Download or read book Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production written by and published by . This book was released on 2011 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a new measurement of the inclusive forward-backward t{bar t} 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{bar p} collisions at √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{bar t} rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and {bar t}. In the t{bar t} rest frame, the asymmetry is observed to increase with the t{bar t} rapidity difference, [Delta]y, and with the invariant mass M{sub t{bar t}} of the t{bar t} 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{sub t{bar t}}. For M{sub t{bar t}} ≥ 450 GeV/c2, the parton-level asymmetry in the t{bar t} rest frame is A{sup t{bar t}} = 0.475 ± 0.114 compared to a next-to-leading order QCD prediction of 0.088 ± 0.013.