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The effects of three nucleon force (3NF) have been actively studied via the nucleon-deuteron ( Nd) scattering states. The differential cross sections and the vector analyzing powers A of the H( p, n) inclusive breakup reaction at 170 MeV were measured for the study of 3NF effects in the intermediate energy region. The polarized proton beam of 170 MeV was injected to the deuterated polyethylene (CD) target and the energy of scattered neutrons were measured by using TOF method. The data were compared with the Faddeev calculations based on modern nucleon-nucleon (NN) forces with and without the 3NF. Concerning the differential cross sections, we can see large discrepancies between the data and the calculations in the region of scattered neutron energies are low, which is similar to the results of the H( p, p) inclusive breakup reaction at 250 MeV. [ABSTRACT FROM AUTHOR]

For the study of three nucleon force (3NF) effects in the intermediate energy region, the differential cross sections and the vector analyzing power A were measured for the H( p, n) inclusive breakup reaction at 170 MeV. The polarized proton beam of 170 MeV was injected to the deuterated polyethylene (CD) target and the energy of scattered neutrons were deduce by TOF method. The data was compared with the results of the Faddeev calculations with and without 3NFs. Concerning about the differential cross sections, we can see large discrepancies between the data and the calculations in the region where the energies of scattered neutrons are low, which are similar to the results of the H( p, p) inclusive breakup reaction at 250 MeV. [ABSTRACT FROM AUTHOR]

The effects of three-nucleon force (3NF) has been actively studied by using the nucleon-deuteron ( Nd) scattering states. The differential cross sections of the elastic Nd scattering at the energy below 150 MeV can be well reproduced by incorporating 3NF in the Faddeev calculation based on modern nucleon-nucleon (NN) interactions. On the other hand, the differential cross sections of Nd elastic and inelastic scatterings at 250 MeV show large discrepancies between the data and the Faddeev calculations with 3NF. It indicates the presence of the missing features of the three nucleon system at this energy region. For the systematic study about the energy dependence of this large discrepancies, we measured the differential cross sections and the vector analyzing power A for the H( p, n) inclusive breakup reaction at 170 MeV. The experiment was carried out at RCNP by detecting scattered neutrons by using the neutron detector NPOL3. The data was compared with the results of the Faddeev calculations with and without the 3NF. [ABSTRACT FROM AUTHOR]

Under the assumption of good isospin symmetry, Tz = ±3/2 → ±1/2 Gamow-Teller (GT) transitions in a mass A isobar are analogous, where Tz is the z component of isospin T defined by 1/2(N - Z). We studied the Tz = +3/2 → +1/2 GT transitions by using the 37Cl(3He,t)37Ar and 41K(3He,t)41Ca reactions at Ebeam = 140 MeV/nucleon. The GT transition strengths in 37Ar and 41Ca were obtained up to the excitation energy (Ex) of 14.2 MeV and 10.4 MeV with energy resolutions of 30 and 35 keV, respectively. The obtained GT strengths were compared with those of the Tz = -2/3 → -1/2 mirror transitions, measured by the β-decay of 37Ca and 41Ti, respectively. It was found that the overall distributions of the mirror transitions were similar in both A = 37 and A = 41 systems. In A = 37 the differences seen at lower excitation energies are suggested to be the effect of the tensor interaction in the charge-exchange reaction. The differences seen at higher excitation energies are suggested to be the effect of the Coulomb interaction that can break the mirror symmetry of the strength distributions. [ABSTRACT FROM AUTHOR]

We made again an experiment of pd radiative capture at $E_{\vec d} = 197\, {\rm MeV}$, and obtained Axx, Ayy and Azz (= -Axx - Ayy) data using a newly-developed data-analysis method of high detection efficiency. Re-analysis of previous data on Axx and Ayy was also made using a new method. All the new and previous data at 197 MeV agree to each other, and Axx anomaly has been confirmed. [ABSTRACT FROM AUTHOR]

The cluster structures of the excited states in 11B and 13C were discussed by measuring the isoscalar monopole strengths in the inelastic α scattering at Eα = 388 MeV. It was found that the $1/2^-_2$, $1/2^-_3$, and $1/2^-_4$ states in 13C are candidates for the α cluster states with a 3α + n molecular configuration. [ABSTRACT FROM AUTHOR]

The investigation of the spin structure of d, 3H, and 3He has been performed at the RIKEN acceleration research facility and VBLHE. Vector A y and tensor A yy , A xx , A xz analyzing powers for $$ \vec d $$ d → 3He n and $$ \vec d $$ d → 3H p are presented at 270 MeV. Themirror channels (3He n and 3H p) are comparedto each other in order to find possible manifestation of charge-symmetry breaking. The preliminary results on the polarization observables for $$ \vec d $$ d → 3H p at 200MeV are also presented. The obtained data are compared with one-nucleon-exchange calculations.As a byproduct, $$ \vec d $$ d → pX and $$ \vec d $$ 12C → pX breakup reactions are investigated at 140, 200, and 270MeV. The experimental data on $$ \vec d $$ p elastic scattering were obtained at 270, 880, and 2000 MeV at the Nuclotron. The polarization of the deuteron beam was measured at 270 MeV at the internal target station. The preliminary data on the vector A y and tensor A yy , A xx analyzing powers for the $$ \vec d $$ p elastic scattering at 880 MeV are presented. The calculations on A y , A yy , and A xx analyzing powers for the $$ \vec d $$ p elastic scattering at 880 MeV were performed in the framework of the multiple-scattering model. [ABSTRACT FROM AUTHOR]

The cluster structures of the excited states in 11B are studied by analyzing the isoscalar monopole and quadrupole strengths in the 11B(d,d ′) reaction at . The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. It is found that the large monopole strength for the state at is well described by the AMD calculation and is an evidence for a developed three-body cluster structure. [Copyright &y& Elsevier]

High-precision vector and tensor analyzing powers of elastic deuteron-proton ( d + p) scattering have been measured at intermediate energies to investigate effects of three-nucleon forces. Angular distributions in the range of 70°-120° in the center-of mass frame for incident-deuteron energies E d lab = 130 and 180 MeV were obtained using the RIKEN facility. The beam polarization was unambiguously determined by measuring the ^12C ( d, α)^10B(2+) reaction at 0°. Results of the measurements are compared with state-of-the-art three-nucleon calculations. The present modeling of nucleon-nucleon forces and its extension to the three-nucleon system is not sufficient to describe the high-precision data consistently and requires, therefore, further investigation. [ABSTRACT FROM AUTHOR]

Decay particles from the s-hole states in 11B and 15N have been measured in coincidence with the quasifree 12C(p, 2p) and 16O(p, 2p) reactions at Ep = 392 MeV. Triton decay is found to be dominant for the 11B(s-hole) state and also found to be larger than α decay for the 15N(s-hole) state despite its smaller Q value compared to α decay. Measured decay branching ratios are discussed in comparison with the results of statistical-model, SU(3)-model, and shell-model calculations. The energy spectra around the s-hole states in both 11B and 15N exhibit some bumplike structures, which can be qualitatively explained by recent shell-model calculations for both nuclei.© 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

The experimental program on the study of deuteron-proton interaction at Internal Target at Nuclotron is discussed. Recent results on the deuteron vector and tensor analyzing powers in dp-elastic scattering obtained at intermediate energies are presented. The status of the DSS setup upgrade is reported. [ABSTRACT FROM AUTHOR]

The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He from polarized protons at 71 MeV/nucleon making use of a newly constructed solid polarized proton target operated in a low magnetic field and at high temperature. Two approaches based on local one-body potentials were applied to investigate the spin-orbit interaction between a proton and a 6He nucleus. An optical model analysis revealed that the spin-orbit potential for 6He is characterized by a shallow and long-ranged shape compared with the global systematics of stable nuclei. A semimicroscopic analysis with an α+n+n cluster folding model suggests that the interaction between a proton and the α core is essentially important in describing the p+6He elastic scattering. The data are also compared with fully microscopic analyses using nonlocal optical potentials based on nucleon-nucleon g matrices. [ABSTRACT FROM AUTHOR]

Measurements of deuteron–proton breakup reactions at 135 MeV/A have been made at RIKEN Accelerator Research Facility, focusing on the specific coplanar configurations. The obtained results are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson-Melbourne99, and UrbanaIX three nucleon forces. [Copyright &y& Elsevier]

The differential cross sections and the vector analyzing powers for the nd elastic scattering at E n = 250 MeV have been measured for the study of the three-nucleon force (3NF) effects in the Coulomb-free system. To cover a wide angular region, the experiments were performed by using two different methods at the (n, p) facility and at the NTOF facility which constructed at the Research Center for Nuclear Physics (RCNP). The results were compared with theoretical predictions of the Faddeev calculations based on the modern nucleon-nucleon (NN) forces with the three-nucleon force (3NF). The inclusion of 3NFs leads to a good description of the cross section except for the backward angles. The results were also compared with the theoretical predictions with relativistic corrections. The direct data-to-data comparison of the cross sections of the nd and pd was performed. [Copyright &y& Elsevier]

The isoscalar giant monopole resonance (GMR) has been investigated in a series of Sn isotopes (A=112–124) using inelastic scattering of 400-MeV α particles at extremely forward angles (including 0°). The primary aim of the investigation has been to explore the role of the “symmetry-energy” term in the expression for nuclear incompressibility. It is found that the excitation energies of the GMR in the Sn isotopes are significantly lower than those expected from the nuclear incompressibility previously extracted from the available data on the compressional-mode giant resonances. [Copyright &y& Elsevier]

Abstract: The cross section of the scattering was measured at a bombarding energy of 295 MeV in the momentum transfer range of . The isovector state at is clearly separated from its neighboring states owing to the high energy resolution of about 30 keV. The cross section data were compared with distorted wave impulse approximation (DWIA) calculations employing shell-model wave functions. The observed cross sections around are significantly larger than obtained by these calculations, suggesting pionic enhancement as a precursor of pion condensation in nuclei. The data are well reproduced by DWIA calculations using random phase approximation response functions including the Δ isobar that predict pionic enhancement. [Copyright &y& Elsevier]

Abstract: We describe the neutron polarimeter NPOL3 for the measurement of polarization transfer observables with a typical high resolution of 300keV at . The NPOL3 system consists of three planes of neutron detectors. The first two planes for neutron polarization analysis are made of 20 sets of one-dimensional position-sensitive plastic scintillation counters with a size of 100cm 10cm 5cm, and they cover the area of . The last plane for detecting doubly scattered neutrons or recoiled protons is made of the two-dimensional position-sensitive liquid scintillation counter with a size of . The effective analyzing powers and double scattering efficiencies were measured by using the three kinds of polarized neutrons from the , , and reactions at . The performance of NPOL3 defined as are similar to that of the Indiana Neutron POLarimeter by taking into account for the counter configuration difference between these two neutron polarimeters. [Copyright &y& Elsevier]

The 58Ni(t,3He)58Co reaction at 112 MeV/nucleon was measured to identify strength associated with Gamow-Teller transitions in the direction. The experiment is a test case for future similar studies. The main aim of such studies is to test theoretical models used to predict Gamow-Teller strength distributions that serve as input for supernovae evolution calculations. The results indicate that the (t,3He) reaction is indeed a powerful tool to perform such tests. [Copyright &y& Elsevier]

Charged particle decay of the s-hole state in 11B was measured in coincidence with the quasifree 12C(p,2p) reaction at 392 MeV incident energy. Triton-decay was found to be dominant despite its smaller Q-value than that of α-decay. The measured decay pattern is compared to the results of statistical model and microscopic SU(3)-cluster model calculations. The energy spectrum around the s-hole state exhibits three bump-like structures, which can be qualitatively explained by a recent shell-model calculation. [Copyright &y& Elsevier]