Isospin breaking in scalar and pseudoscalar channels of radiative $J/\psi$-decays

Abstract

In the framework of simple assumption on factorizing a mixing of vector state with isoscalar components in effective amplitudes of isospin breaking caused by the electromagnetic quark current, a branching fraction of radiative $J/\psi \to a_0$ transition is evaluated at the level of $3\cdot 10^{-3}$.

Comments: 3 pages, revtex4 class, 2 eps-figures; reference, comment and acknowledgement added