γ emission probabilities from unbound states in 78,80Se, populated by a neutron-transfer reaction (d,p) on 77,79Se nuclei in inverse kinematics, were measured by directly detecting reaction residues. ...Assuming the spin distribution at the respective excitation energy of the unbound state, the cross-sections of the 79Se(n,γ)80Se reaction were evaluated using the γ emission probabilities. The surrogate-ratio method with the experimental γ emission probabilities of 78,80Se was also employed to deduce the cross-sections of 79Se(n,γ) reaction by incorporating the theoretical evaluations of the neutron-capture reaction on the isomeric state in 77Se. Our two cross-sections are in good agreement with existing nuclear data compilations for the neutron-capture reaction on 79Se. The presented method contributes to the body of existing knowledge by providing approaches for determining the neutron capture cross-sections of radioactive nuclei at various neutron energies.
We report the results of the first-time test of the local hidden variable theories (Bell-Clauser-Horne-Shimony-Holt) involving strongly interacting pairs of massive spin 1/2 hadrons from the decay of ...short-lived (tau<10;-21sec) 2He spin-singlet state, populated in the nuclear reaction 2H+;1H-->;2He+n. The novel features of this experiment are (a) the use of an 'event-ready' corrected detector of nearly 100% efficiency to prepare an unbiased sample and (b) a focal-plane polarimeter of full 2pi sr acceptance with a random "post selection" of the reference axes. The spin-correlation function is deduced to be Sexp(pi/4)=2.83+/-0.24stat+/-0.07sys. This result is in agreement with nonlocal quantum mechanical prediction and it violates the Bell-CHSH inequality of |S|<or=2 at a confidence level of 99.3%.
The structure of a neutron-rich F25 nucleus is investigated by a quasifree (p,2p) knockout reaction at 270A MeV in inverse kinematics. The sum of spectroscopic factors of π0d5/2 orbital is found to ...be 1.0±0.3. However, the spectroscopic factor with residual O24 nucleus being in the ground state is found to be only 0.36±0.13, while those in the excited state is 0.65±0.25. The result shows that the O24 core of F25 nucleus significantly differs from a free O24 nucleus, and the core consists of ∼35% O24g.s.. and ∼65% excited O24. The result may infer that the addition of the 0d5/2 proton considerably changes neutron structure in F25 from that in O24, which could be a possible mechanism responsible for the oxygen dripline anomaly.
Precision data are presented for the break-up reaction, H2(p→,pp)n, within the framework of nuclear-force studies. The experiment was carried out at KVI using a polarized-proton beam of 190 MeV ...impinging on a liquid-deuterium target and by exploiting the detector, BINA. Some of the vector-analyzing powers are presented and compared with state-of-the-art Faddeev calculations including three-nucleon forces effect. Significant discrepancies between the data and theoretical predictions were observed for kinematical configurations which correspond to the H2(p→,He2)n channel. These results are compared to the H2(p→,d)p reaction to test the isospin sensitivity of the present three-nucleon force models. The current modeling of two and three-nucleon forces is not sufficient to describe consistently polarization data for both isospin states.
Three precise measurements for elastic pd scattering at 135 MeV/A have been performed with the three different experimental setups. The cross sections are described well by the theoretical ...predictions based on modern nucleon-nucleon forces combined with three-nucleon forces. Relativistic Faddeev calculations show that relativistic effects are restricted to backward angles. This result supports the two measurements recently reported by RIKEN and contradicts the KVI data.
For the 111 poled barium titanate (BaTiO
3
) single crystals with the engineered domain configuration, it was clearly observed that the piezoelectric properties increased with decreasing domain ...sizes. To explain the phenomenon, the multidomain single crystals were regarded as the composite of (a) a distorted domain wall region and (b) a normal tetragonal domain region. Using a 2-phases model, the piezoelectric properties from the domain wall were estimated. As a result, ultrahigh piezoelectric constants over 8,000 pC/N were expected from the domain wall region. Moreover, this study suggested that it is possible to obtain the lead-free piezoelectric materials with the d
31
and d
33
over 1,000 pC/N, when the domain sizes can decrease below 1 μ m.
•Report on recent achievement of the SHARAQ spectrometer.•Demonstration of two ion optics modes for high-resolution spectroscopy.•Discussion on measured transport matrix elements by comparison with ...designed values.•Demonstration of event-by-event momentum tagging by the achromatic transport.•Achievement of momentum resolution of 1/8100 by the dispersion-matching transport.
The SHARAQ spectrometer and High-Resolution Beamline, which began operation in March 2009, have been put into use for six experiments using charge exchange reactions with radioactive isotope beams. For experiments at SHARAQ, detector developments and ion optics studies continue to improve performance in high-resolution nuclear spectroscopy. We have introduced improved timing resolution with CVD diamond detectors, high count-rate beamline tracking detectors and development of multi-particle detection by cathode-readout drift chambers. Ion-optics studies for the high-resolution achromatic (HA) and dispersion-matching (DM) transport modes are also reported here. Momentum tagging in the HA mode demonstrated an improvement in spectroscopic resolution with respect to the momentum spread of the radioactive beam. For the DM transportation mode, a momentum resolution of 1/8100 (FWHM) was achieved by taking into account the positions and angles of the beam at the third focal plane of BigRIPS.
The cross section, the deuteron vector A(d)(y) and tensor analyzing powers A(ij), the polarization transfer coefficients K(y('))(ij), and the induced polarization P(y(')) were measured for the dp ...elastic scattering at 270 MeV. The cross section and A(d)(y) are well reproduced by Faddeev calculations with modern data-equivalent nucleon-nucleon forces plus the Tucson-Melbourne three-nucleon force. In contrast, A(ij), K(y('))(ij), or P(y(')) are not described by such calculations. These facts indicate the deficiencies in the spin dependence of the Tucson-Melbourne force and call for extended three-nucleon force models.
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