The Top Quark Forward-backward Asymmetry at Approximate N3LO
نویسنده
چکیده
I calculate the top quark forward-backward asymmetry at the Tevatron in both the laboratory frame and the tt̄ rest frame. I show that soft-gluon corrections are the dominant contribution to the asymmetry and closely approximate exact results through next-tonext-to-leading order (NNLO). I present a calculation of the asymmetry including approximate next-to-next-to-next-to-leading-order (N3LO) soft-gluon contributions from next-tonext-to-leading-logarithm (NNLL) resummation as well as electroweak corrections. Thus approximate N3LO (aN3LO) results are obtained, which significantly enhance and improve previous NNLO results. The theoretical aN3LO result for the top quark forward-backward asymmetry at the Tevatron in the laboratory frame is (6.8±0.3)%, and in the tt̄ rest frame it is (10.0 ± 0.6)% which is in excellent agreement with recent Tevatron data.
منابع مشابه
N3LO Approximate Results for Top-quark Differential Cross Sections and Forward-backward Asymmetry
متن کامل
Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC
At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks produced from quarks and those from gluons: the invariant mass of the top pair, the rapidity of the top-antitop system in the lab frame, the rapidity of the top q...
متن کاملTop quark forward-backward asymmetry and same-sign top quark pairs.
The top quark forward-backward asymmetry measured at the Tevatron collider shows a large deviation from standard model expectations. Among possible interpretations, a nonuniversal Z' model is of particular interest as it naturally predicts a top quark in the forward region of large rapidity. To reproduce the size of the asymmetry, the couplings of the Z' to standard model quarks must be large, ...
متن کاملLHC Predictions from a Tevatron Anomaly in the Top Quark Forward-Backward Asymmetry
We examine the implications of the recent CDF measurement of the top-quark forward-backward asymmetry, focusing on a scenario with a new color octet vector boson at 1-3 TeV. We study several models, as well as a general effective field theory, and determine the parameter space which provides the best simultaneous fit to the CDF asymmetry, the Tevatron top pair production cross section, and the ...
متن کاملMeasurement of the Forward-Backward Charge Asymmetry in Top-Quark Pair Production in Proton-Antiproton Collisions at DØ
A measurement of the forward-backward charge asymmetry in top-antitop (tt̄) pair production in proton-antiproton (pp̄) collisions is presented. The asymmetry is measured for different jet multiplicities in the lepton+jets final state on 0.9 fb−1 of data collected by the DØ experiment at the Fermilab Tevatron Collider. The result is sensitive to new physics, which is demonstrated by setting an upp...
متن کامل