Observables in Neutrino Mass Spectroscopy Using Atoms

TL;DR

This paper explores how atomic radiative emission of neutrino pairs (RENP) can be used to measure neutrino properties, including mass hierarchy, absolute mass scale, and whether neutrinos are Majorana or Dirac particles, using Yb atom transitions.

Contribution

It demonstrates the potential of RENP in atoms to determine neutrino mass hierarchy, absolute mass, and nature, highlighting the importance of atomic level energy differences.

Findings

RENP can provide information on neutrino mass hierarchy.

Sensitivity to neutrino nature depends on atomic level energy differences.

Potential to distinguish Majorana from Dirac neutrinos using atomic transitions.

Abstract

The process of collective de-excitation of atoms in a metastable level into emission mode of a single photon plus a neutrino pair, called radiative emission of neutrino pair (RENP), is sensitive to the absolute neutrino mass scale, to the neutrino mass hierarchy and to the nature (Dirac or Majorana) of massive neutrinos. We investigate how the indicated neutrino mass and mixing observables can be determined from the measurement of the corresponding continuous photon spectrum taking the example of a transition between specific levels of the Yb atom. The possibility of determining the nature of massive neutrinos and, if neutrinos are Majorana fermions, of obtaining information about the Majorana phases in the neutrino mixing matrix, is analyzed in the cases of normal hierarchical, inverted hierarchical and quasi-degenerate types of neutrino mass spectrum. We find, in particular, that the sensitivity to the nature of massive neutrinos depends critically on the atomic level energy difference relevant in the RENP.