))%, with a correlation of −56% between the measurements. If we constrain the forward-backward asymmetry to its expected standard model value, we obtain a measurement of the top polarization of κP=(11.3±9.1(stat)±1.9(syst))%. If we constrain the top polarization to its expected standard model value, we measure a forward-backward asymmetry of Att¯=(17.5±5.6(stat)±3.1(syst))%. A combination with the D0 Att¯ measurement in the lepton+jets final state yields an asymmetry of Att¯=(11.8±2.5(stat)±1.3(syst))%. Within their respective uncertainties, all these results are consistent with the standard model
U2 - 10.1103/PhysRevD.92.052007
DO - 10.1103/PhysRevD.92.052007
M3 - Journal article
VL - 92
JO - Physical Review D
JF - Physical Review D
SN - 1550-7998
IS - 5
M1 - 052007
ER -