Evidence that absorption in the π+ π− π− system in nuclear matter is stronger in the JP = 0− than in the JP = 1+ state☆

Abstract In the reaction π − + A → π + π − π − + A at 15.1 GeV/c the coherently produced 3π mass spectrum has a broad peak around 1.1 GeV which consists mainly of a J P = 1 + state and of a smaller fraction of 0 - . Comparing the observed dependence of the production of these diffractive states on the atomic weight A of the target nuclei with the optical model, we have studied the absorption of the produced states in nuclear matter. We have found the following values of the absorption cross-sections: σ 2 (0 - ) = 49 −7 +9 mb and σ 2 (1 + ) = 15.8 −1.3 +1.5 mb.