"A2" Meson Production fromK−nInteractions at 3.9 GeV/c

Abstract

We report the observation of one narrow ${\rho }^0{\pi }^{-}$ resonance in the $A_2\mathrm{}\left(1300\right)\mathrm{}$ mass region with a width of 40 MeV or less from the reaction $K^{-}n\to \Lambda {\rho }^0{\pi }^{-}$. A spin-and-parity analysis of this narrow enhancement favors $J^{\mathrm{PC}}=1^{-+}$. Branching ratios for other decay modes are also given.