Di-pion System in the Reactionπ−p→nπ0π0at 1.6 to 2.4 GeV/c

Abstract

We report results from a high-statistics study of the reaction ${\pi }^{-}p\to n{\pi }^0{\pi }^0$ between 1.6 and 2.4 GeV/c, in which all the final-state particles were detected. The $2{\pi }^0$ mass spectrum exhibits a marked enhancement in the region of 800 MeV, which is narrower in width than predicted by the recently reported "down-down" solution for $I=0\mathrm{}$, $S$-wave, $\pi -\pi$ phase shifts.