The first spin-transfer observables for the πd→pp reaction have been measured at a number of energies spanning the Δ resonance in this system. These parameters correspond to ${\mathit{K}}_{\mathit{S}\mathit{L}}$ and ${\mathit{K}}_{\mathit{S}\mathit{S}}$ of the pp→dπ reaction for incident proton energies ranging from 600 to 800 MeV. Such data can provide an important constraint on the determination of the partial-wave amplitudes describing this fundamental reaction. The discrepancies between our data, theoretical predictions, and values calculated from published partial-wave amplitudes demonstrate the need for further work in this area.

• Received 11 January 1991

DOI:https://doi.org/10.1103/PhysRevLett.66.2573