Neutron-proton analyzing power measurements from 375 to 775 MeV

As part of an experimental study of the nucleon-nucleon interaction at medium energy, the free neutron-proton analyzing power Aₙ(θₙ*,Tₙ) has been measured at nine incident neutron energies in the range 375{≤}Tₙ{≤}775 MeV and for neutron c.m. angles in the range 57^∘{}{≤}θₙ*{≤}159^∘{}. Unpolarized neutrons with a broad continuum of energies, produced by interaction of an 800 MeV proton beam with a beryllium target, were scattered from a polarized proton target. At each angle, for the whole energy region, the scattered neutron and conjugate recoil proton were detected in coincidence. A previously unseen minimum is observed in the energy dependence of Aₙ(θ*{~}100^∘{}) near 625 MeV.