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A number of top-spin observables are computed within the Standard Model (SM), at next-to-leading order in the strong and weak gauge couplings for hadronic top-quark anti-quark (ttbar) production and decay at the LHC for center-of-mass…

High Energy Physics - Phenomenology · Physics 2015-06-15 Werner Bernreuther , Zong-Guo Si

We consider top-antitop quark ($t{\bar t}$) production at the Large Hadron Collider (LHC) with subsequent decay into dileptonic and lepton plus jets final states. We present a set of leptonic angular correlations and distributions with…

High Energy Physics - Phenomenology · Physics 2016-01-27 Werner Bernreuther , Dennis Heisler , Zong-Guo Si

Top-antitop pairs produced at hadron colliders are largely unpolarized, but their spins are highly correlated. The structure of these correlations varies significantly over top production phase space, allowing very detailed tests of the…

High Energy Physics - Phenomenology · Physics 2015-06-12 Matthew Baumgart , Brock Tweedie

Recent experimental results from the CDF collaboration which study the top forward-backward asymmetry have strengthened the case that new physics is playing a role in t-tbar production. Here we propose a set of measurements, built from the…

High Energy Physics - Phenomenology · Physics 2013-05-29 David Krohn , Tao Liu , Jessie Shelton , Lian-Tao Wang

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

We analyze the impact of effective axial-vector coupling of the gluon on spin polarization observables in $t\bar{t}$ pair production at the LHC. Working at leading order in QCD, we compute the $t\bar{t}$ spin-correlation and left-right spin…

High Energy Physics - Phenomenology · Physics 2013-04-10 E. Gabrielli , A. Racioppi , M. Raidal , H. Veermae

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

We describe the latest results obtained by the CMS Collaboration on top quark spin and polarization properties. The top quark spin asymmetry is measured both targeting single-top quark production in the $t$-channel and single-top quark…

High Energy Physics - Experiment · Physics 2022-11-24 Fabio Iemmi

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 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

Measurements of the top quark-antiquark (t t-bar) spin correlations and the top quark polarization are presented for t t-bar pairs produced in pp collisions at sqrt(s) = 8 TeV. The data correspond to an integrated luminosity of 19.5 inverse…

High Energy Physics - Experiment · Physics 2016-03-23 CMS Collaboration

Spin correlations in the production of top-antitop quark ($t\bar{t}$) pairs at the Large Hadron Collider (LHC) are an experimentally verified prediction of the Standard Model. In this paper, we compute the full spin density matrix for…

High Energy Physics - Phenomenology · Physics 2021-09-17 Baptiste Ravina , Ethan Simpson , James Howarth

Spin correlations in the top quark-antiquark system and the polarization of the top quark are measured using dilepton final states produced in pp collisions at the LHC at sqrt(s) = 7 TeV. The data correspond to an integrated luminosity of…

High Energy Physics - Experiment · Physics 2014-05-07 CMS Collaboration

Measurements of the top quark polarization and top quark pair ($\mathrm{t\bar{t}}$) spin correlations are presented using events containing two oppositely charged leptons (e$^+$e$^-$, e$^\pm\mu^\mp$, or $\mu^+\mu^-$) produced in…

High Energy Physics - Experiment · Physics 2019-10-16 CMS Collaboration

The degree of top polarization and strength of $t\bar{t}$ correlation are dependent on production dynamics, decay mechanism, and choice of the observables. At the LHC, measurement of the top polarization and spin correlations in $t\bar{t}$…

High Energy Physics - Experiment · Physics 2017-09-26 Ajeeta Khatiwada

The top quark decays before it hadronizes. Before its spin state can be changed in a process of strong interaction, it is directly transferred to the top quark decay products. The top quark spin can be deduced by studying angular…

High Energy Physics - Experiment · Physics 2019-08-13 Boris Lemmer

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

Spin correlations of top quarks produced in hadron collisions have not been observed experimentally with large significance. In this Letter, we propose a new variable that may enable demonstration of the existence of spin correlations with…

High Energy Physics - Phenomenology · Physics 2015-03-19 Kirill Melnikov , Markus Schulze

We explore beyond Standard Model (bSM) physics signatures in the $l+jets$ channel of $t\overline{t}$ pair production process at the Tevatron and the LHC. We study the effects of bSM physics scenarios on the top quark polarization and on the…

High Energy Physics - Phenomenology · Physics 2015-11-18 Rohini M. Godbole , Gaurav Mendiratta , Saurabh Rindani

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
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