Related papers: Data driving the top quark forward--backward asymm…
The excess in top quark forward-backward asymmetry has been a hot topic in recent years. Although there are many proposals to explain it, most of them can not fit the differential distributions well. The color octet axial-vector like…
Spin correlations in the top quark-antiquark system and the polarization of the top quark are measured using dilepton final states produced in pp collisions at the LHC at sqrt(s) = 7 TeV. The data correspond to an integrated luminosity of…
As a top quark factory, the LHC can test the new physics models used to explain the top quark forward-backward asymmetry A^t_FB measured at the Tevatron. In this work we perform a comparative study for two such models: the W'-model and the…
We measure the asymmetry in the charge-weighted rapidity of the lepton in semileptonic ttbar decays recorded with the CDF II detector using the full Tevatron Run II sample, corresponding to an integrated luminosity of 9.4/fb. A…
A measurement of spin correlation in ttbar production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb^-1. Candidate events are selected in the dilepton topology with…
When a top quark decays there is a large amount of angular correlation, in its rest frame, between its spin orientation and the direction of flight of the charged lepton from its decay. In this letter we investigate the prospects of…
This paper presents single lepton and dilepton kinematic distributions measured in dileptonic $t\bar{t}$ events produced in 20.2 fb$^{-1}$ of $\sqrt{s}=8$ TeV $pp$ collisions recorded by the ATLAS experiment at the LHC. Both absolute and…
Predictions are made for the forward-backward and charge asymmetries in bottom-quark pair production at hadron colliders. Tree-level exchanges of electroweak (EW) gauge bosons dominate the Standard Model (SM) contribution to the asymmetry…
I present results for the top quark rapidity distribution at LHC and Tevatron energies, including higher-order corrections from threshold resummation. The next-to-next-to-leading-order (NNLO) soft-gluon corrections at…
We perform a model independent analysis on $q \bar{q} \rightarrow t \bar{t}$ using an effective lagrangian with dim-6 four-quark operators, and derive necessary conditions on new physics that are consistent with the $t\bar{t}$ production…
We present an analysis of the forward-backward asymmetry in the production of top quark pairs at the Tevatron collider. We use novel Monte Carlo methods for merging matrix elements and parton showers to combine NLO QCD predictions for tt…
Measurements of the top quark polarization and top quark pair ($\mathrm{t\bar{t}}$) spin correlations are presented using events containing two oppositely charged leptons (e$^+$e$^-$, e$^\pm\mu^\mp$, or $\mu^+\mu^-$) produced in…
The t t-bar charge asymmetry is measured in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data, collected with the CMS experiment at the LHC, correspond to an integrated luminosity of 19.7 inverse femtobarns. Selected…
Recent results from the CDF Collaboration indicate the the top-pair forward-backward asymmetry is largest in regions of high rapidity difference $|\Delta y|$ and invariant mass $M_{t\bar t}.$ We show that experimental observations can be…
The forward-backward asymmetry A_{FB}^t in top quark production at the Tevatron has been seen to be anomalously large both by CDF and D0. Parton-level asymmetries as large as 50%, with a large error bar, have been extracted from the data.…
Within the paradigm of warped extra dimensions, third generation quarks are expected to be the most sensitive to effects beyond the Standard Model. The anomalies observed at the LEP and Tevatron colliders in the forward-backward asymmetries…
The top forward-backward asymmetry (FBA) observed at the Tevatron has been a hot issue in particle physics for the last few years. In this talk, I describe two different approaches for the top FBA at the Tevatron, one in effective field…
We present recent results on top quark pair production cross section and forward-backward asymmetry at the Tevatron. Three new cross section measurements from CDF and one new measurement from DO are presented that utilize the full dataset…
In the presence of an electric dipole coupling of $t \bar t$ to a photon, and an analogous ``weak" dipole coupling to the $Z$, $CP$ violation in the process $e^+e^- \rightarrow t \bar t$ leads to the polarization of the top and anti-top.…
Measurement of the inclusive and differential top-quark charge asymmetry is carried out using full Run 2 data from proton-proton collisions at a center-of-mass energy of $13$ TeV collected by the ATLAS detector. The single-lepton and…