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Related papers: Shaping the top asymmetry

200 papers

The forward-backward asymmetry $A_{FB}$ in top quark pair production, measured at the Tevatron, is probably related to the contribution of new particles. The Tevatron result is more than a $2\sigma$ deviation from the standard model…

High Energy Physics - Phenomenology · Physics 2011-03-21 E. Ramirez Barreto , Y. A. Coutinho , J. Sá Borges

The forward-backward asymmetry for top quarks measured in proton-antiproton collisions at the Tevatron shows an interesting deviation from standard model expectations. Among possible interpretations, the exchange of a non-universal,…

High Energy Physics - Phenomenology · Physics 2011-09-16 Edmond L. Berger

The forward-backward asymmetry in top pair production at the Tevatron has long been in tension with the Standard Model prediction. One of the only viable new physics scenarios capable of explaining this anomaly is an s-channel axigluon-like…

High Energy Physics - Phenomenology · Physics 2015-06-15 Matthew Baumgart , Brock Tweedie

We suggest a new possibility for ATLAS and CMS to explore the t-tbar forward-backward asymmetry measured at the Tevatron, by attempting to reconstruct t-tbar events, with one of the tops decaying semileptonically in the central region…

High Energy Physics - Phenomenology · Physics 2011-12-06 Jean-François Arguin , Marat Freytsis , Zoltan Ligeti

The measurement of the top forward-backward asymmetry in $\ttbar$ production measured at the Tevatron shows deviation from the Standard Model prediction. A $ u \to t$ transition via a flavor changing $Z^{\prime}$ can explain the data. We…

High Energy Physics - Phenomenology · Physics 2011-10-03 Murugeswaran Duraisamy , Ahmed Rashed , Alakabha Datta

Both CDF and DO report a forward-backward asymmetry in t-tbar production that is above the standard model prediction. We review new physics models that can give a large forward backward asymmetry in t-tbar production at the Tevatron and the…

High Energy Physics - Phenomenology · Physics 2012-10-22 Jernej F. Kamenik , Jing Shu , Jure Zupan

We use a recent upper limit from CDF on like-sign top pair production to place constraints on general new vector bosons and scalars mediating u u -> t t. The possible vector bosons comprise neutral colour singlets or octets, and charge 4/3…

High Energy Physics - Phenomenology · Physics 2011-06-28 J. A. Aguilar-Saavedra , M. Perez-Victoria

We consider how the measurement of top polarization at the Tevatron can be used to characterise and discriminate among different new physics models that have been suggested to explain the anomalous top forward-backward asymmetry reported at…

High Energy Physics - Phenomenology · Physics 2015-03-17 Debajyoti Choudhury , Rohini M. Godbole , Saurabh D. Rindani , Pratishruti Saha

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…

High Energy Physics - Phenomenology · Physics 2013-06-18 Li Tianjun , Wan Xia , Wang You-kai , Zhu Shou-hua

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…

High Energy Physics - Phenomenology · Physics 2015-03-18 Yang Bai , JoAnne L. Hewett , Jared Kaplan , Thomas G. Rizzo

The updated CDF measurement of the forward-backward asymmetry (FBA) in the top quark production p{bar p} -> t{bar t} at Tevatron (with the CMS energy 1.96 TeV) shows a deviation of 2*sigma from the value predicted by the Standard QCD Model.…

High Energy Physics - Phenomenology · Physics 2011-04-28 Chuan-Hung Chen , G. Cvetic , C. S. Kim

The CDF collaboration has recently reported a large deviation from the standard model of the t \bar t forward-backward asymmetry in the high invariant mass region. We interpret this measurement as coming from new physics at a heavy scale…

High Energy Physics - Phenomenology · Physics 2015-03-19 Cédric Delaunay , Oram Gedalia , Yonit Hochberg , Gilad Perez , Yotam Soreq

We show that the charge asymmetry in t tbar production at the LHC, A_C, and the forward-backward asymmetry at the Tevatron, A_FB, are in general not tightly correlated. They can even have opposite signs, if the underlying new physics (NP)…

High Energy Physics - Phenomenology · Physics 2013-05-30 Jure Drobnak , Jernej F. Kamenik , Jure Zupan

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

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 use an effective operator framework to study the contributions to the Tevatron t tbar asymmetry from arbitrary vector bosons and scalars, and compare with their effect on the t tbar tail at LHC. Our study shows, for example, that models…

High Energy Physics - Phenomenology · Physics 2011-07-14 J. A. Aguilar-Saavedra , M. Perez-Victoria

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 define a lepton-based asymmetry in semi-leptonic ttbar production at the LHC. We show that the ratio of this lepton-based asymmetry and the ttbar charge asymmetry, measured as a function of the lepton transverse momentum or the ttbar…

High Energy Physics - Phenomenology · Physics 2015-06-18 Adrian Carmona , Mikael Chala , Adam Falkowski , Sara Khatibi , Mojtaba Mohammadi Najafabadi , Gilad Perez , Jose Santiago

We make use of recent results in effective theory and higher-order perturbative calculations to improve the theoretical predictions of the QCD contribution to the top-quark pair production forward-backward asymmetry at the Tevatron. In…

High Energy Physics - Phenomenology · Physics 2013-05-29 Valentin Ahrens , Andrea Ferroglia , Matthias Neubert , Ben D. Pecjak , Li Lin Yang

The CDF and D0 collaborations have recently reported a large forward-backward asymmetry in the ttbar system which deviates from the next to-leading order QCD standard model prediction. We study the asymmetry in the ttbar system within the…

High Energy Physics - Phenomenology · Physics 2015-06-03 Alejandro de la Puente