Neutron Polarization inπ−pCharge-Exchange Scattering at 310 MeV

Abstract

We report the nleasurement of the polarization in the reaction rir-+p -+ 7.ro'fz a t an incident-pion kinetic energy (lab) of 310 MeV and at an angle of 30° in the c.m. system. The polarization v a s obtained from measurements of the left-right asymmetry in the scattering of the neutrons from liquid helium a t lab-scattering angles of 75" and 125". The measured polarization is 0.24rt0.07.

Measurement of the Polarization Parameter for the Reactionπ−p→π0nbetween 1.03 and 1.79 GeV/c

“…Charge-exchange polarization measurements have been made previously at higher energies, 1 primarily to test i high-energy interaction mechanisms, but except for one very rough measurement by Hill et al, 2 at 310 MeV, this marks the first time that measurements of P(0) have been made in a region where phase-shift analyses are available (<2 GeV/c). These measurements of P(9), together with recent results on the differential cross section for the charge-exchange reaction, 3 should provide a strong constraint on the solutions to the various phase-shift analyses.…”