Scattering of low energy neutrinos and antineutrinos by neon and argon

TL;DR

This paper applies a recently developed theoretical framework to calculate the energy spectra of ionization electrons produced by low energy neutrinos and antineutrinos scattering off neon and argon atoms, refining previous results.

Contribution

It provides new calculations of ionization spectra ratios for neon and argon using improved screening constants within the Bound Interaction Picture framework.

Findings

New spectra ratios for neon are larger than previous estimates by 0.03 to 0.14.

Integrated spectra ratios increase with neutrino energy, ranging from 0.16 to 0.59 for neon.

Results are presented as ratios to free electron scattering, highlighting the effects of atomic structure.

Abstract

The theory of scattering of low energy neutrinos and antineutrinos by atomic electrons has recently been developed (I. B. Whittingham, Phys. Rev. D 105, 013008 (2022)) using the Bound Interaction Picture in configuration space to fully implement the relationship between the neutrino helicities and the orbital and spin angular momenta of the atomic electrons. The energy spectra of ionization electrons produced by scattering of neutrinos and antineutrinos with energies of 5, 10, 20, and 30 keV by hydrogen, helium and neon were calculated using Dirac screened Coulombic eigenfunctions. This paper reports further applications of this theory, to a new calculation of the energy spectra for neon, as the original calculation used some screening constants which underestimated the effects of screening in the inner subshells, and to scattering by argon. The results are presented as ratios to the corresponding quantities for scattering by $Z$ free electrons. The new spectra ratios for neon are larger than the original ratios by approx 0.03 to approx 0.14, with the greatest increases occurring for 10 keV neutrinos and antineutrinos. Integrated spectra ratios range from 0.16 to 0.59 for neon, and from 0.15 to 0.48 for argon, as the neutrino energy increases from 5 to 30 keV.