Hirofumi Kameyama

Coupled rearrangement channel calculations of muonic molecules and A =3 nuclei

Abstract We propose a coupled-rearrangement-channel Gaussian-basis variational method for precise calculations of non-adiabatic three-body systems. The method is applied to the muonic molecule (dtμ) which plays a decisive role in the muon catalyzed DT fusion. An extension is made to the muon transfer reaction (d μ ) 1s + t→(t μ ) 1s + d. The method is also applied to the trinucleon bound states, 3 H and 3 He, with the use of realistic two-nucleon and three-nucleon forces. We obtained fast and precise convergence of the calculated results with increasing number of three-body angular-momentum channels. Also shown is an extension of the method to the four-nucleon bound state, 4 He.

Virtual breakup effects in elastic scattering of polarized deuterons

Abstract Elastic scattering of polarized deuterons at Ed = 56 MeV is investigated for 16O, 40Ca, 58Ni, 118Sn and 208Pb target nuclei by the use of folding interactions. Effects of virtual breakup of the deuteron to S- and D-states in the continuum region are taken into account by the CDCC method and are found to make indispensable contributions to cross sections and analyzing powers, where continuum-continuum couplings are substantial. The contribution of the D-state admixture in the ground state is important for the tensor analyzing powers. The calculated results agree well with experimental data. The invariant-amplitude method and the second-order sum rule study clarify the characteristic feature of the spin dependence of the effective interactions due to the virtual breakup. The near-side/far-side decomposition of scattering amplitudes illuminates the difference of the reaction mechanism between light and heavy target nuclei. The investigation for the 208Pb target at Ed = 21.5 MeV gives important information on the energy dependence of the effective interactions. The use of different parameter sets for the input nucleon-target optical potentials shows that the detailed results depend significantly on the choice of the parameter sets.

Coupled-channel approach to deuteron elastic scattering at intermediate energy

Abstract Deuteron elastic scattering at 400 MeV is analyzed with the coupled-channel method to treat the deuteron breakup process. Substantial improvement over the single-folding optical model is obtained in the fit to the experimental cross section. Wine-bottle shaped nucleon optical potentials are superior to Woods—Saxon ones for the deuteron scattering, while both types of potentials reproduce proton-scattering data equally well.

Spin-dependent interactions and polarization observables in elastic scattering of deuterons at intermediate energies

Abstract Deuteron-nucleus spin-dependent interactions are investigated in elastic scattering at intermediate energies. Spin-space tensor amplitudes which characterize spin-dependent interactions are introduced by the invariant-amplitude method so that effects of T R - and T L -type tensor interactions are described separately. Through these amplitudes, numerical calculations based on the folding model clarify that the spin-orbit interactions produce T L -tensor like effects on the scattering amplitude as the higher-order effect and the virtual breakup contribution is only a minor part of this effect in most angles. An additional T L -type tensor interaction, phenomenologically introduced, is found to improve the fit to the experimental data of A yy considerably and A y in less magnitude. The origin of this interaction is discussed. The theoretical prediction is made of which observables enhance the effect of a particular spin-dependent interaction.

TR and TL tensor interactions in deuteron elastic scattering

Abstract For deuteron elastic scattering at intermediate energies, the tensor part of the scattering amplitude is approximately separated into the amplitude from the TR-type tensor interaction and that from the TL-type one. Numerical calculations justify this separation for the folding TR-type interaction and phenomenologically introduced TL-type ones. Some polarization quantities are shown to distinguish between these tensor interactions.

Relativistic dynamics of deuteron-nucleus scattering at intermediate energies

Abstract Three-body dynamics of deuteron scattering is described in relativistically covariant form to order 1 c 2 . For d+58Ni scattering at 700 MeV, the Thomas-precession correction to the internal motion of the deuteron is appreciable for Ayy at angles smaller than 25° where experimental data are available, while the Lorentz-contraction correction to the motion is quite small at the forward angles.

Deuteron breakup effect on deuteron elastic scattering

Abstract The method of coupled discretized continuum channels to treat deuteron breakup processes is applied to elastic scattering of polarized deuterons at 56 and 400 MeV with succeeding in reproducing the data. Effects of the processes are important on the spin-observables as well as the cross sections especially for Pb targets at 56 MeV. The effects are still important even at 400 MeV.