Linked from
The 6 pages that link to SU(2), each with the reason it gives.
IsospinRelated: Isospin transformations have this mathematical symmetry structure.
Pauli matricesRelated: Exponentiating Pauli matrices produces generators of SU(2) rotations.
Electroweak theoryRelated: It supplies the weak-isospin gauge symmetry of the electroweak model.
3-sphereRelated: As a manifold, SU(2) is homeomorphic to the unit 3-sphere.