Author: "D. Beaumel" / Language: undetermined - Searchworks@Jio Institute Digital Library Search Results

1. Multiple Mechanisms in Proton-Induced Nucleon Removal at ∼100 MeV/Nucleon

Author: T. Pohl, Y. L. Sun, A. Obertelli, J. Lee, M. Gómez-Ramos, K. Ogata, K. Yoshida, B. S. Cai, C. X. Yuan, B. A. Brown, H. Baba, D. Beaumel, A. Corsi, J. Gao, J. Gibelin, A. Gillibert, K. I. Hahn, T. Isobe, D. Kim, Y. Kondo, T. Kobayashi, Y. Kubota, P. Li, P. Liang, H. N. Liu, J. Liu, T. Lokotko, F. M. Marqués, Y. Matsuda, T. Motobayashi, T. Nakamura, N. A. Orr, H. Otsu, V. Panin, S. Y. Park, S. Sakaguchi, M. Sasano, H. Sato, H. Sakurai, Y. Shimizu, A. I. Stefanescu, L. Stuhl, D. Suzuki, Y. Togano, D. Tudor, T. Uesaka, H. Wang, X. Xu, Z. H. Yang, K. Yoneda, and J. Zenihiro
Subjects: General Physics and Astronomy
Published: 2023
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2. Structure of Ca36 under the Coulomb Magnifying Glass

Author: L. Lalanne, O. Sorlin, A. Poves, M. Assié, F. Hammache, S. Koyama, D. Suzuki, F. Flavigny, V. Girard-Alcindor, A. Lemasson, A. Matta, T. Roger, D. Beaumel, Y. Blumenfeld, B. A. Brown, F. De Oliveira Santos, F. Delaunay, N. de Séréville, S. Franchoo, J. Gibelin, J. Guillot, O. Kamalou, N. Kitamura, V. Lapoux, B. Mauss, P. Morfouace, M. Niikura, J. Pancin, T. Y. Saito, C. Stodel, and J-C. Thomas
Subjects: General Physics and Astronomy
Published: 2022
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3. New narrow resonances observed in the unbound nucleus F15

Author: V. Girard-Alcindor, A. Mercenne, I. Stefan, F. de Oliveira Santos, N. Michel, M. Płoszajczak, M. Assié, A. Lemasson, E. Clément, F. Flavigny, A. Matta, D. Ramos, M. Rejmund, J. Dudouet, D. Ackermann, P. Adsley, M. Assunção, B. Bastin, D. Beaumel, G. Benzoni, R. Borcea, A. J. Boston, D. Brugnara, L. Cáceres, B. Cederwall, I. Celikovic, V. Chudoba, M. Ciemala, J. Collado, F. C. L. Crespi, G. D'Agata, G. De France, F. Delaunay, C. Diget, C. Domingo-Pardo, J. Eberth, C. Fougères, S. Franchoo, F. Galtarossa, A. Georgiadou, J. Gibelin, S. Giraud, V. González, N. Goyal, A. Gottardo, J. Goupil, S. Grévy, V. Guimaraes, F. Hammache, L. J. Harkness-Brennan, H. Hess, N. Jovančević, D. S. Judson Oliver, O. Kamalou, A. Kamenyero, J. Kiener, W. Korten, S. Koyama, M. Labiche, L. Lalanne, V. Lapoux, S. Leblond, A. Lefevre, C. Lenain, S. Leoni, H. Li, A. Lopez-Martens, A. Maj, I. Matea, R. Menegazzo, D. Mengoni, A. Meyer, B. Million, B. Monteagudo, P. Morfouace, J. Mrazek, M. Niikura, J. Piot, Zs. Podolyak, C. Portail, A. Pullia, B. Quintana, F. Recchia, P. Reiter, K. Rezynkina, T. Roger, J. S. Rojo, F. Rotaru, M. D. Salsac, A. M. Sánchez Benítez, E. Sanchis, M. Şenyigit, N. de Séréville, M. Siciliano, J. Simpson, D. Sohler, O. Sorlin, M. Stanoiu, C. Stodel, D. Suzuki, C. Theisen, D. Thisse, J. C.Thomas, P. Ujic, J. J. Valiente-Dobón, and M. Zielińska
Published: 2022
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4. Occupation probabilities of valence orbitals relevant to neutrinoless double β decay of Sn124

Author: A. Shrivastava, K. Mahata, I. Stefan, M. Assié, P. Adsley, D. Beaumel, V. M. Datar, A. Georgiadou, J. Guillot, F. Hammache, N. Keeley, Y. H. Kim, A. Meyer, V. Nanal, V. V. Parkar, and N. de Séréville
Published: 2022
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5. Structure of ^{36}Ca under the Coulomb Magnifying Glass

Author: L, Lalanne, O, Sorlin, A, Poves, M, Assié, F, Hammache, S, Koyama, D, Suzuki, F, Flavigny, V, Girard-Alcindor, A, Lemasson, A, Matta, T, Roger, D, Beaumel, Y, Blumenfeld, B A, Brown, F De Oliveira, Santos, F, Delaunay, N, de Séréville, S, Franchoo, J, Gibelin, J, Guillot, O, Kamalou, N, Kitamura, V, Lapoux, B, Mauss, P, Morfouace, M, Niikura, J, Pancin, T Y, Saito, C, Stodel, and J-C, Thomas
Abstract: Detailed spectroscopy of the neutron-deficient nucleus ^{36}Ca was obtained up to 9 MeV using the ^{37}Ca(p,d)^{36}Ca and the ^{38}Ca(p,t)^{36}Ca transfer reactions. The radioactive nuclei, produced by the LISE spectrometer at GANIL, interacted with the protons of the liquid hydrogen target CRYPTA, to produce light ejectiles (the deuteron d or triton t) that were detected in the MUST2 detector array, in coincidence with the heavy residues identified by a zero-degree detection system. Our main findings are (i) a similar shift in energy for the 1_{1}^{+} and 2_{1}^{+} states by about -250 keV, as compared with the mirror nucleus ^{36}S; (ii) the discovery of an intruder 0_{2}^{+} state at 2.83(13) MeV, which appears below the first 2^{+} state, in contradiction with the situation in ^{36}S; and (iii) a tentative 0_{3}^{+} state at 4.83(17) MeV, proposed to exhibit a bubble structure with two neutron vacancies in the 2s_{1/2} orbit. The inversion between the 0_{2}^{+} and 2_{1}^{+} states is due to the large mirror energy difference (MED) of -516(130) keV for the former. This feature is reproduced by shell model calculations, using the sd-pf valence space, predicting an almost pure intruder nature for the 0_{2}^{+} state, with two protons (neutrons) being excited across the Z=20 magic closure in ^{36}Ca (^{36}S). This mirror system has the largest MEDs ever observed, if one excludes the few cases induced by the effect of the continuum.
Published: 2021

6. Evaluation of the N13(α,p)O16 thermonuclear reaction rate and its impact on the isotopic composition of supernova grains

Author: D. Beaumel, Fairouz Hammache, L. Audouin, M. G. Pellegriti, Marco Pignatari, Richard Longland, T. Lawson, S. Fortier, Vincent Tatischeff, A. Lefebvre-Schuhl, Anne Meyer, Alison Laird, N. de Séréville, Jürgen Kiener, and M. Stanoiu
Subjects: Physics, 010308 nuclear & particles physics, Monte Carlo method, chemistry.chemical_element, Context (language use), 7. Clean energy, 01 natural sciences, Reaction rate, Nuclear physics, Supernova, Stars, chemistry, 13. Climate action, 0103 physical sciences, Born approximation, 010306 general physics, Stellar evolution, Helium
Abstract: Background: It has been recently suggested that hydrogen ingestion into the helium shell of massive stars could lead to high C13 and N15 excesses when the shock of a core-collapse supernova passes through its helium shell. This prediction questions the origin of extremely high C13 and N15 abundances observed in rare presolar SiC grains which is usually attributed to classical novae. In this context the N13(α,p)O16 reaction plays an important role since it is in competition with N13β+ decay to C13. Purpose: The N13(α,p)O16 reaction rate used in stellar evolution calculations comes from the Caughlan and Fowler compilation with very scarce information on the origin of this rate and with no associated uncertainty. The goal of this work is to provide a recommended N13(α,p)O16 reaction rate, based on available experimental data, with a meaningful statistical uncertainty. Method: Unbound nuclear states in the F17 compound nucleus were studied using the spectroscopic information of the analog states in O17 nucleus that were measured at the Tandem-Alto facility using the C13(Li7,t)O17 α-particle-transfer reaction. The α-particle spectroscopic factors were derived using a finite-range distorted-wave Born approximation analysis. This spectroscopic information was used to calculate a recommended N13(α,p)O16 reaction rate with meaningful uncertainty using a Monte Carlo approach. Results: The N13(α,p)O16 reaction rate from the present work is found to be within a factor of two of the previous evaluation in the temperature range of interest, with a typical uncertainty of a factor ≈2-3. The source of this uncertainty has been identified to come from the three main contributing resonances at Erc.m.=221, 741, and 959 keV. This new error estimation translates to an overall uncertainty in the C13 production of a factor of 50 when using the lower and upper reaction rates in the conditions relevant for the N13(α,p)O16 activation. Conclusions: The main source of uncertainty on the re-evaluated N13(α,p)O16 reaction rate currently comes from the uncertain α-particle width of relevant F17 states.
Published: 2020
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7. Evaluation of the N 13 ( α , p ) O 16

Author: A. Meyer, N. de Séréville, A. M. Laird, F. Hammache, R. Longland, T. Lawson, M. Pignatari, L. Audouin, D. Beaumel, S. Fortier, J. Kiener, A. Lefebvre-Schuhl, M. G. Pellegriti, M. Stanoiu, V. Tatischeff
Published: 2020
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8. Charged-particle decays of highly excited states in $^{19}$F

Author: I. Stefan, I. Sivacek, Marin Chabot, Jérôme Guillot, A. Gottardo, M. Assié, C. Delafosse, A. Georgiadou, J. Riley, Vincent Tatischeff, L. Perrot, Alison Laird, D. Beaumel, I. Matea, F. Flavigny, Valdir Guimaraes, P. Adsley, Jürgen Kiener, S. P. Fox, R. Garg, M. Degerlier, A. Lefebvre-Schuhl, N. de Sereville, L. Olivier, S. Gillespie, Fairouz Hammache, 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), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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, 010308 nuclear & particles physics, Order (ring theory), FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Charged particle, Supernova, Excited state, 0103 physical sciences, Production (computer science), Neutron, Atomic physics, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010303 astronomy & astrophysics
Abstract: Neutron-capture reactions on $^{18}$F in the helium-burning shell play an important role in the production of $^{15}$N during core-collapse supernovae. The competition between the $^{18}$F($n,p/\alpha$)$^{18}$O/$^{15}$N reactions controls the amount of $^{15}$N produced. The strengths of these reactions depend on the decay branching ratios of states in $^{19}$F above the neutron threshold. We report on an experiment investigating the decay branching ratios of these states in order to better constrain the strengths of the reactions., Comment: Submitted as part of the Proceedings of NIC 2018
Published: 2018
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9. Solid hydrogen target for missing mass spectroscopy in inverse kinematics

Author: Yohei Matsuda, Juzo Zenihiro, Zhengyang Tian, Harutaka Sakaguchi, Nori Aoi, S. Kawakami, Satoru Terashima, Yukie Maeda, Takahiro Kawabata, M. Tsumura, D. Beaumel, Tetsuya Yamamoto, S. Gotanda, and Hideaki Otsu
Subjects: Radioactive ion beams, Elastic scattering, Inverse kinematics, Chemistry, Health, Toxicology and Mutagenesis, Public Health, Environmental and Occupational Health, Mechanical press, Mass spectrometry, Spin isomers of hydrogen, Pollution, Analytical Chemistry, Neodymium magnet, Nuclear Energy and Engineering, Solid hydrogen, Radiology, Nuclear Medicine and imaging, Atomic physics, Spectroscopy
Abstract: By using para-hydrogen and a mechanical press made of neodymium magnets, we have succeeded in making a 1-mm-thick and 30-mm-diameter solid hydrogen target (SHT), and have measured elastic scattering of protons with radioactive ion beams at 300 MeV/u. We also succeeded in making not only a 0.5-mm-thick and 10-mm-diameter SHT but also a 2-mm-thick and 30-mm-diameter SHT to study excited-state properties of nuclei via (p,p′) reactions, and quasi-free (p,pα) reactions at intermediate energies. The ortho–para converter and the simple mechanical press show possibilities for making SHTs which have various radii and thicknesses.
Published: 2015
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10. Spectroscopy of Fe61 via the neutron transfer reaction H2(Fe60,p)Fe*61

Author: S. Giron, F. Hammache, N. de Séréville, P. Roussel, J. Burgunder, M. Moukaddam, D. Beaumel, L. Caceres, G. Duchêne, E. Clément, B. Fernandez-Dominguez, F. Flavigny, G. de France, S. Franchoo, D. Galaviz-Redondo, L. Gasques, J. Gibelin, A. Gillibert, S. Grevy, J. Guillot, M. Heil, J. Kiener, V. Lapoux, F. Maréchal, A. Matta, I. Matea, L. Nalpas, J. Pancin, L. Perrot, A. Obertelli, R. Raabe, J. A. Scarpaci, K. Sieja, O. Sorlin, I. Stefan, C. Stodel, M. Takechi, J. C. Thomas, and Y. Togano
Subjects: Physics, Photon, Silicon, 010308 nuclear & particles physics, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Charged particle, Cross section (physics), chemistry, 0103 physical sciences, Bound state, Neutron, Atomic physics, 010306 general physics, Adiabatic process, Spectroscopy
Abstract: The direct component of the 60Fe(n,γ)61Fe cross section was investigated by populating the bound states of the 61Fe nucleus through the (d,pγ) transfer reaction in inverse kinematics using a radioactive beam of 60Fe at 27A MeV. The experiment was performed at GANIL using the MUST2 array and an annular double-sided silicon strip detector for the detection of the light charged particle in coincidence with the photons measured in the EXOGAM γ-ray detectors. For the first time, the spectroscopic factors of the first 3/2−, 5/2−, 1/2−, and 9/2+ states of 61Fe were deduced experimentally from an adiabatic distorted wave approximation analysis of the data. The obtained results show a very good agreement with the shell-model predictions. The calculated direct component of the (n,γ) cross section was found negligible and of about 2% of the total, indicating a dominant resonant component.
Published: 2017
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11. Identification of light particles by means of pulse shape analysis with silicon detector at low energy

Author: V. V. Parkar, Ismael Martel, J.A. Dueñas, M. Assié, R. Berjillos, A. M. Sánchez-Benítez, D. Beaumel, D. Mengoni, Institut de Physique Nucléaire d'Orsay (IPNO), and 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)
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Photon, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Preamplifier, business.industry, Doping, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Particle identification, Charged particle, Optics, 0103 physical sciences, Physics::Accelerator Physics, Neutron, Nuclear Experiment, 010306 general physics, business, Instrumentation, Beam (structure)
Abstract: Particle separation of 1,2,3H at energy of 3 MeV has been achieved by digital pule shape analysis (DPSA) for particles fully stopped in a 500 μ m silicon detector. Light charged particles were produced in a nuclear reaction induced by a 34 MeV beam of 7Li impinging on a 12C target. Proton–deuterium identification has also been observed at 2 MeV using mono-energetic beams. A 20 keV resolution neutron transmutation doped (NTD) silicon detector was employed in a low-field injection setup. The method uses the parameters obtained both from the charge and current pulses generated by a high bandwidth charge sensitive preamplifier. The simplicity of the electronic chain plus the experimental conditions allowed the team to work with very low noise achieving signal-to-noise ratio (SNR) at values greater than 10.
Published: 2012
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12. PROBING PRE-FORMED ALPHA PARTICLES IN THE GROUND STATE OF NUCLEI

Author: J. A. Scarpaci, M. Fallot, Denis Lacroix, J.L. Laville, A. Chbihi, D. Beaumel, J.D. Frankland, E. Plagnol, Ph. Chomaz, J.C. Roynette, P. Roussel-Chomaz, M. Assié, P. Désesquelle, Y. Blumenfeld, C. Bhar, T. Zerguerras, H. Idbarkach, Elias Khan, A. Shrivastava, E. C. Pollacco, N. Frascaria, L. Lefebvre, 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), CSNSM SNO, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (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)-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)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Département d'Electronique, des Détecteurs et d'Informatique pour la Physique (ex SEDI) (DEDIP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, APC - Cosmologie, Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), CEA/DSM Centre de Saclay (CEA/DSM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), 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), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-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)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-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)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear and High Energy Physics, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, FOS: Physical sciences, General Physics and Astronomy, Alpha particle, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear Theory (nucl-th), Angular distribution, medicine.anatomical_structure, Helium-4, 0103 physical sciences, medicine, Alpha decay, Nuclear Experiment (nucl-ex), Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, Nucleus
Abstract: In this Letter, we report on alpha particle emission through the nuclear break-up in the reaction 40Ca on a 40Ca target at 50A MeV. It is observed that, similarly to nucleons, alpha particles can be emitted to the continuum with very specific angular distribution during the reaction. The alpha particle properties can be understood as resulting from an alpha cluster in the daughter nucleus that is perturbed by the short range nuclear attraction of the collision partner and emitted. A time-dependent theory that describe the alpha particle wave-function evolution is able to reproduce qualitatively the observed angular distribution. This mechanism offers new possibilities to study alpha particle properties in the nuclear medium., Comment: 4 pages, 3 figures
Published: 2011
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13. Pair and single neutron transfer with Borromean 8He

Author: Vladimir Zelevinsky, S. Bhattacharyya, Johan Nyberg, R. Raabe, I. Stefan, A. Navin, Roy Crawford Lemmon, N. Keeley, Cedric Simenel, D. Gupta, Y. Blumenfeld, Bertrand Jacquot, A. Shrivastava, K. Ramachandran, M. Rejmund, A. Chatterjee, J.A. Scarpaci, V. Nanal, C. N. Timis, M. Labiche, A. Lemasson, R. G. Pillay, Dominique Bazin, Christian Schmitt, D. Beaumel, 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), Department of Nuclear Reactions, The Andrzej Soltan Intitute for Nuclear Studies, National Superconducting Cyclotron Laboratory, Michigan State University [East Lansing], Michigan State University System-Michigan State University System, Variable Energy Cyclotron Centre, Nuclear Physics Division, Bhabha Atomic Research Centre (BARC), Government of India, Department of Atomic Energy-Government of India, Department of Atomic Energy, 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), CCLRC, Daresbury Laboratory, Department of Nuclear and Atomic Physics, Tata Institute for Fundamental Research (TIFR), Department of Physics and Astronomy [Uppsala], Uppsala University, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Department of Physics, University of Surrey (UNIS), SPIRAL, 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: Excitation function, Physics, Nuclear and High Energy Physics, Fusion, 010308 nuclear & particles physics, Direct observation, Transfer reaction, Borromean nucleus, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Transfer (group theory), Pairing, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics
Abstract: Direct observation of the survival of 199Au residues after 2n transfer in the He 8 + Au 197 system and the absence of the corresponding 67Cu in the He 8 + Cu 65 system at various energies are reported. The measurements of the surprisingly large cross sections for 199Au, coupled with the integral cross sections for the various Au residues, is used to obtain the first model-independent lower limits on the ratio of 2n to 1n transfer cross sections from 8He to a heavy target. A comparison of the transfer cross sections for 6,8He on these targets highlights the differences in the interactions of these Borromean nuclei. These measurements for the most neutron-rich nuclei on different targets highlight the need to probe the reaction mechanism with various targets and represent an experimental advance towards understanding specific features of pairing in the dynamics of dilute nuclear systems.
Published: 2011
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14. NEUTRON CORRELATIONS IN 6<font>He</font> VIEWED THROUGH NUCLEAR BREAK-UP

Author: Denis Lacroix, M. Chabot, C. Monrozeau, J. C. Angélique, M. Assié, C. M. Petrache, A. Chatterjee, H. Iwasaki, J. A. Scarpaci, W. N. Catford, Muriel Fallot, T. Tuna, F. Maréchal, F. Skaza, Y. Blumenfeld, D. Beaumel, D. Bazin, and Johan Nyberg
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Break-Up, 010308 nuclear & particles physics, General Physics and Astronomy, Astronomy and Astrophysics, 01 natural sciences, Nuclear physics, Correlation function (statistical mechanics), Mean field theory, 0103 physical sciences, Neutron, Nuclear drip line, Atomic physics, 010306 general physics, Nucleon, Beam (structure)
Abstract: Nuclear break-up as a tool to study neutron correlations is investigated both theoretically and experimentally. First a time dependent theory going beyond mean field has been developed and shows that correlations between nucleons can be probed through nuclear break-up. Secondly, nuclear break-up of 6 He on 208 Pb target was studied at 20 A.MeV using a secondary beam of 6 He produced by the SPIRAL facility at GANIL. From the correlation function, a strong contribution of the di-neutron configuration of 6 He is found.
Published: 2010
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15. Shell evolution in light nuclei inferred from transfer reactions

Author: D. Beaumel, Institut de Physique Nucléaire d'Orsay (IPNO), and 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)
Subjects: Physics, Nuclear and High Energy Physics, Light nucleus, Quenching (fluorescence), 010308 nuclear & particles physics, Nuclear Theory, Shell (structure), chemistry.chemical_element, Germanium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Transfer (group theory), medicine.anatomical_structure, chemistry, 0103 physical sciences, medicine, Particle, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus, Excitation
Abstract: Recent results on shell evolution in light exotic nuclei obtained through experiments performed at GANIL using the MUST2 particle array are reported. The one-nucleon transfer reactions 20 O(d,t) was investigated using a setup combining the MUST2 and TIARA particle arrays, together with EXOGAM germanium detectors. Preliminary results on the populated states as well as comparison with calculated spectroscopic factors are presented. In a second study, the Z = 8 shell closure was investigated by means of the two-neutron transfer reaction 14 O(p,t) using a set of MUST2 telescopes. A newly observed state at low excitation energy in the unbound 12 O points to the Z = 8 shell quenching, analogously to the established case at N = 8 in the neutron-rich mirror nucleus 12 Be.
Published: 2010
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16. Candidate Resonant Tetraneutron State Populated by theHe4(He8,Be8)Reaction

Author: C. S. Lee, Shintaro Go, H. Baba, N. Fukuda, Daisuke Kameda, F. Hammache, Motonobu Takaki, Yukie Maeda, M. Itoh, Shumpei Noji, Rin Yokoyama, Yuya Kubota, Kentaro Yako, H. Sato, Yosuke Kondo, M. Assie, D. Beaumel, Michikazu Kobayashi, Yohei Shimizu, H. Sakai, Hiroyuki Takeda, Takeo Kawabata, K. Miki, Yoshiko Sasamoto, Toshiyuki Kubo, Shoichiro Kawase, Masaki Sasano, Teruo Fujii, Susumu Shimoura, T. Nishi, Shin'ichiro Michimasa, Tomohiro Uesaka, Hiroshi Tokieda, L. Tang, Satoshi Takeuchi, Atsushi Tamii, Satoshi Sakaguchi, Eiji Ideguchi, Y. Yanagisawa, T. Baba, M. Tsumura, Hiroyuki Miya, K. Kisamori, Hiroaki Matsubara, Andreas Stolz, K. Yoshida, Shuichi Ota, Masanori Dozono, Naohito Inabe, H. Suzuki, and M. Kurata-Nishimura
Subjects: Physics, 010308 nuclear & particles physics, Q value, Spectrum (functional analysis), General Physics and Astronomy, State (functional analysis), 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, Tetraneutron, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Energy (signal processing)
Abstract: A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst) MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.
Published: 2016
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17. Indirect study of 19Ne states near the threshold

Author: N. de Séréville, B. Bouzid, Marc Loiselet, Jürgen Kiener, Carmen Angulo, Vincent Tatischeff, A. Coc, Michel Gaelens, P. Figuera, F. de Oliveira Santos, Guido Ryckewaert, Daniel Labar, Alain Ninane, S. Fortier, S. Ouichaoui, P. Demaret, Marlete Assunção, S. Cherubini, F. Hammache, Pierre Leleux, E. Berthoumieux, D. Beaumel, N. Smirnova, Manoel Couder, and A. Lefebvre-Schuhl
Subjects: Physics, Reaction rate, Nuclear reaction, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Scattering, 0103 physical sciences, Atomic physics, 010306 general physics, 01 natural sciences, Radioactive beam
Abstract: The early E ⩽ 511 keV gamma-ray emission from novae depends critically on the F 18 ( p , α ) O 15 reaction. Unfortunately the reaction rate of the F 18 ( p , α ) O 15 reaction is still largely uncertain due to the unknown strengths of low-lying proton resonances near the F 18 + p threshold which play an important role in the nova temperature regime. We report here our last results concerning the study of the d ( F 18 , p ) F 19 ( α ) N 15 transfer reaction. We show in particular that these two low-lying resonances cannot be neglected. These results are then used to perform a careful study of the remaining uncertainties associated to the F 18 ( p , α ) O 15 and F 18 ( p , γ ) Ne 19 reaction rates.
Published: 2007
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18. Measurement of the GMR in the Unstable 56Ni Nucleus using the Active Target Maya

Author: U. Garg, A. Gillibert, N. Frascaria, M. Gelin, M. Caamaño, D. Beaumel, D. Cortina-Gil, D. Gupta, A. Obertelli, J. A. Scarpaci, C. Monrozeau, W. Mittig, Y. Blumenfeld, P. Roussel-Chomaz, F. Maréchal, Elias Khan, C. E. Demonchy, 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), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), 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: Active target, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Isoscalar, Nuclear Theory, Magnetic monopole, Resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Inelastic scattering, 01 natural sciences, Nuclear physics, medicine.anatomical_structure, 0103 physical sciences, Energy spectrum, medicine, Atomic physics, Nuclear Experiment, 010303 astronomy & astrophysics, Nucleus, Excitation
Abstract: The measurement of the Isoscalar Giant Monopole Resonance(GMR) in unstable nuclei remains a major experimental challenge due to low radioactive beam intensities and unfavourable conditions in reverse kinematics. At GANIL, we have tested a new experimental method based on the unique capabilities of the active target Maya to probe the GMR by the inelastic scattering reaction 56Ni(d,d') at 50 AMeV. The preliminary excitation energy spectrum of 56Ni presents a bump between 12 and 25 MeV where isoscalar resonances are expected. © 2007 Elsevier B.V. All rights reserved.
Published: 2007
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19. Low-lying states and structure of the exotic 8He via direct reactions on the proton

Author: F. Skaza, A. Gillibert, R. Wolski, D. Beaumel, A. Drouart, J. L. Sida, K. Rusek, V. Lapoux, P. Roussel-Chomaz, A. Pakou, N. Keeley, F. Auger, Lydie Giot, J.A. Scarpaci, E. Becheva, Y. Blumenfeld, E. C. Pollacco, N. Alamanos, Elias Khan, R. Raabe, S. V. Stepantsov, F. Delaunay, L. Nalpas, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), 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), Peter von Neumann-Cosel, Thomas Aumann, 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, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Resonance (particle physics), Charged particle, medicine.anatomical_structure, Excited state, 0103 physical sciences, medicine, Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, Nucleus, Excitation
Abstract: The structure of the light exotic nucleus 8 He was investigated using direct reactions of the 8 He SPIRAL beam on a proton-rich target. The (p,p') scattering to the 2 1 + state, the (p,d) 7 He and (p,t) 6 He transfer reactions, were measured at the energy E l a b = 15.7 A.MeV . The light charged particles (p,d,t) were detected in the MUST Si-strip telescope array. The excitation spectrum of 8 He was extracted from the (p,p') reaction. Above the known 2 1 + excited state at 3.6 MeV, a second resonance was found around 5.4 MeV. The cross sections were analyzed within the coupled-reaction channels framework, using microscopic potentials. It is inferred that the 8 He ground state has a more complex neutron-skin structure than suggested by previous α + 4 n models assuming a pure ( 1 p 3 / 2 ) 4 configuration.
Published: 2007
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20. Isoscalar response ofNi68toα-particle and deuteron probes

Author: L. Caceres, M. Caamaño, J. C. Thomas, Gianluca Colò, Marine Vandebrouck, F. Delaunay, O. Sorlin, J. Pancin, D. Beaumel, B. Fernández-Domínguez, P. Roussel-Chomaz, H. Savajols, J. Gibelin, Nasser Kalantar-Nayestanaki, D. Suzuki, N.L. Achouri, Elias Khan, C. Stodel, Riccardo Raabe, T. Roger, W. Mittig, Mohsen Harakeh, Hidetada Baba, U. Garg, G. F. Grinyer, N. Keeley, and Y. Blumenfeld
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, Isoscalar, Nuclear Theory, Magnetic monopole, Resonance, Alpha particle, 01 natural sciences, Nuclear physics, Dipole, Deuterium, 0103 physical sciences, Quadrupole, Atomic physics, Nuclear Experiment, 010306 general physics, Astrophysics::Galaxy Astrophysics
Abstract: Isoscalar giant resonances have been measured in the unstable Ni68 nucleus using inelastic alpha and deuteron scattering at 50A MeV in inverse kinematics with the active target MAYA at GANIL. Using alpha scattering, the extracted isoscalar giant monopole resonance (ISGMR) centroid was determined to be 21.1±1.9 MeV and the isoscalar giant quadrupole resonance (ISGQR) to be 15.9±1.3 MeV. Indications for soft isoscalar monopole and dipole modes are provided. Results obtained with both (α,α′) and (d,d′) probes are compatible. The evolution of isoscalar giant resonances along the Ni isotopic chain from Ni56 to Ni68 is discussed.
Published: 2015
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21. Candidate Resonant Tetraneutron State Populated by the ^{4}He(^{8}He,^{8}Be) Reaction

Author: K, Kisamori, S, Shimoura, H, Miya, S, Michimasa, S, Ota, M, Assie, H, Baba, T, Baba, D, Beaumel, M, Dozono, T, Fujii, N, Fukuda, S, Go, F, Hammache, E, Ideguchi, N, Inabe, M, Itoh, D, Kameda, S, Kawase, T, Kawabata, M, Kobayashi, Y, Kondo, T, Kubo, Y, Kubota, M, Kurata-Nishimura, C S, Lee, Y, Maeda, H, Matsubara, K, Miki, T, Nishi, S, Noji, S, Sakaguchi, H, Sakai, Y, Sasamoto, M, Sasano, H, Sato, Y, Shimizu, A, Stolz, H, Suzuki, M, Takaki, H, Takeda, S, Takeuchi, A, Tamii, L, Tang, H, Tokieda, M, Tsumura, T, Uesaka, K, Yako, Y, Yanagisawa, R, Yokoyama, and K, Yoshida
Abstract: A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst) MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.
Published: 2015

22. Study of the N = 28 shell closure in the Ar isotopic chain

Author: E. Rich, Zsolt Dombrádi, D. Sohler, L. Nalpas, Karl Kratz, Yu. E. Penionzhkevich, J. Gibelin, F. Hammache, S. Franchoo, J.A. Scarpaci, M. Gelin, D. Beaumel, K. W. Kemper, E. C. Pollacco, S. Grévy, S. Fortier, M. Stanoiu, Thomas Rauscher, M. G. St. Laurent, Y. Blumenfeld, F. Nowacki, P. Roussel-Chomaz, O. Sorlin, A. N. Ostrowski, L. Gaudefroy, Erik Tryggestad, S. M. Lukyanov, D. Verney, F. Ibrahim, C. Monrozeau, 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), 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), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), SPIRAL, 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 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: Nuclear and High Energy Physics, Nuclear Theory, Hadron, 21.10.Hw, 21.10.Jx, 25.60.Je, 26.30.+k, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Reaction rate, Spin, Transfer reactions, Atomic orbital, 0103 physical sciences, Nuclear astrophysics, medicine, Astrophysics::Solar and Stellar Astrophysics, Nuclear fusion, Neutron, Nuclear Experiment, 010306 general physics, Physics, 010308 nuclear & particles physics, Nucleosynthesis in novae, and isobaric spin, Neutron capture, medicine.anatomical_structure, parity, Physics::Space Physics, Spectroscopic factors, Atomic physics, supernovae and other explosive environments, Nucleus
Abstract: Expérience au GANIL NESTER; The structure of the neutron-rich nucleus $^{47}$Ar has been investigated through the d( $^{46}$Ar, $^{47}$Ar)p transfer reaction. The radioactive beam of $^{46}$Ar at 10A·MeV was provided by the SPIRAL facility at GANIL. The protons corresponding to a neutron pick-up on bound or unbound states mechanism in $^{47}$Ar nuclei were detected at backward angles by the position-sensitive Si array-detector MUST. The transfer-like ejectiles were detected in the SPEG spectrometer. Level scheme, spin assignments and spectroscopic factors have been deduced for $^{47}$Ar and compared to shell model predictions. They suggest a slight erosion of the N = 28 shell gap from the weakening of the spin-orbit interaction arising from the f and p orbitals. These spectroscopic information are subsequently used to infer (n,$\gamma$) reaction rates in the Ar isotopic chain to understand the origin of the $^{48}$Ca/ $^{46}$Ca abnormal isotopic ratio observed in certain inclusions of meteorites.
Published: 2006
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23. Investigation of Isovector Excitations via the (t,3He) reaction at on 58Ni and 48Ca targets: microscopic interpretation

Author: M. de Huu, Gianluca Colò, H.J. Wörtche, D. Frekers, E. Rich, B. C. Junk, Sydney Gales, P. Haefner, M. Fujiwara, D. Beaumel, Sijtze Brandenburg, Mohsen Harakeh, M.D. Hunyadi, N. Van Giai, Jérôme Guillot, Barry Davids, C. Bäumer, A.M. van den Berg, S. Fortier, S.Y. van der Werf, and E.-W. Grewe
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Thesaurus (information retrieval), Isovector, 010308 nuclear & particles physics, 0103 physical sciences, 010306 general physics, 01 natural sciences, Interpretation (model theory)
Published: 2005
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24. Analysis of the 11B(7Li,7Be)11Be reaction at 57 MeV in a microscopic approach

Author: Francesco Cappuzzello, H. Lenske, Js Winfield, A. Cunsolo, A. Foti, S. Fortier, Sea Orrigo, D. Beaumel, A. Lazzaro, and C. Nociforo
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Isovector, 010308 nuclear & particles physics, Nuclear Theory, 01 natural sciences, Dipole, Excited state, 0103 physical sciences, Neutron, Born approximation, Atomic physics, Nuclear Experiment, 010306 general physics, Random phase approximation, Ground state
Abstract: The 11B(7Li, 7Be)11Be charge exchange reaction has been studied at an incident energy of 57 MeV. Spectra were measured at forward angles, θcm⩽35°. The good energy resolution (∼50 keV) allowed the identification of transitions both to the 7Be (3/2−, gs) and 7Be(1/2−, 429 keV) exit channels and hence the direct measurement of the ratio of the respective cross sections and angular distributions. Besides the bound ground and first excited state of 11Be several low lying excitations just above the neutron threshold are observed. A structure seen at E ∗ =9.4 MeV with FWHM ∼7 MeV is compatible with the spin dipole resonance (SDR). The data are analysed in a many-body approach. For the projectile transitions shell model results are used. In order to account properly for the special features of the weakly bound 11Be system the target transitions are described microscopically by Hartree–Fock–Bogoliubov (HFB) and quasi-particle random phase approximation (QRPA) theory. The HFB ground state densities and the QRPA transition densities, respectively, are used in folding calculations for the optical potentials and transition form factors. Spectra and β-decay transitions strengths are reasonably well described. The measured cross section are well reproduced by one-step direct charge exchange distorted wave born approximation (DWBA) calculations. A dominance of unnatural parity transitions is found. This is explained in terms of the spin transfer behaviour of the nucleon–nucleon isovector interaction at low bombarding energy.
Published: 2004
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25. Excited states of 15 C

Author: A. Lazzaro, D. Beaumel, S. Fortier, Francesco Cappuzzello, S. E. A. Orrigo, H. Lenske, J. S. Winfield, A. Cunsolo, C. Nociforo, A. Foti, and M. C. Allia
Subjects: Physics, Excited state, Resolution (electron density), Energy spectrum, General Physics and Astronomy, Level structure, Incident energy, Atomic physics, Nuclear Experiment, Ground state, Excitation
Abstract: The 15N(7Li,7Be)15C reaction at 55 MeV incident energy was studied at forward angles in order to explore the 15C excitation energy spectrum. The 15C ground state and the states at Ex = 0.77, 6.77, 7.30, 8.50 MeV excitation energies were populated. The energy resolution ( ~ 250 keV) allowed the identification of these transitions each for 7Be ground and first-excited state at Ex = 0.429 MeV. QRPA calculations reproduce the 15C level structure below 1.5 MeV excitation energy. The strength observed at higher excitation energies probably arises from core-excited components of 15C.
Published: 2004
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26. Measurement of the Isoscalar Monopole Response in the Neutron-Rich NucleusNi68

Author: Marine Vandebrouck, C. Stodel, Gianluca Colò, U. Garg, D. Suzuki, Julien Gibelin, H. Baba, Elias Khan, O. Sorlin, B. Fernández-Domínguez, Y. Blumenfeld, W. Mittig, Franck Delaunay, J. C. Thomas, N. L. Achouri, Riccardo Raabe, N. Keeley, H. Savajols, P. Roussel-Chomaz, T. Roger, D. Beaumel, Nasser Kalantar-Nayestanaki, M. Caamaño, Mohsen Harakeh, G. F. Grinyer, J. Pancin, and L. Caceres
Subjects: Physics, 010308 nuclear & particles physics, Scattering, Isoscalar, Nuclear Theory, Magnetic monopole, General Physics and Astronomy, Soft modes, 01 natural sciences, Resonance (particle physics), Nuclear physics, Cross section (physics), medicine.anatomical_structure, 0103 physical sciences, medicine, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus
Abstract: The isoscalar monopole response has been measured in the unstable nucleus (68)Ni using inelastic alpha scattering at 50A MeV in inverse kinematics with the active target MAYA at GANIL. The isoscalar giant monopole resonance (ISGMR) centroid was determined to be 21.1 ± 1.9 MeV and indications for a soft monopole mode are provided for the first time at 12.9 ± 1.0 MeV. Analysis of the corresponding angular distributions using distorted-wave-born approximation with random-phase approximation transition densities indicates that the L = 0 multipolarity dominates the cross section for the ISGMR and significantly contributes to the low-energy mode. The L=0 part of this low-energy mode, the soft monopole mode, is dominated by neutron excitations. This demonstrates the relevance of inelastic alpha scattering in inverse kinematics in order to probe both the ISGMR and isoscalar soft modes in neutron-rich nuclei.
Published: 2014
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27. Determination of the astrophysical S factor of the 8B(p,γ)9C capture reaction from the d(8B,9C)n reaction

Author: D. Beaumel, H. Laurent, H. Ohnuma, H. Kumagai, Hiroyoshi Sakurai, T. Motobayashi, S. Fortier, Naoki Fukuda, Kenichiro Yoneda, Hironori Iwasaki, M. Ishihara, J.M. Maison, M. Hirai, Takashi Nakamura, S. M. Lukyanov, S. Pita, T. Kubo, Nori Aoi, N. Imai, Alberto Mengoni, and Toshiharu Teranishi
Subjects: Physics, Nuclear and High Energy Physics, S-factor, Atomic physics
Abstract: The asymptotic normalization coefficients for the virtual decay 9 C → 8 B + p have been determined by measuring the crosssection of the 8 B(d, n) 9 C reaction in inverse kinematics at 14.4 MeV/u, using the RIPS facility. The deduced astrophysical S factor S18 of the 8 B(p ,γ ) 9 C capture reaction in the center of mass energy range 1–100 keV is S18 = 45 ± 13 eV b.  2001
Published: 2001
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28. Test of the ANC method via (d,p) reaction

Author: H. Ohnuma, D. Beaumel, Meiko Kurokawa, M. Ishihara, Shin'ichiro Michimasa, Toshiyuki Kubo, Nori Aoi, Toshiharu Teranishi, Shigeru Kubono, S. Kato, K. Abe, Patrick Strasser, X. Liu, Alberto Mengoni, N. Imai, Hiroyoshi Sakurai, Kazukiyo Kumagai, Institut de Physique Nucléaire d'Orsay (IPNO), and 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)
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, 0103 physical sciences, Particle Physics - Lattice, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, Simulation, Test (assessment)
Published: 2001
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29. Light particles emitted with very forward quasi-projectiles in the fragmentation of 44 MeV amu-140Ar on27Al,58,64Ni, and197Au

Author: E. Kashy, F. Clapier, M. Bernas, C. Stephan, M. Mirea, L. Tassan-Got, Ch.O. Bacri, D Beaumel, V. Borrel, and P. Roussel
Subjects: Physics, Nuclear and High Energy Physics, Photon, Fragmentation (mass spectrometry), Proton, Coincident, Projectile, Incident beam, Neutron, Atomic physics, Nuclear Experiment, Coincidence
Abstract: A first measurement is reported on coincident fast protons and neutrons evaporated by fragments detected in the incident beam direction. For all targets, the proton coincidence ratio is shown to increase with fragment velocity loss. This increase is correlated to the decrease of the fragment yield, with the coincidence ratio doubling when the yield decreases by a factor of 10. The coincidence ratio is found to also be proportional to the fragment mass loss for fragments with the beam velocity. A two-step mechanism is sketched out to describe these results.
Published: 2000
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30. Evidence for particle stability of F and particle instability of N and O

Author: D. Beaumel, Nakamura Takahiro, Yu. E. Penionzhkevich, M. Hirai, Eiji Ideguchi, H. Kumagai, Yoshiki Watanabe, Hiroshi Ogawa, Hironori Iwasaki, Masahiro Notani, Kenichiro Yoneda, Toshiharu Teranishi, K. Kusaka, M. Ishihara, N. Imai, N. Aoi, S. M. Lukyanov, N. Fukuda, Hiroyoshi Sakurai, A. Yoshida, and T. Kubo
Subjects: Physics, Nuclear and High Energy Physics, Isotope, Nuclear Theory, Particle stability, chemistry.chemical_element, Oxygen, Instability, chemistry, Fluorine, Nuclear drip line, Physics::Chemical Physics, Atomic physics, Nuclear Experiment, Projectile fragmentation
Abstract: The neutron drip line up to fluorine has been investigated by the projectile fragmentation of a 94.1A MeV 40 Ar beam at the fragment separator RIPS at RIKEN. A new neutron-rich isotope, 31 F, has been observed for the first time while clear evidence for the particle instability of 24,25 N, 27,28 O and 30 F has been obtained. The sudden change in stability from oxygen to fluorine may demonstrate the onset of deformation for the neutron-rich fluorine isotopes.
Published: 1999
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31. Beta-delayed proton spectroscopy of

Author: Hiroyoshi Sakurai, D. Beaumel, Arup Bandyopadhyay, Alok Chakrabarti, Kenichiro Yoneda, T. Kubo, Kosuke Morita, Hiroshi Ogawa, V. Banerjee, and S. M. Lukyanov
Subjects: Physics, Nuclear and High Energy Physics, Proton, Isotope, Projectile, Proton decay, Nuclear Theory, Detector, Nuclear physics, Beta (plasma physics), Physics::Accelerator Physics, Atomic physics, Proton emission, Nuclear Experiment, Spectroscopy
Abstract: Recently an experiment has been carried out at RIKEN, Japan, using the projectile fragment separator RIPS to test a new approach of studying -delayed proton emitters. The approach consists of reduction of contamination from neighbouring isotones and isotopes by using a set of Al absorbers at the RIPS focal plane and stopping the fragments of interest on a thin foil placed in front of a gas -Si E detector telescope for delayed proton measurement. These two together have led to a remarkable reduction of -background in the delayed proton spectrum of and a number of new levels in decaying by proton emission to have been observed. The details of the technique and the results obtained from the -delayed proton decay of will be discussed.
Published: 1998
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32. A new phenomenon in heavy ion inelastic scattering: the towing mode

Author: J.A. Scarpaci, A. van der Woude, N. Frascaria, T. Suomijärvi, J.C. Roynette, F. Maréchal, D. Beaumel, Ph. Chomaz, V. Pascalon-Rozier, I. Lhenry, J.R. Jongman, Y. Blumenfeld, H. Laurent, Denis Lacroix, P. Roussel-Chomaz, Research unit Nuclear & Hadron Physics, 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), Physique théorique, 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)-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 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)-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)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Mode (statistics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Inelastic scattering, Deep inelastic scattering, 01 natural sciences, Inelastic neutron scattering, Spectral line, Coincidence, Nuclear physics, 0103 physical sciences, SPECTRA, Atomic physics, 010306 general physics, Nucleon, DECAY, Excitation
Abstract: The inelastic scattering of Ar-40 on Ni-58 has been studied at 44 MeV per nucleon incident energy in coincidence with light particle emission. Besides the well known mechanisms of inelastic excitation, pick up break up and nucleon knock out, a new phenomenon has been observed, giving rise to fast forward moving particles with specific angular correlations. This newly observed mechanism seems to be a generic phenomenon present for various projectile-target combinations and incident energies. Its contribution to the inelastic spectrum has been extracted and a tentative interpretation is given. (C) 1998 Elsevier Science B.V. All rights reserved.
Published: 1998
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33. Proton emission in inelastic scattering of40Ca on40Ca at 50 MeV/nucleon

Author: A. van der Woude, J.C. Roynette, I. Lhenry, D. Beaumel, T. Suomijärvi, M. Lamehi-Rachti, J.A. Scarpaci, J.P. Garron, Ph. Chomaz, A. Gillibert, N. Frascaria, N. Alamanos, and Y. Blumenfeld
Subjects: Physics, Nuclear and High Energy Physics, Decay scheme, 010308 nuclear & particles physics, Nuclear Theory, Inelastic scattering, 01 natural sciences, 7. Clean energy, Resonance (particle physics), Charged particle, Nuclear physics, Giant resonance, 0103 physical sciences, Quadrupole, Proton emission, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: Inelastic scattering of {sup 40}Ca on {sup 40}Ca at 50 MeV/nucleon has been measured in coincidence with light charged particles detected over a large angular domain. The giant resonance region of the inelastic spectrum is shown to be dominated by the isoscalar giant quadrupole resonance. The characteristics of the emitted protons allow us to separate four reaction mechanisms contributing to the high excitation energy region of the inelastic spectrum (E{sup {asterisk}}{gt} 30 MeV): pickup breakup, knockout, inelastic scattering to high-lying target states, and a new mechanism responsible for the emission of fast-moving protons. A sizable direct decay branch towards hole states of {sup 39}K is measured for the giant quadrupole resonance in {sup 40}Ca. Evidence is given for the excitation of the two-phonon giant quadrupole resonance, characterized by its direct decay scheme. The energy and width of this two-phonon state are in agreement with a harmonic picture for collective nuclear excitations. {copyright} {ital 1997} {ital The American Physical Society}
Published: 1997
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34. New indirect study of the 12 C(α,γ) 16 O reaction via the 12 C( 7 Li,t) 16 O transfer reaction

Author: A. Bouda, A. Lefebvre-Schuhl, Jürgen Kiener, Pierre Descouvemont, Fairouz Hammache, Laurent Audouin, D. Beaumel, Vincent Tatischeff, L. Gaudefroy, M. G. Pellegriti, S. Fortier, N. Oulebsir, and P. Roussel
Subjects: Transfer (group theory), Chemistry, Physical chemistry
Published: 2013
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35. The(7Li,7Beγ) reaction and isovector spin strength inCa40

Author: S. E. Hirzebruch, T. Suomijärvi, I. Lhenry, S. Danczyk, S. Gales, J. Stasko, G. M. Crawley, J. S. Winfield, D. Beaumel, J.M. Maison, and H. Laurent
Subjects: Physics, Nuclear and High Energy Physics, Dipole, Isovector, Giant resonance, Spin transfer, Resonance, Atomic physics, Energy (signal processing), Excitation, Spin-½
Abstract: The $^{40}\mathrm{Ca}$${(}^{7}$Li,${\mathrm{}}^{7}$Be\ensuremath{\gamma}) reaction at E${(}^{7}$Li)/A = 70 MeV has been used to investigate isovector giant resonances and to measure the ratio of \ensuremath{\Delta}S=1 to \ensuremath{\Delta}S=0 spin strength in $^{40}\mathrm{Ca}$ at high excitation energy. In the singles spectrum, the analogue of the giant dipole resonance is observed. Another resonance is observed at ${\mathit{E}}_{\mathit{x}}$\ensuremath{\approxeq}15 MeV in the residual nucleus, which we suggest is a collective ${2}^{\mathrm{\ensuremath{-}}}$ state. The isovector spin transfer strength at high excitation for the calcium target is compared to that measured with a carbon target under the same experimental conditions. Although more spin transfer strength at high excitation is observed for the calcium target than for the carbon target, this only accounts in part for an apparent discrepancy between previous $^{40}\mathrm{Ca}$(p\ensuremath{\rightarrow},p${\ensuremath{\rightarrow}}^{\ensuremath{'}}$) and $^{12}\mathrm{C}$${(}^{7}$Li,${\mathrm{}}^{7}$Be) experiments. The general utility of the ${(}^{7}$Li, $^{7}\ensuremath{\gamma}$) reaction is discussed. \textcopyright{} 1996 The American Physical Society.
Published: 1996
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36. A search for the isovector monopole resonance in 208Pb

Author: S. Fortier, G. M. Crawley, J. Guillot, Sijtze Brandenburg, T. Suomijärvi, H. Laurent, Joseph E. Finck, F. Azaiez, H. Langevin-Joliot, J. Stasko, S. Gales, Y. Blumenfeld, I. Lhenry, D. Beaumel, and J.M. Maison
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Isovector, Magnetic monopole, Resonance (particle physics)
Published: 1995
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37. Indirect study of the12C(α,γ)16O reaction via the12C(7Li, t)16O transfer reaction

Author: Jürgen Kiener, A. Bouda, P. Roussel, L. Audouin, Fairouz Hammache, D. Beaumel, L. Gaudefroy, S. Fortier, M. G. Pellegriti, A. Lefebvre-Schuhl, Vincent Tatischeff, N. Oulebsir, and Pierre Descouvemont
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Radiative capture, chemistry.chemical_element, 01 natural sciences, Transfer (group theory), chemistry, Nucleosynthesis, 0103 physical sciences, Born approximation, Atomic physics, 010306 general physics, Helium
Abstract: The ${}^{12}$C($\ensuremath{\alpha}$,$\ensuremath{\gamma}$)${}^{16}$O reaction plays a crucial role in stellar evolution. The rate of this reaction determines directly the ${}^{12}$C-to-${}^{16}$O abundance ratio at the end of the helium burning phase of stars and consequently has a big effect on the subsequent nucleosynthesis and even on the evolution of massive stars. However, despite many experimental studies, the low-energy cross section of ${}^{12}$C($\ensuremath{\alpha}$,$\ensuremath{\gamma}$)${}^{16}$O remains uncertain. The extrapolation of the measured cross sections to stellar energies ($E\ensuremath{\sim}300$ keV) is made particularly difficult by the presence of the 2${}^{+}$ (${E}_{x}=6.92$ MeV) and 1${}^{\ensuremath{-}}$ (${E}_{x}=7.12$ MeV)subthreshold states of ${}^{16}$O. To further investigate the contribution of these two subthreshold resonances to the ${}^{12}$C($\ensuremath{\alpha}$,$\ensuremath{\gamma}$)${}^{16}$O cross section, we determine their $\ensuremath{\alpha}$-reduced widths via a measurement of the transfer reaction ${}^{12}$C(${}^{7}$Li, $t$)${}^{16}$O at two incident energies, 28 and 34 MeV. The uncertainties on the determined $\ensuremath{\alpha}$-spectroscopic factors and the $\ensuremath{\alpha}$-reduced widths were reduced thanks to a detailed distorted-wave Born approximation analysis of the transfer angular distributions measured at the two incident energies. The $R$-matrix calculations of ${}^{12}$C($\ensuremath{\alpha}$,$\ensuremath{\gamma}$)${}^{16}$O cross section using our obtained $\ensuremath{\alpha}$-reduced widths for the 2${}^{+}$ and 1${}^{\ensuremath{-}}$ subthreshold resonances lead to an $E1$ $S$ factor at 300 keV of $100\ifmmode\pm\else\textpm\fi{}28$ keV b, which is consistent with values obtained in most of the direct and indirect measurements as well as the NACRE collaboration compilation while the result for the $E2$ component ${S}_{E2}\phantom{\rule{0.28em}{0ex}}(300\phantom{\rule{4.pt}{0ex}}\text{keV})=50\ifmmode\pm\else\textpm\fi{}19$ keV b disagrees with the NACRE adopted value.
Published: 2012
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38. Low-lying neutronfp-shell intruder states in27Ne

Author: S. M. Brown, W. N. Catford, J. S. Thomas, B. Fernández-Domínguez, N. A. Orr, M. Labiche, M. Rejmund, N. L. Achouri, H. Al Falou, N. I. Ashwood, D. Beaumel, Y. Blumenfeld, B. A. Brown, R. Chapman, M. Chartier, N. Curtis, G. de France, N. de Sereville, F. Delaunay, A. Drouart, C. Force, S. Franchoo, J. Guillot, P. Haigh, F. Hammache, V. Lapoux, R. C. Lemmon, A. Leprince, F. Maréchal, X. Mougeot, B. Mouginot, L. Nalpas, A. Navin, N. P. Patterson, B. Pietras, E. C. Pollacco, A. Ramus, J. A. Scarpaci, I. Stefan, and G. L. Wilson
Subjects: Physics, Nuclear and High Energy Physics, Quenching (fluorescence), 010308 nuclear & particles physics, Nuclear Theory, SHELL model, Shell (structure), 01 natural sciences, Nuclear physics, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Beam (structure)
Abstract: The quenching of the N=20 shell gap in neutron-rich nuclei is investigated by studying the single-particle structure of 27Ne via neutron transfer using a 26Ne beam. Two low-lying negative-parity intruder states have been observed, the lowest of which is identified as Jπ=3/2−, confirming earlier speculations. A level identified as 7/2− is observed higher in energy than the 3/2−, contrary to the ordering at β-stability and at an energy significantly different from the predictions of previous shell-model calculations. The measured energies and deduced spectroscopic factors are well reproduced in full (0,1)-ℏω 0s-0p-0d-1s-0f-1p calculations in which there is a significant ad hoc reduction (∼0.7 MeV) in the N=20 shell gap.
Published: 2012
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39. New excited states in the halo nucleus 6He

Author: K. Rusek, L. Gaudefroy, J. A. Scarpaci, T. J. Mertzimekis, E. C. Pollacco, V. Lapoux, A. Drouart, Jérôme Guillot, B. Avez, Xavier Mougeot, Daisuke Suzuki, N. Keeley, P. Roussel-Chomaz, I. Strojek, N. Alamanos, Hironori Iwasaki, Cedric Simenel, A. Pakou, D. Beaumel, C. Force, L. Nalpas, R. Dayras, W. Mittig, R. Wolski, F. Auger, T. Roger, K. W. Kemper, Y. Blumenfeld, T. Al Kalanee, A. Gillibert, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Resonant states, Halo nucleus, He 8 ( p , t ), Transfer reaction, Astrophysics::Cosmology and Extragalactic Astrophysics, Borromean nucleus, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Charged particle, law.invention, Telescope, 8He(p, law, Excited state, 0103 physical sciences, Atomic physics, t), 010306 general physics, Spectroscopy, Nuclear Experiment, Excitation
Abstract: Expérience GANIL/SPIRAL/MUST2/E525S; The low-lying spectroscopy of 6He was investigated via the 2-neutron transfer reaction p(8He, t) with the 8He beam delivered by the SPIRAL facility at 15.4 A MeV. The light charged particles produced by the direct reactions were measured using the MUST2 Si-strip telescope array. Above the known 2+ state, two new resonances were observed: at E∗ = 2.6±0.3 MeV (width Γ = 1.6±0.4 MeV) and at 5.3±0.3 MeV with Γ = 2 ± 1 MeV. Through the analysis of the angular distributions, they correspond to a 2+ state and to an L = 1 state, respectively. These new states, challenging the nuclear theories, could be used as benchmarks for checking the microscopic inputs of the newly improved structure models, and should trigger development of models including the treatments of both core excitation and continuum coupling effects.
Published: 2012
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40. Systematic behavior of ejectile spin polarization in the projectile fragmentation reaction

Author: Koichiro Asahi, H. Miyatake, Naohito Inabe, H. Ueno, Masayasu Ishihara, D. Beaumel, David J. Morrissey, Hirohiko Sato, J. Kura, Hiroshi G. Okuno, W. ‐D. Schmidt‐Ott, N. Takahashi, Tadashi Shimoda, M Iwamoto, Takashi Nakamura, Y. Ohkubo, F Ambe, T. Ichihara, Y. Kobayashi, M. Adachi, Jin Nakamura, A. Yoshida, and T. Kubo
Subjects: Nuclear physics, Momentum, Physics, Nuclear and High Energy Physics, Spin polarization, Incident energy, Atomic number, Atomic physics, Nuclear Experiment, Projectile fragmentation, Beam (structure)
Abstract: Ejectile spin polarization P in intermediate-energy projectile fragmentation has been measured for different targets and incident energies using the RIPS fragment separator at RIKEN. The observed P as a function of the fragment momentum shows a systematic change when the atomic number of the target or the incident energy is varied. Most remarkably, P does not vanish at the momentum corresponding to the beam velocity, indicating an important effect which has not been considered in the previously proposed model.
Published: 1994
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41. Decay modes of high-lying single-particle states inPb209

Author: S. Fortier, J. Guillot, Sydney Gales, H. Laurent, J.A. Bordewijk, J. Vernotte, A. Krasznahorkay, J.M. Maison, D. Beaumel, M. Renteria, G. M. Crawley, H. Langevin-Joliot, C.P. Massolo, and Sijtze Brandenburg
Subjects: Physics, Nuclear physics, Nuclear reaction, Nuclear and High Energy Physics, Neutron emission, Helium-3, Excited state, Neutron, Atomic physics, Nuclear Experiment, Isotopes of helium, Excitation, Neutron spectroscopy
Abstract: The neutron decay of high-lying single-particle states in Pb-209 excited by means of the (alpha, He-3) reaction has been investigated at 122 MeV incident energy using a multidetector array. The high-spin values of these states, inferred from previous inclusive experiments, are confirmed by the present data involving angular correlation measurements and the determination of branching ratios to low-lying levels in Pb-208. The structure located between 8.5 and 12 MeV excitation energy in Pb-209 displays large departures from a pure statistical decay with significant direct feeding of the low-lying collective states (3-,5-) of Pb-208. At higher excitation energy up to 20 MeV, the measured neutron decay is in agreement with the predictions of the statistical model.
Published: 1994
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42. Publisher’s Note: Emergence of theN=16shell gap in21O [Phys. Rev. C84, 011301(R) (2011)]

Author: B. Fernandez-Dominguez, J. S. Thomas, W. N. Catford, F. Delaunay, S. M. Brown, N. A. Orr, M. Rejmund, M. Labiche, M. Chartier, N. L. Achouri, H. Al Falou, N. I. Ashwood, D. Beaumel, Y. Blumenfeld, B. A. Brown, R. Chapman, N. Curtis, C. Force, G. de France, S. Franchoo, J. Guillot, P. Haigh, F. Hammache, V. Lapoux, R. C. Lemmon, F. Marechal, A. M. Moro, X. Mougeot, B. Mouginot, L. Nalpas, A. Navin, N. Patterson, B. Pietras, E. C. Pollacco, A. Leprince, A. Ramus, J. A. Scarpaci, N. de Sereville, I. Stephan, O. Sorlin, and G. L. Wilson
Subjects: Nuclear physics, Physics, Nuclear reaction, Nuclear and High Energy Physics, Light nucleus, Mathematical model, Isotope, Excited state, Shell (structure), Atomic physics, Isotopes of oxygen, Radioactive decay
Published: 2011
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43. Indirect study of 60Fe(n,\gamma )61Fe via the transfer reaction 60Fe(d,p\gamma )61Fe

Author: Sandra Giron, F. Hammache, Nicolas de Sereville, D. Beaumel, Geoffroy Burgunder, Lucia Caceres, Gilbert Duchêne, Emmanuel Clément, Beatriz Fernandez, Freddy Flavigny, Gilles De France, S. Franchoo, Daniel Galaviz Redondo, Leandro Gasques, Julien Gibelin, Alain Gilibert, Stéphane Grevy, Jacques Guillot, Michael Heil, Jurgen Kiener, Valérie Lapoux, F. Marechal, A. Matta, Iolanda Matea, Mohamad Moukaddam, Laurent Nalpas, L. Perrot, Alexandre Obertelli, Riccardo Raabe, Pierre Roussel, J.A. Scarpaci, O. Sorlin, Iulian Stephan, Christelle Stoedel, M. Takechi, J.C. Thomas, and Yasuhiro Togano
Subjects: Transfer (group theory), Chemistry, Physical chemistry
Published: 2011
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44. Emergence of theN=16shell gap inO21

Author: B. Fernández-Domínguez, J. S. Thomas, W. N. Catford, F. Delaunay, S. M. Brown, N. A. Orr, M. Rejmund, M. Labiche, M. Chartier, N. L. Achouri, H. Al Falou, N. I. Ashwood, D. Beaumel, Y. Blumenfeld, B. A. Brown, R. Chapman, N. Curtis, C. Force, G. de France, S. Franchoo, J. Guillot, P. Haigh, F. Hammache, V. Lapoux, R. C. Lemmon, F. Maréchal, A. M. Moro, X. Mougeot, B. Mouginot, L. Nalpas, A. Navin, N. Patterson, B. Pietras, E. C. Pollacco, A. Leprince, A. Ramus, J. A. Scarpaci, N. de Séréville, I. Stephan, O. Sorlin, and G. L. Wilson
Subjects: Physics, Radioactive ion beams, Nuclear and High Energy Physics, Light nucleus, 010308 nuclear & particles physics, 0103 physical sciences, SHELL model, Shell (structure), Atomic physics, 010306 general physics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), 01 natural sciences
Abstract: This is the publisher's version, also available electronically from http://journals.aps.org/prc/abstract/10.1103/PhysRevC.84.011301.
Published: 2011
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45. Probing the pairing interaction through two-neutron transfer reactions

Author: D. Beaumel, Jérôme Margueron, Elias Khan, Andrea Vitturi, Marcella Grasso, Denis Lacroix, 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), Théorie, 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)-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), 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 de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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)-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: Nuclear reaction, History, Nuclear and High Energy Physics, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Proton, QC1-999, FOS: Physical sciences, Molecular physics, 01 natural sciences, Education, Nuclear Theory (nucl-th), Nuclear physics, Isotopes of tin, 0103 physical sciences, Cr isotopes, Neutron, Nuclear drip line, Statistical physics, Born approximation, Wave function, Nuclear Experiment, 010306 general physics, Line (formation), Physics, Isotope, 010308 nuclear & particles physics, Fermi energy, Computer Science Applications, Excited state, Pairing, Quasiparticle, Atomic physics, Nucleon, Ground state
Abstract: International audience; The treatment of the pairing interaction in mean-field-based models is addressed. In particular, the possibility to use pair transfers as a tool to better constrain this interaction is discussed. First, pairing inter- actions with various density dependencies (surface/volume mixing) are used in the microscopic Hartree-Fock- Bogoliubov + quasiparticle random-phase approximation model to generate the form factors to be used in reac- tion calculations. Cross sections for (p,t) two-neutron transfer reactions are calculated in the one-step zero-range distorted-wave Born approximation for some Tin isotopes and for incident proton energies from 15 to 35 MeV. Three different surface/volume mixings of a zero-range density-dependent pairing interaction are employed in the microscopic calculations and the sensitivity of the cross sections to the different mixings is analyzed. Differences among the three different theoretical predictions are found espacially for the nucleus 136Sn and they are more important at the incident proton energy of 15 MeV. We thus indicate (p,t) two-neutron transfer reactions with very neutron-rich Sn isotopes and at proton energies around 15 MeV as good experimental cases where the sur- face/volume mixing of the pairing interaction may be probed. In the second part of the manuscript, ground-state to ground-state transitions are investigated. Approximations made to estimate two-nucleon transfer probabilities in ground-state to ground-state transitions and the physical interpretation of these probabilities are discussed. Probabilities are often calculated by approximating both ground states of the initial nucleus A and of the final nucleus A±2 by the same quasiparticle vacuum.We analyze two improvements of this approach. First, the effect of using two different ground states with average numbers of particles A and A±2 is quantified. Second, by using projection techniques, the role of particle number restoration is analyzed. Our analysis shows that the improved treatment plays a role close to magicity, leading to an enhancement of the pair-transfer probability. In midshell regions, part of the error made by approximating the initial and final ground states by a single vacuum is com- pensated by projecting onto a good particle number. Surface effects are analyzed by using pairing interactions with a different volume/surface mixing. Finally, a simple expression of the pair-transfer probability is given in terms of occupation probabilities in the canonical basis.We show that, in the canonical basis formulation, surface effects that are visible in the transfer probability are related to the fragmentation of single-particle occupancies close to the Fermi energy. This provides a complementary interpretation with respect to the standard quasiparti- cle representation where surface effects are generated by the integrated radial profiles of the contributing wave functions.
Published: 2011
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46. EDEN: a neutron time-of-flight multidetector for decay studies of giant states

Author: J. Guillot, J.C. Roynette, H. Lefort, H. Laurent, P. Volkov, S. Fortier, D. Beaumel, Y. Blumenfeld, Sijtze Brandenburg, S. Gales, KVI - Center for Advanced Radiation Technology, Damage and Repair in Cancer Development and Cancer Treatment (DARE), Institut de Physique Nucléaire d'Orsay (IPNO), and 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)
Subjects: Physics, Nuclear and High Energy Physics, NUCLEI, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Resolution (electron density), Scintillator, 7. Clean energy, 01 natural sciences, Nuclear physics, Time of flight, 0103 physical sciences, Neutron, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], DETECTION EFFICIENCY, Nuclear Experiment, 010306 general physics, RESONANCES, Instrumentation, Overall efficiency
Abstract: A neutron time-of-flight multidetector has been built to study the decay of giant states. It is made of 40 individual detectors. A liquid scintillator is used for neutron-gamma-ray pulse shape discrimination. The overall efficiency of the multidetector (epsilonOMEGA/4pi) is 1% for 6 MeV neutrons and the energy resolution is about 60 keV and 500 keV for 1 MeV and 6 MeV neutrons respectively.
Published: 1993
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47. Probing preformedαparticles in the ground state of nuclei

Author: P. Desesquelles, J.A. Scarpaci, M. Fallot, J. L. Laville, N. Frascaria, T. Zerguerras, J. Frankland, C. Bhar, E. Plagnol, P. Roussel-Chomaz, L. Lefebvre, A. Shrivastava, J.C. Roynette, H. Idbarkach, M. Assié, D. Beaumel, A. Chbihi, E. C. Pollacco, Ph. Chomaz, D. Lacroix, Elias Khan, and Y. Blumenfeld
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Elementary particle, Alpha particle, 01 natural sciences, Charged particle, Baryon, 0103 physical sciences, Continuum (set theory), Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Ground state
Abstract: In this Rapid Communication, we report on $\ensuremath{\alpha}$-particle emission through the nuclear breakup in the reaction $^{40}\mathrm{Ca}$ on a $^{40}\mathrm{Ca}$ target at 50 A MeV. It is observed that, similar to nucleons, $\ensuremath{\alpha}$ particles can be emitted to the continuum with very specific angular distribution during the reaction. The $\ensuremath{\alpha}$-particle properties seem to be compatible with an $\ensuremath{\alpha}$ cluster in the daughter nucleus that is perturbed and is emitted by the short-range nuclear attraction of the collision partner. A time-dependent theory that describes the $\ensuremath{\alpha}$-particle wave-function evolution is able to qualitatively reproduce the observed angular distribution. This mechanism offers new possibilities for studying $\ensuremath{\alpha}$-particle properties in the nuclear medium.
Published: 2010
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48. Study of the N = 28 shell closure in the Ar isotopic chain

Author: L. Gaudefroy, O. Sorlin, D. Beaumel, Y. Blumenfeld, Z. Dombrádi, S. Fortier, S. Franchoo, M. Gélin, J. Gibelin, S. Grévy, F. Hammache, F. Ibrahim, K. Kemper, K. L. Kratz, S. M. Lukyanov, C. Monrozeau, L. Nalpas, F. Nowacki, A. N. Ostrowski, Yu. -E. Penionzhkevich, E. Pollacco, P. Roussel-Chomaz, E. Rich, J. A. Scarpaci, M. G. St. Laurent, T. Rauscher, D. Sohler, M. Stanoiu, E. Tryggestad, and D. Verney
Published: 2010
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49. Exploring the Nα + 3n light nuclei via the (7Li, 7Be) reaction

Author: C. Nociforo, F. Cappuzzello, A. Cunsolo, A. Foti, S. E. A. Orrigo, J. S. Winfield, M. Cavallaro, S. Fortier, D. Beaumel, and H. Lenske
Published: 2010
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50. Study of [sup 60]Fe(n,γ)[sup 61]Fe reaction of astrophysical interest via d([sup 60]Fe,pγ) indirect reaction

Author: S. Giron, F. Hammache, N. de Séréville, D. Beaumel, J. Burgunder, L. Caceres, E. Clement, G. Duchene, F. Flavigny, G. De France, S. Franchoo, B. Fernandez, D. Galaviz-Redondo, L. Gasques, J. Gibelin, A. Gillibert, S. Grevy, J. Guillot, M. Heil, J. Kiener, V. Lapoux, F. Maréchal, A. Matta, Y. Matea, M. Moukaddam, L. Nalpas, A. Obertelli, L. Perrot, R. Raabe, J. A. Scarpaci, O. Sorlin, I. Stefan, C. Stoedel, M. Takechi, J. C. Thomas, Y. Togano, Claudi Spitaleri, Claus Rolfs, and Rosario G. Pizzone
Subjects: Nuclear reaction, Physics, Angular momentum, 010308 nuclear & particles physics, Context (language use), 7. Clean energy, 01 natural sciences, Nuclear physics, Supernova, Nucleosynthesis, Excited state, 0103 physical sciences, Atomic physics, Radioactive decay, Excitation
Abstract: INTEGRAL and RHESSI spacecrafts recently detected the 1.173 and 1.333 MeV γ‐ray lines coming from the 60Fe—60Co—60Ni radioactive decay chain. The long lived isotope 60Fe (T1/2 = 1.5 106y) is believed to be primarily produced in core‐collapse supernovae. However the interpretation of the observations is difficult because of the large uncertainties concerning 59Fe(n,γ)60Fe and 60Fe(n,γ)61Fe cross sections, involved in 60Fe nucleosynthesis.The direct component of the 60Fe(n,γ)61Fe reaction was studied indirectly via the d(60Fe,pγ)61Fe transfer reaction. The experiment performed in GANIL in spring 2009 will allow to determine the excitation energies of the populated excited states of 61Fe and for the first time their spectroscopic factors as well as their transfer angular momentum.I will first give an overview of the astrophysical context, then I will describe the experimental setup and finally present some preliminary results of the ongoing analysis.
Published: 2010
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