feynlag.vacuum.masses.gauge_mass_matrix¶

feynlag.vacuum.masses.gauge_mass_matrix(kinetic, vacuum, gauge_components, tadpole_subs=None)[source]¶

Gauge boson mass matrix from the scalar kinetic sector.

Evaluates L_kin = (D_μ φ)†(D^μ φ) on the vacuum (where every scalar is constant, so all ∂_μ terms drop) and takes M²_ab = ∂² L_kin,vac / ∂A^a ∂A^b — the vector mass term in the Lagrangian is +½ M²_ab A^a A^b, no sign flip.

Parameters:

kinetic – the scalar kinetic Lagrangian (with PartialMu heads).
vacuum – Vacuum.
gauge_components – gauge boson component symbols (e.g. W1, W2, W3, B).

Returns:

Symmetric M² Matrix over gauge_components.