Electromagnetic interactions in elastic neutrino-nucleon scattering

Abstract

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.

Figures (4)

• Figure 1: The effect of the neutrino transition charge radii on the differential cross section for elastic neutrino-proton scattering in the cases of different initial neutrino spin states in the detector: (a) left-handed, (b) fully unpolarazed and (c) right-handed. The neutrino energy is $E_\nu=10$ MeV, which is typical for a supernova source.
• Figure 2: The same as in fig. \ref{['TCR']}, but in the case of the effective neutrino transition charge radii.
• Figure 3: The differential cross section for elastic neutrino-proton scattering in the cases of different initial neutrino states in the detector. Top, middle and bottom rows correspond to the electron, muon and tau flavors, respectively. Left, middle and right columns correspond to left-handed, fully unpolarizaed and right-handed neutrinos, respectively.
• Figure 4: The angular differential cross section for elastic neutrino-proton scattering in the cases of different initial neutrino spin states in the detector. In the first row, the 3d plot presents cross sections for fully unpolarized neutrinos (i) within the SM and (ii) accounting for neutrino magnetic moments of $10^{-11}\mu_B$, and the 2d density plot shows only the latter cross section. In the second row, the 3d plot compares the cross sections accounting for neutrino magnetic moments of $10^{-11}\mu_B$ in the cases of fully unpolarized and transversely polarized neutrinos, while the 2d density plot shows the difference between these cross sections. Finally, the third row is the same as the second row, but taking into account the effect of the SM charge radii and anapole moments.