"On the Flavor Yukawa coupling for the Lepton Mass Hierarchy and the Koide Relation" (Olivier Rousselle)
This paper builds on #327 by Shulga, using ansatze in a QFT framework. The author is French and cites the oft-overlooked Francis Goffinet; he seems to have a math PhD from Sorbonne and some association with a Louis de Broglie Foundation.
To obtain Higgs-fermion couplings for the charged leptons, he supposes a complex 3x3 field S which he calls a flavor spurion and which another author might have called a flavon. The field coupling schematically is
(left-fermion) (S-transpose) (Higgs) (S) (right-fermion)
S is supposed to initially possess a U(3) flavor symmetry that is broken to U(1) x Z3. This gives S a circulant vev and the charged lepton yukawa matrix is (S-transpose) (S). The Koide constant Q comes out as 2/3 because energies associated with the flavor-singlet and flavor-octet parts of S are assumed equal; the Brannen phase comes out as 2/9 because of a "topological condensation" that obeys a formula due to Shulga (equations 12-13 here).
I am here just paraphrasing the paper's own assertions. Whether the physical definitions and mechanisms actually make sense, I cannot yet testify, but it seems plausible that some version of them should make sense.
The paper also makes use of an alternative formulation of the Koide relation (ultimately due to Koide himself), in terms of quantities z0,...,z3, that
@arivero also used in a 2024 paper (see #277 forward, this thread). In Rousselle, these come from the singlet-octet decomposition of the eigenvalues of S; in Rivero, they are charges of preons, raising the question as to whether this Rousselle-Shulga scenario could be realized within Rivero's framework.