Spreading width of the isobaric analog state and isospin mixing

We study a relation between the spreading width of the isobaric analog state and the isospin mixing probability of the corresponding parent state by using the Feshbach projection method. The formula is applied for calculations of the spreading width of several heavy isotopes and compared with available experimental data. Contributions from isovector monopole states are found to be important to explain quantitatively the experimental spreading width. The isospin dependence of the calculated width of several isotopes is also found to be consistent with the experimental observations.