feynlag.suggest.suggest_yukawa

feynlag.suggest.suggest_yukawa(fermions, scalars, gauge_groups, discrete_groups=(), flavor_indices=None, max_dim=4, verify=True)[source]

Enumerate Yukawa / bare-mass / Weinberg invariants over fermion pairs.

Pairs run over ordered (F_L, F_R) of opposite chirality (two WeylFermions — vector-like fermions are two Weyls with identical reps, per CLAUDE.md). Each pair is offered every gauge-invariant scalar contraction (direct doublet, the H̃ pattern, or a bare mass); U(1) neutrality and discrete invariance filter, and the + h.c. partner is generated (Bilinear._eval_conjugate produces the correct P_L partner).

With max_dim >= 5 it also enumerates the dim-5 Weinberg operator (F ε H)(F ε H) — a same-chirality Majorana contraction of a doublet fermion with two doublet scalars, generating a Majorana neutrino mass after EWSB (majorana_mass_matrix() + diagonalize_takagi()).

Parameters:

  • flavor_indices – (i, j) symbols for the bar/field legs (default fresh i, j).

  • max_dim – mass-dimension ceiling (default 4; 5 admits the Weinberg operator).

Returns:

list of SuggestedTerm (sector "yukawa"), a minimal basis.