ONE LOOP-INDUCED WZH COUPLING IN THE TWO HIGGS DOUBLET MODEL

1989 ◽  
Vol 04 (28) ◽  
pp. 2757-2766 ◽  
Author(s):  
THOMAS G. RIZZO
Keyword(s):  
Standard Model ◽  
Higgs Doublet ◽  
New Physics ◽  
Tree Level ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Charged Higgs ◽  
Doublet Model ◽  
The One ◽  
Two Higgs Doublet Model

Although absent at the tree level in models with only doublet and singlet Higgs representations, the WZH coupling can be induced at the one-loop level. We examine the size of this induced coupling in the two Higgs doublet model due to fermion as well as Higgs/gauge boson loops. Such couplings could provide a new mechanism for charged Higgs production at colliders and are ‘backgrounds’ to new physics beyond the Standard Model. We find, however, that these couplings are very weak for all regions of the parameter space explored.

scholarly journals Interplay of New Physics effects in (g − 2)ℓ and h → ℓ+ℓ− — lessons from SMEFT

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Svjetlana Fajfer ◽  
Jernej F. Kamenik ◽  
M. Tammaro
Keyword(s):  
Closed Operator ◽  
Higgs Doublet ◽  
New Physics ◽  
Effective Field ◽  
Tree Level ◽  
Electroweak Symmetry ◽  
Scalar Leptoquark ◽  
Doublet Model ◽  
The One ◽  
Two Higgs Doublet Model

Abstract We explore the interplay of New Physics (NP) effects in (g− 2)ℓ and h→ℓ+ℓ− within the Standard Model Effective Field Theory (SMEFT) framework, including one-loop Renormalization Group (RG) evolution of the Wilson coefficients as well as matching to the observables below the electroweak symmetry breaking scale. We include both the leading dimension six chirality flipping operators including a Higgs and SU(2)L gauge bosons as well as four-fermion scalar and tensor operators, forming a closed operator set under the SMEFT RG equations. We compare present and future experimental sensitivity to different representative benchmark scenarios. We also consider two simple UV completions, a Two Higgs Doublet Model and a single scalar LeptoQuark extension of the SM, and show how tree level matching to SMEFT followed by the one-loop RG evolution down to the electroweak scale can reproduce with high accuracy the (g−2)ℓ and h→ℓ+ℓ− contributions obtained by the complete one- and even two-loop calculations in the full models.

scholarly journals Detailed study of the Λb → Λcτν̄τ decay

2018 ◽  
Vol 33 (29) ◽  
pp. 1850169 ◽  
Author(s):  
E. Di Salvo ◽  
F. Fontanelli ◽  
Z. J. Ajaltouni
Keyword(s):  
Standard Model ◽  
Semileptonic Decay ◽  
Form Factors ◽  
Higgs Doublet ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Left Handed ◽  
The Standard Model ◽  
Analogous Formula ◽  
Two Higgs Doublet Model

We examine in detail the semileptonic decay [Formula: see text], which may confirm previous hints, from the analogous [Formula: see text] decay, of a new physics beyond the Standard Model. First of all, starting from rather general assumptions, we predict the partial width of the decay. Then we analyze the effects of five possible new physics interactions, adopting in each case five different form factors. In particular, for each term beyond the Standard Model, we find some constraints on the strength and phase of the coupling, which we combine with those found by other authors in analyzing the analogous semileptonic decays of [Formula: see text]. Our analysis involves some dimensionless quantities, substantially independent of the form factor, but which, owing to the constraints, turn out to be strongly sensitive to the kind of nonstandard interaction. We also introduce a criterion thanks to which one can discriminate among the various new physics terms: the left-handed current and the two-Higgs-doublet model appear privileged, with a neat preference for the former interaction. Finally, we suggest a differential observable that could, in principle, help to distinguish between the two cases.

scholarly journals IMPLICATION OF sin 2β FROM GLOBAL FIT AND B→J/ψKS

2001 ◽  
Vol 16 (28) ◽  
pp. 4547-4565 ◽  
Author(s):  
YUE-LIANG WU ◽  
YU-FENG ZHOU
Keyword(s):  
Standard Model ◽  
Higgs Doublet ◽  
New Physics ◽  
Current Data ◽  
Beyond The Standard Model ◽  
Flavor Violation ◽  
Flavor Changing ◽  
The Standard Model ◽  
Global Fit ◽  
The One

The measurement of sin 2β is discussed within and beyond the standard model. In the presence of new physics, the angle β extracted from the global fit (denoted by [Formula: see text]) and the one extracted from B→J/ψKS(denoted by βJ/ψ) are in general all different from the "true" angle β which is the weak phase of CKM matrix element [Formula: see text]. Possible new physics effects on the ratio [Formula: see text] is studied and parametrized in a most general form. It is shown that the ratio Rβmay provide a useful tool in probing new physics. The experimental value of Rβis obtained through an update of the global fit of the unitarity triangle with the latest data and found to be less than unity at 1σ level. The new physics effects on Rβfrom the models with minimum flavor violation (MFV) and the standard model with two-Higgs-doublet (S2HDM) are studied in detail. It is found that the MFV models seem to give a relative large value Rβ≥1. With the current data, this may indicate that this kind of new physics may be disfavored and alternative new physics with additional phases appears more relevant. As an illustration for models with additional phase beyond CKM phase, the S2HDM effects on Rβare studied and found to be easily coincide with the data due to the flavor changing neutral Higgs interaction.

scholarly journals CP violating effects in 210Fr and prospects for new physics beyond the Standard Model

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Nanako Shitara ◽  
Nodoka Yamanaka ◽  
Bijaya Kumar Sahoo ◽  
Toshio Watanabe ◽  
Bhanu Pratap Das
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Internal Electric Field ◽  
Many Body ◽  
The Standard Model ◽  
The Many ◽  
Two Higgs Doublet Model

Abstract We report theoretical results of the electric dipole moment (EDM) of 210Fr which arises from the interaction of the EDM of an electron with the internal electric field in an atom and the scalar-pseudoscalar electron-nucleus interaction; the two dominant sources of CP violation in this atom. Employing the relativistic coupled-cluster theory, we evaluate the enhancement factors for these two CP violating interactions to an accuracy of about 3% and analyze the contributions of the many-body effects. These two quantities in combination with the projected sensitivity of the 210Fr EDM experiment provide constraints on new physics beyond the Standard Model. Particularly, we demonstrate that their precise values are necessary to account for the effect of the bottom quark in models in which the Higgs sector is augmented by nonstandard Yukawa interactions such as the two-Higgs doublet model.

scholarly journals Grand Unified Origin of Gauge Interactions and Families Replication in the Standard Model

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 461
Author(s):  
António P. Morais ◽  
Roman Pasechnik ◽  
Werner Porod
Keyword(s):  
Standard Model ◽  
Higgs Doublet ◽  
New Physics ◽  
Effective Field ◽  
Tree Level ◽  
Emergent Properties ◽  
Grand Unified Theory ◽  
Yukawa Couplings ◽  
The Standard Model ◽  
Doublet Model

The tremendous phenomenological success of the Standard Model (SM) suggests that its flavor structure and gauge interactions may not be arbitrary but should have a fundamental first-principle explanation. In this work, we explore how the basic distinctive properties of the SM dynamically emerge from a unified New Physics framework tying together both flavor physics and Grand Unified Theory (GUT) concepts. This framework is suggested by a novel anomaly-free supersymmetric chiral E6×SU(2)F×U(1)F GUT containing the SM. Among the most appealing emergent properties of this theory is the Higgs-matter unification with a highly-constrained massless chiral sector featuring two universal Yukawa couplings close to the GUT scale. At the electroweak scale, the minimal SM-like effective field theory limit of this GUT represents a specific flavored three-Higgs doublet model consistent with the observed large hierarchies in the quark mass spectra and mixing already at tree level.

scholarly journals Direct CP violation in $$D^+ \rightarrow K^0({\bar{K}}^0) \pi ^+$$ decays as a probe for new physics

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
David Delepine ◽  
Gaber Faisel ◽  
Carlos A. Ramirez
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Parameter Space ◽  
Higgs Doublet ◽  
New Physics ◽  
Cp Asymmetry ◽  
The Standard Model ◽  
Doublet Model ◽  
Two Higgs Doublet Model ◽  
Cp Asymmetries

Abstract In this paper we investigate CP violation in charged decays of D meson. Particularly, we study the direct CP asymmetry of the Cabibbo favored non-leptonic $$D^+ \rightarrow {\bar{K}}^0 \pi ^+$$D+→K¯0π+ and the doubly Cabibbo-suppressed decay mode $$D^+ \rightarrow K^0 \pi ^+$$D+→K0π+ within standard model, two Higgs doublet model with generic Yukawa structure and left right symmetric models. In the standard model, we first derive the contributions from box and di-penguin diagrams contributing to their amplitudes which are relevant to the generation of the weak phases essential for non-vanishing direct CP violation. Then, we show that the generated phases are so tiny leading to null direct CP asymmetries of both decay modes. Regarding the two Higgs doublet model with generic Yukawa structure, after taking into account all constraints on the parameter space of the model, we show that the weak phases of the amplitudes can be enhanced compared to the standard model ones. However, the enhancement is still not enough to have sizable direct CP asymmetries. Finally, within left right symmetric models, we find that $$|A^{SM+LR}_{CP} (D^+ \rightarrow {\bar{K}}^0 \pi ^+)|\lesssim \mathcal {O}(10^{-3})$$|ACPSM+LR(D+→K¯0π+)|≲O(10-3) after respecting all relevant constraints on the parameter space of the model.

scholarly journals A final word on FCNC-Baryogenesis from two Higgs doublets

2021 ◽  
Vol 10 (6) ◽  
Author(s):  
Wei-Shu Hou ◽  
Tanmoy Modak ◽  
Tilman Plehn
Keyword(s):  
Higgs Doublet ◽  
Higgs Bosons ◽  
Beyond The Standard Model ◽  
Final Word ◽  
Flavor Changing ◽  
The Standard Model ◽  
Charged Higgs ◽  
General Search ◽  
Doublet Model ◽  
Two Higgs Doublet Model

Electroweak baryogenesis in a two-Higgs doublet model is a well-motivated and testable scenario for physics beyond the Standard Model. An attractive way of providing CP violation is through flavor-changing Higgs couplings, where the top-charm coupling is hardly constrained. This minimal scenario can be tested by searching for heavy charged and neutral Higgs bosons at the LHC. While the charged Higgs signature requires a dedicated analysis, the neutral Higgs signature will be covered by a general search for same-sign top pairs. Together, they provide a conclusive test of this kind of baryogenesis.

scholarly journals Fitting the $$ Zb\overline{b} $$ vertex in the two-Higgs-doublet model and in the three-Higgs-doublet model

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Darius Jurčiukonis ◽  
Luís Lavoura
Keyword(s):  
Experimental Data ◽  
Standard Model ◽  
Opposite Sign ◽  
Higgs Doublet ◽  
Yukawa Couplings ◽  
The Standard Model ◽  
Doublet Model ◽  
The One ◽  
Two Higgs Doublet Model

Abstract We investigate the new contributions to the parameters gL and gR of the $$ Zb\overline{b} $$ Zb b ¯ vertex in a multi-Higgs-doublet model (MHDM). We emphasize that those contributions generally worsen the fit of those parameters to the experimental data. We propose a solution to this problem, wherein gR has the opposite sign from the one predicted by the Standard Model; this solution, though, necessitates light scalars and large Yukawa couplings in the MHDM.

scholarly journals Finger printing the presence of extra scalars in the h → Vff′ forward-backward asymmetry

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Victor Ilisie
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Standard Model Prediction ◽  
Higgs Doublet ◽  
New Physics ◽  
The Standard Model ◽  
Model Predictions ◽  
Finger Printing ◽  
Doublet Model ◽  
Two Higgs Doublet Model

Abstract In this work we analyse the forward-backward asymmetry of the h → V f f′ decay in the Aligned two-Higgs Doublet Model. The Standard Model prediction for this asymmetry for V = W is small, as it suffers from Yukawa suppression and is absent for V = Z. This does not necessarily have to hold true in the Aligned model where these contributions can in principle be re-enhanced through the independent alignment factors ςf. In this analysis we conclude that, due to the additional contributions corresponding to the Aligned two-Higgs Doublet Model together with extra sources of CP-violation for the V = Z channel, the Standard Model predictions can be significantly modified in a great region of the parameter space. These deviations, that could be potentially measured at the High Luminosity LHC or future Higgs factories, would be a clear signal of new physics, and would shed new light on the possible extensions of the Standard Model and new sources of CP-violation.

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