Comments on "On the Dirac-Majorana neutrinos distinction in four-body decays" (arXiv:2305.14140 [hep-ph], Phys. Rev. D 109, no.3, 033005 (2024))

TL;DR

This paper critiques a recent analysis claiming to distinguish Dirac from Majorana neutrinos via a specific decay process, arguing that the original analysis's use of back-to-back kinematics is flawed, invalidating its conclusions.

Contribution

The authors identify and explain errors in a recent study's use of back-to-back kinematics, emphasizing the importance of correct kinematic analysis in neutrino nature discrimination.

Findings

The original analysis's back-to-back kinematic approach is incorrect.

Correct analysis shows the original conclusions are invalid.

Highlights the necessity of proper kinematic configurations in neutrino studies.

Abstract

In arXiv:2305.14140 [hep-ph] the authors analyze the radiative leptonic decay $\ell^- \to \nu_\ell \, \overline{\nu}_{\ell'} \, \ell^{\prime -} \, \gamma$ to distinguish between Dirac and Majorana nature of neutrinos. They utilize the back-to-back kinematics for this purpose, a special kinematic configuration which we first proposed in our paper arXiv:2106.11785 [hep-ph]. Here we point out how and why their analysis of the back-to-back configuration is incorrect. This makes their conclusion and comments invalid and untenable.