feynlag.models.higgs_doublet¶

feynlag.models.higgs_doublet(SU2L, U1Y, v=246.0, mh=125.25, lam=None, extra_reps=None, name='H')[source]¶

The SM Higgs doublet with its VEV expanded and potential parameters.

Parameters:

SU2L – the electroweak gauge groups.
U1Y – the electroweak gauge groups.
v – the VEV (numeric default for ExternalParameter v).
mh – Higgs mass, used to fix lam = mh²/(2v²) when lam is not given.
lam – an explicit quartic value; overrides the mh-derived default (some models pin λ directly rather than through m_h).
extra_reps – additional {group: rep} charges to merge into the doublet (e.g. a U(1)_X charge for a Z′ model).
name – field name.

Returns:

(H, v_param, lam_param, mu2_param). mu2 is an InternalParameter (fixed later by the tadpole condition).