arXiv subjects
Publications and source records attributed to Alexander Studenikin.
Phenomenology of possible neutrino millicharge in terrestrial and astrophysical settings is discussed. Two new limits on the millicharge from terrestrial experiments and astrophysics are reported.
Neutrino flavour oscillations in a nonuniformly moving matter are considered. The neutrino oscillation resonance condition in presence of matter, in the most general case when matter is moving with acceleration, is derived for the first time. We predict that the effect of matter acceleration can have significant influence on neutrino oscillations pattern in different astrophysical environments.
A short review on electromagnetic properties of neutrinos is presented. In spite of many efforts in the theoretical and experimental studies of neutrino electromagnetic properties, they still remain one of the main puzzles related to neutrinos.
The main goal of the paper is to give a short review on neutrino electromagnetic properties. In the introductory part of the paper a summary on what we really know about neutrinos is given: we discuss the basics of neutrino mass and mixing as well as the phenomenology of neutrino oscillations. This is important for the following discussion on neutrino electromagnetic properties that starts with a derivation of the neutrino electromagnetic vertex function in the most general form, that follows from the requirement of Lorentz invariance, for both the Dirac and Majorana cases. Then, the problem of the neutrino form factors definition and calculation within gauge models is considered. In particular, we discuss the neutrino electric charge form factor and charge radius, dipole magnetic and electric and anapole form factors. Available experimental constraints on neutrino electromagnetic properties are also discussed, and the recently obtained experimental limits on neutrino magnetic moments are reviewed. The most important neutrino electromagnetic processes involving a direct neutrino coupling with photons (such as neutrino radiative decay, neutrino Cherenkov radiation, spin light of neutrino and plasmon decay into neutrino-antineutrino pair in media) and neutrino resonant spin-flavor precession in a magnetic field are discussed at the end of the paper.
The spin light of neutrino is considered in the process of a neutrino radiative transition between two different mass states in presence of medium. By this study we investigate the influence of background matter on the initial and final neutrino states in the process of massive Dirac neutrino decay due to the non-zero transition magnetic moment. We derive corresponding corrections to the total width of the process over the matter density in most important for applications cases.
Using the exact solutions for the Dirac neutrino wave function in presence of matter we study the spin light mode in the process of neutrino transition from initial heavier to final lighter state. The spin light is emitted due to the neutrino nonzero transitional magnetic moment.
A short review on a neutrino magnetic moment is presented.
We consider the matter effects on neutrinos moving in background on the basis of the corresponding quantum wave equations. Both Dirac and Majorana neutrino cases are discussed. The effects for Dirac neutrino reflection and trapping as well as neutrino-antineutrino annihilation and $ν\overlineν$ pair creation in matter at the interface between two media with different densities are considered. The spin light of neutrino in matter is also discussed.
Exact solution of the modified Dirac equation in rotating medium is found in polar coordinates in the limit of vanishing neutrino mass. The solution for the active left-handed particle exhibit properties similar to those peculiar for the charged particle moving in the presence of a constant magnetic field. Accordingly, the particle in the rotating matter has circle orbits with energy levels, analogous to the Landau levels in magnetic field. The relevant physical realization of the problem is motion of neutrino inside the rotating neutron star. The feature of such motion to form binding states leads to the prediction of the new mechanism for neutrino trapping. The solution found can be used for detailed description of relativistic and nearly massless neutrino dynamics in neutron stars. Results obtained further develop the "method of exact solutions" in application to particle interactions in presence of dense matter.
We present quite a powerful method in investigations of different phenomena that can appear when neutrinos and electrons propagate in background matter. This method implies use of exact solutions of modified Dirac equations that contain the correspondent effective potentials accounting for the matter influence on particles. For several particular cases the exact solutions of modified Dirac and Dirac-Pauli equations for a neutrino and an electron in the background environment of different composition are obtained (the case of magnetized matter is also considered). Neutrino reflection, trapping, neutrino pair creation and annihilation in matter and neutrino energy quantization in a rotating medium are discussed. The neutrino Green functions in matter are also derived. The two recently proposed mechanisms of electromagnetic radiation by a neutrino and an electron in matter (the spin light of neutrino and electron, $SLν$ and $SLe$) are considered. A possibility to introduce an effective "matter-induced Lorentz force" acting on a neutrino and an electron is discussed. A new mechanism of electromagnetic radiation that can be emitted by an electron moving in the neutrino background with non-zero gradient of density is predicted.
We derive the modified Dirac equation for an electron undergos an influence of the standard model interaction with the nuclear matter. The exact solutions for this equation and the electron energy spectrum in matter are obtained. This establishes a rather powerful method for investigation of different processes that can appear when electrons propagate in background matter. On this basis we study in detail the spin light of electron in nuclear matter, a new type of electromagnetic radiation which can be emitted by an electron moving in dense matter.
We present a rather powerful method in investigations of different phenomena that can appear when neutrinos and electrons are moving in the background matter. This method is based on the use of the modified Dirac equations for the particles wave functions, in which the correspondent effective potentials that account for the matter influence on particles are included. The developed approach establishes a basis for investigation of different phenomena which can arise when neutrinos and electrons move in dense media, including those peculiar for astrophysical and cosmological environments. The approach developed is similar to the Furry representation of quantum electrodynamics, widely used for description of particles interactions in the presence of external electromagnetic fields, and it works when a macroscopic amount of the background particles are confined within the scale of a neutrino or electron de Broglie wave lengths. We consider the modified Dirac equations for neutrinos (of both Dirac and Majorana types) and electrons having the standard model interactions with the background matter, however generalization to extensions of the standard model is just straightforward. To illustrate how the developed method works, we elaborate the quantum theories of the spin light of neutrino ($SLν$) and spin light of electron ($SLe$) in matter.
We present a rather powerful method in investigations of different phenomena that can appear when neutrinos and electrons propagate in background matter. This method is based on the use of the modified Dirac equations for particles wave functions, in which the correspondent effective potentials accounting for the matter influence on particles are included.
Motivated by the need of elaboration of the quantum theory of the spin light of neutrino in matter ($SLν$), we have studied in more detail the exact solutions of the Dirac equation for neutrinos moving in the background matter. These exact neutrino wavefunctions form a basis for a rather powerful method of investigation of different neutrino processes in matter, which is similar to the Furry representation of quantum electrodynamics in external fields. Within this method we also derive the corresponding Dirac equation for an electron moving in matter and consider the electromagnetic radiation ("spin light of electron in matter", $SLe$) that can be emitted by the electron in this case.
We further generalize the powerful method, which we have recently developed for description of the background matter influence on neutrinos, for the case of an electron moving in matter. On the basis of the modified Dirac equation for the electron, accounting for the standard model interaction with particles of the background, we predict and investigate in some detail a new mechanism of the electromagnetic radiation that is emitted by moving in matter electron due to its magnetic moment. We have termed this radiation the ``spin light of electron" in matter and predicted that this radiation can have consequences accessible for experimental observations in astrophysical and cosmological settings.
A short review of the properties of the spin light of neutrino ($SLν$) in matter, supplied with some historical notes on the discussed subject, is given. It is shown that consideration of the $SLν$ in matter in hep-ph/0605114 is based on erroneous calculations which ignore the fact that the energy-momentum conservation law can not be violated for this process. An attempt to rename the $SLν$ in matter, undertaken in hep-ph/0606262, is groundless.
The relativistic theory of the inverse beta-decay of polarized neutron, $ν_{e} + n \to p + e ^{-}$, in strong magnetic field is developed. For the proton wave function we use the exact solution of the Dirac equation in the magnetic filed that enables us to account exactly for effects of the proton momentum quantization in the magnetic field and also for the proton recoil motion. The effect of nucleons anomalous magnetic moments in strong magnetic fields is also discussed. We examine the cross section for different energies and directions of propagation of the initial neutrino accounting for neutrons polarization. It is shown that in the super-strong magnetic field the totally polarized neutron matter is transparent for neutrinos propagating antiparallel to the direction of polarization. The developed relativistic approach can be used for calculations of cross sections of the other URCA processes in strong magnetic fields.
The claim of preprint hep-ph/0605114 that there is "no neutrino spin light because of photon dispersion in medium" is wrong.