Yasuo Hara

ON THE EXCHANGE MAGNETIC MOMENTS

The exchange magnetic moment operators for the two-nucleon system are obtained in terms of photopion production matrix elements. This photopion production part is closely related with the pion-nucleon scattering part, thus enabling one to use pi -N scattering experi-mental values in the expressions of the exchange magnetic moment operators. These formulas are applied to eases of triton magnetic moment and those of heavy nuclei (the Fermi gas model). In the former case, rather a good result is obtained, while in the latter it is found that exchange magnetic moments can explain only small parts of the deviations from the Schmidt lines. (auth)

Note on the Dispersion Relations in Nucleon-Nucleon Scattering and Resonances in Many-Pion System

Using dispersion relations as sum rules, a resonance in either the neutral vector or the neutral pseudoscalar boson state, or in both states of the many-pion system was found (Y. Hara, Progr. Theoret. Phys. (Kyoto), 26: 627 (1961)). Agreement of theory with experiment is improved by identifying the resonance with one found in p-p-bar annihilation, with mass at 787 Mev T = 0, and J = 1-. Results of calculations for unpolarized p-p forward scattering are presented in graphical form. (L.N.N.)

Note on the Low Energy Electron-Hydrogen Scattering

In a previous paper the low-energy electron-hydrogen scattering was discussed on the effective range approximation. An exa1aination of the energy range of the incident electron to which this method can be applied is presented. An error is corrected in the normalization of the ground state wave function of the negative hydrogen ion. A comparison is made of the results obtained by the variational method with those predicted by the effective rarge theory, (B.O.G.)

Low Energy Electron-Hydrogen Scattering

The effective range theory is developed for electron-hydrogen scattering. The scattering length a 8 and the effective range r0, of the singlet state are determined by making use of the accurate soluxad tion of the H- ion state, as a,=7.03, r08 =3.37 (in atc?mic unit). The scattering length a1 and the effective range r01 of the triplet state are calculated from the zero energy solution by a variation-perturbation method. The results are a1 =2.3.4, r01 =1.29.

On the full symmetry in Sakata model.

Some 1dnematical consequences of the full symmetry in the Sakata model on the scattering of mesons by baryons (p, n and A), and on baryon-(anti-)baryon scattering and on meson-meson scattering are derived. Some of the relations are compared with experiment. The agreement is not satisfactory at low energies as is expected because of the mass differences among nucleons and A-particle. Some of the disagreements may be explained if the renormalization effect, e. g. g2KNA is taken into account. Starting from ll:NA/ g~~N=2 which must be satisfied if the full symmetry holds good for particles without soft clouds, we find the ratio g2KNAfg2,.NN is consistent with the value 1/10, using the static theory. Relations among total cross sections in Gell-Manns scheme are also derived.

Two-Nucleon Problem and Dispersion Relation in Nucleon-Nucleon Scattering

A mathematical treatment for nucleon--nucleon interactions is presented in which dispersion relations with a unitary condition are used instead of the ordinary Schrodinger equations for the meson theoretical potential. The integral over the unphysical region is calculated exactly with the aid of Feymnan diagrams. The s-wave behavior at low energies and the d-state mixings of alpha -waves and of the deuteron are computed.