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Related papers: Explaining the t-tbar asymmetry with a light axigl…

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A long-standing discrepancy between the bottom-quark production cross section and predictions of perturbative quantum chromodynamics is addressed. We show that pair production of light gluinos, of mass 12 to 16 GeV, with two-body decays…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. L. Berger , B. W. Harris , D. E. Kaplan , Z. Sullivan , T. M. P. Tait , C. E. M. Wagner

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

The presence of a light b-squark (with mass about 4 GeV) and gluino (with mass about 15 GeV) might explain the observed excess in b-quark production at the Tevatron. Though provocative, this model is not excluded by present data. The light…

High Energy Physics - Phenomenology · Physics 2008-11-26 Thomas Becher , Stephan Braig , Matthias Neubert , Alexander L. Kagan

A gauge model with chiral color symmetry is considered and possible effects of the color $G'$-boson octet predicted by this symmetry are investigated in dependence on two free parameters, the mixing angle $\theta_G$ and $G'$ mass $m_{G'}$.…

High Energy Physics - Phenomenology · Physics 2009-09-24 M. V. Martynov , A. D. Smirnov

The contributions into radiative correction parameters S, T, U from scalar leptoquark and scalar gluon doublets are investigated in the minimal four color symmetry model. It is shown that the current experimental data on S, T, U allow the…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. D. Smirnov

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

The anomaly of the top quark forward-backward asymmetry $A^t_{FB}$ observed at the Tevatron can be explained by the t-channel exchange of a neutral gauge boson (Z') which has sizable flavor changing coupling for top and up quarks. This…

High Energy Physics - Phenomenology · Physics 2013-05-29 Junjie Cao , Lin Wang , Lei Wu , Jin Min Yang

We study contributions of a scalar diquark particle in a color representation of anti-triplet and sextet to the top quark pair production at the Tevatron and the Large hadron collider (LHC). The model can give Forward-Backward (FB)…

High Energy Physics - Phenomenology · Physics 2015-06-05 Kaoru Hagiwara , Junya Nakamura

We investigate a model of R-parity violating (RPV) supersymmetry in which the right-handed sbottom is the lightest supersymmetric particle, and a baryon number violating coupling involving a top is the only non-negligible RPV coupling. This…

High Energy Physics - Phenomenology · Physics 2015-06-17 B. C. Allanach , S. A. Renner

The ATLAS collaboration (and also CMS) has recently reported an excess over Standard Model expectations for gauge boson pair production in the invariant mass region $1.8-2.2$ TeV. In the light of these results, we argue that such signal…

High Energy Physics - Phenomenology · Physics 2016-01-27 D. Aristizabal Sierra , J. Herrero-Garcia , D. Restrepo , A. Vicente

In the event that the Higgs mass is large or that the electroweak interactions are strongly interacting at high energy, top quark couplings to longitudinal components of the weak gauge bosons could offer important clues to the underlying…

High Energy Physics - Phenomenology · Physics 2016-09-06 Stephen Godfrey , Shou-hua Zhu

In this talk, I describe a supersymmetric solution to the long-standing discrepancy between the bottom-quark production cross section and predictions of perturbative quantum chromodynamics. Pair production of light gluinos, of mass 12-16…

High Energy Physics - Phenomenology · Physics 2007-05-23 Z. Sullivan

A flavor-universal extension of the strong interactions was recently proposed in response to the apparent excess of high-$E_T$ jets in the inclusive jet spectrum measured at the Tevatron. The color octet of massive gauge bosons (`colorons')…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. H. Simmons

We apply Bogoliubov compensation principle to the problem of forward-backward asymmetry in $t \bar t$ production at TEVATRON. The non-trivial solution of compensation equation for anomalous four-fermion interaction effective interaction of…

High Energy Physics - Phenomenology · Physics 2015-06-12 Boris A. Arbuzov , Ivan V. Zaitsev

We present the first observation of the Zgamma to nunugamma process at the Tevatron at 5.1 standard deviations significance, based on 3.6 fb-1 of integrated luminosity collected with the D0 detector at the Fermilab Tevatron ppbar Collider…

High Energy Physics - Experiment · Physics 2009-06-30 V. M. Abazov

A reanalysis is presented on the CMS result on a search for a W' boson that couples to the top and down quarks. The model is motivated by the Tevatron results on the forward-backward asymmetry of ttbar pair production. In the evaluation of…

High Energy Physics - Experiment · Physics 2015-06-05 Motoi Endo , Sho Iwamoto

Models of top condensation can provide both a compelling solution to the hierarchy problem as well as an explanation of why the top-quark mass is large. The spectrum of such models, in particular topcolor-assisted technicolor, includes…

High Energy Physics - Phenomenology · Physics 2015-05-28 Yanou Cui , Zhenyu Han , Matthew D. Schwartz

In this paper we determine the weak-interaction corrections of order $\alpha_s^2\alpha$ to hadronic top-quark pair production. First we compute the one-loop weak corrections to $t \bar t$ production due to gluon fusion and the order…

High Energy Physics - Phenomenology · Physics 2008-11-26 Werner Bernreuther , Michael Fuecker , Zong-Guo Si

We propose that, within the standard model, the correlation between the $t\bar{t}$ forward--backward asymmetry $A_{t\bar t}$ and the corresponding lepton-based asymmetry $A_l$ -- at the differential level -- is strong and rather clean both…

High Energy Physics - Phenomenology · Physics 2013-03-14 Adam Falkowski , Michelangelo L. Mangano , Adam Martin , Gilad Perez , Jan Winter

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