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Electric dipole (E1) reduced transition probability B(E1) of 90Zr was obtained by the inelastic proton scattering near 0 degrees using a 295 MeV proton beam and multipole decomposition analysis of the angular distribution by the distorted-wave Born approximation with the Hartree-Fock plus random-phase approximation model and inclusion of El Coulomb excitation, and the E1 strength of the pygmy dipole resonance was found in the vicinity of the neutron threshold in the low-energy tail of the giant dipole resonance. Using the data, we plan to determine the precise dipole polarizability αD which is defined as an inversely energy-weighted sum value of the elecrric dipole strength. The dipole polarizability is expected to constrain the symmetry energy term of the neutron matter equation of state. Thus systematical measurement of the dipole polarizability is important.

The Gamow‐Teller (GT) transitions in the β+ (electron capture) direction from the ground state of 56Fe to the excited states of 56Mn play an important role in the core collapse of presupernova. Assuming that isospin analogous transitions in isobars have corresponding strengths, we deduced these GT strengths by combining the results of the 56Fe(p, p′)56Fe experiment performed at 200 MeV and 0° and the 56Fe(3He, t)56Co experiment in the ββ direction at 140 MeV/u and 0°. The ground state of 56Fe has the isospin value of T = 2, while the GT states in 56Mn have T = 3. In order to identify the analogous T = 2→3, GT transitions in the 56Fe(p, p′)56Fe and the 56Fe(3He, t)56Co measurements, we used the fact that the isospin Clebsch‐Gordan (CG) coefficients for these T = 2→3 transitions are different in these measurements. Then the GT transition strengths B(GT) in the β+ direction can be deduced from the B(GT) values of the corresponding transitions well determined in the 56Fe(3He, t)56Co measurement assuming the i...

Reaction cross sections for stable nuclei at intermediate energies have been measured precisely and systematically. The data have been found to be reproduced nicely by the optical‐limit approximation of Glauber theory modified to include the nucleon multiple scattering effect and the Fermi‐motion effect. Applying this prescription, the nucleon density distribution of 17Ne has been studied. The surface structure of 8B and 11Be has been also studied using this prescription and hydrogen targets. Using the RIBF that has just started application to studies of exotic nuclei, neutron‐rich Ne isotopes around the Island of Inversion have been investigated through measurements of their interaction cross sections.

The rp‐process nucleosynthesis proceeds through nuclei near the proton drip‐line, in which Gamow‐Teller (GT) transitions starting from unstable pf‐shell nuclei play important roles. In the β‐decay study of these nuclei, half‐lives can be measured rather accurately. On the other hand, in the high‐resolution (3He, t) charge‐exchange reactions on mirror nuclei, individual GT transitions can be studied up to high excitations. For the accurate study of the GT transition strengths in the A = 52, T = 2, system, we compare and combine the β‐decay study of the proton‐rich nucleus 52Ni and the 52Cr(3He, t) measurement assuming the isospin symmetry of the Tz = ±2→±1 transitions.

The main source of uncertainties in stellar rate calculations of the rp‐process and the competing αp‐process is often the lack of knowledge of the resonance states above the p‐ and α‐thresholds and their precise energies. We have started a program to study these resonances in proton‐rich unstable nuclei via the (p, t) and other neutron‐pickup reactions using the high resolution spectrometer Grand Raiden. Here, we are presenting the status of the project and recent results of the 25Al(P, γ) reaction rates based on the analysis of measured 28Si(p, t)26Si spectra.

The magnetic moment of 28P(Iπ = 3+, T1/2 = 270.3 ms) has been measured precisely by means of β‐NMR technique. The obtained magnetic moment is |μ(28P)| = 0.3115 (34) μN. Combined with the magnetic moment of its mirror partner 28Al, the nuclear spin I = 3 is decomposed into its 4 components. The measurement of the Q moment has also been tried. From the preliminary NQR spectrum, it was found that the quadrupole coupling constant eqQ/h may be slightly larger than the prediction, which may show enhancement of the Q moment.

We performed a 37Cl(3He, t)37Ar experiment at E = 140 MeV/nucleon and 0° with a resolution of 30 keV. The Gamow‐Teller (GT) strength distribution was obtained up to the excitation energy (Ex) of 14.2 MeV in 37Ar. Under the assumption of isospin symmetry, the GT strengths in the 37Cl→37Ar and 37Ca→37K transitions are analogous. The obtained strength distribution was compared with the mirror 37Ca β decay up to Ex = 8.6 MeV. The overall shapes of the distributions were similar, but the details were not necessary the same. In order to understand those differences, the experimental distribution was compared with the shell model (SM) calculation using the USD interaction. The SM calculation suggests that differences at lower energies can be caused by a large tensor contribution in the charge‐exchange reaction. On the other hand, the differences seen at higher energies are due to the breaking of the mirror symmetry. The neutrino cross section for the 8B solar neutrino source was calculated using the obtained data.

In violent neutrino‐induced reactions at the core‐collapse stage of type II supernovae, Gamow‐Teller (GT) transitions starting from stable as well as unstable pf‐shell nuclei play important roles. In the β‐decay study of these unstable pf‐shell nuclei, half‐lives can be measured rather accurately. On the other hand, in high‐resolution (3He,t) charge‐exchange reactions at 0°, individual GT transitions up to high excitations can be studied. Assuming the isospin symmetry for the strengths of Tz = ±2→±1 analogous GT transitions, we present a “merged analysis” for the determination of GT transition strengths starting from proton‐rich Tz = −2 nuclei. We applied this analysis to the A = 52, T = 2 system, and it was found that the GT transitions and the properties of the 52Ni β decay can be understood better by combining the mirror GT strength distribution obtained from the 52Cr(3He,t) reaction.

International audience; The high-resolution SHARAQ spectrometer and the dedicated high-resolution beamline have been constructed at RI beam factory and commissioned in 2009. Lateral and angular dispersion matching conditions were achieved simultaneously for a primay beam with a momentum spread of 0.1% and an emittance of 3pi mm·mrad (sigma). An overview of the spectrometer and the beam-line, preliminary results from the commissioning runs, and future experimental plan with the system are described.

The high‐resolution SHARAQ spectrometer and the dedicated high‐resolution beam‐line have been constructed at the RI beam factory and commissioned in 2009. Multi‐wire drift chambers placed in the beam‐line and cathode read‐out drift chambers placed at the SHARAQ focal plane worked well for heavy ion beams with Z=1–7 at 200–300 MeV/nucleon. By introducing a dispersion matched operation of the beam‐line, we have achieved a momentum resolution of δp/p = 1/8100 for a primary beam of 14N beam with a momentum spread of ±0.1%. Experiments by use of novel RI‐beam induced charge exchange reactions are planned.

It has been shown that the (3He,t) charge exchange reaction at intermediate energies, used at zero momentum transfer in combination with high‐resolution magnetic spectrometers is a very powerful probe for Gamow‐Teller strengths. Several N = Z nuclei such as 46V [1] or 50Mn [2] have been investigated. Recently ab‐initio nuclear structure calculations have become possible for light nuclei. Thus experimental studies on light nuclei have become of great current interest [3]. We review previous results obtained in 11C with respect to nuclear structure aspects and the Hoyle state, and present some early results of a 9Be(3He,t)9B experiment carried out recently, pointing out the significance of high‐resolution charge‐exchange reactions and the investigation of Gamow‐Teller strengths for the understanding of nuclear structure in light nuclei.

Absolute transition probabilities of the first 2+ state in 110,114Pd were remeasured using the recoil distance Doppler shift technique following projectile Coulomb excitation at intermediate beam energies for the first time. The 110Pd experiment served to check the novel technique as well as the method used for the data analysis which is based on the examination of γ‐ray lineshapes. Whereas the measured B(E2) value for 110Pd agrees very well with the literature, the value obtained for 114Pd differs considerably. The data is also used to test a novel concept, called the valence proton symmetry, which allows one to extrapolate nuclear properties to very neutron rich nuclei.

Experimental technique for measuring proton inelastic scattering with high‐resolution at 295 MeV and at forward angles including zero degrees is described. The method is useful for extracting spin part of the M1 strength via nuclear excitation as well as E1 strength via Coulomb excitation. An excitation energy resolution of 20 keV, good scattering angle resolution, and low background condition have been achieved. The experimental technique was applied for several sd and pf shell nuclei.

Two charge‐exchange reactions were performed at intermediate energies in order to investigate the Gamow‐Teller strength distribution starting from 14Ng.s. in β+ and β− directions: 14N(d,2He)14C and 14N(3He,t)14O. We describe here a few delicate details of the experimental techniques used in these investigations.

Spin‐isospin (Gamow‐Teller) excitations in 64Cu and 64Co have been studied using (3He,t) and (d,2He) charge‐exchange reactions on 64Ni. As the isospin of the 64Ni ground‐state is T0=4, states with T=3, 4 and 5 in 64Cu are excited via the (3He,t) reaction and states with T=5 in 64Co via (d,2He). If we assume that the nuclear interaction is charge symmetric, the T=5 states in 64Cu should appear at corresponding excitation energies (if corrected for the Coulomb displacement) and with similar strengths as the T=5 states in 64Co. As in the 64Cu spectrum the T=5 states are very weakly excited, only by combining the results of the two complementary experiments one can estimate the Gamow‐Teller strength starting from 64Ni in a consistent way.

Some aspects of the importance of neutrino‐induced reactions on nuclei within supernova physics are discussed. It is argued that important constraints on the experimentally unknown cross sections can be obtained from experimental studies of the nuclear response in selected cases. Examples are neutral‐current induced reactions on fp‐shell nuclei extracted from high‐resolution inelastic electron scattering data providing the M1 strength distributions and the production of the exotic heavy, odd‐odd nuclei 138La and 180Ta through charged‐current reactions dominated by Gamow‐Teller transitions. The Gamow‐Teller strength can deduced from the (3He,t) charge‐exchange reaction at zero degree.

The cross sections and analyzing powers were measured for 3He+12C, 58Ni, and 90Zr elastic scattering at T3He=450 MeV. The incident energy dependence of the volume integral per nucleon for 3He shows the similar behavior to that of protons if the spin‐orbit potential is taken into account. This result supports the assumption that interactions between 3He and nucleus are dominated by the interactions between constituent nucleons of 3He and target nucleus in the intermediate energy region. The results of the single folding calculation suggest the interaction between point nucleon and target nucleus is modified in the 3He+nucleus elastic scattering.

Cross sections and polarization transfer observables in the 16O(p,p′) reactions at 392 MeV were measured at forward angles including 0°. The non‐spin‐flip (ΔS = 0) and spin‐flip (ΔS = 1) strengths in transitions to several discrete states and broad resonances in 16O were extracted using a model‐independent method. The giant resonances in the energy region of E x = 19–27 MeV were found to be predominantly excited by ΔL = 1 transitions. The strength distribution of spin‐dipole transitions with ΔS = 1 and ΔL = 1 were deduced. The obtained distribution was compared with a recent shell model calculation. Experimental results are reasonably explained by distorted‐wave impulse‐approximation calculations with the shell model wave functions.

The angular dependence of analyzing power for pp→ppπ0 reaction was measured at 392 MeV using a polarized proton beam and liquid hydrogen target. It is demonstrated that meson exchange model fails to reproduce observed behavior of the analyzing power.

We have designed and constructed a new beam line which can accomplish both lateral and angular dispersion matching with the Grand Raiden spectrometer. In dispersive mode, lateral and angular dispersions of the beam line are b16=37.1 m and b26=−20.0 rad, respectively, to satisfy matching conditions for Grand Raiden. In achromatic mode, the beam line satisfies the double achromatic condition of b16=b26=0. The magnifications of the beam line are (Mx ,M y) = (−0.98, 0.89) and (−1.00, −0.99) for dispersive and achromatic modes, respectively. In the commissioning experiments, we have succeeded to separate the first excited 2 + state of 168 Er with Ex=79.8 keV clearly from the ground state in the (p, p � ) reaction. We achieved energy resolutions of ∆E=13.0±0.3 keV and 16.7±0.3 keV in full width at half maximum for 295 MeV and 392 MeV protons, respectively. These energy resolutions agree with the resolving power of Grand Raiden for an object size of about 1 mm.

Gamow-Teller and M1 states excited in 25Mg(3He,t)25Al and 25Mg(p,p′) reactions at 0° and 450 MeV incident energy, respectively, have been measured and compared. Good symmetry structure in the mirror nuclei 25Al and 25Mg has been identified up to the highest measured excitation energy of Ex∼16 MeV.

Assuming isospin symmetry of structures in mirror nuclei, the four terms of the title in M1 transitions have been decomposed by comparing the strengths of analogous M1 transitions in Tz=±1/2 nuclei and Gamow-Teller transitions, which are caused only by the isovector-spin term. For details, see Y. Fujita et al., Phys. Rev. C 59 (1999) 90 and Y. Fujita et al., Phys. Rev. C 62 (2000) 044314.

High-resolution measurements of proton inelastic and charge-exchange (3He,t) reactions at 0° on 58Ni were performed. These reactions mainly cause isovector spin flip transitions of M1 states in 58Ni and GT states in 58Cu. The “level-by-level” comparison of analogous M1 and GT transition strengths allows the study of the isospin symmetry structure of highly-excited analog states in 58Ni and 58Cu and identification of isospin T (T=1 and 2) based on the different sensitivities of inelastic and charge exchange reactions.