Comment on the article by D. Borah and B. Karmakar "Linear seesaw for Dirac neutrinos with A4 flavour symmetry", Phys. Lett. B789 (2019) 59-70, arXiv: 1806.10685

TL;DR

This comment critiques a proposed A4 flavoured linear seesaw model for Dirac neutrinos, highlighting missing interactions that alter the neutrino mass predictions and challenge previous conclusions about the neutrino mass spectrum.

Contribution

It identifies missing neutrino Yukawa interactions in the original model, leading to revised formulas and conclusions about neutrino mass spectra.

Findings

The inverted neutrino mass spectrum is not ruled out.

Missing interactions affect the effective neutrino mass calculations.

Revised formulas change the interpretation of the model's predictions.

Abstract

D. Borah and B. Karmakar in Phys. Lett. B789 (2019) have proposed an A4 flavoured linear seesaw model to realise light Dirac neutrinos. In this comment article, we show that some neutrino Yukawa interactions were missed in the model, thus implying that a different formula would be needed to determine the effective neutrino mass matrix, with significantly different results. Our result shows that, unlike stated in Phys. Lett. B789 (2019), that the inverted neutrino mass spectrum is not ruled out.