scholarly journals Charged lepton flavor violating processes in neutrinophilic Higgs + seesaw model

2020 ◽  
Vol 2020 (7) ◽  
Author(s):  
Naoyuki Haba ◽  
Tsuneharu Omija ◽  
Toshifumi Yamada
Keyword(s):  
Charged Lepton ◽  
Higgs Field ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Charged Scalar ◽  
Yukawa Couplings ◽  
Scalar Particles ◽  
Lepton Flavor ◽  
Seesaw Model ◽  
The Right

Abstract We investigate charged lepton flavor violating (CLFV) processes in the “neutrinophilic Higgs + seesaw model”, in which right-handed neutrinos couple only with an extra Higgs field which develops a tiny vacuum expectation value and the right-handed neutrinos also have Majorana mass. The model realizes a seesaw mechanism around TeV scale without extremely small Dirac Yukawa couplings. A phenomenological feature of the model is CLFV processes induced by loop diagrams of the charged scalar particles and heavy neutrinos. Therefore, first we constrain the model’s parameter space from the search for $\mu\to e\gamma$. Next, we predict the branching ratios of other CLFV processes including the $\mu\to3e$, $\mu+{\rm Al}\to e+{\rm Al}$, $\mu+{\rm Ti}\to e+{\rm Ti}$, $Z\to e\mu$, $Z\to e\tau$, $Z\to \mu\tau$, $h\to e\tau$ and $h\to\mu\tau$ processes, and discuss their detectability in future experiments.

scholarly journals Muon and electron g − 2 and the origin of the fermion mass hierarchy

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Naoyuki Haba ◽  
Yasuhiro Shimizu ◽  
Toshifumi Yamada
Keyword(s):  
Charged Lepton ◽  
Higgs Sector ◽  
Vacuum Expectation ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Lepton Flavor Violation ◽  
Scalar Particles ◽  
Lepton Flavor ◽  
Flavor Violation ◽  
Charged Leptons

Abstract We present a model that gives a natural explanation to the charged lepton mass hierarchy and study the contributions to the electron and the muon $g-2$. In the model, we introduce lepton-flavor-dependent $U(1)_F$ symmetry and three additional Higgs doublets with $U(1)_F$ charges, to realize that each generation of charged leptons couples to one of the three additional Higgs doublets. The $U(1)_F$ symmetry is softly broken by $+1$ charges, and the smallness of the soft breaking naturally gives rise to the hierarchy of the Higgs vacuum expectation values, which then accounts for the charged lepton mass hierarchy. Since electron and muon couple to different scalar particles, each scalar contributes to the electron and the muon $g-2$ differently. We survey the space of parameters of the Higgs sector and find that there are sets of parameters that explain the muon $g-2$ discrepancy. On the other hand, we cannot find parameter sets that can explain the $g-2$ discrepancy within 2 $\sigma$. Here, the $U(1)_F$ symmetry suppresses charged lepton flavor violation.

scholarly journals The serendipity of electroweak baryogenesis

2018 ◽  
Vol 376 (2114) ◽  
pp. 20170124 ◽  
Author(s):  
Géraldine Servant
Keyword(s):  
Particle Physics ◽  
Dipole Moments ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Yukawa Couplings ◽  
Composite Higgs ◽  
The Standard Model ◽  
The Right ◽  
Right Order ◽  
The Universe

The origin of the matter–antimatter asymmetry of the universe remains unexplained in the Standard Model (SM) of particle physics. The origin of the flavour structure is another major puzzle of the theory. In this article, we report on recent work attempting to link the two themes through the appealing framework of electroweak (EW) baryogenesis. We show that Yukawa couplings of SM fermions can be the source of CP violation for EW baryogenesis if they vary at the same time as the Higgs is acquiring its vacuum expectation value, offering new avenues for EW baryogenesis. The advantage of this approach is that it circumvents the usual severe bounds from electric dipole moments. These ideas apply if the mechanism explaining the flavour structure of the SM is connected to EW symmetry breaking, as motivated for instance in Randall–Sundrum or Composite Higgs models. We compute the resulting baryon asymmetry for different configurations of the Yukawa coupling variation across the bubble wall and show that it can naturally be of the right order. This article is part of the Theo Murphy meeting issue ‘Higgs cosmology’.

scholarly journals Doubly Charged Higgs Bosons and Spontaneous Symmetry Breaking at eV and TeV Scales

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 153
Author(s):  
Janusz Gluza ◽  
Magdalena Kordiaczyńska ◽  
Tripurari Srivastava
Keyword(s):  
Gauge Group ◽  
Vacuum Expectation ◽  
Higgs Bosons ◽  
Symmetric Model ◽  
Charged Scalar ◽  
Scalar Particles ◽  
Lepton Flavor ◽  
Triplet Model ◽  
Standard Models ◽  
Doubly Charged

In this paper, beyond standard models are considered with additional scalar triplets without modification of the gauge group (Higgs Triplet Model—HTM) and with an extended gauge group S U ( 2 ) R ⊗ S U ( 2 ) L ⊗ U ( 1 ) (Left–Right Symmetric Model—LRSM). These models differ drastically in possible triplet vacuum expectation values (VEV). Within the HTM, we needed to keep the triplet VEV at most within the range of GeV to keep the electroweak ρ parameter strictly close to 1, down to electronvolts due to the low energy constraints on lepton flavor-violating processes and neutrino oscillation parameters. For LRSM, the scale connected with the S U ( 2 ) R triplet is relevant, and to provide proper masses of non-standard gauge bosons, VEV should at least be at the TeV level. Both models predict the existence of doubly charged scalar particles. In this paper, their production in the e + e − collider is examined for making a distinction in the s- and t- channels between the two models in scenarios when masses of doubly charged scalars are the same.

scholarly journals NONPERTURBATIVE FIELD CORRELATOR AND STRING REPRESENTATION FOR THE 't HOOFT LOOP AVERAGE IN THE ABELIAN HIGGS MODEL

1998 ◽  
Vol 13 (09) ◽  
pp. 659-671 ◽  
Author(s):  
D. V. ANTONOV
Keyword(s):  
Field Strength ◽  
Higgs Field ◽  
Exact Result ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
String Tension ◽  
Higgs Model ◽  
Effective Theory ◽  
Abelian Higgs Model ◽  
String Representation

Making use of the duality transformation, we derive in the Londons' limit of the Abelian Higgs model string representation for the 't Hooft loop average defined on the string worldsheet, which yields the values of two coefficient functions parametrizing the bilocal correlator of the dual field strength tensors. The asymptotic behaviors of these functions agree with the ones obtained within the method of vacuum correlators in QCD in the lowest order of perturbation theory. We demonstrate that the bilocal approximation to the method of vacuum correlators is an exact result in the Londons' limit, i.e. all the higher cumulants in this limit vanish. We also show that at large distances, apart from the integration over metrics, the obtained string effective theory (which in this case reduces to the nonlinear massive axionic sigma model) coincides with the low energy limit of the dual version of 4D compact QED, the so-called universal confining string theory. We derive string tension of the Nambu–Goto term and the coupling constant of the rigidity term for the obtained string effective theory and demonstrate that the latter is always negative, which means the stability of strings, while the positiveness of the former is confirmed by the present lattice data. These data enable us to find the Higgs boson charge and the vacuum expectation value of the Higgs field, which well-described QCD. We also study dynamics of the weight factor of the obtained string representation for the 't Hooft average in the loop space. In conclusion, we obtain string representation for the partition function of the correlators of an arbitrary number of Higgs currents, by virtue of which we rederive the structure of the bilocal correlator of the dual field strength tensors, which yields the surface term in the string effective action.

scholarly journals THE HIGGS SECTOR AND ELECTRON ELECTRIC DIPOLE MOMENT IN NEXT-TO-MINIMAL SUPERSYMMETRY WITH EXPLICIT CP VIOLATION

2006 ◽  
Vol 21 (03) ◽  
pp. 243-264 ◽  
Author(s):  
MÜGE BOZ
Keyword(s):  
Dipole Moment ◽  
Cp Violation ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Higgs Field ◽  
Higgs Sector ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Supersymmetric Model ◽  
Numerical Predictions

We study the explicit CP violation of the Higgs sector in the next-to-minimal supersymmetric model with a gauge singlet Higgs field. Our numerical predictions show that electric dipole moment of electron lies around the present experimental upper limits. The mass of the lightest Higgs boson is quite sensitive to the CP violating phases in the theory. It is observed that as the vacuum expectation value of the singlet gets higher values, CP violation increases.

scholarly journals Fermion mass hierarchies from supersymmetric gauged flavour symmetry in 5D

2021 ◽  
Vol 10 (6) ◽  
Author(s):  
Ketan Patel
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Fermion Mass ◽  
Order Unity ◽  
Anomaly Cancellation ◽  
Fundamental Parameters ◽  
Yukawa Couplings ◽  
Fifth Dimension ◽  
Fermion Masses ◽  
The Masses

A mechanism to generate realistic fermion mass hierarchies based on supersymmetric gauged U(1)_FU(1)F symmetry in flat five-dimensional (5D) spacetime is proposed. The fifth dimension is compactified on S^1/Z_2S1/Z2 orbifold. The standard model fermions charged under the extra abelian symmetry along with their superpartners live in the 5D bulk. Bulk masses of fermions are generated by the vacuum expectation value of N=2N=2 superpartner of U(1)_FU(1)F gauge field, and they are proportional to U(1)_FU(1)F charges of respective fermions. This decides localization of fermions in the extra dimension, which in turn gives rise to exponentially suppressed Yukawa couplings in the effective 4D theory. Anomaly cancellation puts stringent constraints on the allowed U(1)_FU(1)F charges which leads to correlations between the masses of quarks and leptons. We perform an extensive numerical scan and obtain several solutions for anomaly-free U(1)_FU(1)F, which describe the observed pattern of fermion masses and mixing with all the fundamental parameters of order unity. It is found that the possible existence of SM singlet neutrinos substantially improves the spectrum of solutions by offering more freedom in choosing U(1)_FU(1)F charges. The model predicts Z^\primeZ′ boson mediating flavour violating interactions in both the quark and lepton sectors with the couplings which can be explicitly determined from the Yukawa couplings.

scholarly journals FLAVOR SYMMETRY AND VACUUM ALIGNED MASS TEXTURES

2007 ◽  
Vol 16 (05) ◽  
pp. 1427-1436 ◽  
Author(s):  
SATORU KANEKO ◽  
HIDEYUKI SAWANAKA ◽  
TAKAYA SHINGAI ◽  
MORIMITSU TANIMOTO ◽  
KOICHI YOSHIOKA
Keyword(s):  
Scalar Potential ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Flavor Symmetry ◽  
Yukawa Couplings ◽  
Flavor Changing ◽  
Symmetry Approach ◽  
Mass Matrices ◽  
Vanishing Elements ◽  
Higgs Fields

A texture-zeros is an approach to reduce the number of free parameters in Yukawa couplings and it is one of the most attractive ones. In our paper, we discuss the origin of zero-structure in texture-zeros by S3 flavor symmetry approach. Some of electroweak doublet Higgs fields have vanishing vacuum expectation value (VEV) which leads to vanishing elements in quark and lepton mass matrices. Then, the structure of supersymmetric scalar potential is analyzed and Higgs fields have non-trivial S3 charges. As a prediction of our paper, a lower bound of a MNS matrix element, Ue3 ≥ 0.04, is obtained. The suppression of flavor-changing neutral currents (FCNC) mediated by the Higgs fields is discussed and lower bounds of the Higgs masses are derived.

scholarly journals Reconciling(g−2)μand charged lepton flavor violating processes through a doubly charged scalar

2016 ◽  
Vol 93 (11) ◽  
Author(s):  
Joydeep Chakrabortty ◽  
Pradipta Ghosh ◽  
Subhadeep Mondal ◽  
Tripurari Srivastava
Keyword(s):  
Charged Lepton ◽  
Charged Scalar ◽  
Lepton Flavor ◽  
Doubly Charged

scholarly journals Massive Quantum Vortex Excitations in a Pure Gauge Abelian Theory in 2 + 1D

1997 ◽  
Vol 12 (23) ◽  
pp. 4155-4165
Author(s):  
E. C. Marino ◽  
Flávio I. Takakura
Keyword(s):  
Canonical Ensemble ◽  
Three Dimensional ◽  
Higgs Field ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Quantum Vortex ◽  
Abelian Theory ◽  
Pure Gauge ◽  
Logarithmic Interaction ◽  
Grand Canonical

We introduce and study a pure gauge Abelian theory in 2 + 1D in which massive quantum vortex states do exist in the spectrum of excitations. This theory can be mapped in a three-dimensional gas of point particles with a logarithmic interaction, in the grand-canonical ensemble. We claim that this theory is the 2 + 1D analog of the sine–Gordon, the massive vortices being the counterparts of sine–Gordon solitons. We show that a symmetry breaking, order parameter, similar to the vacuum expectation value of a Higgs field does exist.

scholarly journals K0-K¯0 Mixing in the Minimal Flavor-Violating Two-Higgs-Doublet Models

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Natthawin Cho ◽  
Xin-Qiang Li ◽  
Fang Su ◽  
Xin Zhang
Keyword(s):  
Mass Difference ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Higgs Doublet ◽  
New Physics ◽  
Point Of View ◽  
Minimal Flavor Violation ◽  
Yukawa Couplings ◽  
Charged Higgs ◽  
Current Experimental Data

The two-Higgs-doublet model (2HDM), as one of the simplest extensions of the Standard Model (SM), is obtained by adding another scalar doublet to the SM and is featured by a pair of charged Higgs, which could affect many low-energy processes. In the “Higgs basis” for a generic 2HDM, only one scalar doublet gets a nonzero vacuum expectation value and, under the criterion of minimal flavor violation, the other one is fixed to be either color-singlet or color-octet, which are named as type III and type C 2HDM, respectively. In this paper, we study the charged-Higgs effects of these two models on the K0-K¯0 mixing, an ideal process to probe New Physics (NP) beyond the SM. Firstly, we perform a complete one-loop computation of the box diagrams relevant to the K0-K¯0 mixing, keeping the mass and momentum of the external strange quark up to the second order. Together with the up-to-date theoretical inputs, we then give a detailed phenomenological analysis, in the cases of both real and complex Yukawa couplings of the charged Higgs to quarks. The parameter spaces allowed by the current experimental data on the mass difference ΔmK and the CP-violating parameter ϵK are obtained and the differences between these two 2HDMs are investigated, which are helpful to distinguish them from each other from a phenomenological point of view.

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