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11 results on '"R.-B. Gerst"'

1. Investigation of the ground-state spin inversion in the neutron-rich Cl47,49 isotopes

Author

Jason D. Holt, Carlo Barbieri, Zaihong Yang, I. Murray, D. M. Rossi, K. I. Hahn, S. Y. Park, C. Hilaire, Kazuyuki Ogata, C. Lehr, H. Baba, Duo Yan, David Steppenbeck, H. Törnqvist, P. Koseoglou, Masahiro Yasuda, V. Lapoux, Yasuhiro Togano, N. L. Achouri, R.-B. Gerst, Alessandra Corsi, T. Lokotko, B. D. Linh, L. Stuhl, H. Wang, Dóra Sohler, M. Gómez-Ramos, Igor Gašparić, H. N. Liu, Y. L. Sun, Takashi Nakamura, E. Sahin, Petr Navrátil, V. Panin, W. Rodriguez, N. Shimizu, J. M. Gheller, A. Moro, Victor Vaquero, L. X. Chung, Thomas Duguet, K. Moschner, Hiroyoshi Sakurai, Kathrin Wimmer, Dong-Wook Kim, A. Delbart, N. T. Khai, V. Wagner, N. Paul, P. Doornenbal, T. Motobayashi, V. Somà, D. Calvet, T. Isobe, K. Yoneda, O. Aktas, V. Werner, Y. Yamada, Thomas Aumann, F. Flavigny, N. D. Ton, T. Kobayashi, A. Giganon, X. X. Xu, F. Château, Hideaki Otsu, Julien Gibelin, Si-Ge Chen, N. T. T. Phuc, P. A. Söderström, A. Gillibert, Nobuyuki Chiga, A. Obertelli, T. Koiwai, Tomohiro Uesaka, F. Browne, M. MacCormick, Satoshi Takeuchi, M. L. Cortés, Masaki Sasano, S. Franchoo, Yutaka Utsuno, Jenny Lee, Yuya Kubota, L. Zanetti, and Yosuke Kondo

Subjects
Physics, Isotope, 010308 nuclear & particles physics, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Spin (physics), Ground state, 01 natural sciences, Inversion (discrete mathematics), Nuclear theory
Published
2021

2. Pairing Forces Govern Population of Doubly Magic Ca54 from Direct Reactions

Author

J. M. Gheller, S. Y. Park, K. Yoneda, Masaki Sasano, P. A. Söderström, D. Sohler, D. Körper, H. Simon, A. Gillibert, K. Miki, Satoshi Takeuchi, Yasuhiro Togano, M. MacCormick, R.-B. Gerst, Duo Yan, Tomohiro Uesaka, Fabia Schindler, V. Wagner, B. D. Linh, M. Holl, A. Corsi, N. Paul, Igor Gašparić, H. N. Liu, P. Koseoglou, E. Sahin, Yosuke Kondo, T. Lokotko, T. Isobe, Victor Vaquero, M. L. Cortés, V. Werner, Takashi Nakamura, W. Rodriguez, Zaihong Yang, A. Delbart, S. Franchoo, F. Château, V. Lapoux, P. Doornenbal, K. I. Hahn, L. Stuhl, I. Murray, C. Caesar, Kazuyuki Ogata, C. Lehr, T. Kobayashi, X. X. Xu, C. Hilaire, Si-Ge Chen, Yutaka Utsuno, V. Panin, A. Giganon, Jenny Lee, N. L. Achouri, L. X. Chung, Y. L. Sun, K. Moschner, Yuya Kubota, D. M. Rossi, H. Baba, F. Flavigny, Masahiro Yasuda, L. Zanetti, Kathrin Wimmer, Dong-Wook Kim, O. Aktas, F. Browne, S. Wang, A. Obertelli, J. Kahlbow, Hiroyoshi Sakurai, T. Motobayashi, Julien Gibelin, K. Boretzky, D. Calvet, David Steppenbeck, H. Törnqvist, Thomas Aumann, Nobuyuki Chiga, T. Koiwai, Kazuki Yoshida, Hideaki Otsu, Hirofumi Yamada, and J. Tscheuschner

Subjects
Physics, education.field_of_study, Proton, 010308 nuclear & particles physics, Nuclear Theory, Population, Nuclear shell model, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Pairing, Excited state, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Ground state, education
Abstract

Direct proton-knockout reactions of ^{55}Sc at ∼220 MeV/nucleon were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of ^{54}Ca were investigated through γ-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological internucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors, which describe the wave function overlap of the ^{55}Sc ground state with states in ^{54}Ca. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of ^{55}Sc, valence proton removals populated predominantly the ground state of ^{54}Ca. This counterintuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.

Published
2021

3. Angular momentum generation in nuclear fission

Author

B. Fornal, M. S. Yavahchova, C. Delafosse, A. Boso, V. Sánchez-Tembleque, K. Rezynkina, M. Lebois, K. Hauschild, T. Kröll, Muriel Fallot, P. Adsley, J. Ljungvall, Ł. W. Iskra, F. Ibrahim, E. Adamska, C. Henrich, A. Gottardo, Stephan Oberstedt, R. Chakma, C. Sürder, V. Guadilla, C. Porzio, P. H. Regan, J. Benito, A. Korgul, R. Lozeva, L. Le Meur, M. Piersa, P. Ivanov, V. Vedia, J. Nemer, B. Wasilewska, N. Jovančević, Y. Popovitch, W. Paulsen, C. Schmitt, N. Cieplicka-Oryńczak, R. B. Gerst, Sunniva Siem, G. Tocabens, P. A. Söderström, K. Belvedere, S. Courtin, S. Ziliani, R. Canavan, D. Gjestvang, L. Qi, D. Etasse, P. Koseoglou, G. Häfner, I. Matea, I. Homm, M. Heine, L. M. Fraile, T. Kurtukian-Nieto, Fabio Zeiser, P. Davies, D. Thisse, M. L. Cortés, A. Blazhev, S. Jazrawi, M. Bunce, A. Lopez-Martens, K. Miernik, Alejandro Algora, M. Rudigier, J. N. Wilson, N. Warr, J. Wiederhold, D. Verney, D. Ralet, M. Babo, L. Gaudefroy, G. Benzoni, S. Bottoni, S. Leoni, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Oslo (UiO), Department of Physics, University of Surrey, University of Surrey (UNIS), Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt), 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), CEA, Bruyeres le Chatel, France, affiliation inconnue, University of Warsaw (UW), Facultat de Fisica [València] (UV), Universitat de València (UV), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Università degli Studi di Milano = University of Milan (UNIMI), Institut für Kernphysik der Universität zu Köln, Universität zu Köln = University of Cologne, National Physical Laboratory [Teddington] (NPL), Instytut Fizyki Jądrowej PAN (IFJ), Polskiej Akademii Nauk, 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), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), University of Manchester [Manchester], Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), Istituto Nazionale di Fisica Nucleare (INFN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), 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), European Commission - Joint Research Centre [Geel] (JRC), 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), Horia Hulubei Natl Inst Phys & Nucl Engn IFIN HH, ELI NP Dept, Reactorului Str 30, Magurele 077125, Romania, Софийски университет = Sofia University, Technische Universität Darmstadt (TU Darmstadt), Universidad Complutense de Madrid [Madrid] (UCM), Università degli studi di Milano [Milano], Universität zu Köln, Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Technical University Darmstadt (TU), 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), University of Sofia, Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Università degli Studi di Milano [Milano] (UNIMI), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Direction des Applications Militaires (DAM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Physics, [PHYS]Physics [physics], Angular momentum, Multidisciplinary, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Spins, 010308 nuclear & particles physics, Fission, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Nuclear fission, 0103 physical sciences, Atomic nucleus, Nuclear Experiment, 010306 general physics, Nucleon, Excitation, ComputingMilieux_MISCELLANEOUS, Spin-½
Abstract

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4–12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18. γ-ray spectroscopy experiments on the origin of spin in the products of nuclear fission of spin-zero nuclei suggest that the fission fragments acquire their spin after scission, rather than before.

Published
2021

4. Prompt and delayed γ spectroscopy of neutron-rich Kr94 and observation of a new isomer

Author

R. Chakma, N. Cieplicka-Oryńczak, P. Adsley, G. Tocabens, Muriel Fallot, K. Belvedere, D. Gjestvang, L. Qi, J. Wiederhold, S. Leoni, C. Sürder, J. Benito, J. N. Wilson, K. Hauschild, R. B. Gerst, Stephan Oberstedt, Ł. W. Iskra, C. Porzio, P. A. Söderström, G. Häfner, M. Rudigier, I. Matea, C. Henrich, D. Verney, R.L. Canavan, K. Miernik, V. Vedia, D. Ralet, J. Nemer, P. Koseoglou, M. Piersa, N. Warr, R. Lozeva, L. Le Meur, A. Algora, M. Lebois, N. Jovančević, K. Rezynkina, S. Jazrawi, A. Blazhev, S. Courtin, M. Bunce, S. Bottoni, P. H. Regan, A. Boso, A. Lopez-Martens, C. Schmitt, B. Fornal, P. Ivanov, B. Wasilewska, L. M. Fraile, F. Ibrahim, M. Babo, T. Kurtukian-Nieto, A. Gottardo, G. Benzoni, T. Kröll, D. Reygadas-Tello, E. Adamska, J. Ljungvall, V. Guadilla, A. Korgul, Y. Popovitch, W. Paulsen, I. Homm, D. Thisse, M. L. Cortés, M. Heine, Fabio Zeiser, C. Delafosse, V. Sánchez-Tembleque, P. Davies, M. Yavachova, S. Ziliani, and D. Etasse

Subjects
Physics, Spectrometer, 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, Yrast, Nuclear Theory, 01 natural sciences, 7. Clean energy, Atomic orbital, Nuclear fission, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Spin (physics), Spectroscopy
Abstract

Prompt and delayed γ -ray spectroscopy of the neutron-rich 94 Kr was performed, as part of the fission campaign at the ALTO facility of the IPN Orsay, using the fast-neutron-induced fission reaction 238 U ( n , f ) in combination with the ν -Ball array, a novel hybrid γ spectrometer for energy and lifetime measurements. Several new yrast and nonyrast transitions were observed for the first time, extending the previously known level scheme. Additionally, we report on the observation of a new short-lived isomer at 3444 keV with a half-life of 32(3) ns. The analysis of the Nilsson orbitals obtained from Gogny cranked Hartree-Fock-Bogoliubov calculations suggests a ( 9 − ) spin and an oblate deformation for this isomer corresponding to a two-quasineutron state, indicating an isomeric structure very similar to that of the neighboring isotones 96 Sr and 92 Se

Published
2020

5. Competition between Allowed and First-Forbidden β Decay: The Case of Hg208→Tl208

Author

V. F. E. Pucknell, R.-B. Gerst, M. Lund, I.H. Lazarus, P. H. Regan, N. Marginean, R. Shearman, J. Phrompao, M. Piersa, V. Vedia, Miguel Madurga, R. Lica, Marc Huyse, F. Wearing, J. Kurcewicz, J. R. Creswell, María José García Borge, R. Mărginean, L. M. Fraile, W. Gelletly, S. Pascu, István Kuti, S. Stegemann, T. Alexander, A. Negret, C. R. Nita, Paul Greenlees, C. Mihai, Raymond J. Carroll, Andrei Andreyev, F. Rotaru, Ángel Perea, R. D. Page, P. M. Walker, M. Brunet, Zs. Podolyák, I. Marroquin, R. Wadsworth, D. S. Judson, A. Gredley, P. Van Duppen, E. Rapisarda, M. Rudigier, H. De Witte, Zena Patel, T. Berry, Enrique Nácher, H. Grawe, M. Górska, N. Warr, L. J. Harkness-Brennan, S. Lalkovski, S. M. Judge, P. Rahkila, Joonas Konki, S. Ansari, Thierry Stora, C. M. Shand, R. E. Mihai, E. R. Gamba, Claes Fahlander, H. O. U. Fynbo, Olof Tengblad, and C. Sotty

Subjects
Physics, Nuclear Theory, General Physics and Astronomy, Parity (physics), 01 natural sciences, 7. Clean energy, Neutron capture, medicine.anatomical_structure, Nucleosynthesis, Excited state, 0103 physical sciences, medicine, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus, Fermi Gamma-ray Space Telescope
Abstract

The β decay of ^{208}Hg into the one-proton hole, one neutron-particle _{81}^{208}Tl_{127} nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z

Published
2020

6. Shell evolution of $N=40$ isotones towards $^{60}$Ca: First spectroscopy of $^{62}$Ti

Author

Masaki Sasano, S. M. Lenzi, Kazuki Yoshida, E. Sahin, V. Wagner, Hiroyoshi Sakurai, F. Nowacki, T. Isobe, W. Rodriguez, P. Doornenbal, Donghang Yan, D. Kim, T. Motobayashi, M.L. Cortés, Jason D. Holt, V. Lapoux, D. M. Rossi, Toshio Kobayashi, F. Flavigny, A. Giganon, B. D. Linh, F. Château, V. Panin, H. Baba, N. Paul, L. X. Chung, D. Calvet, X. X. Xu, David Steppenbeck, V. Werner, Igor Gašparić, H. N. Liu, A. Delbart, Yosuke Kondo, Si-Ge Chen, L. Achouri, Julien Gibelin, Tomohiro Uesaka, J. M. Gheller, A. Corsi, S. R. Stroberg, Alfredo Poves, Achim Schwenk, Satoshi Takeuchi, Thomas Aumann, R.-B. Gerst, C. Lehr, Jenny Lee, Yasuhiro Togano, C. Hilaire, Y.L. Sun, P. Koseoglou, Nobuyuki Chiga, K. Yoneda, F. Browne, Victor Vaquero, Yuya Kubota, T. Lokotko, T. Koiwai, Zaihong Yang, Takashi Nakamura, S. Wang, J. Simonis, I. Murray, Javier Fernandez Menendez, A. Obertelli, Kazuyuki Ogata, A. Gillibert, H. Toernqvist, M. MacCormick, Masahiro Yasuda, Hideaki Otsu, K. I. Hahn, L. Stuhl, O. Aktas, Hirofumi Yamada, Dóra Sohler, S. Franchoo, Tomás R. Rodríguez, L. Zanetti, K. Moschner, Kathrin Wimmer, S. Y. Park, P. A. Söderström, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), 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), UAM. Departamento de Física Teórica, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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), RIKEN Nishina Center for Accelerator-Based Science, Japan Society for the Promotion of Science, Ministerio de Ciencia, Innovación y Universidades (España), Ministry of Science and Technology of Vietnam, Helmholtz International Center for FAIR, Croatian Science Foundation, National Research, Development and Innovation Office (Hungary), Ministerio de Economía y Competitividad (España), National Research Foundation of Korea, European Commission, Natural Sciences and Engineering Research Council of Canada, Federal Ministry of Education and Research (Germany), and National Research Council of Canada

Subjects
Nuclear and High Energy Physics, Nuclear Theory, Ab initio, FOS: Physical sciences, Shell evolution, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Radioactive beams, Gamma-ray spectroscopy, Nuclear Theory (nucl-th), 0103 physical sciences, ddc:530, Nuclear Experiment (nucl-ex), 010306 general physics, Spectroscopy, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Island of inversion, Isotone, Starke Wechselwirkung und exotische Kerne – Abteilung Blaum, Física, lcsh:QC1-999, Excited state, Quadrupole, Atomic physics, Nucleon, Ground state, lcsh:Physics
Abstract

7 pags., 4 figs., 1 tab., Excited states in the N=40 isotone Ti were populated via the V(p,2p)Ti reaction at ∼200 MeV/nucleon at the Radioactive Isotope Beam Factory and studied using γ-ray spectroscopy. The energies of the 2 →0 and 4 →2 transitions, observed here for the first time, indicate a deformed Ti ground state. These energies are increased compared to the neighboring Cr and Fe isotones, suggesting a small decrease of quadrupole collectivity. The present measurement is well reproduced by large-scale shell-model calculations based on effective interactions, while ab initio and beyond mean-field calculations do not yet reproduce our findings. The shell-model calculations for Ti show a dominant configuration with four neutrons excited across the N=40 gap. Likewise, they indicate that the N=40 island of inversion extends down to Z=20, disfavoring a possible doubly magic character of the elusive Ca., We thank the RIKEN Nishina Center accelerator staff and the Bi-gRIPS team for the stable operation of the high-intensity Zn beam and for the preparation of the secondary beam setting. K.O. ac-knowledges the support by Grant-in-Aid for Scientific Research of the Japan Society for the Promotion of Science (JSPS) JP16K05352. A.P. is supported in part by the Ministerio de Ciencia, Innovación y Universidades (Spain), Severo Ochoa Programme SEV-2016-0597 and grant PGC-2018-94583. F.B. is supported by the RIKEN Spe-cial Postdoctoral Researcher Program. L.X.C. and B.D.L. would like to thank the Vietnam Ministry of Science and Technology (MOST) for its support through the Physics Development Program Grant No. ÐTÐLCN.25/18. I.G. has been supported by HIC for FAIR and Croatian Science Foundation under projects no. 1257 and 7194. D. So. was supported by the the European Regional Develop-ment Fund contract No. GINOP-2.3.3-15-2016-00034 and the National Research, Development and Innovation Fund of Hungary via Project No. K128947. V.V. acknowledges support from the Span-ish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P. K.I.H., D.K. and S.Y.P. acknowledge the sup-port from the National Research Foundation of Korea grant No. 2018R1A5A1025563 and 2019M7A1A1033186. The development of MINOS was supported by the European Research Council through the ERC Grant No. MINOS-258567. This work was also supported by the JSPS KAKENHI Grant No. 18K03639, MEXT as “Priority is-sue on post-K computer” (Elucidation of the fundamental laws and evolution of the universe), the Joint Institute for Computational Fundamental Science (JICFuS), the CNS-RIKEN joint project for large-scale nuclear structure calculations, Natural Sciences and Engineering Research Council (NSERC) of Canada, the Deutsche Forschungsgemeinschaft – Projektnummer 279384907 – SFB 1245, the PRISMA Cluster of Excellence, and the BMBF under Contracts No. 05P18RDFN1 and 05P19RDFN1. TRIUMF receives funding via a contribution through the National Research Council Canada. Com-putations were performed at the Jülich Supercomputing Center (JURECA)

Published
2020

7. Quasifree Neutron Knockout from Ca54 Corroborates Arising N=34 Neutron Magic Number

Author

V. Wagner, V. Somà, F. Flavigny, K. Moschner, S. Y. Park, V. Panin, Kathrin Wimmer, M. MacCormick, S. Takeuchi, M. L. Cortés, S. Franchoo, Hideaki Otsu, D. Calvet, D. M. Rossi, Toshio Kobayashi, K. Yoneda, Tomohiro Uesaka, Masaki Sasano, T. Lokotko, P. Koseoglou, Dóra Sohler, H. Baba, N. Paul, P. A. Söderström, David Steppenbeck, Nobuyuki Chiga, E. Sahin, Petr Navrátil, Thomas Aumann, Takashi Nakamura, F. Browne, S. J. Chen, Donghang Yan, V. Werner, T. Isobe, R.-B. Gerst, P. Doornenbal, T. Koiwai, F. Château, A. Corsi, A. Gillibert, Takaharu Otsuka, Hiroyoshi Sakurai, A. Delbart, F. Raimondi, H. Yamada, Shuopei Wang, Y. L. Sun, Victor Vaquero, T. Motobayashi, L. X. Chung, H. Törnqvist, J. M. Gheller, Yasuhiro Togano, W. Rodriguez, Y. Chazono, A. Giganon, Carlo Barbieri, Kazuyuki Ogata, C. Lehr, Masahiro Yasuda, C. Hilaire, N. L. Achouri, Yosuke Kondo, Julien Gibelin, X. X. Xu, B. D. Linh, J. Kahlbow, Igor Gašparić, H. N. Liu, A. Obertelli, L. Zanetti, Yutaka Utsuno, Jenny Lee, Yuya Kubota, V. Lapoux, K. Yoshida, Dong-Wook Kim, O. Aktas, Zaihong Yang, I. Murray, K. I. Hahn, and L. Stuhl

Subjects
Physics, Hydrogen, Nuclear Theory, General Physics and Astronomy, chemistry.chemical_element, Impulse (physics), 01 natural sciences, Vertex (geometry), Isotopes of calcium, Transverse plane, chemistry, Excited state, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Excitation
Abstract

Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a ^{54}Ca beam striking on a liquid hydrogen target at ∼200 MeV/u. A significantly larger cross section to the p_{3/2} state compared to the f_{5/2} state observed in the excitation of ^{53}Ca provides direct evidence for the nature of the N=34 shell closure. This finding corroborates the arising of a new shell closure in neutron-rich calcium isotopes. The distorted-wave impulse approximation reaction formalism with shell model calculations using the effective GXPF1Bs interaction and ab initio calculations concur our experimental findings. Obtained transverse and parallel momentum distributions demonstrate the sensitivity of quasifree one-neutron knockout in inverse kinematics on a thick liquid hydrogen target with the reaction vertex reconstructed to final state spin-parity assignments.

Published
2019

8. $\gamma$-ray Spectroscopy of $^{85}$Se Produced in $^{232}$Th Fission

Author

I. Homm, M. Ciemała, Stephan Oberstedt, K. Rezynkina, P. A. Söderström, B. Fornal, A. Lopez-Martens, M. Bunce, V. Vedia, D. Verney, J. N. Wilson, J. Nemer, B. Wasilewska, A. Algora, M. Babo, R. B. Gerst, L. M. Fraile, Y. Popovitch, R. Chakma, T. Kurtukian-Nieto, Ł. W. Iskra, W. Paulsen, E. Adamska, D. Ralet, G. Häfner, M. Piersa, G. Benzoni, M. Rudigier, A. Fijałkowska, A. Blazhev, S. Leoni, D. Reygadas Tello, K. Hauschild, P. H. Regan, M. S. Yavahchova, J. Wiederhold, V. Guadilla, N. Warr, C. Delafosse, C. Schmitt, R.L. Canavan, V. Sánchez-Tembleque, K. Miernik, R. Lozeva, I. Matea, P. Davies, Muriel Fallot, N. Jovančević, S. Bottoni, M. Lebois, N. Cieplicka-Oryńczak, P. Adsley, C. Henrich, G. Tocabens, K. Belvedere, D. Gjestvang, T. Kröll, L. Cortes, C. Sürder, L. Qi, S. M. Collins, D. Etasse, M. Heine, Fabio Zeiser, A. Boso, F. Ibrahim, J. Benito, A. Korgul, J. Ljungvall, D. Thisse, L. Le-meur, A. Gottardo, P. Koseoglou, 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)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-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), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-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), Grand Accélérateur National d'Ions Lourds (GANIL), 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), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), 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), 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), and 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)

Subjects
Physics, Spectrometer, Isotope, 010308 nuclear & particles physics, Fission, Yrast, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Aucun, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Excited state, 0103 physical sciences, Neutron source, Gamma spectroscopy, Nuclear Experiment
Abstract

International audience; Excited states in the neutron-rich 85Se nucleus have been studied using for the first time a fast neutron-induced fission of 232Th. The experiment was performed at the ALTO facility of the IPN Orsay. Coupling of the LICORNE directional neutron source with the ν-ball high-resolution γ-ray spectrometer provided unique access to high-spin states in neutron-rich fission fragments from the 232Th(n, f) reaction. A preliminary level scheme of 85Se was established by the analysis of prompt γ–γ–γ coincidences. Identification of the all known yrast states in 85Se is the first step towards studies of more neutron-rich Se isotopes.

Published
2019

9. Lifetime measurement around $^{132}$Sn with the ν-Ball array

Author

G Häfner, R Lozeva, A Blazhev, R L Canavan, D Etasse, J Jolie, N Jovancevic, R B Gerst, Th Kröll, M Lebois, P H Regan, M Rudigier, D Thisse, N Warr, J N Wilson, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-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), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), 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
Physics, [PHYS]Physics [physics], History, Scintillation, Spectrometer, Fission, Nuclear Theory, Actinide, 01 natural sciences, 010305 fluids & plasmas, Computer Science Applications, Education, Nuclear physics, 0103 physical sciences, Electromagnetic shielding, Neutron source, Neutron, 010306 general physics, Spectroscopy, Nuclear Experiment
Abstract

Neutron-rich nuclei were studied after fast neutron-induced fission of 238U and 232Th at the ALTO facility in Orsay, France. The neutrons were produced with the LICORNE directional neutron source using a pulsed 7Li beam provided by the Tandem accelerator. The actinide targets were surrounded by the ν-Ball array to measure the de-excitation of fission fragments. The ν-Ball array is a hybrid spectrometer which consists of HPGe detectors (equipped with BGO shielding) and LaBr3(Ce) scintillation detectors allowing for high-resolution γ-ray spectroscopy and lifetime measurements in the ns/sub-ns range. This contribution presents preliminary results on 134Te and 137I populated in the 238U(n,f) reaction.

Published
2019

10. How Robust is the N=34 Subshell Closure? First Spectroscopy of Ar52

Author

Nobuyuki Chiga, T. Lokotko, Si Chen, T. Koiwai, Takashi Nakamura, D. Calvet, K. Moschner, E. Sahin, Yosuke Kondo, A. Corsi, N.L. Achouri, Kathrin Wimmer, T. Kobayashi, F. Browne, X. X. Xu, David Steppenbeck, B. D. Linh, A. Delbart, J. M. Gheller, V. Wagner, H. Törnqvist, P. Doornenbal, M. MacCormick, R.-B. Gerst, Igor Gašparić, C. Lehr, Hiroyoshi Sakurai, Masahiro Yasuda, C. Hilaire, H.N. Liu, A. Giganon, F. Flavigny, M. L. Cortés, T. Motobayashi, S. Franchoo, Thomas Aumann, C.A. Bertulani, A. Gillibert, V. Panin, Hideaki Otsu, L. X. Chung, P. A. Söderström, Gustav R. Jansen, Hirofumi Yamada, Masaki Sasano, R. Stroberg, D. Sohler, Julien Gibelin, L. Zanetti, Victor Vaquero, V. Lapoux, T. Isobe, N. Paul, S. Wang, Yasuhiro Togano, Jenny Lee, Achim Schwenk, Yuya Kubota, Satoshi Takeuchi, V. Werner, A. Obertelli, F. Château, P. Koseoglou, Gaute Hagen, Dong-Wook Kim, O. Aktas, Zaihong Yang, I. Murray, K. I. Hahn, L. Stuhl, Jason D. Holt, Tomohiro Uesaka, K. Yoneda, S. Y. Park, Duo Yan, D. M. Rossi, H. Baba, Y. L. Sun, T. D. Morris, and W. Rodriguez

Subjects
Physics, Isotope, Closure (topology), General Physics and Astronomy, 01 natural sciences, 3. Good health, Neutron number, 0103 physical sciences, Atomic number, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Nuclear theory, Excitation, Energy (signal processing)
Abstract

The first γ-ray spectroscopy of ^{52}Ar, with the neutron number N=34, was measured using the ^{53}K(p,2p) one-proton removal reaction at ∼210 MeV/u at the RIBF facility. The 2_{1}^{+} excitation energy is found at 1656(18) keV, the highest among the Ar isotopes with N>20. This result is the first experimental signature of the persistence of the N=34 subshell closure beyond ^{54}Ca, i.e., below the magic proton number Z=20. Shell-model calculations with phenomenological and chiral-effective-field-theory interactions both reproduce the measured 2_{1}^{+} systematics of neutron-rich Ar isotopes, and support a N=34 subshell closure in ^{52}Ar.

Published
2019

11. Spectroscopy of neutron-rich scandium isotopes

Author

A. Delbart, T. Motobayashi, L. Zanetti, Julien Gibelin, Tomohiro Uesaka, T. Kobayashi, X. X. Xu, H. Toernqvist, Si-Ge Chen, P. A. Söderström, S. Wang, F. Flavigny, A. Obertelli, V. Wagner, M. Lettmann, D. Calvet, J. M. Gheller, T. Isobe, A. Giganon, F. Château, Thomas Aumann, Makoto Yasuda, Victor Vaquero, A. Gillibert, V. Panin, L. X. Chung, E. Sahin, S. Y. Park, T. Lokotko, Duo Yan, P. Doornenbal, K. Moschner, M. MacCormick, C. Hilaire, Kathrin Wimmer, Alessandra Corsi, Satoshi Takeuchi, Takashi Nakamura, R.-B. Gerst, B. D. Linh, M. L. Cortés, S. Franchoo, Igor Gašparić, H. N. Liu, K. Yoneda, C. Lehr, Jenny Lee, F. Browne, Yuya Kubota, Masaki Sasano, N. Paul, D. M. Rossi, V. Werner, Yasuhiro Togano, Yosuke Kondo, H. Baba, N. L. Achouri, Hideaki Otsu, Hirofumi Yamada, Y. L. Sun, Dong-Wook Kim, O. Aktas, V. Lapoux, Zaihong Yang, I. Murray, K. I. Hahn, David Steppenbeck, L. Stuhl, W. Rodriguez, Nobuyuki Chiga, T. Koiwai, Norbert Pietralla, D. Sohler, P. Koseoglou, Hiroyoshi Sakurai, RIKEN Nishina Center for Accelerator-Based Science, Technische Universität Darmstadt, Helmholtz Centre for Heavy Ion Research, Federal Ministry of Education and Research (Germany), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), 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), 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)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, History, Isotope, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Computer Science Applications, Education, International school, Neutron physics, Nuclear physics, chemistry, 0103 physical sciences, Physics::Accelerator Physics, ddc:530, Neutron, Scandium, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

7 pags., 7 figs. -- XXIII International School on Nuclear Physics, Neutron Physics and Applications 22-28 September 2019, Varna, Bulgaria, Within the SEASTAR III campaign at the Radioactive Isotope Beam Factory, at the RIKEN Nishina Center, neutron-rich isotopes in the vicinity of 53K were produced from the fragmentation of the primary 70Zn beam on a 9Be target. After nucleon knockout reactions on the secondary liquid hydrogen MINOS target the known γ rays of the neutron-rich 55Sc isotope were observed (shown in this proceedings) and γ rays from 57,59Sc isotopes have been identified for the first time. The evolution of the occupied nucleon orbitals of these nuclei in the ground and excited state is investigated under the prism of the tensor force., We are grateful to the RIKEN Nishina Center accelerator staff for their work in the primary beam delivery and the BigRIPS team for preparing the secondary beams. This work was supported by the cooperation between TU Darmstadt and the GSI Helmholtz Center for Heavy Ion Research, by the Helmholtz Graduate School for Hadron and Ion Research for FAIR and its abroad program and the BMBF under grant No. 05P19RDFN1. D.S. was supported by projects No. GINOP2.3.3-15-2016-00034 and No. K128947.

Published
2020

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