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Related papers: Shaping the top asymmetry

200 papers

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 computed the bottom-quark forward-backward asymmetry at the Tevatron in the Standard Model and for several new physics scenarios. Near the $Z$-pole, the SM bottom asymmetry is dominated by tree level exchanges of electroweak gauge…

High Energy Physics - Phenomenology · Physics 2014-07-14 Benjamín Grinstein , Christopher W. Murphy

Motivated by recent measurements of the top quark forward-backward asymmetry at the Tevatron, we study how t-channel new physics can contribute to a large value. We concentrate on a theory with an abelian gauge boson possessing flavor…

High Energy Physics - Phenomenology · Physics 2010-04-06 Sunghoon Jung , Hitoshi Murayama , Aaron Pierce , James D. Wells

In the $pp \rightarrow t\bar{t}$ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a…

High Energy Physics - Experiment · Physics 2016-11-21 ATLAS Collaboration

A sizeable difference in the differential production cross section of top and antitop quarks, respectively, is predicted for hadronically produced heavy quarks. It is of order $\alpha_s$ and arises from the interference between charge odd…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. H. Kühn , G. Rodrigo

We determine the dominant missing Standard Model (SM) contribution to the top quark pair forward-backward asymmetry at the Tevatron. Contrary to past expectations, we find a large, around 27%, shift relative to the well-known value of the…

High Energy Physics - Phenomenology · Physics 2015-07-30 Michal Czakon , Paul Fiedler , Alexander Mitov

In light of the recent measurements of the top quark forward-backward asymmetry at the Fermilab Tevatron experiment, which in some regions of the parameter space shows a discrepancy of 3$\sigma$ compared to the SM prediction, we analyze top…

High Energy Physics - Phenomenology · Physics 2013-05-29 Mariana Frank , Alper Hayreter , Ismail Turan

We argue that the $t \bar t$ production asymmetry observed at the tevatron might be simply explained if the standard $SU(3)_c$ QCD theory is extended to $SU(N_c)$ which is spontaneously broken at a scale just above the weak scale. The…

High Energy Physics - Phenomenology · Physics 2013-02-14 R. Foot

We present measurements of the forward-backward asymmetry in the angular distribution of leptons from decays of top quarks and antiquarks produced in proton-antiproton collisions. We consider the final state containing a lepton and at least…

High Energy Physics - Experiment · Physics 2014-10-15 D0 Collaboration

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…

High Energy Physics - Phenomenology · Physics 2011-08-08 Nikolaos Kidonakis

I present theoretical results at approximate NNLO from NNLL resummation for top quark production at the LHC and the Tevatron, including new results at 8 TeV LHC energy. Total cross sections are shown for t tbar production, for single top…

High Energy Physics - Phenomenology · Physics 2012-05-16 Nikolaos Kidonakis

We present recent preliminary measurements at the Tevatron of t-tbar and single top production cross section, top quark mass and width, top pair spin correlations and forward-backward asymmetry. In the electroweak sector, we present the…

High Energy Physics - Experiment · Physics 2011-01-24 L. Cerrito

We report on the calculation of the next-to-leading order QCD corrections to the production of top--anti-top quark pairs in association with a hard jet at the Tevatron and at the LHC. We present results for the t tbar + jet cross section…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Dittmaier , P. Uwer , S. Weinzierl

Motivated by a possible anomaly in the forward-backward (FB) asymmetry of top quark (A_{\rm FB}) observed at the Tevatron, we perform a model independent analysis on q \bar{q} \to t \bar{t} using an effective lagrangian with dim-6…

High Energy Physics - Phenomenology · Physics 2014-11-20 Dong-Won Jung , P. Ko , Jae Sik Lee , Soo-hyeon Nam

The production of a tt(bar) pair from lepton-antilepton annihilation is considered for values of the center of mass energy much larger than the top mass, typically of the few TeV size. In this regime a number of simplifications occurs that…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Beccaria , F. M. Renard , C. Verzegnassi

We investigate the invariant-mass distribution of top-quark pairs near the $2m_t$ threshold, which has strong impact on the determination of the top-quark mass $m_t$. We show that higher-order non-relativistic corrections lead to large…

High Energy Physics - Phenomenology · Physics 2021-01-21 Wan-Li Ju , Guoxing Wang , Xing Wang , Xiaofeng Xu , Yongqi Xu , Li Lin Yang

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

I present results for high-order corrections from threshold resummation to cross sections and differential distributions in top-antitop pair production and in single-top production. I show aN$^3$LO results for the total $t{\bar t}$ cross…

High Energy Physics - Phenomenology · Physics 2015-09-28 Nikolaos Kidonakis

We present a new method to measure a theoretically well-defined mass of the top quark at the LHC. This method uses lepton energy distribution and has a boost-invariant nature. We perform a simulation analysis of the top mass reconstruction…

High Energy Physics - Phenomenology · Physics 2016-01-29 Sayaka Kawabata

We consider top-quark pair production at the LHC within the MSbar scheme for the renormalisation of the top-quark mass, and we present predictions for total and differential cross sections at next-to-next-to-leading order (NNLO) in QCD. Our…

High Energy Physics - Phenomenology · Physics 2020-08-26 Stefano Catani , Simone Devoto , Massimiliano Grazzini , Stefan Kallweit , Javier Mazzitelli