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15 results on '"Sumikama, T."'

1. $g$ Factor of the $^{99}\mathrm{Zr}$ ($7/{2}^{+}$) Isomer: Monopole Evolution in the Shape-Coexisting Region

Author

Boulay, F., Simpson, G.S., Ichikawa, Y., Kisyov, S., Bucurescu, D., Takamine, A., Ahn, D.S., Asahi, K., Baba, H., Balabanski, D.L., Egami, T., Fujita, T., Fukuda, N., Funayama, C., Furukawa, T., Georgiev, G., Gladkov, A., Hass, M., Imamura, K., Inabe, N., Ishibashi, Y., Kawaguchi, T., Kawamura, T., Kim, W., Kobayashi, Y., Kojima, S., Kusoglu, A., Lozeva, R., Momiyama, S., Mukul, I., Niikura, M., Nishibata, H., Nishizaka, T., Odahara, A., Ohtomo, Y., Ralet, D., Sato, T., Shimizu, Y., Sumikama, T., Suzuki, H., Takeda, H., Tao, L.C., Togano, Y., Tominaga, D., Ueno, H., Yamazaki, H., Yang, X.F., Daugas, J.M., Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Physics
Abstract

International audience; The gyromagnetic factor of the low-lying E=251.96(9) keV isomeric state of the nucleus Zr99 was measured using the time-dependent perturbed angular distribution technique. This level is assigned a spin and parity of Jπ=7/2+, with a half-life of T1/2=336(5) ns. The isomer was produced and spin aligned via the abrasion-fission of a U238 primary beam at RIKEN RIBF. A magnetic moment |μ|=2.31(14)μN was deduced showing that this isomer is not single particle in nature. A comparison of the experimental values with interacting boson-fermion model IBFM-1 results shows that this state is strongly mixed with a main νd5/2 composition. Furthermore, it was found that monopole single-particle evolution changes significantly with the appearance of collective modes, likely due to type-II shell evolution.

Published
2020
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2. Sequential Nature of $(p,3p)$ Two-Proton Knockout from Neutron-Rich Nuclei

Author

Frotscher, A., Gómez-Ramos, M., Obertelli, A., Doornenbal, P., Authelet, G., Baba, H., Calvet, D., Château, F., Chen, S., Corsi, A., Delbart, A., Gheller, J.M., Giganon, A., Gillibert, A., Isobe, T., Lapoux, V., Matsushita, M., Momiyama, S., Motobayashi, T., Niikura, M., Otsu, H., Paul, N., Péron, C., Peyaud, A., Pollacco, E.C., Roussé, J.Y., Sakurai, H., Santamaria, C., Sasano, M., Shiga, Y., Shimizu, N., Steppenbeck, D., Takeuchi, S., Taniuchi, R., Uesaka, T., Wang, H., Yoneda, K., Ando, T., Arici, T., Blazhev, A., Browne, F., Bruce, A.M., Carroll, R., Chung, L.X., Cortés, M.L., Dewald, M., Ding, B., Dombradi, Zs., Flavigny, F., Franchoo, S., Giacoppo, F., Górska, M., Gottardo, A., Hadyńska-Klęk, K., Korkulu, Z., Koyama, S., Kubota, Y., Jungclaus, A., Lee, J., Lettmann, M., Linh, B.D., Liu, J., Liu, Z., Lizarazo, C., Louchart, C., Lozeva, R., Matsui, K., Miyazaki, T., Moschner, K., Nagamine, S., Nakatsuka, N., Nita, C., Nishimura, S., Nobs, C.R., Olivier, L., Ota, S., Patel, Z., Podolyák, Zs., Rudigier, M., Sahin, E., Saito, T.Y., Shand, C., Söderström, P.A., Stefan, I.G., Sumikama, T., Suzuki, D., Orlandi, R., Vaquero, V., Vajta, Zs., Werner, V., Wimmer, K., Wu, J., Xu, Z., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear Theory, ddc:530, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Nuclear Physics
Abstract

Twenty-one two-proton knockout (p; 3p) cross sections from neutron-rich nuclei at ~ 250 MeV/nucleon were measured. For the first time, the angular distribution of the three emitted protons were measured in coincidence with the tracker and hydrogen target MINOS, demonstrating that the (p; 3p) kinematics is consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p; 3p) over (p; 2p) inclusive cross sections follow the trend of other many-proton (neutron) removal reactions, further reinforcing the sequential nature of (p; 3p) in neutron-rich nuclei.

Published
2020
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3. Improved Value for the Gamow-Teller Strength of the ^{100}Sn Beta Decay

Author

Lubos, D., Park, J., Faestermann, T., Gernhäuser, R., Krücken, R., Lewitowicz, M., Nishimura, S., Sakurai, H., Ahn, D.S., Baba, H., Blank, B., Blazhev, A., Boutachkov, P., Browne, F., Čeliković, I., De France, G., Doornenbal, P., Fang, Y., Fukuda, N., Giovinazzo, J., Goel, N., Górska, M., Ilieva, S., Inabe, N., Isobe, T., Jungclaus, A., Kameda, D., Kim, Y.K., Kojouharov, I., Kubo, T., Kurz, N., Kwon, Y.K., Lorusso, G., Moschner, K., Murai, D., Nishizuka, I., Patel, Z., Rajabali, M.M., Rice, S., Schaffner, H., Shimizu, Y., Sinclair, L., Söderström, P.A., Steiger, K., Sumikama, T., Suzuki, H., Takeda, H., Wang, Z., Warr, N., Watanabe, H., Wu, J., Xu, Z., Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Physics
Abstract

International audience; A record number of Sn100 nuclei was detected and new isotopic species toward the proton dripline were discovered at the RIKEN Nishina Center. Decay spectroscopy was performed with the high-efficiency detector arrays WAS3ABi and EURICA. Both the half-life and the β-decay end point energy of Sn100 were measured more precisely than the literature values. The value and the uncertainty of the resulting strength for the pure 0+→1+ Gamow-Teller decay was improved to BGT=4.4-0.7+0.9. A discrimination between different model calculations was possible for the first time, and the level scheme of In100 is investigated further.

Published
2019
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4. Proton Shell Evolution below $^{132}\mathrm{Sn}$: First Measurement of Low-Lying $\beta$-Emitting Isomers in $^{123,125}\mathrm{Ag}$

Author

Chen, Z.Q., Li, Z.H., Hua, H., Watanabe, H., Yuan, C.X., Zhang, S.Q., Lorusso, G., Nishimura, S., Baba, H., Browne, F., Benzoni, G., Chae, K.Y., Crespi, F.C.L., Doornenbal, P., Fukuda, N., Gey, G., Gernhäuser, R., Inabe, N., Isobe, T., Jiang, D.X., Jungclaus, A., Jung, H.S., Jin, Y., Kameda, D., Kim, G.D., Kim, Y.K., Kojouharov, I., Kondev, F.G., Kubo, T., Kurz, N., Kwon, Y.K., Li, X.Q., Lou, J.L., Lane, G.J., Li, C.G., Luo, D.W., Montaner-Pizá, A., Moschner, K., Niu, C.Y., Naqvi, F., Niikura, M., Nishibata, H., Odahara, A., Orlandi, R., Patel, Z., Podolyák, Zs., Sumikama, T., Söderström, P.A., Sakurai, H., Schaffner, H., Simpson, G.S., Steiger, K., Suzuki, H., Taprogge, J., Takeda, H., Vajta, Zs., Wang, H.K., Wu, J., Wendt, A., Wang, C.G., Wu, H.Y., Wang, X., Wu, C.G., Xu, C., Xu, Z.Y., Yagi, A., Ye, Y.L., Yoshinaga, K., Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut Laue-Langevin (ILL), ILL, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)

Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Physics
Abstract

International audience; The β-delayed γ-ray spectroscopy of neutron-rich Ag123,125 isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2− β-emitting isomers in Ag123,125 are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2+ and 1/2− levels is extended in Ag isotopes up to N=78, providing a clear signal for the reduction of the Z=40 subshell gap in Ag towards N=82. Shell-model calculations with the state-of-the-art VMU plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in Ag123,125. The tensor force is found to play a crucial role in the evolution of the size of the Z=40 subshell gap. The observed inversion of the single-particle levels around Ag123 can be well interpreted in terms of the monopole shift of the π1g9/2 orbitals mainly caused by the increasing occupation of ν1h11/2 orbitals.

Published
2019
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5. β-decay half-lives of neutron-rich nuclei around158Nd, relevant to the formation of the A≈165 rare-earth element peak

Author

Wu, J., Nishimura, S., Lorusso, G., Xu, Z.Y., Ideguchz, E, Simpson, G.S., Baba, H., Browne, F., Daido, R., Doornebal, P., Fang, Y.F., Isobe, T., Li, Z., Patel, Z., Rice, S., Sinclair, L., Söderström, P.-A., Sumikama, T., Watanabe, H., Yagi, A., Yokoyama, R., Aoi, N., Bello Garrote, F.L., Benzoni, G., Gey, G., Gottardo, A., Nishibata, H., Odahara, A., Sakurai, H., Tanaka, M., Taprogge, J., Yamamoto, T., the EURICA collaboration, and, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), and ILL

Subjects
Engineering, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Rare-earth element, business.industry, Physics, QC1-999, Mechanical engineering, Creative commons, 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, Neutron, 010306 general physics, business
Abstract

International audience; A β-decay spectroscopy experiment around 158Nd was performed at RI Beam Factory (RIBF), RIKEN Nishina Center, in order to understand the production mechanism of the A≈165 rare-earth element (REE) peak in the r-process mass abundance pattern. In this experiment, 53 half-lives are measured including 34 new results, which could be employed in a fully dynamic r-process network calculation.

Published
2016
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6. β-DECAY STUDIES AROUND 78Ni: INVESTIGATION OF NEUTRON-RICH Ni ISOTOPES.

Author

Morales, A. I., Benzoni, G., Watanabe, H., Sohler, D., Sahin, E., de Angelis, G., Nishimura, S., Lorusso, G., Sumikama, T., Doornenbal, P., Xu, Z. Y., Isobe, T., Sβderstrβm, P. A., Browne, F., Wu, J., Baba, H., Patel, Z., Rice, S., Sinclair, L., and Yokoyama, R.

Subjects
NEUTRONS, ISOTOPES, NUCLIDES, NUCLEAR physics, NUCLEAR science
Published
2015

7. ß-decay of neutron-rich Z∼60 nuclei and the origin of Rare Earth Elements.

Author

Wu, J., Nishimura, S., Lorusso, G., Xu, Z. Y., Baba, H., Browne, F., Daido, R., Doornenbal, P., Fang, Y. F., Ideguchi, E., Isobe, T., Li, Z., Patel, Z., Rice, S., Simpson, G., Sinclair, L., Söderström, P. A., Sumikama, T., Watanabe, H., and Yagi, A.

Subjects
NUCLEAR physics, SPECTRUM analysis, INNER planets, ASTROPHYSICS research, ASTRONOMICAL spectroscopy, RARE earths spectra
Abstract

A large fraction of the rare-earth elements observed in the solar system is produced in the astrophysical rapid neutron capture process (r-process). However, current stellar models cannot completely explain the relative abundance of these elements partially because of nuclear physics uncertainties. To address this problem, a ß-decay spectroscopy experiment was performed at RI Beam Factory (RIBF) at RIKEN, aimed at studying a wide range of very neutron-rich nuclei with Z∼60 that are progenitors of the rare-earth elements with mass number A∼160. The experiment provides a test of nuclear models as well as experimental inputs for r-process calculations. This contribution presents the experimental setup and some preliminary results of the experiment. [ABSTRACT FROM AUTHOR]

Published
2014
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8. Beta Decay Spectroscopy of Neutron-Rich Nuclei at RIBF.

Author

Lorusso, G., Nishimura, S., Baba, H., Doornenbal, P., Isobe, T., Söderström, P.-A., Browne, F., Daido, R., Yifan, F., Nishibata, H., Yagi, A., Gey, G., Li, Z., Wu, J., Lubos, D., Moschner, K., Patel, Z., Rice, S., Sinclair, L., and Sumikama, T.

Subjects
BETA decay, NUCLEAR structure, NUCLEAR physics, PROTON emission decay, ASTROPHYSICS, NEUTRON capture
Published
2014

9. Nuclear Structure Study through Nuclear Moments of Mirror Pairs.

Author

Matsuta, K., Nagatomo, T., Ozawa, A., Mihara, M., Matsumiya, R., Yamada, K., Yamaguchi, T., Ohtsubo, T., Momota, S., Izumikawa, T., Sumikama, T., Nakashima, Y., Fujiwara, H., Kumashiro, S., Ota, M., Shinojima, D., Tanaka, H., Yasuno, T., Nakajima, S., and Susuki, T.

Subjects
NUCLEAR physics, PHYSICS, SPECTRUM analysis, QUALITATIVE chemical analysis, INTERFEROMETRY
Abstract

β-NMR spectra have been observed for 33Cl, 23Al and 23Ne. As a result, the magnetic moment of 33Cl was determined as |μ(33Cl)| = 0.7549(3) μN. Combined with the known magnetic moment of 33S and the ft-value of the 33Cl β decay, the orbital angular momenta and the intrinsic spins for proton and neutron groups, are deduced separately as = 1.3, = 0.3, = -0.12 and = -0.02. The magnetic moment of 23Al, and that of 23Ne were determined as |μ(23Al)| = 3.89(22) μN and |μ(23Ne)| = 1.0817(9) μN, respectively. As a result, the orbital angular momentum and the intrinsic spin were deduced to be 2.09(29) and 0.41(29), respectively. Combined with the ft-value of the β transition from the ground state of 23Al to the excited state of 23Mg, proton and neutron contributions are separated. The obtained expectation values , , and are compared with the shell model predictions. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2006
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10. Evidence for a new nuclear 'magic number' from the level structure of 54Ca.

Author

Steppenbeck, D., Takeuchi, S., Aoi, N., Doornenbal, P., Matsushita, M., Wang, H., Baba, H., Fukuda, N., Go, S., Honma, M., Lee, J., Matsui, K., Michimasa, S., Motobayashi, T., Nishimura, D., Otsuka, T., Sakurai, H., Shiga, Y., Söderström, P.-A., and Sumikama, T.

Subjects
MAGIC number (Nuclear physics), ATOMIC nucleus, FERMIONS, NEUTRONS, ISOTOPES, NUCLEAR physics
Abstract

Atomic nuclei are finite quantum systems composed of two distinct types of fermion-protons and neutrons. In a manner similar to that of electrons orbiting in an atom, protons and neutrons in a nucleus form shell structures. In the case of stable, naturally occurring nuclei, large energy gaps exist between shells that fill completely when the proton or neutron number is equal to 2, 8, 20, 28, 50, 82 or 126 (ref. 1). Away from stability, however, these so-called 'magic numbers' are known to evolve in systems with a large imbalance of protons and neutrons. Although some of the standard shell closures can disappear, new ones are known to appear. Studies aiming to identify and understand such behaviour are of major importance in the field of experimental and theoretical nuclear physics. Here we report a spectroscopic study of the neutron-rich nucleus 54Ca (a bound system composed of 20 protons and 34 neutrons) using proton knockout reactions involving fast radioactive projectiles. The results highlight the doubly magic nature of 54Ca and provide direct experimental evidence for the onset of a sizable subshell closure at neutron number 34 in isotopes far from stability. [ABSTRACT FROM AUTHOR]

Published
2013
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11. Alignment correlation term in mass A = 8 system and G-parity irregular term.

Author

Sumikama, T., Iwakoshi, T., Nagatomo, T., Ogura, M., Nakashima, Y., Fujiwara, H., Matsuta, K., Minamisono, T., Mihara, M., Fukuda, M., Minamisono, K., and Yamaguchi, T.

Subjects
*NUCLEAR magnetic resonance, *PARTICLES (Nuclear physics), *NUCLEAR reactions, *NUCLEAR physics, *PHYSICS
Abstract

The pure nuclear spin alignments of 8Li and 8B were produced from the nuclear spin polarization applying the β-NMR method. The alignment correlation terms in the β-ray angular distribution of the mirror pair 8Li and 8B were observed to limit the G parity irregular term in the weak nuclear current. The significant deviation due to the forbidden matrix elements between the alignment correlation terms and the β-α correlation terms was observed. The determination of the alignment correlation terms was essential to extract the G-parity violating induced tensor term without the influence of the forbidden term in the vector current. [ABSTRACT FROM AUTHOR]

Published
2005
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12. Nucleon density distribution of proton drip-line nucleus 17Ne.

Author

Tanaka, K., Fukuda, M., Mihara, M., Takechi, M., Chinda, T., Sumikama, T., Kudo, S., Matsuta, K., Minamisono, T., Suzuki, T., Ohtubo, T., Izumikawa, T., Momota, S., Yamaguchi, T., Onishi, T., Ozawa, A., Tanihata, I., and Zheng Tao

Subjects
PROTONS, PARTICLES (Nuclear physics), NEUTRONS, NEUTRON-proton interactions, NUCLEAR physics
Abstract

17Ne is one of the candidates for proton halo nuclei. To study the halo structure of 17Ne, we measured the reaction cross-sections ( σ{}R) and deduced the density distribution of 17Ne through the energy dependence of σ{}R. From the deduced density, it is found that 17Ne has a long density tail which is consistent with the picture of two valence protons of 17Ne occupying the 2 s1/2 orbital. [ABSTRACT FROM AUTHOR]

Published
2005
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13. Low-energy test of second-class current in β decays of spin-aligned 20F and 20Na.

Author

Minamisono, K., Nagatomo, T., Matsuta, K., Levy, C. D. P., Tagishi, Y., Ogura, M., Yamaguchi, M., Ota, H., Behr, J. A., Jackson, K. P., Ozawa, A., Fukuda, M., Sumikama, T., Fujiwara, H., Iwakoshi, T., Matsumiya, R., Mihara, M., Chiba, A., Hashizume, Y., and Yasuno, T.

Subjects
*PARTICLES (Nuclear physics), *NUCLEAR physics, *GAMMA rays, *FORM factor (Nuclear physics), *APPROXIMATION theory
Abstract

The G-parity-violating, second-class current- (SCC) induced tensor term in the weak-nucleon axial-vector current was determined from β-decay correlation measurements of the mass A = 20 mirror pair. The alignment correlation terms in the β-decay angular distribution from the purely spin aligned mirror pair, 20F and 20Na, were measured in the present study. Combining the present results with existing results of β and delayed γ-ray angular correlation measurements for the A = 20 mirror pair, the SCC-induced tensor term was extracted to be dII/Ac = 0.18 ± 0.48. In the extraction, the weak-magnetism term, b/Ac = 8.58 ± 0.28, evaluated from the M1 analog γ-ray decay strength, was used in a framework of the conserved vector current hypothesis. This is the first unambiguous extraction of the (b = dII)/Ac term free from the contribution of the second-forbidden form factor, j2, in the axial-vector current, which was a limiting factor for accurate determination of nonexistence of the SSC in the β decay of the A = 20 system. [ABSTRACT FROM AUTHOR]

Published
2011
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14. Is Seniority a Partial Dynamic Symmetry in the First $\nu g_{9/2}$ Shell?

Author

Takaharu Otsuka, Toshiyuki Sumikama, Ryo Taniuchi, Giuseppe Lorusso, Zsolt Podolyak, R. Avigo, István Kuti, G. de Angelis, Shunji Nishimura, A. I. Morales, Nunzio Itaco, P. A. Söderström, D. R. Napoli, A. Gottardo, Yusuke Tsunoda, N. Blasi, Stephen Rice, Zena Patel, P. Van Isacker, Rin Yokoyama, I. Kojouharov, G. Benzoni, V. Modamio-Hoybjor, Jinguang Wu, Zs. Dombradi, F. Browne, F. L. Bello Garrote, T. Isobe, Jan Taprogge, E. Sahin, S. Lalkovski, Satoru Momiyama, L. Coraggio, N. Kurz, Hiroyoshi Sakurai, Tsuyoshi Miyazaki, P. Doornenbal, Oliver Wieland, M. Yalcinkaya, B. Melon, Ayumi Yagi, R. Daido, F. Camera, R. Orlandi, P. H. Regan, Y. F. Fang, A. Gargano, Hirofumi Watanabe, K. Matsui, H. Schaffner, D. Mengoni, F. C. L. Crespi, M. C. Delattre, J. J. Valiente-Dobón, A. Bracco, H. Baba, Zs. Vajta, Dóra Sohler, S. Ceruti, Megumi Niikura, Zhengyu Xu, Alison Bruce, L. Sinclair, Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds ( GANIL ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Morales, A. I., Benzoni, G., Watanabe, H., de Angelis, G., Nishimura, S., Coraggio, L., Gargano, A., Itaco, N., Otsuka, T., Tsunoda, Y., Van Isacker, P., Browne, F., Daido, R., Doornenbal, P., Fang, Y., Lorusso, G., Patel, Z., Rice, S., Sinclair, L., Söderström, P. -A., Sumikama, T., Valiente-Dobón, J. J., Wu, J., Xu, Z. Y., Yagi, A., Yokoyama, R., Baba, H., Avigo, R., Bello Garrote, F. L., Blasi, N., Bracco, A., Bruce, A. M., Camera, F., Ceruti, S., Crespi, F. C. L., Delattre, M. -C., Dombradi, Zs., Gottardo, A., Isobe, T., Kojouharov, I., Kurz, N., Kuti, I., Lalkovski, S., Matsui, K., Melon, B., Mengoni, D., Miyazaki, T., Modamio-Hoybjor, V., Momiyama, S., Napoli, D. R., Niikura, M., Orlandi, R., Podolyák, Zs., Regan, P. H., Sakurai, H., Sahin, E., Sohler, D., Schaffner, H., Taniuchi, R., Taprogge, J., Vajta, Zs., Wieland, O., Yalcinkaya, M., Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Nuclear and High Energy Physics, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 29.30.Kv, 23.40.-s, Nuclear physics, 21.60.Cs, 0103 physical sciences, Neutron, Seniority, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Nuclear Experiment, [ PHYS.NUCL ] Physics [physics]/Nuclear Theory [nucl-th], Spin-½, Physics, 010308 nuclear & particles physics, 23.20.Lv, Fermion, Quantum number, lcsh:QC1-999, Atomic physics, Nucleon, lcsh:Physics, Radioactive decay
Abstract

The low-lying structures of the midshell νg9/2 Ni isotopes 72Ni and 74Ni have been investigated at the RIBF facility in RIKEN within the EURICA collaboration. Previously unobserved low-lying states were accessed for the first time following β decay of the mother nuclei 72Co and 74Co. As a result, we provide a complete picture in terms of the seniority scheme up to the first (8+) levels for both nuclei. The experimental results are compared to shell-model calculations in order to define to what extent the seniority quantum number is preserved in the first neutron g9/2 shell. We find that the disappearance of the seniority isomerism in the (81+) states can be explained by a lowering of the seniority-four (6+) levels as predicted years ago. For 74Ni, the internal de-excitation pattern of the newly observed (62+) state supports a restoration of the normal seniority ordering up to spin J=4. This property, unexplained by the shell-model calculations, is in agreement with a dominance of the single-particle spherical regime near 78Ni. The low-lying structures of the midshell νg9/2 Ni isotopes 72Ni and 74Ni have been investigated at the RIBF facility in RIKEN within the EURICA collaboration. Previously unobserved low-lying states were accessed for the first time following β decay of the mother nuclei 72Co and 74Co. As a result, we provide a complete picture in terms of the seniority scheme up to the first (8+) levels for both nuclei. The experimental results are compared to shell-model calculations in order to define to what extent the seniority quantum number is preserved in the first neutron g9/2 shell. We find that the disappearance of the seniority isomerism in the (81+) states can be explained by a lowering of the seniority-four (6+) levels as predicted years ago. For 74Ni, the internal de-excitation pattern of the newly observed (62+) state supports a restoration of the normal seniority ordering up to spin J=4. This property, unexplained by the shell-model calculations, is in agreement with a dominance of the single-particle spherical regime near 78Ni. ispartof: Physics Letters B vol:781 pages:706-712 status: published

Published
2018
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15. Measurements of nuclear radii for neutron-rich Ne isotopes 28−32Ne

Author

Takechi, M., Ohtsubo, T., Kuboki, T., Fukuda, M., Nishimura, D., Suzuki, T., Yamaguchi, T., Ozawa, A., Moriguchi, T., Sumikama, T., Geissel, H., Aoi, N., Fukuda, N., Hachiuma, I., Inabe, N., Ishibashi, Y., Itoh, Y., Kameda, D., Kusaka, K., and Lantz, M.

Subjects
*NUCLEAR size (Physics), *NEON isotopes, *NEUTRONS, *COLLISIONS (Nuclear physics), *NUCLEAR shapes, *NUCLEAR physics
Abstract

Abstract: Interaction cross sections () for neutron-rich Ne isotopes, 28–32Ne on C target have been measured at 240A MeV using the RIBF at RIKEN. A large enhancement of beyond the systematics of stable nuclei have been observed for neutron-rich Ne isotopes, particularly for 31Ne. The possible halo structure for 29,31Ne which would be caused by the lowering of the pf-shell and nuclear deformation of Ne isotopes are discussed by the preliminary analysis. [Copyright &y& Elsevier]

Published
2010
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