Neutrino Capture Reactions on $^{40}$Ar

TL;DR

This paper investigates neutrino capture on argon-40 using shell-model calculations, revealing enhanced cross sections for solar neutrinos and emphasizing the importance of higher multipole contributions at energies above 50 MeV.

Contribution

It provides a detailed shell-model analysis of Gamow-Teller strength in $^{40}$Ar and updates neutrino capture cross sections, including multipole effects at higher energies.

Findings

GT strength aligns with recent experimental data

Neutrino capture cross sections are higher than previous estimates

Higher multipole contributions are significant above 50 MeV

Abstract

Gamow-Teller (GT) strength in $^{40}$Ar is studied by shell-model calculations with monopole-based universal intearction, which has tensor components of $\pi$\rho$-meson exchanges. Calculated GT strength is found to be consistent with the experimental data obtained by recent ($p, n$) reactions. Neutrino capture cross sections on $^{40}$Ar for solar neutrinos from $^{8}$B are found to be enhanced compared with previous calculations. The reaction cross sections for multipoles other than $0^{+}$ and $1^{+}$ are obtained by random-phase approximation (RPA). Their contributions become important for neutrino energies larger than 50 MeV.