Another relation among the neutrino mass-squared differences?

Abstract

Determining the absolute neutrino mass scale remains a compelling challenge in particle physics. Establishing precise mathematical connections among the neutrino masses could significantly facilitate this task and shed additional light on the underlying mass-generation mechanism. We highlight the possible existence of a simple algebraic relation between the mass-squared differences, $(\sqrt{\hat{I}”m_{31}^2}+\sqrt{\hat{I}”m_{21}^2})/(\sqrt{\hat{I}”m_{31}^2}-\sqrt{\hat{I}”m_{21}^2})=\sqrt{2}$, which exhibits excellent agreement with the central values of recent global fits of neutrino oscillation data. We investigate the implications of adopting this ansatz and how it reduces the number of independent parameters in the neutrino sector. Notably, for a vanishing $\hat{I}{½}_1$ mass, this expression directly simplifies to the elegant Fritzsch relation: $\sqrt{m_2/m_3}=\tan (\ddot{I}€/8)$.

6 pages, 1 table. Major revision to clarify exposition, typos corrected, references updated