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Alexander I. Studenikin

Publications and source records attributed to Alexander I. Studenikin.

At least 19 recordsLinked to original sources
arXiv2026

The potential of directional neutrino detection to observe neutrino spin oscillations

A nonzero neutrino magnetic moment arises already in the minimally extended Standard Model with right-handed massive Dirac neutrinos. The well-known consequence of the neutrino magnetic moment is the phenomenon of neutrino spin oscillations in a magnetic field. It can manifest itself not only as a lack in the flux of active cosmic neutrinos arriving on Earth but also as characteristic features in low-energy neutrino elastic scattering processes. Following our approach developed earlier, in this work we study the influence of arbitrary spin-flavor state of incoming neutrino on low-energy neutrino scattering off different particles in a detector. We demonstrate that superposition of left- and right-handed helicity neutrino states gives rise to an azimuthal asymmetry in the angular distribution of the recoil momenta. We present numerical calculations for elastic neutrino scattering on electrons, protons and 40Ar and 132Xe nuclei, demonstrating the azimuthal-asymmetry effect. Our results indicate the unique potential of directional neutrino detection to observe the neutrino spin oscillations.

hep-ph↗
arXiv2026

Electromagnetic interactions in elastic neutrino-nucleon scattering

A thorough account of electromagnetic interactions of massive Dirac neutrinos as well as their spin-flavor state in the theoretical formulation of elastic neutrino-nucleon scattering is given. The formalism of neutrino charge, magnetic, electric, and anapole form factors defined as matrices in the mass basis is employed under the assumption of three-neutrino mixing. The flavor and spin change of neutrinos propagating from the source to the detector is taken into account in the form of a spin-flavor density matrix of the neutrino arriving at the detector. The potential effects of the neutrino charge radii, magnetic moments, and spin polarization in the neutrino-nucleon scattering experiments are outlined.

hep-ph↗
arXiv2020

Constraints on neutrino millicharge and charge radius from neutrino-atom scattering

We consider possible effects of neutrino electric charge (millicharge) and charge radius on the neutrino-atom interaction processes such as (i) atomic ionization by neutrino impact and (ii) coherent elastic neutrino-nucleus scattering. The bounds on the neutrino millicharge and charge radius that follow from, respectively, the GEMMA and COHERENT experiments are presented and discussed.

hep-ph↗
arXiv2017

Spin-flavor oscillations of ultrahigh-energy cosmic neutrinos in interstellar space: The role of neutrino magnetic moments

A theoretical analysis of possible influence of neutrino magnetic moments on the propagation of ultrahigh-energy cosmic neutrinos in the interstellar space is carried out under the assumption of two-neutrino mixing. The exact solution of the effective equation for neutrino evolution in the presence of a magnetic field and matter is obtained, which accounts for four neutrino species corresponding to two different flavor states with positive and negative helicities. Using most stringent astrophysical bounds on the putative neutrino magnetic moment, probabilities of neutrino flavor and spin oscillations are calculated on the basis of the obtained exact solution. Specific patterns of spin-flavor oscillations are determined for neutrino-energy values characteristic of, respectively, the cosmogenic neutrinos, the Greisen-Zatsepin-Kuz'min (GZK) cutoff, and well above the cutoff.

hep-ph↗
arXiv2017

Electromagnetic interactions of neutrinos in processes of low-energy elastic neutrino-electron scattering

Electron energy and angular distributions in the process of low-energy elastic neutrino-electron scattering are treated in the free-electron approximation. The effects of the millicharges, magnetic, electric, and anapole moments of massive neutrinos along with the flavor change of neutrinos traveling from the source to the detector are taken into account under the assumption of three-neutrino mixing. The footprints of neutrino electromagnetic interactions in the electron energy and angle distributions are discussed.

hep-ph↗
arXiv2017

Electromagnetic properties of massive neutrinos in low-energy elastic neutrino-electron scattering

A thorough account of electromagnetic interactions of massive neutrinos in the theoretical formulation of low-energy elastic neutrino-electron scattering is given. The formalism of neutrino charge, magnetic, electric, and anapole form factors defined as matrices in the mass basis is employed under the assumption of three-neutrino mixing. The flavor change of neutrinos traveling from the source to the detector is taken into account and the role of the source-detector distance is inspected. The effects of neutrino flavor-transition millicharges and charge radii in the scattering experiments are pointed out.

hep-ph↗
arXiv2016

Neutrino-atom collisions

Neutrino-atom scattering provides a sensitive tool for probing nonstandard interactions of massive neutrinos in laboratory measurements. The ionization channel of this collision process plays an important role in experiments searching for neutrino magnetic moments. We discuss some theoretical aspects of atomic ionization by massive neutrinos. We also outline possible manifestations of neutrino electromagnetic properties in coherent elastic neutrino-nucleus scattering.

hep-ph↗
arXiv2015

Electromagnetic neutrinos in laboratory experiments and astrophysics

An overview of neutrino electromagnetic properties, which open a door to the new physics beyond the Standard Model, is given. The effects of neutrino electromagnetic interactions both in terrestrial experiments and in astrophysical environments are discussed. The experimental bounds on neutrino electromagnetic characteristics are summarized. Future astrophysical probes of electromagnetic neutrinos are outlined.

hep-ph↗
arXiv2014

New bounds on neutrino electric millicharge from GEMMA experiment on neutrino magnetic moment

Using the new limit on the neutrino anomalous magnetic moment recently obtained by GEMMA experiment we get an order-of-magnitude estimation for possible new direct upper bound on the neutrino electric millicharge $\mid q_ν \mid \sim 1.5 \times 10^{-12} e_0$ ($e_0$ is the absolute value of the electron charge) by comparing the neutrino magnetic moment and millicharge contributions to the total cross section at the electron recoil energy threshold of the experiment. This estimation is confirmed by the performed analysis of the GEMMA data using established statistical procedures and a new direct bound on the neutrino millicharge absolute value $\mid q_ν \mid < 2.7 \times 10^{-12} e_0 \ (90\% CL)$ is derived. This limit is more stringent than the previous one obtained from the TEXONO reactor experiment data that is included to the Review of Particle Properties 2012.

hep-ph↗
arXiv2014

New astrophysical limit on neutrino millicharge

An impact of a nonzero neutrino millicharge in astrophysics is tested. It is shown that in astrophysical environments electromagnetic interactions of the neutrino millicharge with strong electromagnetic fields as well as weak interactions of the neutrinos with dense background matter can produce new phenomena accessible for astrophysical observations. On this basis a new limit on the neutrino millicharge $q_0<1.3\times10^{-19}e_0$ is obtained. This limit is among the strongest astrophysical constraint on the neutrino millicharge. Some other possible applications of the obtained results to astrophysics are discussed in details.

hep-ph↗
arXiv2014

Electromagnetic neutrino: a short review

A short review on selected issues related to the problem of neutrino electromagnetic properties is given. After a flash look at the theoretical basis of neutrino electromagnetic form factors, constraints on neutrino magnetic moments and electric millicharge from terrestrial experiments and astrophysical observations are discussed. We also focus on some recent studies of the problem and on perspectives.

hep-ph↗
arXiv2014

Theory of ionizing neutrino-atom collisions: The role of atomic recoil

We consider theoretically ionization of an atom by neutrino impact taking into account electromagnetic interactions predicted for massive neutrinos by theories beyond the Standard Model. The effects of atomic recoil in this process are estimated using the one-electron and semiclassical approximations and are found to be unimportant unless the energy transfer is very close to the ionization threshold. We show that the energy scale where these effects become important is insignificant for current experiments searching for magnetic moments of reactor antineutrinos.

hep-ph↗
arXiv2014

Spin light of relativistic electrons in neutrino fluxes

A new mechanism of electromagnetic radiation by electrons under the influence of a dense neutrino flux, termed "the spin light of electron" in neutrino flux ($SLe_ν$), is considered. It is shown that in the case when electrons are moving against the neutrino flux with relativistic energy there is a reasonable increase of the efficiency of the energy transfer from the neutrino flux to the electromagnetic radiation by the $SLe_ν$ mechanism. The proposed radiation process is applied to an astrophysical environment with characteristics peculiar to supernovae. It is shown that a reasonable portion of energy of the neutrino flux can be transferred by the $SLe_ν$ to gamma-rays .

hep-ph↗
arXiv2014

Theory of neutrino-atom collisions: the history, present status and BSM physics

An overview of the current theoretical studies on neutrino-atom scattering processes is presented. The ionization channel of these processes, which is studied in experiments searching for neutrino magnetic moments, is brought into focus. Recent developments in the theory of atomic ionization by impact of reactor antineutrinos are discussed. It is shown that the stepping approximation is well applicable for the data analysis practically down to the ionization threshold.

hep-ph↗
arXiv2012

Flavor neutrino oscillations in matter moving with acceleration

A short review on studies of neutrino flavor oscillations in moving with a constant speed matter is presented. Then neutrino flavor oscillations in matter moving with acceleration are considered. We develop an approach that is valid for both non-relativistic and relativistic matter motion. For both these cases the effective neutrino potentials in accelerating matter are obtained and neutrino flavor oscillation probabilities and the Mikheyev-Smirnov-Wolfenstein resonance conditions are evaluated. The obtained results in the limit of zero matter acceleration reproduce the corresponding expressions for the case of matter at rest. The developed approach is applied for neutrino flavor oscillations in the case of rotating matter. The results obtained might be of interest for astrophysical applications.

hep-ph↗
arXiv2011

Electromagnetic neutrino-atom collisions: The role of electron binding

We present a new theoretical approach to neutrino-impact atomic excitation and/or ionization due to neutrino magnetic moments. The differential cross section of the process is given by a sum of the longitudinal and transverse terms, which are induced by the corresponding components of the force that the neutrino magnetic moment imposes on electrons with respect to momentum transfer. In this context, the recent theoretical studies devoted to the magnetic neutrino scattering on atoms are critically examined.

hep-ph↗