We present a new measurement of the inclusive forward-backward t (t) over bar production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV, recorded with the CDF-II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the t (t) over bar rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and (t) over bar. In the t (t) over bar rest frame, the asymmetry is observed to increase with the t (t) over bar rapidity difference, Delta y, and with the invariant mass M(t (t) over bar) of the t (t) over bar system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large Delta y and M(t (t) over bar). For M(t (t) over bar) >= 450 GeV/c(2), the parton-level asymmetry in the t (t) over bar rest frame is A(t (t) over bar) = 0.475 +/- 0.114 compared to a next-to-leading order QCD prediction of 0.088 +/- 0.013.

Evidence for a mass dependent forward-backward asymmetry in top quark pair production RID G-1087-2011 RID E-4473-2011

DELL'ORSO, MAURO;DONATI, SIMONE;PUNZI, GIOVANNI;
2011-01-01

Abstract

We present a new measurement of the inclusive forward-backward t (t) over bar production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV, recorded with the CDF-II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the t (t) over bar rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and (t) over bar. In the t (t) over bar rest frame, the asymmetry is observed to increase with the t (t) over bar rapidity difference, Delta y, and with the invariant mass M(t (t) over bar) of the t (t) over bar system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large Delta y and M(t (t) over bar). For M(t (t) over bar) >= 450 GeV/c(2), the parton-level asymmetry in the t (t) over bar rest frame is A(t (t) over bar) = 0.475 +/- 0.114 compared to a next-to-leading order QCD prediction of 0.088 +/- 0.013.
2011
Aaltonen, T; Gonzalez, Ba; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, Ja; Apresyan, A; Arisawa, T; Artikov, A; As...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/147371
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