arXiv subjects

Alexey Lichkunov

Publications and source records attributed to Alexey Lichkunov.

4 recordsLinked to original sources

arXiv2025

Three-flavour neutrino oscillations in a magnetic field

In this paper we study Dirac and Majorana neutrino oscillations in a magnetic field in the three-flavour case. A theoretical framework developed in \cite{Popov:2019} is extended to the case of three neutrino species, as well as to the Majorana neutrinos case. The closed expression for the Dirac neutrinos flavour and spin oscillations are given. Majorana neutrino oscillations are studied numerically. We show that the probabilities exhibit a complicated interplay of oscillation on magnetic $μ_νB$ and vacuum $Δm^2_{ij}/2p$ frequencies. It is also shown that neutrino oscillations in an interstellar magnetic field can modify neutrino fluxes observed in neutrino telescopes.

hep-ph↗

arXiv2025

Neutrino quantum decoherence in a fluctuating ALPs field

The evolution of neutrinos in a fluctuating classical axion-like particles (ALPs) field is investigated. The equation for the neutrino density matrix is obtained in the Redfield form, and the corresponding dissipative matrix is derived. Estimates on the correlation time of the ALPs field fluctuations and on the ALP-neutrino coupling constants are obtained using the limits on the decoherence parameter determined from the analysis of reactor neutrino experiments data.

hep-ph↗

arXiv2023

Neutrino mixing angle and neutrino oscillation in ALPs matter

Axions and axion-like particles (ALPs) are among of the most popular candidates for dark matter. Axions are also considered as new physics contributions to the muon g-2. Following the existed interest to ALPs we consider interaction between neutrinos and hypothetical axion-like particles and derive for the first time the probability of neutrino oscillations accounting for their interactions mediated by ALPs. The corresponding effective mixing angle is derived.

hep-ph↗

arXiv2020

Neutrino eigenstates and flavour, spin and spin-flavour oscillations in a constant magnetic field

We develop the approach to the problem of neutrino oscillations in a magnetic field introduced in \cite{Popov:2019nkr} and extend it to the case of three neutrino generations. The theoretical framework suitable for computation of the Dirac neutrino spin, flavour and spin-flavour oscillations probabilities in a magnetic field is given. It is shown that there is an entanglement between neutrino flavour and spin oscillations and in the general case it is not possible to consider these two types of neutrino oscillations separately. The closed analytic expressions for the probabilities of oscillations are obtained accounting for the normal and inverted hierarchies and the possible effect of CP violation. In particular, it is shown that the probabilities of the conversions without neutrino flavor change, i.e. $ν_e^L \rightarrow ν_e^L$ and $ν_e^L \rightarrow ν_e^R$, do not exhibit the dependence on the CP phase, while the other neutrino conversions are affected by the CP phase. In general, the neutrino oscillation probabilities exhibit quite a complicated interplay of oscillations on the magnetic $μ_ν B$ and vacuum frequencies. The obtained results are of interest in applications to neutrino oscillations under the influence of extreme astrophysical environments, for example peculiar to magnetars and supernovas, as well as in studying neutrino propagation in interstellar magnetic fields.

hep-ph↗