scholarly journals The impact of the Kaluza–Klein excitedWboson on the single top at the LHC and comparison with other models

2011 ◽  
Vol 38 (8) ◽  
pp. 085002 ◽  
Author(s):  
Seyed Yaser Ayazi ◽  
Mojtaba Mohammadi Najafabadi
Keyword(s):  
2018 ◽  
Vol 191 ◽  
pp. 02008 ◽  
Author(s):  
Eduard Boos ◽  
Viacheslav Bunichev ◽  
Georgi Vorotnikov ◽  
Lev Dudko ◽  
Igor Myagkov ◽  
...  

The impact of anomalous Wtb couplings on tWb process of the single top quark production has been probed in different schemes of tWb modeling. A special attention devotes to influence of the particular schemes to the anomalous couplings sensitivity. The distributions of representative variables demonstrate different behaviour in different simulation schemes, therefore the correct probe for anomalous Wtb couplings require specific approach to simulate BSM contribution. Special approach to search for BSM contribution in the off-shell tWb process is proposed in this paper. The approach is based on the kinematic separation of the double and single resonant contributions by means of neural network. The specific BSM properties are considered separately for the double and single resonant events. Such approach allows to add information on the anomalous Wtb coupling from simultaneous consideration of the tt¯ (double resonant) and tWb (off-shell, single resonant) contribution of tWb processes and therefore can improve the sensitivity to the anomalous Wtb couplings.


Author(s):  
Yeongkwon Son ◽  
Clifford Weisel ◽  
Olivia Wackowski ◽  
Stephan Schwander ◽  
Cristine Delnevo ◽  
...  

Health impacts of electronic cigarette (e-cigarette) vaping are associated with the harmful chemicals emitted from e-cigarettes such as carbonyls. However, the levels of various carbonyl compounds under real-world vaping conditions have been understudied. This study evaluated the levels of carbonyl compounds (e.g., formaldehyde, acetaldehyde, glyoxal, and diacetyl, etc.) under various device settings (i.e., power output), vaping topographies, and e-liquid compositions (i.e., base liquid, flavor types). The results showed that e-vapor carbonyl levels were the highest under higher power outputs. The propylene glycol (PG)-based e-liquids generated higher formaldehyde and acetaldehyde than vegetable glycerin (VG)-based e-liquids. In addition, fruit flavored e-liquids (i.e., strawberry and dragon fruit) generated higher formaldehyde emissions than mint/menthol and creamy/sweet flavored e-liquids. While single-top coils formed 3.5-fold more formaldehyde per puff than conventional cigarette smoking, bottom coils generated 10–10,000 times less formaldehyde per puff. In general, increases in puff volume and longer puff durations generated significantly higher amounts of formaldehyde. While e-cigarettes emitted much lower levels of carbonyl compounds compared to conventional cigarettes, the presence of several toxic carbonyl compounds in e-cigarette vapor may still pose potential health risks for users without smoking history, including youth. Therefore, the public health administrations need to consider the vaping conditions which generated higher carbonyls, such as higher power output with PG e-liquid, when developing e-cigarette product standards.


2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Avirup Shaw

AbstractWe measure the impact of nonvanishing boundary localised terms on $$\Delta B=2$$ Δ B = 2 transitions in five-dimensional Universal Extra Dimensional scenario where masses and coupling strengths of several interactions of Kaluza–Klein modes are significantly modified with respect to the minimal counterpart. In such scenario we estimate the Kaluza–Klein contributions of quarks, gauge bosons and charged Higgs by evaluating the one-loop box diagrams that are responsible for the $$\Delta B=2$$ Δ B = 2 transitions. Using the loop function (obtained from one-loop box diagrams) we determine several important elements that are involved in Wolfenstein parametrisation. Moreover, with these elements we also study the geometrical shape of unitarity triangle. Besides, we compute the quantity $$\Delta M_s$$ Δ M s scaled by the corresponding Standard Model value. Outcomes of our theoretical predictions have been compared to the allowed ranges of the corresponding observables simultaneously. Our current analysis shows that, depending on the parameters in this scenario the lower limit on the inverse of the radius of compactification can reach to an appreciable large value ($$\approx 1.48$$ ≈ 1.48 TeV or even higher).


2000 ◽  
Vol 483 (1-3) ◽  
pp. 203-209 ◽  
Author(s):  
A. Datta ◽  
P.J. O'Donnell ◽  
Z.-H. Lin ◽  
X. Zhang ◽  
T. Huang

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Christian Brønnum-Hansen ◽  
Kirill Melnikov ◽  
Jérémie Quarroz ◽  
Chen-Yu Wang

Abstract We compute the non-factorisable contribution to the two-loop helicity amplitude for t-channel single-top production, the last missing piece of the two-loop virtual corrections to this process. Our calculation employs analytic reduction to master integrals and the auxiliary mass flow method for their fast numerical evaluation. We study the impact of these corrections on basic observables that are measured experimentally in the single-top production process.


2020 ◽  
Vol 59 (10) ◽  
pp. 3023-3031
Author(s):  
Alim Ablat ◽  
Sayipjamal Dulat ◽  
Reyima Rashidin ◽  
Alim Ruzi ◽  
Nijat Yalkun
Keyword(s):  

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Miguel G. Folgado ◽  
Andrea Donini ◽  
Nuria Rius

AbstractWe study the possibility that Dark Matter (DM) particles of spin 0, 1/2 or 1 may interact gravitationally with Standard Model (SM) particles within the framework of a warped Randall–Sundrum (RS) model. Both the Dark Matter and the Standard Model particles are assumed to be confined to the infra-red (IR) brane and only interchange Kaluza–Klein excitations of the graviton and the radion (adopting the Goldberger–Wise mechanism to stabilize the size of the extra-dimension). We analyze the different DM annihilation channels and find that the presently observed Dark Matter relic abundance, $$\Omega _{\mathrm{DM}}$$ Ω DM , can be obtained within the freeze-out mechanism for DM particles of all considered spins. This extends our first work concerning scalar DM in RS scenarios (Folgado et al., in JHEP 01:161. 10.1007/JHEP01(2020)161, 2020) and put it on equal footing with our second work in which we studied DM particles of spin 0, 1/2 and 1 in the framework of the Clockwork/Linear Dilaton (CW/LD) model (Folgado et al., in JHEP 20:036. 10.1007/JHEP04(2020)036, 2020). We study the region of the model parameter space for which $$\Omega _{\mathrm{DM}}$$ Ω DM is achieved and compare it with the different experimental and theoretical bounds. We find that, for DM particles mass $$m_{\mathrm{DM}} \in [1,15]$$ m DM ∈ [ 1 , 15 ] TeV, most of the parameter space is excluded by the current constraints or will be excluded by the LHC Run III or by the LHC upgrade, the HL-LHC. The observed DM relic abundance can still be achieved for DM masses $$m_{\mathrm{DM}} \in [4,15]$$ m DM ∈ [ 4 , 15 ] TeV and $$m_{G_1} < 10$$ m G 1 < 10 TeV for scalar and vector boson Dark Matter. On the other hand, for spin 1/2 fermion Dark Matter, only a tiny region with $$m_{\mathrm{DM }} \in [4, 15]$$ m DM ∈ [ 4 , 15 ] TeV, $$m_{G_1} \in [5,10]$$ m G 1 ∈ [ 5 , 10 ] TeV and $$\Lambda > m_{G_1}$$ Λ > m G 1 is compatible with theoretical and experimental bounds. We have also studied the impact of the radion in the phenomenology, finding that it does not modify significantly the allowed region for DM particles of any spin (differently from the CW/LD case, where its impact was quite significant in the case of scalar DM). We, eventually, briefly compare results in RS with those obtained in the CW/LD model.


1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.


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