Doublet-triplet splitting
= Doublet-triplet splitting
In a minimal SU(5) scalar multiplet, the weak doublet and a colored triplet share a unified representation. The doublet must remain near the electroweak scale while the triplet is much heavier, notably to suppress <proton decay>. Arranging this splitting without an unprotected cancellation is a model-building problem distinct from merely embedding the <Standard Model> gauge group.