scholarly journals Tau lepton charge asymmetry and new physics at the LHC

2011 ◽  
Vol 84 (3) ◽  
Author(s):  
Sudhir Kumar Gupta ◽  
German Valencia
Keyword(s):  
Charge Asymmetry ◽  
New Physics ◽  
Tau Lepton ◽  
Lepton Charge

scholarly journals Non-standard interactions in $\tau^- \to (\pi^-\eta,\pi^-\pi^0)\nu_{\tau}$ decays

2019 ◽  
Author(s):  
Gabriel Lopez Castro
Keyword(s):  
Weak Interactions ◽  
High Energy ◽  
New Physics ◽  
Tau Lepton ◽  
Tau Decays ◽  
Set Constraints ◽  
Belle Ii ◽  
Lepton Decays ◽  
Energy Processes ◽  
New Interactions

Originally thought as clean processes to study the hadronization of the weak currents, semileptonic tau lepton decays can be useful to set constraints on non-standard (NS) weak interactions. We study the effects of new interactions in \tau^- \to (\pi^-\eta,\pi^-\pi^0)\nu_{\tau}τ−→(π−η,π−π0)ντ decays and find that they are sensitive probes of these New Physics effects in the form of scalar and tensor interactions, respectively. Further improved measurements at Belle II will set limits on these scalar interactions that are similar to other low and high energy processes.

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.

scholarly journals Measurement of the Lepton Charge Asymmetry inW-Boson Decays Produced inpp¯Collisions

1998 ◽  
Vol 81 (26) ◽  
pp. 5754-5759 ◽  
Author(s):  
F. Abe ◽  
H. Akimoto ◽  
A. Akopian ◽  
M. G. Albrow ◽  
A. Amadon ◽  
...  
Keyword(s):  
Charge Asymmetry ◽  
Lepton Charge

scholarly journals Testing new physics models by top charge asymmetry and polarization at the LHC

2012 ◽  
Vol 85 (1) ◽  
Author(s):  
Junjie Cao ◽  
Kenichi Hikasa ◽  
Lin Wang ◽  
Lei Wu ◽  
Jin Min Yang
Keyword(s):  
Charge Asymmetry ◽  
New Physics

scholarly journals EFFECT OF BOTH Z AND Z′-MEDIATED FLAVOR-CHANGING NEUTRAL CURRENTS ON Bs →τ+τ- DECAY

2012 ◽  
Vol 27 (31) ◽  
pp. 1250184 ◽  
Author(s):  
S. SAHOO ◽  
D. BANERJEE ◽  
M. KUMAR ◽  
S. MOHANTY
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Rare Decay ◽  
Charge Asymmetry ◽  
Branching Ratio ◽  
New Physics ◽  
Neutral Currents ◽  
Flavor Changing ◽  
Potential Source ◽  
Flavor Changing Neutral Currents

In recent years, Bs →τ+τ- rare decay has attracted a lot of attention since it is very sensitive to the structure of standard model (SM) and potential source of new physics beyond SM. In this paper, we study the effect of both Z and Z′-mediated flavor-changing neutral currents on the Bs →τ+τ- decay. We find the branching ratio B(Bs→τ+τ-) is enhanced relative to SM prediction, which would help to explain the recently observed CP-violation from like-sign dimuon charge asymmetry in the B system.

scholarly journals Charge Asymmetry in Top Quark Pair Production

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1278
Author(s):  
Roman Lysák
Keyword(s):  
Elementary Particle ◽  
Pair Production ◽  
Top Quark ◽  
Charge Asymmetry ◽  
New Physics ◽  
Current Theory ◽  
Elementary Particles ◽  
Standard Deviations ◽  
Theoretical Side

The top quark is the heaviest elementary particle known. It has been proposed many times that new physics beyond the current theory of elementary particles may reveal itself in top quark interactions. The charge asymmetry in the pair production of a fermion and its antiparticle has been known for many decades. Early measurements of such asymmetry in top quark pair production showed a disagreement with the prediction by more than 3 standard deviations. Many years of an effort on both experimental and theoretical side have allowed to understand the top quark pair charge asymmetry better and to bring back the agreement between the measurements and the theory. In this article, these efforts are reviewed together with the discussion about a potential future of such measurements.

Sign in / Sign up

Export Citation Format

Share Document