scholarly journals Complete angular analysis of polarized top quark decay atO(αs)

2002 ◽  
Vol 65 (5) ◽  
Author(s):  
M. Fischer ◽  
S. Groote ◽  
J. G. Körner ◽  
M. C. Mauser
Keyword(s):  
Top Quark ◽  
Angular Analysis ◽  
Top Quark Decay ◽  
Quark Decay

scholarly journals Top physics at the LHC

2015 ◽  
Vol 30 (35) ◽  
pp. 1530063 ◽  
Author(s):  
Vittorio Del Duca ◽  
Eric Laenen
Keyword(s):  
Top Quark ◽  
Charge Asymmetry ◽  
Top Physics ◽  
Present Situation ◽  
Top Quark Mass ◽  
Single Top ◽  
Key Concepts ◽  
Theoretical Predictions ◽  
Top Quark Decay ◽  
Quark Decay

We review the present situation in top quark physics, in these early days of Run II of the LHC. We take mostly a Standard Model perspective, showing recent results, and review the key concepts and results of the associated theoretical predictions. The issues we discuss are the top quark mass, top quark pair and single top production, production in association with other particles, charge asymmetry and top quark decay.

scholarly journals NLO QCD corrections to off-shell $${t{\bar{t}}W^\pm }$$ production at the LHC: correlations and asymmetries

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Giuseppe Bevilacqua ◽  
Huan-Yu Bi ◽  
Heribertus Bayu Hartanto ◽  
Manfred Kraus ◽  
Jasmina Nasufi ◽  
...  
Keyword(s):  
Top Quark ◽  
Charge Asymmetry ◽  
New Physics ◽  
Atlas Collaboration ◽  
Narrow Width Approximation ◽  
Theoretical Predictions ◽  
Top Quark Decay ◽  
Quark Decay ◽  
Precision Observables ◽  
The Impact

AbstractRecent discrepancies between theoretical predictions and experimental data in multi-lepton plus b-jets analyses for the $$t{\bar{t}}W^\pm $$ t t ¯ W ± process, as reported by the ATLAS collaboration, have indicated that more accurate theoretical predictions and high precision observables are needed to constrain numerous new physics scenarios in this channel. To this end we employ NLO QCD computations with full off-shell top quark effects included to provide theoretical predictions for the $$\mathcal{R}= \sigma _{t{\bar{t}}W^+}/\sigma _{t{\bar{t}}W^-}$$ R = σ t t ¯ W + / σ t t ¯ W - cross section ratio at the LHC with $$\sqrt{s}=13$$ s = 13 TeV. Depending on the transverse momentum cut on the b-jet we obtain 2–3% theoretical precision on $$\mathcal{R}$$ R , which should help to shed some light on new physics effects that can reveal themselves only once sufficiently precise Standard Model theoretical predictions are available. Furthermore, triggered by these discrepancies we reexamine the charge asymmetry of the top quark and its decay products in the $$t{\bar{t}}W^\pm $$ t t ¯ W ± production process. In the case of charge asymmetries, that are uniquely sensitive to the chiral nature of possible new physics in this channel, theoretical uncertainties below 15% are obtained. Additionally, the impact of the top quark decay modelling is scrutinised by explicit comparison with predictions in the narrow-width approximation.

ONE-LOOP RADIATIVE CORRECTIONS TO A HEAVY TOP DECAY IN THE STANDARD MODEL

1991 ◽  
Vol 06 (27) ◽  
pp. 4925-4948 ◽  
Author(s):  
JIANG LIU ◽  
YORK-PENG YAO
Keyword(s):  
Top Quark ◽  
Asymmetry Parameter ◽  
Partial Width ◽  
Angular Distributions ◽  
Radiative Corrections ◽  
Inclusive Process ◽  
The Standard Model ◽  
Top Quark Decay ◽  
Quark Decay ◽  
Exclusive Or

We study one-loop radiative corrections to the top-quark decay: t→bW. For a heavy top (i.e. mt≳100 GeV ), simple analytic formulas are derived. For the inclusive process, t→bW+X due to QCD, cancellations of infrared and mass singularities are shown explicitly. The final result agrees with an earlier calculation in the literature, and is an 8% reduction in the partial width for αs=0.1. Also, leading terms of the electroweak corrections are shown to be proportional to an enhancement factor [Formula: see text]. Their effect is about 1-3%. We also study the angular distributions of the leptons from the subsequent exclusive (or semi-inclusive) W decay. An asymmetry parameter which measures the polarizations of the W is introduced. We find that it is sensitive to the QCD corrections especially in the vicinity of [Formula: see text].

scholarly journals Electroweak corrections to the top quark decay

2001 ◽  
Vol 64 (1) ◽  
Author(s):  
S. M. Oliveira ◽  
L. Brücher ◽  
R. Santos ◽  
A. Barroso
Keyword(s):  
Top Quark ◽  
Top Quark Decay ◽  
Quark Decay ◽  
Electroweak Corrections
Sign in / Sign up

Export Citation Format

Share Document