arXiv subjects
Publications and source records attributed to A. Ternov.
We found a spin integral of motion for neutrino, which propagates in moving and polarized matter. The operator obtained opens up the possibility of consistent classification of neutrino states in such a medium and, as a consequence, a systematic description of the related physical phenomena. Using the operator, we obtain a dispersion relation for neutrinos and consider its particular cases.
We study the neutrino spin oscillations, i.e., neutrino spin precession caused by the neutrino interaction with matter polarized by external magnetic field (or, equivalently, by the interaction of the induced magnetic moment (IMM) of a neutrino with the magnetic field). In the analysis, we consider realistic conditions inside supernovae and discuss both the Dirac and Majorana cases. We show that due to the interaction with the polarized matter a neutrino flux from a supernova suffers additional attenuation at low neutrino energies. Another possible effect is that when taken together the effects of conventional magnetic moment and polarized matter can cancel each other so that under certain condition the oscillations disappear. We note that this can lead to the appearance of a characteristic maximum in the spectrum of electron neutrinos from supernovae. Accounting for neutrino mixing (in the two-flavor approximation) can significantly increase (almost twice) the effective value of the IMM of the electron neutrino. As a result, electron neutrinos with twice as high energy will be able to participate in the processes of spin conversion. Various feedback mechanisms accompanying the considered phenomena are also discussed.
We develop the theory of spin light of neutrino in matter ($SLν$) and include the effect of plasma influence on the emitted photon. We use the special technique based on exact solutions of particles wave equations in matter to perform all the relevant calculations, and track how the plasmon mass enters the process characteristics including the neutrino energy spectrum, $SLν$ rate and power. The new feature it induces is the existence of the process threshold for which we have found the exact expression and the dependence of the rate and power on this threshold condition. The $SLν$ spatial distribution accounting for the above effects has been also obtained. These results might be of interest in connection with the recently reported hints of ultra-high energy neutrinos $E = 1 ÷10$ PeV observed by IceCube.
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 quantum theory of the spin light of neutrino ($SLν$) exactly accounting for the effect of the background matter is developed. The $SLν$ rate and power, and also the emitted photon's energy are obtained for the different values of the neutrino momentum and density of matter. The spatial distribution of the radiation power and the dependence of the emitted photon's energy on the direction of radiation are studied. It is also shown that, in a wide range of the neutrino momentum and densities of matter, the $SLν$ radiation is characterized by nearly total circular polarization. Conditions for the effective neutrino spin-light radiation in the electron plasma are discussed.