Speaker
Description
In the PMNS matrix, the relation $|U_{\mu i}| = |U_{\tau i}|$ (with $i = 1, 2, 3$) is currently favored by experimental data. This observation has sparked significant interest in the neutrino community due to its potential link to an underlying flavor symmetry. In this paper, we explore the implications of the condition $|U_{\mu i}| = |U_{\tau i}|$ within the framework of the canonical seesaw mechanism. While the minimal $\mu$-$\tau$ symmetry proposed in JHEP 06 (2022) 034 can explain this relation, we show that it is a sufficient but not necessary condition. In particular, we identify several other nontrivial scenarios that can also accommodate the observed PMNS matrix relation. Furthermore, we demonstrate that these scenarios are physically inequivalent, as evidenced by their distinct flavor invariants.
