We present new measurements of the inclusive forward-backward t (y) over bar production asymmetry, A(FB), and its dependence on several properties of the t (t) over bar system. The measurements are performed with the full Tevatron data set recorded with the CDF II detector during p (p) over bar collisions at root s = 1.96 TeV, corresponding to an integrated luminosity of 9.4 fb(-1). We measure the asymmetry using the rapidity difference Delta y = y(t) - y((t) over bar) Parton-level results are derived, yielding an inclusive asymmetry of 0.164 +/- 0.047(stat + syst). We establish an approximately linear dependence of AFB on the top-quark pair mass M-t (t) over bar and the rapidity difference vertical bar Delta y vertical bar at detector and parton levels. Assuming the standard model, the probabilities to observe the measured values or larger for the detector-level dependencies are 7.4 x 10(-3) and 2.2 x 10(-3) for M-tt and vertical bar Delta y vertical bar respectively. Lastly, we study the dependence of the asymmetry on the transverse momentum of the t (t) over bar system at the detector level. These results are consistent with previous lower-precision measurements and provide additional quantification of the functional dependencies of the asymmetry.
|Titolo:||Measurement of the top quark forward-backward production asymmetry and its dependence on event kinematic properties|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevD.87.092002|
|Appare nelle tipologie:||1.1 Articolo in rivista|