ΔI=1 axial-vector mixing and charge symmetry breaking

الأصل · EN

Phenomenological Lagrangians that exhibit (broken) chiral symmetry as well as isospin violation suggest short-range charge symmetry breaking (CSB) nucleon-nucleon potentials with a σ₁ · σ₂ structure. This structure could be realized by the mixing of axial-vector (1+) mesons in a single-meson exchange picture. The Coleman-Glashow scheme for ΔIz=1 charge symmetry breaking applied to meson and baryon SU(2) mass splittings suggests a universal scale. This scale can be extended to ΔI=1 nonstrange CSB transitions a₁∘|Hem|f₁ of size -0.005 GeV². The resulting nucleon-nucleon axial-vector meson exchange CSB potential then predicts ΔI=1 effects which are small.