  We have proposed a new method for the Coulomb wave function correction which
includes the momentum resolution for charged hadron pairs and applied it to the
precise data on pi^+pi^- correlations obtained in p + Ta reaction at 70 GeV/c.
It is found that interaction regions of this reaction (assuming Gaussian source
function) are 9.8+-5.8 fm and 7.7+-4.8 fm for the thicknesses of the target 8
micro m and 1.4 micro m, respectively. We have also analyzed the data by the
formula including strong interaction effect. The physical picture of the source
size obtained in this way is discussed.
