A formulation for description of $\pi^{+}(2\pi^{-})$ and $\pi^{-}(2\pi^{+})$ channels in Bose-Einstein correlation by Coulomb wave function

In order to analyze data on charged pions correlation channels, pi /sup +/(2 pi /sup -/) and pi /sup -/(2 pi /sup +/), we propose new interferometry approach using the Coulomb wave function. We show that to describe adequately data we have to introduce new parameter describing the contribution of pi /sup -/(k/sub 1/) pi /sup +/(k/sub 2/) to pi /sup -/(k/sub 2/) pi /sup +/(k/sub 1/) process. Using this new formula we analyze data on pi /sup +/(2 pi /sup -/) and pi /sup - /(2 pi /sup +/) channels at square root s =91 GeV by DELPHI Collaboration, and estimate the magnitude of this new parameter as well as the degree of coherence. (9 refs).