scholarly journals IMPLICATIONS OF $D^0$--$\overline{D^0}$ ON THE RARE TOP QUARK DECAYS t → uγ AND t → ug

2009 ◽  
Vol 24 (39) ◽  
pp. 3219-3226 ◽  
Author(s):  
J. I. ARANDA ◽  
A. CORDERO-CID ◽  
F. RAMÍREZ-ZAVALETA ◽  
J. J. TOSCANO ◽  
E. S. TUTUTI
Keyword(s):  
Top Quark ◽  
Mass Difference ◽  
Branching Ratios ◽  
Lagrangian Approach ◽  
Effective Lagrangian ◽  
Quark Decays ◽  
Model Independent

The recently observed mass difference of the [Formula: see text] mixing is used to predict the branching ratios of the rare top quark decays t → uγ and t → ug in a model-independent way using the effective Lagrangian approach. It is found that Br (t → uγ) < 4 × 10-4 and Br (t → ug) < 2 × 10-3, which may still be within reach of the LHC collider.

Revisiting rare top quark decays in the littlest Higgs Model with T-parity

2016 ◽  
Vol 31 (32) ◽  
pp. 1650165 ◽  
Author(s):  
Jinzhong Han ◽  
Bingfang Yang ◽  
Jitao Li
Keyword(s):  
Parameter Space ◽  
Top Quark ◽  
Branching Ratios ◽  
Higgs Model ◽  
Strong Constraint ◽  
Quark Decays

In this paper, we calculate rare top quark 2-body and 3-body decays in the littlest Higgs Model with T-parity (LHT). We find that the branching ratios of [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text] can be greatly enhanced in the LHT model in the allowed parameter space. The recent measurements of the decay [Formula: see text] can give a strong constraint on the LHT parameters and the decays of [Formula: see text] and [Formula: see text] can be accessible at the LHC.

scholarly journals Rare decays of the top quark mediated by Z′ gauge bosons and flavor violation

2020 ◽  
Vol 35 (18) ◽  
pp. 2050153
Author(s):  
J. I. Aranda ◽  
D. Espinosa-Gómez ◽  
J. Montaño ◽  
F. Ramírez-Zavaleta ◽  
E. S. Tututi
Keyword(s):  
Gauge Boson ◽  
Top Quark ◽  
Branching Ratios ◽  
Gauge Bosons ◽  
Flavor Violation ◽  
Gauge Symmetries ◽  
Quark Decays ◽  
The Standard Model ◽  
Order Of Magnitude ◽  
The One

The rare top quark decays mediated by a new neutral massive gauge boson that is predicted in models with extended gauge symmetries are studied. We focus on the processes [Formula: see text] induced at the one loop level, where [Formula: see text], by considering different extended models. It is found that, within a broad range of mass of the new neutral gauge boson, the models predict branching ratios for the decays in study that are competitive with respect to the corresponding branching ratios in the Standard Model (SM). In order to establish bound on our branching ratios, we consider the recent experimental bounds as [Formula: see text], depending on the model, which also impose restrictions on our calculation. Even in this case, the resulting branching ratios are of the same order of magnitude as that predicted by the SM. It should be noted that for the case of two models studied here, since no experimental bound exists to compare with, the results could be important, as they are, in the best of cases, two orders of magnitude larger than the predicted by the SM.

scholarly journals AnomaloustqγCouplings inγpCollision at the LHC

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
M. Köksal ◽  
S. C. İnan
Keyword(s):  
Confidence Level ◽  
Lagrangian Approach ◽  
Anomalous Couplings ◽  
Effective Lagrangian ◽  
Forward Detector ◽  
Incoming Proton ◽  
Model Independent

We have examined the constraints on the anomaloustqγ  (q=u,c)couplings through the processpp→pγp→pWbXat the LHC by considering four forward detector acceptances:0.0015<ξ<0.5,0.0015<ξ<0.15,0.015<ξ<0.15, and0.1<ξ<0.5, whereξ=Eγ/EwithEγandEthe energies of the photon and of the incoming proton, respectively. The sensitivity bounds on the anomalous couplings have been obtained at the 95% confidence level in a model independent effective Lagrangian approach. We have found that the bounds on these couplings can be highly improved compared to current experimental bounds.

TOP WINDOW FOR DARK MATTER

2011 ◽  
Vol 20 (08) ◽  
pp. 1413-1421 ◽  
Author(s):  
K. CHEUNG ◽  
K. MAWATARI ◽  
E. SENAHA ◽  
P.-Y. TSENG ◽  
T.-C. YUAN
Keyword(s):  
Dark Matter ◽  
Large Hadron Collider ◽  
Top Quark ◽  
Hadron Collider ◽  
Lagrangian Approach ◽  
Effective Lagrangian ◽  
Collider Signature

We consider a scenario in which a dark matter can couple only to the top quark. The analysis is conducted by using the effective Lagrangian approach. In the light of the latest data on dark matter, we obtain a maximally allowed magnitude of the coupling between the dark matter and the top quark. The collider signature at the Large Hadron Collider is also discussed.

scholarly journals Model-Independent Measurement of theW-Boson Helicity in Top-Quark Decays at D0

2008 ◽  
Vol 100 (6) ◽  
Author(s):  
V. M. Abazov ◽  
B. Abbott ◽  
M. Abolins ◽  
B. S. Acharya ◽  
M. Adams ◽  
...  
Keyword(s):  
Top Quark ◽  
Independent Measurement ◽  
Quark Decays ◽  
Model Independent
Sign in / Sign up

Export Citation Format

Share Document