H. Noya

Polarizations of spin 32 particles and 7Li58Ni interactions

Abstract New representations of polarizations of spin 3 2 particles are proposed for elastic scattering. They are useful in investigating spin-dependent interactions. The application to 7 Li 58 Ni scattering gives weak spin-orbit interactions and rather strong tensor ones of 7 Li.

Deuteron breakup by low-energy α-particles☆

Abstract An investigation of the 2 H(α, αp)n reaction at a lab energy of 15 MeV has been performed. Results from kinematically complete measurements at eleven angular combinations are presented and analyzed in terms of a semiphenomenological impulse approximation. It is found that if contributions from three-nucleon transfer reactions and n-p final state interactions as well as sequential reactions via states in 6 Li are included, it is possible to reach qualitative agreement with the data.

A study of the n-p final state interaction in the 2H(α, pα)n reaction at 18 MeV☆

Abstract Absolute cross sections of the 2 H(α, pα)n reaction have been measured at an incident energy and angle suitable for observing the effects of the n-p final state interaction (n-p FSI). The data are analysed by a semi-phenomenological modified impulse approximation (MIA). In the energy range E np ⪅ 0.6 MeV, destructive interference is clearly seen between the MIA matrix elements and n-p FSI.

The analysis of the q2q2 system based on the diquark cluster model

Abstract Based on the diquark cluster model, the widths and branching ratios of the q 2 q 2 states, which consist of u and d quarks, as well as the mass spectrum are predicted. The mass spectrum is calculated using a mass formula in which all of the parameters are determined using known baryon masses and experimental data for dibaryon resonances: no free parameters remain. The widths and branching ratios are also estimated by the use of an approximated formula in which experimental data for the masses and widths of the meson q q are used and again no free parameters remain. It is shown that the present model can explain in a satisfactory fashion the masses and the widths of many exotic mesons discovered recently in s s - depleted reactions.

Effects of imaginary potentials on the vector analyzing power in elastic scattering of polarized deuterons

Abstract In elastic scattering from nuclei, the vector analyzing powers of polarized deuterons are found to be strongly affected by the imaginary parts of optical potentials. A definite relationship is postulated between the analyzing power and the imaginary potential depth. The relationship shows that the shell-closure effect of the analyzing power observed for Se isotope targets is the reflection of the isotope dependence of the imaginary potential. Coupled-channel calculations show that some low-lying levels of the target nuclei are responsible for the isotope dependence. By the use of the relationship, deuteron scattering from medium-weight nuclei at incident energies of about 15 MeV are reanalyzed to give a systematic variation with target mass number for the potential parameters, which is emphasized by a nearly constant volume integral of the real potential per pair of interacting nucleons.

Vector analyzing power of polarized deuterons in elastic scattering

Abstract Isotope dependence of vector analyzing powers of polarized deuterons in elastic scattering off Se targets is discussed by optical-model and coupled-channel calculations. Attention is particularly directed to relations between analyzing power and imaginary potential.

Vector analyzing power in the 4He(d, p) reaction at 10–11 MeV☆

Abstract The vector analyzing power in the 4 He ( d , p ) reaction at 10–11 MeV deuteron energy is analyzed by using a semi-phenomenological method. The values for the free parameters are determined by an analysis of the 4He(d, αp)n reaction at 9 MeV deuteron energy. An excellent fit to the experimental data for the vector analyzing power as well as the absolute differential cross sections is obtained.

Comparison of A D(α, n)αp measurement with a modified impulse approximation prediction☆

Abstract A measurement of the polarization of neutrons from the D(α, n )αp reaction at 18° for Eα = 39.4 MeV compares favorably with a prediction given by a modified impulse approximation (semi-phenomenological method) although the need for some further improvements in the theory is indicated.

Measurement and semi-phenomenological analysis of the 2H(α, pα)n reaction at 18 MeV☆

Abstract Kinematically complete measurements of the 2 (α, pα)n reaction at 18 MeV lab energy have been performed at various pairs of angles θ p and θ α . The p-α quasi-free scattering peak cross sections show an angular dependence similar to that predicted in the plane wave impulse approximation. From the analysis in a modified impulse approximation, it is found that two correction terms reflecting the effects of the three-nucleon transfer reaction and 6 Li resonances are necessary to reproduce the data, as was the case for the 15 MeV 2 H(α, pα)n reaction.

Measurement and MIA analysis of the neutron differential cross section and polarization in the alpha -D break-up at 33 MeV c.m

Differential cross sections at 0 degrees and 20 degrees and polarizations at 20 degrees have been measured for the /sup 2/H( alpha ,n) alpha p reaction at /b E//sub alpha /=100 MeV and the /sup 4/He(d,n) alpha p reaction at /b E//sub d/=50 MeV. Data have been analyzed by the Modified Impulse Approximation (MIA). Satisfactory agreement was obtained but some discrepancy remained in the analysis of polarization data.