Reactionπd→pπnin theΔresonance region

Abstract

Differential cross sections for the reaction $^{2}\mathrm{H}({\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},p{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})n$ at incident pion momentum 340 MeV/c in a kinematically complete experiment are reported for eleven angle pairs. At neutron momenta \ensuremath{\lesssim} 40 MeV/c the cross section peaks sharply and is described well by an impulse approximation corrected for entrance channel effects; the ratio of ${\ensuremath{\pi}}^{+}$ to ${\ensuremath{\pi}}^{\ensuremath{-}}$ cross section is approximately 9 to 1. For neutron momenta \ensuremath{\gtrsim} 40 MeV/c, the data are well fit by a combination of a ${J}^{\ensuremath{\pi}}={2}^{+} N\ensuremath{\Delta}$ dibaryon resonance amplitude and an impulse approximation background; in some cases the ratio of ${\ensuremath{\pi}}^{+}$ to ${\ensuremath{\pi}}^{\ensuremath{-}}$ cross section is 1 to 1.NUCLEAR REACTIONS $^{2}\mathrm{H}({\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},p{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})n$, $p=340$ MeV/c; measured $\frac{{d}^{3}\ensuremath{\sigma}}{d{p}_{p}d{\ensuremath{\Omega}}_{p}d{\ensuremath{\Omega}}_{\ensuremath{\pi}}}$; model with DWIA, ${p}_{n}\ensuremath{\lesssim}40$ MeV/c; model with ${J}^{\ensuremath{\pi}}={2}^{+} T=1 N\ensuremath{\Delta}$ dibaryon resonance, ${p}_{n}\ensuremath{\gtrsim}40$ MeV/c.