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.
We study the electromagnetic contribution to elastic neutrino-proton and neutrino-neutron scattering processes. The neutrino electromagnetic charge, magnetic, electric, and anapole form factors of both diagonal and transition types in the mass basis are taken into account in the present formalism. When treating the nucleon electromagnetic vertex, we take into account not only the charge and magnetic form factors of a nucleon, but also its electric and anapole form factors. We examine how the effects of the neutrino magnetic moment can be disentangled from those of the strange quark contributio…
There is merely a short note on the selected issues of neutrino electromagnetic properties with focus on effects of new physics. The meaning of "new physics" is twofold: 1) a massive neutrino have nonzero electromagnetic properties that can be considered as manifestation of new physics beyond the Standard Model, and 2) in studies of neutrinos electromagnetic interactions new effects are predicted that can lead to new phenomena accessible for observations.
Search for electromagnetic properties of the neutrinos at the LHC
通过光子-光子聚变产生的中微子为在LHC上探测中微子的电磁性质提供了一个极好的机会。我们探讨了pp-> p gamma p -> p nu anti-nu p和pp -> p gamma p -> p nu anti-nu Z p过程探测中微子-光子和中微子-双光子耦合的可能性。我们发现,这些反应提供了超过7个数量级的改善中微子双光子耦合相比,LEP限制。
In studies of neutrino electromagnetic properties we discuss three very interesting aspects related to neutrino spin oscillations. First we consider neutrino mixing and oscillations in the mass and flavour bases under the influence of a constant magnetic field with nonzero transversal and longitudinal components. Then we discuss the effect of neutrino spin oscillations induced by electroweak interactions of neutrino with moving matter in case there is matter transversal current or polarization. In the final part of the paper we discuss recently developed approach to description of neutrino spi…
Continuing the discussion of the problem of electromagnetic properties of neutrinos, in this note we present additional information on this problem and focus on selected issues that have been developed recently, after the publication of our previous brief review on this topic [1].
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 k…
We study spin and spin-flavor oscillations of Dirac neutrinos in a plane electromagnetic wave with circular polarization. The evolution of massive neutrinos with nonzero magnetic moments in the field of an electromagnetic wave is based on the exact solution of the Dirac-Pauli equation. We formulate the initial condition problem to describe spin-flavor oscillations in an electromagnetic wave. The transition probabilities for spin and spin-flavor oscillations are obtained. In case of spin-flavor oscillations, we analyze the transition and survival probabilities for different neutrino magnetic mo…
Massive neutrinos have nonzero magnetic moments. It is known that the neutrino spin oscillations can be induced by the neutrino magnetic moment interaction with the transversal magnetic field. We perform a regions derivation of the effective neutrino evolution Hamiltonian in moving matter and show that spin oscillations can be engendered by the interaction with the transversal current of matter. The obtained general expression for the neutrino effective evolution Hamiltonian can be used for investigations of various types of neutrino spin oscillations in the transversal matter currents conside…
Electromagnetic properties of the neutrinos and the pion radiative decay
本文研究了中微子电磁偶极矩对辐射衰变$π\rightarrow e νγ$的影响。我们表明,占主导地位的新效应来自与中微子发射的光子的过程的振幅和结构相关的标准振幅之间的干扰。这种干涉只有在大质量中微子是马约拉纳费米子时才会发生。此外,由于电偶极矩和磁偶极矩产生相反符号的贡献,未来的实验可能能够区分它们。
We study future DUNE sensitivity to various electromagnetic couplings of neutrinos, including magnetic moments, milli-charges, and charge radii. The DUNE PRISM capabilities play a crucial role in constraining the electron flavored couplings. We find that DUNE will be able to place the strongest terrestrial constraint on the muon-neutrino magnetic moment by improving on LSND's bounds by roughly a factor of two, although Borexino's solar constraint will still be stronger. For the muon neutrino milli-charge DUNE can place the leading experimental bound, with two orders of magnitude improvement co…
We study oscillations of Dirac neutrinos in background matter and a plane electromagnetic wave. First, we find the new exact solution of the Dirac-Pauli equation for a massive neutrino with the anomalous magnetic moment electroweakly interacting with matter under the influence of a plane electromagnetic wave with the circular polarization. We use this result to describe neutrino spin oscillations in the external fields in question. Then we consider several neutrino flavors and study neutrino spin-flavor oscillations in this system. For this purpose we formulate the initial condition problem an…
The neutrino magnetic dipole moment is studied in a simple extension of the SM augmented with a scalar Leptoquark with quantum numbers $(\bar{\boldsymbol{3}},\boldsymbol{1},1/3)$. In order to reach a sizeable neutrino magnetic moment, we include in the framework the contribution of right-handed neutrinos and analytical result for the one-loop contribution of a scalar LQ is presented. The allowed parameter space is found through recent restrictions on the muon $(g-2)$, the $τ\to μγ$ and the $B_c \to τ^- \bar ν$ decay. It is shown that exist a region of the parameter space where the recent anoma…
Neutrino pair emission off electrons in a strong electromagnetic wave field
$ν\barν$的发射是在极化的超强电磁场(例如,激光)波场进行了分析。我们阐述了非线性电动力学效应的意义(即,多光子过程)和中微子生产的特殊性。特别注意的是致力于收敛的反应概率作为一个函数的吸收光子的数量。提供了大场强的表达式。电子和$μ+τ$中微子产生几率之间的不对称性取决于初始条件,如波场光子的能量和场强。这些结果不同于反应$γ+ e \to e' + ν\bar ν$的最低阶微扰计算。
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.
We consider the generation and evolution of magnetic field in a primordial plasma at temperature T < 1 MeV in presence of asymmetric neutrino background i.e. the number densities of right- handed and left-handed neutrinos are not same. Semi-classical equations of motion of a charged fermion are derived using the effective low-energy Lagrangian. It is shown that the spin degree of freedom of the charged fermion couples with the neutrino background. Using this kinetic equation we study the collective modes of the plasma. We find that there exist an unstable mode. This instability is closely rela…
After a brief reminder on the electromagnetic properties of neutrinos, the main processes of the electromagnetic interactions of neutrinos in astrophysics and the corresponding limitations on millicharges and effective magnetic moments of the particle are discussed.
After a brief introduction to neutrino electromagnetic properties we 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.