π−p→π−π+π−pReaction at 6 GeV/c

This report is based on the study of 2300 events representing the ${\pi }^{-}{\pi }^{+}{\pi }^{-}p$ final state produced by the interactions of 5.97-GeV/c ${\pi }^{-}$ mesons with protons in the Argonne National Laboratory 30-in. hydrogen bubble chamber. This final state has a cross section of 1.39±0.15 mb and is dominated by ${\rho }^0$ production (0.60±0.08 mb) and ${\Delta }^{++}\mathrm{}\left(1236\right)\mathrm{}$ production (0.39±0.06 mb). There is evidence for the production of $A_1$ and $A_{1.5}$ mesons in the $3\pi$ mass spectrum in addition to the $A_2$. Some characteristics of the $\pi \rho p$ and $\pi \pi \Delta$ final states can be explained with a double-Regge-exchange model.