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Related papers: Massive Spin-2 States as the Origin of the Top Qua…

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The forward-backward asymmetry (FBA) in top-pair production that was observed in 2008 gets a boost in a recent CDF publication. Not only has the FBA further been confirmed, but also distributional preferences are shown. Strikingly, the FBA…

High Energy Physics - Phenomenology · Physics 2015-03-17 Kingman Cheung , Tzu-Chiang Yuan

We examine loop-mediated effects of new heavy quarks Q=(t',b') on t tbar production at hadron colliders, using a phenomenological model with flavor off-diagonal couplings of charged and neutral scalars phi=(phi^+-,phi^0) to Q. We show that…

High Energy Physics - Phenomenology · Physics 2013-05-30 Hooman Davoudiasl , Thomas McElmurry , Amarjit Soni

The forward-backward asymmetry $A_{FB}^{t\bar t}$ in top quark production at the Tevatron has been observed to be anomalously large by both CDF and D0. It has been suggested that a model with a $W'$ coupling to $td$ and $ub$ might explain…

High Energy Physics - Phenomenology · Physics 2011-09-08 Nathaniel Craig , Can Kilic , Matthew J. Strassler

We propose a simple model where dark matter (DM) carries top flavor and couples to the Standard Model through the top quark within a framework of minimal flavor violation (MFV). Top-flavored DM can explain the anomalous top forward-backward…

High Energy Physics - Phenomenology · Physics 2013-05-15 Abhishek Kumar , Sean Tulin

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…

High Energy Physics - Phenomenology · Physics 2013-01-09 P. Ko

Top-quark pair production at the Tevatron is discussed within the Randall-Sundrum model of warped extra dimensions. Generically, the exchange of massive Kaluza-Klein gluons has the potential to generate a large forward-backward asymmetry.…

High Energy Physics - Phenomenology · Physics 2015-03-19 Susanne Westhoff

Reconstructable final state kinematics and charge assignment in the reaction ppbar->ttbar allows tests of discrete strong interaction symmetries at high energy. We define frame dependent forward-backward asymmetries for the outgoing top…

High Energy Physics - Experiment · Physics 2010-05-12 CDF Collaboration , T. Aaltonen

Both CDF and D0 at Tevatron reported the measurements of forward-backward asymmetry in top pair production, which showed possible deviation from the standard model QCD prediction. In this paper, we show that a new color-octet massive vector…

High Energy Physics - Phenomenology · Physics 2010-11-02 Bo Xiao , You-kai Wang , Shou-hua Zhu

Top quark pair production at photon-photon colliders is studied in low scale quantum gravity scenario. From the dependence of the cross sections on the spin configuration of the top quark and anti-quark, we introduce a new observable, top…

High Energy Physics - Phenomenology · Physics 2009-10-31 Kang Young Lee , Seong Chan Park , H. S. Song , Jeonhyeon Song , Chaehyun Yu

A large forward-backward asymmetry is seen in both the top quark rapidity distribution $A_{FB}^t$ and in the rapidity distribution of charged leptons $A_{FB}^\ell$ from top quarks produced at the Tevatron. We study the kinematic and dynamic…

High Energy Physics - Phenomenology · Physics 2012-02-15 Edmond L. Berger , Qing-Hong Cao , Chuan-Ren Chen , Jiang-Hao Yu , Hao Zhang

We construct flavor-dependent chiral U(1)' models with a Z' boson which couples to the right-handed up-type quarks in the standard model (SM). To make the models have realistic renormalizable Yukawa couplings, we introduce new Higgs…

High Energy Physics - Phenomenology · Physics 2022-03-02 P. Ko , Yuji Omura , Chaehyun Yu

The top quark forward-backward asymmetry A_{FB}^t measured at the Tevatron is above the Standard Model prediction by more than 2-sigma deviation, which might be a harbinger for new physics. In this work we examine the contribution to…

High Energy Physics - Phenomenology · Physics 2010-04-06 Junjie Cao , Zhaoxia Heng , Lei Wu , Jin Min Yang

We consider the recent measurement of the top quark forward-backward asymmetry at the Fermilab Tevatron, which shows a discrepancy of slightly more than 2$\sigma$ compared to the SM prediction. We find that $t$-channel exchange of a color…

High Energy Physics - Phenomenology · Physics 2010-12-09 Jing Shu , Tim M. P. Tait , Kai Wang

The top quark forward-backward asymmetry measured at the Tevatron collider shows a large deviation from standard model expectations. Among possible interpretations, a non-universal $Z^\prime$ model is of particular interest as it naturally…

High Energy Physics - Phenomenology · Physics 2011-05-23 Edmond L. Berger , Qing-Hong Cao , Chuan-Ren Chen , Chong Sheng Li , Hao Zhang

Both D0 and CDF at Tevatron reported the measurements of forward-backward asymmetry in top pair production, which showed possible deviation from the standard model QCD prediction. In this paper, we explore how to examine the {\em same}…

High Energy Physics - Phenomenology · Physics 2011-02-01 You-kai Wang , Bo Xiao , Shou-hua Zhu

We present a new measurement of the inclusive forward-backward t-tbar production asymmetry and its rapidity and mass dependence. The measurements are performed with 5.3 fb^{-1} of p-pbar collisions at \sqrt{s} = 1.96 TeV, recorded with CDF…

High Energy Physics - Experiment · Physics 2011-06-24 The CDF Collaboration , T. Aaltonen

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…

High Energy Physics - Phenomenology · Physics 2011-09-08 Dong-won Jung , P. Ko , Jae Sik Lee , Soo-hyeon Nam

Forward-backward asymmetries $A_{FB}^t$ and $A_{FB}^\ell$ are observed in the top quark $t$ rapidity distribution and in the rapidity distribution of charged leptons $\ell$ from top quark decay at the Tevatron proton-antiproton collider,…

High Energy Physics - Phenomenology · Physics 2013-01-23 Edmond L. Berger

We propose to measure the threshold lepton asymmetry, that is the forward-backward asymmetry of the charged lepton in ttbar events near the production threshold. At threshold top quark pairs are produced in an s-wave. Angular momentum…

High Energy Physics - Phenomenology · Physics 2013-03-14 Adam Falkowski , Gilad Perez , Martin Schmaltz

We compute the order $\alpha_s^2$ QCD corrections to the $b$-quark forward-backward asymmetry in $e^+e^-\to b{\bar b}$ collisions at the $Z$ boson resonance, taking the non-zero mass of the $b$ quark into account. We determine these…

High Energy Physics - Phenomenology · Physics 2017-02-01 Werner Bernreuther , Long Chen , Oliver Dekkers , Thomas Gehrmann , Dennis Heisler