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Related papers: Shaping the top asymmetry

200 papers

The Tevatron has measured a discrepancy relative to the Standard Model prediction in the forward-backward asymmetry in top quark pair production. This asymmetry grows with the rapidity difference of the two top quarks. It also increases…

High Energy Physics - Phenomenology · Physics 2013-05-30 Sudhansu S. Biswal , Subhadip Mitra , Rui Santos , Pankaj Sharma , Ritesh K. Singh , Miguel Won

We study the phenomenology of same sign top pair production at the LHC in a model-independent way. The complete set of dimension six operators involving two top (or anti-top) quarks is introduced and the connection with all possible t- or…

High Energy Physics - Phenomenology · Physics 2015-03-19 Celine Degrande , Jean-Marc Gerard , Christophe Grojean , Fabio Maltoni , Geraldine Servant

A large forward-backward asymmetry in $t\bar t$ production, for large invariant mass of the $t\bar t$ system, has been recently observed by the CDF collaboration. Among the scalar mediated mechanisms that can explain such a large asymmetry,…

High Energy Physics - Phenomenology · Physics 2015-05-28 Kfir Blum , Yonit Hochberg , Yosef Nir

We present a phenomenological analysis of the recent Tevatron results on the $t \bar t$ forward-backward asymmetry and invariant-mass spectrum assuming a new contribution from an s-channel gluon resonance with a mass in the range from 700…

High Energy Physics - Phenomenology · Physics 2011-09-13 Ezequiel Alvarez , Leandro Da Rold , Juan Ignacio Sanchez Vietto , Alejandro Szynkman

Measurements of the top quark forward-backward asymmetry performed at the Tevatron suggest that new-physics may be playing a role in t-tbar production. To better understand the source of the asymmetry, recent proposals have called for a…

High Energy Physics - Phenomenology · Physics 2015-05-30 Dilani Kahawala , David Krohn , Matthew J. Strassler

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

At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks…

High Energy Physics - Phenomenology · Physics 2015-05-28 Yang Bai , Zhenyu Han

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

Copious production of top-antitop quark pairs at hadron colliders has enabled various probes into the properties and interactions of top quarks. Among the various presently measured observables, the forward-backward asymmetry (FBA) in t…

High Energy Physics - Phenomenology · Physics 2015-03-20 Svjetlana Fajfer , Jernej F. Kamenik , Blazenka Melic

The charge asymmetry in top quark pair production in the di-lepton $t\bar t$ channel using the ATLAS experiment at Large Hadron Collider is presented. The asymmetry is studied in the distribution of absolute rapidity difference between top…

High Energy Physics - Experiment · Physics 2012-12-04 Jakub Cúth

The top asymmetries measured at the Tevatron, and the discrepancy in the di-photon Higgs rate under investigation at the LHC represent two possible hints of physics beyond the Standard Model (SM). In this paper we address the possibility to…

High Energy Physics - Phenomenology · Physics 2015-06-12 Wei-Chih Huang , Alfredo Urbano

In this note we demonstrate the use of top polarization in the study of $t \bar t$ resonances at the LHC, in the possible case where the dynamics implies a non-zero top polarization. As a probe of top polarization we construct an asymmetry…

High Energy Physics - Phenomenology · Physics 2010-12-09 Rohini M. Godbole , Kumar Rao , Saurabh D. Rindani , Ritesh K. Singh

We present the current status of the Tevatron charge asymmetry and its sister asymmetry at the LHC. The relation between both is elucidated, using as framework the collider-independent asymmetries they originate from. Other related…

High Energy Physics - Phenomenology · Physics 2013-02-28 J. A. Aguilar-Saavedra , M. Perez-Victoria

The latest measurements of the asymmetry in the angular distributions of the $t\bar{t}$ events are reviewed. The measurements of the forward-backward asymmetry $A_{FB}$ in the $p\bar{p}$ 1.98 TeV collision at the Tevatron show some tension…

High Energy Physics - Experiment · Physics 2013-12-03 Viatcheslav Sharyy

A sizeable difference in the differential production cross section of top- compared to antitop-quark production, denoted charge asymmetry, has been observed at the Tevatron. The experimental results seem to exceed the theory predictions…

High Energy Physics - Phenomenology · Physics 2015-05-30 Johann H. Kuhn , German Rodrigo

The recent forward-backward asymmetry recorded by the CDF Collaboration for the top and anti-top quark pair production indicates more than $2\sigma$ deviation from the Standard Model prediction, while its total production cross section…

High Energy Physics - Phenomenology · Physics 2009-12-04 Kingman Cheung , Wai-Yee Keung , Tzu-Chiang Yuan

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…

High Energy Physics - Phenomenology · Physics 2011-03-28 Vernon Barger , Wai-Yee Keung , Chiu-Tien Yu

We compute, for top quark pair production at the Tevatron and the Large Hadron Collider, the collider-independent forward-backward asymmetries defined in [1] in the standard model at next-to-leading order in QCD, including also…

High Energy Physics - Phenomenology · Physics 2013-05-30 J. A. Aguilar-Saavedra , W. Bernreuther , Z. -G. Si

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

A sizable charge asymmetry in top quark pair production has been observed at the Tevatron. The experimental results seem to exceed systematically the Standard Model theory predictions by a significant amount and have triggered a large…

High Energy Physics - Phenomenology · Physics 2012-07-03 German Rodrigo