Forbidden transitions in neutral and chargedcurrent interactions between lowenergy neutrinos and argon
Abstract
Background: The study of lowenergy neutrinos and their interactions with atomic nuclei is crucial to several open problems in physics, including the neutrino mass hierarchy, C P violation, candidates of physics beyond the standard model, and supernova dynamics. Examples of experiments include CAPTAIN at the Spallation Neutrino Source (SNS) as well as DUNE's planned detection program of supernova neutrinos.
Purpose: We present cross section calculations for charged current and neutral current neutrinonucleus scattering at low energies, with a focus on ^{40}Ar. We also take a close look at pion decayatrest neutrino spectra, which are used in e.g. the SNS experiment at Oakridge.
Methods: We employ a HartreeFock + continuum random phase approximation (HF +CRPA ) framework, which allows us to model the responses and include the effects of longrange correlations. It is expected to provide a good framework to calculate forbidden transitions, whose contribution we show to be nonnegligible.
Results: Our results for a ^{56}Fe nucleus compare favorably to others models. Calculations performed for a ^{40}Ar target shows that the cross section contributions by 1^{} and 2^{} transitions in the continuum channels are nontrivial for the energies considered.
Conclusions: Forbidden transitions can be expected to contribute sizeably to the reaction strength at typical lowenergy kinematics. Modeling and Monte Carlo simulations need to take all due care to account for the influence of their contributions.
 Publication:

Physical Review C
 Pub Date:
 November 2019
 DOI:
 10.1103/PhysRevC.100.055503
 arXiv:
 arXiv:1903.07726
 Bibcode:
 2019PhRvC.100e5503V
 Keywords:

 Nuclear Theory
 EPrint:
 11 pages, 16 figures