Ryozo Tamagaki

Energy Gap in Nuclear Matter

An equation for the energy of the one particle mode and the energy gap of nuclear matter is directly solved in the momentum space for the realistic soft- core potentials without introducing ambiguities entering in the transformation to the configuration space. (C.E.S.)

ALPHA-CLUSTERING IN NUCLEAR MATTER AT LOW DENSITY

A gas of alpha particles is studied to get some idea of the mechanism of clustering in the surface region of heavy nuclei by considering this region to be represented by dilute nuclear matter. It is shown to be energetically more favorable for nucleons to cluster into alpha particles than to behave as single particles in a Fermi gas. The sparseness of nucleons in the surface region is the principal cause of cluster formation. (C.E.S.)

Two-Nucleon Potential with Full Recoil. III Detailed Discussions on Its Characteristic Features

Characteristic features of the nonstatic one- and two-pion-exchange potentials derived by Hoshizaki and Machicla are discussed in detail and compared with experimental data. The contents are on ( i) the difference between the ps- and pv-coupling cases, (ii) the need for taking account of effect clue to tl::e (3/2, 3/2) -resonance and (iii) weak tail of spin-orbit coupling potential. Possible indications that the pion-nucleon interaction may not be only of the ps-type but also of the pv-type are discussed.

Two-Nucleon Spin-Orbit Forces and the Doublet Splitting in Low Energy n-α Scattering

Doublet splitting in neutron-alpha reactions is investigated to study spin-orbit forces at low energies (less than 100 Mev). The pion theory of nuclear forces is used to predict spin-orbit forces as a part of two-pion- exchange potential. Other origins are possible, and the conditions to be imposed on strong spin-orbit effects are clarified by phenomenological analyses. It is found that the strong spin-orbit forces playing an important role at high energies become weaker at low energies, and therefore it is not appropriate to describe such effects of two-nucleon spin-orbit coupling beside the spin-orbit potential of twopion-exchange potential by spin-orbit potentials. (L.N.N.)