The presence of medium and external magnetic field change electromagnetic properties of neutrino. In this article the behavior of neutrino magnetic moment in electromagnetic field is considered. On the basis the Bargmann-Michel-Telegdi equation for the case of models with CP invariance and P nonconservation the new type of neutrino resonances $ u_L leftrightarrow u_R$ in the electromagnetic field is predicted.
Oscillations of neutrinos $ u_L leftrightarrow u_R$ in presence of an arbitrary electromagnetic field are considered. We introduce the Hamiltonian for the neutrino spin evolution equation that accounts for possible effects of interaction of neutrino
magnetic $mu$ and electric $epsilon$ dipole moments with the transversal (in respect to the neutrino momentum) and also the longitudinal components of electromagnetic field. Using this Hamiltonian we predict the new types of resonances in the neutrino oscillations $ u_L leftrightarrow u_R$ in the presence of the field of an electromagnetic wave and in combination of an electromagnetic wave and constant magnetic field. The possible influence of the longitudinal magnetic field on neutrino oscillations is emphasized.
The electromagnetic properties of neutrinos have attracted considerable attention from researchers for many decades (see [1] for a review). However, until recently, there was no indication in favour of nonzero electromagnetic properties of neutrinos
either from laboratory experiments with ground-based neutrino sources or from observations of astrophysical neutrino fluxes. The situation changed after the XENON collaboration reported [2] results of the search for new physics with low-energy electronic recoil data recorded with the XENON1T detector. The results show an excess of events over the known backgrounds in the recoil energy which, as one of the possible explanations, admit the presence of a sizable neutrino magnetic moment, the value of which is of the order of the existing laboratory limitations. In these short notes we give a brief introduction to neutrino electromagnetic properties and focus on the most important constraints on neutrino magnetic moments, charge radii and millicharges from the terrestrial experiments and astrophysical considerations. The promising new possibilities for constraining neutrino electromagnetic properties in future experiments are also discussed.
The electromagnetic properties of neutrinos, which are either trivial or negligible in the context of the Standard Model, can probe new physics and have significant implications in astrophysics and cosmology. The current best direct limits on the neu
trino millicharges and magnetic moments are both derived from data taken with germanium detectors with low thresholds at keV levels. In this paper, we discuss in detail a robust, ab initio method: the multiconfiguration relativistic random phase approximation, that enables us to reliably understand the germanium detector response at the sub-keV level, where atomic many-body physics matters. Using existing data with sub-keV thresholds, limits on reactor antineutrinos millicharge, magnetic moment, and charge radius squared are derived. The projected sensitivities for next generation experiments are also given and discussed.
The Spin Light of neutrino, the process that becomes possible in matter for a neutrino with nontrivial electromagnetic properties, is considered for the case of nonequal neutrino masses in the initial and final states.
The possibility of measuring neutral-current coherent elastic neutrino-nucleus scattering (CENNS) at the TEXONO experiment has opened high expectations towards probing exotic neutrino properties. Focusing on low threshold Germanium-based targets with
kg-scale mass, we find a remarkable efficiency not only for detecting CENNS events due to the weak interaction, but also for probing novel electromagnetic neutrino interactions. Specifically, we demonstrate that such experiments are complementary in performing precision Standard Model tests as well as in shedding light on sub-leading effects due to neutrino magnetic moment and neutrino charge radius. This work employs realistic nuclear structure calculations based on the quasi-particle random phase approximation (QRPA) and takes into consideration the crucial quenching effect corrections. Such a treatment, in conjunction with a simple statistical analysis, shows that the attainable sensitivities are improved by one order of magnitude as compared to previous studies.