scholarly journals PATHWAYS TO TESTABLE LEPTOGENESIS

2010 ◽  
Vol 25 (07) ◽  
pp. 501-509 ◽  
Author(s):  
PEI-HONG GU ◽  
UTPAL SARKAR
Keyword(s):  
Higgs Doublet ◽  
Neutrino Masses ◽  
High Scale ◽  
Cp Asymmetry ◽  
Decay Products ◽  
Doublet Model ◽  
Mass Degeneracy ◽  
Three Body ◽  
Two Higgs Doublet Model ◽  
Very High

In the conventional seesaw models of neutrino masses, leptogenesis occurs at a very high scale. Three approaches have been discussed in the literature to lower the scale of leptogenesis making them testable: mass degeneracy, hierarchy of couplings and three-body decays. We advocate yet another approach to a testable leptogenesis, whereby the decaying particles could go out of equilibrium at an accessible scale due to kinematics, although their couplings to the decay products are larger for generating a desired CP asymmetry. We demonstrate this new possibility for the testable leptogenesis in a two-Higgs doublet model where the neutrino masses originate from a one-loop diagram.

scholarly journals Dark matter, neutrino masses, and high scale validity of an inert Higgs doublet model

2015 ◽  
Vol 92 (1) ◽  
Author(s):  
Nabarun Chakrabarty ◽  
Dilip Kumar Ghosh ◽  
Biswarup Mukhopadhyaya ◽  
Ipsita Saha
Keyword(s):  
Dark Matter ◽  
Higgs Doublet ◽  
Neutrino Masses ◽  
High Scale ◽  
Scale Validity ◽  
Doublet Model

scholarly journals A two Higgs doublet model for dark matter and neutrino masses

2019 ◽  
Vol 795 ◽  
pp. 319-326 ◽  
Author(s):  
Daniel A. Camargo ◽  
Miguel D. Campos ◽  
Téssio B. de Melo ◽  
Farinaldo S. Queiroz
Keyword(s):  
Dark Matter ◽  
Higgs Doublet ◽  
Neutrino Masses ◽  
Doublet Model ◽  
Two Higgs Doublet Model

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 Probing electroweak baryogenesis induced by extra bottom Yukawa coupling via EDMs and collider signatures

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Tanmoy Modak ◽  
Eibun Senaha
Keyword(s):  
Yukawa Coupling ◽  
Top Quark ◽  
Hadron Collider ◽  
Higgs Doublet ◽  
Top Quark Mass ◽  
Cp Asymmetry ◽  
Systematic Uncertainties ◽  
Doublet Model ◽  
Two Higgs Doublet Model ◽  
Heavy Higgs Boson

Abstract We study the prospect of probing electroweak baryogenesis driven by an extra bottom Yukawa coupling ρbb in a general two Higgs doublet model via electric dipole moment (EDM) measurements and at the collider experiments. The parameter space receives meaningful constraints from 125 GeV Higgs h boson signal strength measurements as well as several heavy Higgs boson searches at the Large Hadron Collider (LHC). In addition, we show that the asymmetry of the CP asymmetry of inclusive B → Xsγ decay would provide complementary probe. A discovery is possible at the LHC via bg → bA → bZh process if |ρbb| ∼ 0.15 and 250 GeV≲ mA ≲ 350 GeV, where A is CP odd scalar. For mA> 2mt threshold, where mt is the top quark mass, one may also discover bg → bA →$$ bt\overline{t} $$ bt t ¯ at the high luminosity LHC run if an extra top Yukawa coupling |ρtt| ∼ 0.5, though it may suffer from systematic uncertainties. For completeness we study gg →$$ t\overline{t}A $$ t t ¯ A →$$ t\overline{t}b\overline{b} $$ t t ¯ b b ¯ but find it not promising.

scholarly journals Rare three-body decayt→chγ in the standard model and the two-Higgs doublet model

2006 ◽  
Vol 32 (4) ◽  
pp. 529-545 ◽  
Author(s):  
A Cordero-Cid ◽  
J L García-Luna ◽  
F Ramírez-Zavaleta ◽  
G Tavares-Velasco ◽  
J J Toscano
Keyword(s):  
Standard Model ◽  
Higgs Doublet ◽  
The Standard Model ◽  
Doublet Model ◽  
Three Body ◽  
Two Higgs Doublet Model

scholarly journals Neutrino masses in a two Higgs doublet model with a U(1) gauge symmetry

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Daniel A. Camargo ◽  
Alex G. Dias ◽  
Téssio B. de Melo ◽  
Farinaldo S. Queiroz
Keyword(s):  
Gauge Symmetry ◽  
Higgs Doublet ◽  
Neutrino Masses ◽  
Doublet Model ◽  
Two Higgs Doublet Model

scholarly journals Exploring new physics contributions to CP violation in $$\tau ^- \rightarrow K^-\pi ^0\nu _{\tau } $$

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
David Delepine ◽  
Gaber Faisel ◽  
Carlos A. Ramirez
Keyword(s):  
Cp Violation ◽  
Decay Rate ◽  
Standard Model Prediction ◽  
Form Factors ◽  
Higgs Doublet ◽  
Tensor Operator ◽  
Effective Hamiltonian ◽  
Cp Asymmetry ◽  
Doublet Model ◽  
Two Higgs Doublet Model

AbstractA general analysis of possible violation of CP in processes like $$\tau \rightarrow K\pi \nu $$ τ → K π ν , for unpolarized $$\tau $$ τ is presented. In this paper, we derive the new contributions to the effective Hamiltonian governs $$\vert \Delta S \vert =1$$ | Δ S | = 1 semileptonic tau decays in the framework of two Higgs doublet model with generic Yukawa structure and Leptoquarks models. Within these models, we list all operators, in the effective Hamiltonian and provide analytical expression for their corresponding Wilson coefficients. Moreover, we analyze the role of the different contributions, originating from the scalar, vecor and tensor hadronic currents, in generating direct CP asymmetry in the decay rate of $$\tau ^-\rightarrow K^-\pi ^0\nu _\tau $$ τ - → K - π 0 ν τ . We show that non vanishing direct CP asymmetry in the decay rate of $$\tau ^-\rightarrow K^-\pi ^0\nu _\tau $$ τ - → K - π 0 ν τ can be generated due to the presence of both, the weak phase in the Wilson coefficient corresponding to the tensor operator and the strong phase difference resulting from the interference between the form factors expressing the matrix elements of the vector and tensor hadronic currents. After taking into account all relevant constraints, we find that the generated direct CP asymmetry is of order $$10^{-8}$$ 10 - 8 which is several orders of magnitude larger than the standard model prediction. We show also that, in two Higgs doublet model with generic Yukawa structure , direct local or non integrated CP violation can be as large as 0.3 % not far from experimental possibilities. This kind of asymmetry can be generated due to the interference between vector and scalar contributions with different weak phases which is not the case in the SM.

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