Masaaki Kawaguchi

Effects of the Pion-Pion Interaction on Photonuclear Reactions

>Various effects of the pion-pion interaction on the photonuclear reactions through the phenomenological gamma -3 pi interaction are investigated. Processes discussed here are pion photoproduction, double pion photoproduction, and electromagnetic properties of the deuteron. The following problems are investigated in detail: angular distribution, polari-zation of the recoil proton, photopion with polarized gamma rays, for neutral pion photoproduction; and plus- minus ratio of charged pion photoproduction, double pion photoproduction. For the electromagnetic properties of the deutei on, magnetic moment, electric quadrupole moment, and photodisintegration are studied. The effective gamma -3 pi hamiltonian is given, and appropriate approximation is made for the I = J = 1 pion-pion resonance in the matrix elements of photoprocesses. These approximations of en lead to overestimation of the effects, as is criticized. (auth)

Some Comments on Models for Polarization Structure at High Energies

A number of simple intuitive models are considered for highenergy amplitudes of particle reactions and their consequences are calculated for high- energy nucleon-nucleon interaction in terms of predictions for the various experimental observables involving polarized particles. A prescription is given for the set of experiments which can test the models. (auth)

Radiative pion capture in 16O

Abstract The absolute values of the radiative capture rate in 16 O are predicted to be of order of 10 17 sec −1 by the shell model calculation. The observed peak of the gamma ray spectra is interpreted as the giant resonance similar to that of the photo absorption.

Photopion Production and (γ, 3 π) Interaction. II Polarization of the Recoil Proton

Effects of the ( gamma ,3 pi ) interaction on the polarization of the recoil proton from neutral pion photoproduction are investigated for 450 Mev and 600 Mev gamma rays. It is found that this interaction with a positive effective coupling constant contributes to the polarization negative in sense. The effect is surprisingly large for the recoil proton from large angle pion production, namely for the forward proton, while the effect on the angular distribution is only within experimental error. (auth)