Yasuhisa Hiratsuka

Proton–proton phase shifts calculations in momentum space by a rigorous Coulomb treatment

We present a two-body calculation method for a rigorous treatment of Coulomb interaction in momentum (p-)space. The method is based on a modified Coulomb potential which is equivalent to the genuine Coulomb potential in configuration (r-)space. We also use the two-potential theory with the auxiliary potential. The calculated proton–proton phase shifts are in very good agreement with the experimental data for the states 0 ⩽ l ⩽ 2. The phase shifts for the 3 ⩽ l ⩽ 5 states are also calculated. Practical applications of our method in a few hadron problems are discussed.

D(p,p)D elastic scattering with rigorous Coulomb treatment

Low-energy D(p,p)D elastic scattering using a rigorous Coulomb treatment in momentum space is considered. The treatment is an extension of an exact two-body Coulomb theory?different from the approximate method which is based on a screened Coulomb potential. In contrast to the latter, the two-body Coulomb potential employed is fully equivalent to the pure Coulomb potential in configuration space. It is shown that the approximation based on the Coulomb half-shell function ensures the reliability of the renormalization method. The difference between the rigorous treatment and the approximate method is demonstrated by numerical results.

OFF-SHELL EFFECTS IN FEW-BODY SYSTEMS WITH COULOMB FORCE

The exact treatment of the two-body problem in momentum space in the presence of Coulomb forces is discussed. Convergence of the traditionally used renormalization approximation is investigated with respect to increasing ranges of the screened Coulomb potentials. The permissible energy range for this approximation is obtained for the first time in this work.

Three‐body force and Coulomb force in three‐body systems

We review a novel, rigorous three‐body Coulomb treatment that incorporates the mesonic three‐body force and the excited‐nucleon three‐body force such as the Fujita‐Miyazawa type. Our method is mainly based on many‐potential theory and the coupled‐channels method. We clarify the difference between our theory and the approximate Coulomb treatment in the renormalization technique of Alt‐Sandhas‐Ziegelmann (ASZ), by examining the two‐body and three‐body equations term by term. Furthermore, we demonstrate why the ASZ method can numerically converge to a finite value regardless of its validity.

A Three‐Body Faddeev Calculation of the Double Polarized 3He(d,p)4He Reaction in the Super Low‐Energy Region

The total cross section of the 3He(d,p)4He reaction at the super low‐energy region is calculated by the three‐body Faddeev equations in the 3He‐p‐n model. The result is compared with the “double polarized” total cross section in which both of the incident deuteron and the target 3He are set in a spin parallel way. The PEST potential for the p‐n interaction, the REST potential for the p‐3He and n‐3He interactions are adopted, respectively. The off‐shell importance of the p‐3He and n‐3He potentials is emphasized to reproduce the 5Li (3/2+) resonance. The cross section enhancement of 3He(d,p)4He reaction by the spin polarizations is confirmed.