  Electromagnetic mass difference between neutral $K^*$ and charged $K^*$ has
been calculated in the $U(3)_L\times U(3)_R$ chiral fields theory of mesons. It
has been revealed that the non-abelian gauge structure of the massive
Yang-Mills lagrangian obeyed by $K^*$ plus VMD (vector meson dominace) causes
the EM-mass of neutral one larger than charged one. Experiment supports this
effect.
