DELTA-I=1 AXIAL-VECTOR MIXING AND CHARGE-SYMMETRY BREAKING

Phenomenological Lagrangians that exhibit (broken) chiral symmetry as well as isospin violation suggest short-range charge symmetry breaking (CSB) nucleon-nucleon potentials with a sigma(1) .sigma(2) 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 Delta I-z = 1 charge symmetry breaking applied to meson and baryo n SU(2) mass splittings suggests a universal scale. This scale can be extended to Delta I = 1 nonstrange CSB transitions [a(1) degrees\H-em\ f(1)] of size -0.005 GeV2. The resulting nucleon-nucleon axial-vector meson exchange CSB potential then predicts Delta I = 1 effects which a re small.