Spin observables in proton deuteron elastic scattering

Abstract

Some interesting aspects of spin observables in medium energy proton‐deuteron scattering are discussed. It is argued that measurements of spin observables in this reaction can provide new information on the three‐body (contact) interactions. Such an information is not available from measurements of NN observables and can be obtained from the analysis of the 12 amplitudes which describe p‐d elastic scattering. We discuss the sensitivity of the spin observables to such three‐body interactions in the framework of a realistic model in which each of these amplitudes is separated into 1) ‘‘trivial part,’’ involving single and double scattering terms, unambiguously expressible in terms of physical nucleon‐nucleon (NN) scattering amplitudes and 2) the ‘‘nontrivial part’’ which can not be expressed in terms of two‐body interactions, and represents contributions generated by three‐body forces. We find that the agreement between the data and the model predictions is considerably improved when such three‐nucleon inte...