A
bstract
New physics can emerge at low energy scales, involving very light and very weakly interacting new particles. These particles can mediate interactions between neutrinos and usual matter and ...contribute to the Wolfenstein potential relevant for neutrino oscillations. We compute the Wolfenstein potential in the presence of ultra-light scalar and vector mediators and study the dependence of the potential on the mediator mass
m
A
, taking the finite size of matter distribution (Earth, Sun, supernovae) into consideration. For ultra-light mediators with
m
A
−
1
comparable to the size of the medium (
R
), the usual
m
A
−
2
dependence of the potential is modified. In particular, when
m
A
−
1
≫
R
, the potential does not depend on
m
A
. Taking into account existing bounds on light mediators, we find that for the scalar case significant effects on neutrino propagation are not possible, while for the vector case large matter effects are allowed for
m
A
∈ 2
×
10
−
17
, 4
×
10
−
14
eV and the gauge coupling
g ∼
10
−
25
.
A
bstract
We consider the low scale (10-100 TeV) left-right symmetric model with “naturally” small neutrino masses generated through the inverse seesaw mechanism. The Dirac neutrino mass terms are ...taken to be similar to the masses of charged leptons and quarks in order to satisfy the quark-lepton similarity condition. The inverse seesaw implies the existence of fermion singlets
S
with Majorana mass terms as well as the “left” and “right” Higgs doublets. These doublets provide the portal for
S
and break the left-right symmetry. The inverse seesaw allows to realize a scenario in which the large lepton mixing originates from the Majorana mass matrix of
S
fields which has certain symmetry. The model contains heavy pseudo-Dirac fermions, formed by
S
and the right-handed neutrinos, which have masses in the 1 GeV-100 TeV range and can be searched for at current and various future colliders such as LHC, FCC-ee and FCC-hh as well as in SHiP and DUNE experiments. Their contribution to neutrinoless double beta decay is unobservable. The radiative corrections to the mass of the Higgs boson and the possibility for generating the baryon asymmetry of the Universe are discussed. Modification of the model with two singlets (
S
L
and
S
R
) per generation can provide a viable keV-scale dark matter candidate.
We study in detail the Earth matter effects on the boron neutrinos from the Sun using recently developed 3D models of the Earth. The models have a number of new features of the density profiles, in ...particular, a substantial deviation from spherical symmetry. In this connection, we further elaborate on relevant aspects of oscillations ( ε2 corrections, adiabaticity violation, entanglement, etc.) and the attenuation effect. The night excesses of the ν e − and ν N − events and the day-night asymmetries, AND, are presented in terms of the matter potential and the generalized energy resolution functions. The energy dependences of the cross section and the flux improve the resolution, and consequently, sensitivity to remote structures of the profiles. The nadir angle ( η ) dependences of AND are computed for future detectors DUNE, THEIA, Hyper-Kamiokande, and MICA at the South pole. Perspectives of the oscillation tomography of the Earth with the boron neutrinos are discussed. Next-generation detectors will establish the integrated day-night asymmetry with high confidence level. They can give some indications of the η − dependence of the effect, but will discriminate among different models at most at the ( 1 − 2 ) σ level. For high-level discrimination, the MICA-scale experiments are needed. MICA can detect the ice-soil borders and perform unique tomography of Antarctica.
In this article, we report research data on the propagation of coupled surface TE and leaky TM polarized electromagnetic waves in a Goubau line (an perfectly conducting cylinder covered with a ...concentric dielectric layer) filled with an inhomogeneous nonlinear medium. The problem is solved using the Green function method. The new regimes of surface TE and leaky TM polarized waves in the Goubu line has been found. The method is an efficient way to analyze coupled surface TE and leaky TM waves.
We study TE-polarized electromagnetic waves propagating in an inhomogeneous dielectric waveguide of circular cross-section filled with a nonlinear medium where the nonlinearity is described by Kerr’s ...law. The existence of infinitely many nonlinear waves (surface as well as leaky) is proved. Sufficient conditions under which several waves can propagate are found, and the localization domains of the corresponding propagation constants are determined.
For the study of nonlinear multiparameter eigenvalue problems, a method of
Y
-mappings, making it possible to prove the existence of solutions, is proposed. The problem of propagation of coupled ...polarized electromagnetic waves in a nonlinear layer with saturating nonlinearity is studied. The concept of a
Y
-mapping, which puts into correspondence to the potential a special nonlinear function of several arguments: eigenfunctions of a linear problem, is defined. The multiparameter nonlinear eigenvalue problem is reduced to the problem of finding fixed points of
Y
-mappings. Using the Schauder theorem, the existence of an infinite set of fixed points of
Y
-mappings and, accordingly, solutions in a nonlinear multiparameter eigenvalue problem for sufficiently small values of the nonlinearity coefficient is proved.
A method is proposed for optimizing the diffraction efficiency of multilayer dielectric gratings in the problem of spectral addition of signals in a wide range of wavelengths. From a physical point ...of view, we pose a direct problem of electromagnetic wave diffraction on multilayer dielectric gratings for the solution of which a modified method of separation of variables is applied. To optimize the diffraction efficiency, a gradient method with a constant step is used, while the gradient is calculated analytically. Numerical results are presented.
We present an analysis of propagation of coupled electromagnetic TE-TE waves in a nonlinear plane waveguide located between two half-spaces with constant permittivities in which the permittivity of ...the guiding layer is described by a saturated nonlinearity. The physical problem is reduced to a nonlinear two-parameter eigenvalue problem for a system of nonlinear ordinary differential equations on a segment. Existence and uniqueness of solution to two-parameter eigenvalue problem is proved. Iteration method for solving given problem is presented. Convergence theorem of the iteration method is proved. Numerical results are presented.
The properties of the resonant frequency spectrum in the problem on the oscillations of 3D magnetodielectric resonators are studied. A theorem on the discreteness of the spectrum of resonant ...frequencies in the problem of oscillations in cavity resonators is proved. The problem is reduced to the analysis of a system of volumetric singular integral equations that defines a holomorphic Fredholm operator function of the spectral parameter. The system of Maxwell equations is solved in the case of a space with a dielectric ball by reduction to the solution of a scalar equation for Debye potentials. A characteristic equation of a radially three-layer ball with arbitrary sizes and permeabilities of the layers is obtained and studied.
A scalar three-dimensional boundary value problem of wave diffraction for the Helmholtz equation with transmission conditions that assume the presence of an infinitely thin material at the media ...interface is considered. Uniqueness and existence theorems for solutions are proved. The original problem is reduced to a system of integral equations over the media interface. Calculation formulas for the system of linear algebraic equations obtained after applying the collocation method and numerical results for solving the problem when the domain is a ball with certain transmission conditions are given.
PDF
