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79 results on '"Vandebrouck M"'

1. Experimental investigation of ground-state properties of H with transfer reactions

Author: Caamaño, M., Roger, T., Moro, A.M., Grinyer, G.F., Pancin, J., Bagchi, S., Sambi, S., Gibelin, J., Fernández–Domínguez, B., Itagaki, N., Benlliure, J., Cortina–Gil, D., Farget, F., Jacquot, B., Pérez–Loureiro, D., Pietras, B., Raabe, R., Ramos, D., Rodríguez Tajes, C., Savajols, H., and Vandebrouck, M.
Abstract: The properties of nuclei with extreme neutron–to–proton ratios, far from those naturally occurring on Earth, are key to understand nuclear forces and how nucleons hold together to form nuclei. $^{7}$H, with six neutrons and a single proton, is the nuclear system with the most unbalanced neutron–to–proton ratio known so far. However, its sheer existence and properties are still a challenge for experimental efforts and theoretical models. Here we report experimental evidences on the formation of $^{7}$H as a resonance, detected with independent observables, and the first measurement of the structure of its ground state. The resonance is found at ∼0.7 MeV above the $^{3}$H+4n mass, with a narrow width of ∼0.2 MeV and a 1/2+ spin and parity. These data are consistent with a $^{7}$H as a $^{3}$H core surrounded by an extended four-neutron halo, with a unique four-neutron decay and a relatively long half-life thanks to neutron pairing; a prime example of new phenomena occurring in what would be the most pure-neutron nuclear matter we can access in the laboratory.
Published: 2023

2. Neutron-proton pairing in the N=Z radioactive -shell Nuclei Ni and Fe probed by pair transfer

Author: Le Crom, B., Assié, M., Blumenfeld, Y., Guillot, J., Sagawa, H., Suzuki, T., Honma, M., Achouri, N.L., Bastin, B., Borcea, R., Catford, W.N., Clément, E., Cáceres, L., Caamaño, M., Corsi, A., De France, G., Delaunay, F., De Séréville, N., Fernandez-Dominguez, B., Fisichella, M., Franchoo, S., Georgiadou, A., Gibelin, J., Gillibert, A., Hammache, F., Kamalou, O., Knapton, A., Lapoux, V., Leblond, S., Macchiavelli, A.O., Marqués, F.M., Matta, A., Ménager, L., Morfouace, P., Orr, N.A., Pancin, J., Pereira-Lopez, X., Perrot, L., Piot, J., Pollacco, E., Ramos, D., Roger, T., Rotaru, F., Sánchez-Benítez, A.M., Sénoville, M., Sorlin, O., Stanoiu, M., Stefan, I., Stodel, C., Suzuki, D., Thomas, J.C., and Vandebrouck, M.
Abstract: The isovector and isoscalar components of neutron-proton pairing are investigated in the N=Z unstable nuclei of the fp-shell through the two-nucleon transfer reaction (p,$^{3}$He) in inverse kinematics. The combination of particle and gamma-ray detection with radioactive beams of $^{56}$Ni and $^{52}$Fe, produced by fragmentation at the GANIL/LISE facility, made it possible to carry out this study for the first time in a closed and an open-shell nucleus in the fp-shell. The transfer cross-sections for ground-state to ground-state (J=0$^{+}$, T=1) and to the first (J=1$^{+}$, T=0) state were extracted for both cases together with the transfer cross-section ratios σ(0+,T=1)/σ(1+,T=0). They are compared with second-order distorted-wave born approximation (DWBA) calculations. The enhancement of the ground-state to ground-state pair transfer cross-section close to mid-shell, in $^{52}$Fe, points towards a superfluid phase in the isovector channel. For the “deuteron-like” transfer, very low cross-sections to the first (J=1$^{+}$, T=0) state were observed both for $^{56}$Ni(p,$^{3}$He) and $^{52}$Fe(p,$^{3}$He) and are related to a strong hindrance of this channel due to spin-orbit effect. No evidence for an isoscalar deuteron-like condensate is observed.
Published: 2023

3. Unbound states in C and - Shell-model Interactions

Author: Kim, S., Hwang, J.W., Satou, Y., Orr, N.A., Nakamura, T., Kondo, Y., Gibelin, J., Achouri, N.L., Aumann, T., Baba, H., Delaunay, F., Doornenbal, P., Fukuda, N., Inabe, N., Isobe, T., Kameda, D., Kanno, D., Kobayashi, N., Kobayashi, T., Kubo, T., Leblond, S., Lee, J., Marqués, F.M., Minakata, R., Motobayashi, T., Murai, D., Murakami, T., Muto, K., Nakashima, T., Nakatsuka, N., Navin, A., Nishi, S., Ogoshi, S., Otsu, H., Sato, H., Shimizu, Y., Suzuki, H., Takahashi, K., Takeda, H., Takeuchi, S., Tanaka, R., Togano, Y., Tuff, A.G., Vandebrouck, M., and Yoneda, K.
Abstract: Unbound states in C17 were investigated via one-neutron removal from a C18 beam at an energy of 245 MeV/nucleon on a carbon target. The energy spectrum of C17, above the single-neutron decay threshold, was reconstructed using invariant mass spectroscopy from the measured momenta of the C16 fragment and neutron, and was found to exhibit resonances at Er=0.52(2), 0.77(2), 1.36(1), 1.91(1), 2.22(3) and 3.20(1) MeV. The resonance at Er=0.77(2) MeV [Ex=1.51(3) MeV] was provisionally assigned as the second 5/2+ state. The two resonances at Er=1.91(1) and 3.20(1) MeV [Ex=2.65(2) and 3.94(2) MeV] were identified, through comparison of the energies, cross sections and momentum distributions with shell-model and eikonal reaction calculations, as p-shell hole states with spin-parities 1/21− and 3/21−, respectively. A detailed comparison was made with the results obtained using a range of shell-model interactions. The YSOX shell-model Hamiltonian, the cross-shell part of which is based on the monopole-based universal interaction, was found to provide a very good description of the present results and those for the neighbouring odd-A carbon isotopes – in particular for the negative parity cross-shell states.
Published: 2023

4. Cross-shell states in $^{15}$C: a test for p-sd interactions

Author: Lois-Fuentes, J., Fernandez-Dominguez, B., Pereira-Lopez, X., Delaunay, F., Catford, W.N., Matta, A., Orr, N.A., Duguet, T., Otsuka, T., Soma, V., Sorlin, O., Suzuki, T., Achouri, N.L., Assie, M., Bailey, S., Bastin, B., Blumenfeld, Y., Borcea, R., Caamano, M., Caceres, L., Clement, E., Corsi, A., Curtis, N., Deshayes, Q., Farget, F., Fisichella, M., de France, G., Franchoo, S., Freer, M., Gibelin, J., Gillibert, A., Grinyer, G.F., Hammache, F., Kamalou, O., Knapton, A., Kokalova, Tz., Lapoux, V., Le Crom, B., Leblond, S., Marques, F.M., Morfouace, P., Pancin, J., Perrot, L., Piot, J., Pollacco, E., Ramos, D., Regueira-Castro, D., Rodriguez-Tajes, C., Roger, T., Rotaru, F., Senoville, M., de Sereville, N., Smith, R., Stanoiu, M., Stefan, I., Stodel, C., Suzuki, D., Thomas, J.C., Timofeyuk, N., Vandebrouck, M., Walshe, J., Wheldon, C., Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut 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), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear Theory (nucl-th), [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: International audience; The low-lying structure of $^{15}$C has been investigated via the neutron-removal $^{16}$C$(d,t)$ reaction. Along with bound neutron sd-shell hole states, unbound p-shell hole states have been firmly confirmed. The excitation energies and the deduced spectroscopic factors of the cross-shell states are an important measure of the $[(p)^{-1}(sd)^{2}]$ neutron configurations in $^{15}$C. Our results show a very good agreement with shell-model calculations using the SFO-tls interaction for $^{15}$C. However, a modification of the $p$-$sd$ and $sd$-$sd$ monopole terms was applied in order to reproduce the $N=9$ isotone $^{17}$O. In addition, the excitation energies and spectroscopic factors have been compared to the first calculations of $^{15}$C with the $ab~ initio$ self-consistent Green's function method employing the NNLO$_{sat}$ interaction. The results show the sensitivity to the size of the $N=8$ shell gap and highlight the need of going beyond the current truncation scheme in the theory.
Published: 2023
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5. Level structure of <math><mmultiscripts><mi>Ac</mi><mprescripts/><none/><mn>221</mn></mmultiscripts></math> and <math><mmultiscripts><mi>Fr</mi><mprescripts/><none/><mn>217</mn></mmultiscripts></math> from decay spectroscopy, and reflection asymmetry in <math><mmultiscripts><mi>Ac</mi><mprescripts/><none/><mn>221</mn></mmultiscripts></math>

Author: Rey-Herme, E, Raggio, A, Vandebrouck, M, Moore, I, Pohjalainen, I, Delafosse, C, de Groote, R, Ge, Z, Geldhof, S, Hukkanen, M, Kankainen, A, Koszorus, A, Nesterenko, D, Sarén, J, Sulignano, B, Theisen, Ch, Thisse, D, Weaver, A.P, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique 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), 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), and IGISOL
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract: International audience; Pa225 and Ac221 were produced at the IGISOL facility through proton-induced fusion-evaporation reactions and have been studied using α-particle spectroscopy, as well as α-γ and α-electron coincidence spectroscopy. The level scheme of Ac221, daughter of Pa225, and of Fr217, daughter of Ac221 were reconstructed. An interpretation of Ac221 levels as K=5/2± and K=3/2± parity-doublet bands is proposed. Such bands appear in reflection-asymmetric models and would be an indication of a static reflection asymmetric shape for Ac221.
Published: 2023

6. Unbound states in $^{17}C$ and p-sd shell-model interactions

Author: Kim, S., Hwang, J. W., Satou, Y., Orr, N. A., Nakamura, T., Kondo, Y., Gibelin, J., Achouri, N. L., Aumann, T., Baba, H., Delaunay, F., Doornenbal, P., Fukuda, N., Inabe, N., Isobe, T., Kameda, D., Kanno, D., Kobayashi, N., Kobayashi, T., Kubo, T., Leblond, S., Lee, J., Marqués, F. M., Minakata, R., Motobayashi, T., Murai, D., Murakami, T., Muto, K., Nakashima, T., Nakatsuka, N., Navin, A., Nishi, S., Ogoshi, S., Otsu, H., Sato, H., Shimizu, Y., Suzuki, H., Takahashi, K., Takeda, H., Takeuchi, S., Tanaka, R., Togano, Y., Tuff, A. G., Vandebrouck, M., Yoneda, K., 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), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique 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), and ANR-14-CE33-0022,EXPAND,Explorations autour de la dripline neutron(2014)
Subjects: Nuclear Theory (nucl-th), Nuclear and High Energy Physics, Cross-shell states, Shell-model Hamiltonian, Nuclear Theory, FOS: Physical sciences, One-neutron removal reaction, ddc:530, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Neutron-rich carbon isotopes
Abstract: Unbound states in 17C were investigated via one-neutron removal from a 18C beam at an energy of 245 MeV/nucleon on a carbon target. The energy spectrum of 17C, above the single-neutron decay threshold, was reconstructed using invariant mass spectroscopy from the measured momenta of the 16C fragment and neutron, and was found to exhibit resonances at Er=0.52(2), 0.77(2), 1.36(1), 1.91(1), 2.22(3) and 3.20(1) MeV. The resonance at Er=0.77(2) MeV [Ex=1.51(3) MeV] was provisionally assigned as the second 5/2+ state. The two resonances at Er=1.91(1) and 3.20(1) MeV [Ex=2.65(2) and 3.94(2) MeV] were identified, through comparison of the energies, cross sections and momentum distributions with shell-model and eikonal reaction calculations, as p-shell hole states with spin-parities 1/2- and 3/2-, respectively. A detailed comparison was made with the results obtained using a range of shell-model interactions. The YSOX shell-model Hamiltonian, the cross-shell part of which is based on the monopole-based universal interaction, was found to provide a very good description of the present results and those for the neighbouring odd-A carbon isotopes - in particular for the negative parity cross-shell states., Physics Letters B 836 (2023) 137629, published
Published: 2023

7. Isotopic cross sections of fragmentation residues produced by light projectiles on carbon near 400A MeV

Author: Boillos, J. M., Cortina-Gil, D., Benlliure, J., Rodríguez-Sánchez, J. L., Alvarez-Pol, H., Atar, L., Aumann, T., Avdeichikov, V. V., Beceiro-Novo, S., Bemmerer, D., Bertulani, C. A., Boretzky, K., Borge, M. J.G., Caamaño, M., Caesar, C., Casarejos, E., Catford, W., Cederkall, J., Chartier, M., Chulkov, L., Cravo, E., Crespo, R. N.P., Dillmann, I., Díaz Fernández, P., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz Redondo, D., Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J. F.D.C., Marganiec, J., Movsesyan, A., Nacher, E., Najafi, M. A., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Rossi, D. M., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I. J., Tengblad, O., Thies, R., Togano, Y., Vandebrouck, M., Velho, P. J.F., Volkov, V., Wagner, A., Wamers, F., Weick, H., Wheldon, C., Wilson, G. L., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.
Abstract: We measured 135 cross sections of residual nuclei produced in fragmentation reactions of C12, N14, and O13−16,20,22 projectiles impinging on a carbon target at kinetic energies of near 400A MeV, most of them for the first time, with the RB3/LAND setup at the GSI facility in Darmstadt (Germany). The use of this state-of-the-art experimental setup in combination with the inverse kinematics technique gave the full identification in atomic and mass numbers of fragmentation residues with a high precision. The cross sections of these residues were determined with uncertainties below 20% for most of the cases. These data are compared to other previous measurements with stable isotopes and are also used to benchmark different model calculations.
Published: 2022

8. Isotopic cross sections of fragmentation residues produced by light projectiles on carbon near 400A MeV

Author: Boillos, J. M., Cortina-Gil, D., Benlliure, J., Rodríguez-Sánchez, J. L., Alvarez-Pol, H., Atar, L., Aumann, T., Avdeichikov, V. V., Beceiro-Novo, S., Bemmerer, D., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caamaño, M., Caesar, C., Casarejos, E., Catford, W., Cederkall, J., Chartier, M., Chulkov, L., Cravo, E., Crespo, R. N. P., Dillmann, Iris, Díaz Fernández, P., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz Redondo, D., Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J. F. D. C., Marganiec, J., Movsesyan, A., Nacher, E., Najafi, M. A., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, Ralf, Reifarth, R., Ribeiro, G., Rigollet, C., Rossi, D. M., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I. J., Taylor, J. T., Tengblad, O., Thies, R., Togano, Y., Vandebrouck, M., Velho, P. J. F., Volkov, V., Wagner, A., Wamers, F., Weick, H., Wheldon, C., Wilson, G. L., Winfield, John Stuart, Woods, P., Yakorev, D., Zhukov, M., Zilges, A., Zuber, K., 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), 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), and R3B
Subjects: nuclear physics, low and intermediate energy heavy-ion collisions, ddc:530, Física nuclear, nuclear fragmentation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], unstable nuclear induced reactions, nuclear reactions
Abstract: Physical review / C 105(1), 014611 (2022). doi:10.1103/PhysRevC.105.014611, Published by APS, Woodbury, NY
Published: 2022

9. Coulomb excitation of $^{102}\mathrm{Ru}$ with $^{12}\mathrm{C}$ and $^{16}\mathrm{O}$

Author: Garrett, P.E., Zielińska, M., Bergmaier, A., Rodríguez, T.R., Kalaydjieva, D., Siciliano, M., Bidaman, H., Bildstein, V., Burbadge, C., Diaz Varela, A., Doherty, D.T., Faestermann, T., Hadyńska-Klȩk, K., Hertenberger, R., Keeley, N., Laffoley, A., Maclean, A.D., Mahgoub, M., Radich, A.J., Rocchini, M., Spagnoletti, P., Triambak, S., Vandebrouck, M., Wrzosek-Lipska, K., University of Guelph, University of the Western Cape (UWC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Universidad Autónoma de Madrid (UAM), Argonne National Laboratory [Lemont] (ANL), University of Surrey (UNIS), Ludwig-Maximilians-Universität München (LMU), National Centre for Nuclear Research [Otwock], Narodowe Centrum Badań Jądrowych (NCBJ), Jazan University [Jazan, Saudi Arabia], Sudan University of Science and Technology [Khartoum] (SUST), University of the West of Scotland (UWS), and University of Warsaw (UW)
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract: International audience; The Coulomb excitation of Ru102 was performed with beams of C12 and O16 ions. The beam particles scattered at forward angles were momentum analyzed with a magnetic spectrograph. The resolution achieved enabled the populations of the 21+ state, the unresolved 22+/41+, and 24+/31−, doublets of states, and the 32− state to be determined as a function of the scattering angle. These populations are compared with gosia calculations, yielding B(E2;21+→01+)=41.5±2.3 W.u., B(E2;22+→01+)=1.75±0.11 W.u., B(E3;31−→01+)=31.5±3.5 W.u., and B(E3;32−→01+)=6.8±0.5 W.u. The B(E3;31−→01+) value is significantly larger than previously measured. The weakly populated 23+ state, presumed to be a member of the band built on the 02+ state, was observed clearly for a single angle only, and a fit to its population results in B(E2;23+→01+)=0.053±0.011 W.u. Using the known γ-ray branching ratios for the 23+ level, the B(E2;23+→02+) value is calculated to be 18±4 W.u., substantially less than the B(E2;21+→01+). This suggests that the deformation of the 02+ state is lower than that of the 01+ state. The results are compared with beyond-mean-field calculations with the Gogny-D1S interaction using the symmetry-conserving configuration-mixing method.
Published: 2022

10. Isotopic cross sections of fragmentation residues produced by light projectiles on carbon near

Author: Boillos, J. M., Cortina-Gil, D., Benlliure, J., Rodríguez-Sánchez, J. L., Alvarez-Pol, H., Atar, L., Aumann, T., Avdeichikov, V. V., Beceiro-Novo, S., Bemmerer, D., Bertulani, C. A., Boretzky, K., García Borge, María José, Caamaño, M., Caesar, C., Casarejos, E., Catford, W., Cederkall, J., Chartier, M., Chulkov, L., Cravo, E., Crespo, R. N.P., Dillmann, I., Díaz Fernández, P., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz Redondo, D., Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Johansson, H.T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J. F.D.C., Marganiec, J., Movsesyan, A., Nacher, E., Najafi, M.A., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, Ángel, Petri, M., Pietri, S., Plag, R., Reifarth, R., Ribeiro, Guillermo, Rigollet, C., Rossi, D. M., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I. J., Taylor, J. T., Tengblad, Olof, Thies, R., Togano, Y., Vandebrouck, M., Velho, P. J.F., Volkov, V., Wagner, A., Wamers, F., Weick, H., Wheldon, C., Wilson, G. L., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., Zuber, K., Ministerio de Ciencia e Innovación (España), Xunta de Galicia, Federal Ministry of Education and Research (Germany), Swedish Research Council, and Department of Energy (US)
Abstract: 13 pags., 8 figs., 1 tab., We measured 135 cross sections of residual nuclei produced in fragmentation reactions of C12, N14, and O13−16,20,22 projectiles impinging on a carbon target at kinetic energies of near 400A MeV, most of them for the first time, with the RB3/LAND setup at the GSI facility in Darmstadt (Germany). The use of this state-of-the-art experimental setup in combination with the inverse kinematics technique gave the full identification in atomic and mass numbers of fragmentation residues with a high precision. The cross sections of these residues were determined with uncertainties below 20% for most of the cases. These data are compared to other previous measurements with stable isotopes and are also used to benchmark different model calculations., This work has been partially supported by the Spanish Ministry for Science and Innovation under Grants No. PGC2018-099746-B-C21, No. PGC2018-099746-B-C22, and No. PID2019-104390GB-100; Xunta de Galicia under program “Grupos de referencia competitiva” (Project No. ED431C 2017/54); the German Bundesministerium für Bildung und Forschung (BMBF) (Grants No. 05P12RDFN8, No. 05P15RDFN1, and No. 05P19RDFN); the Swedish Research Council; and U.S. Department of Energy Grant No. DE-FG02-08ER41533. J.J.R.S. acknowledges the support of Xunta de Galicia under Grant No. ED481B-2017/002.
Published: 2022

11. Multinucleon Transfer Reactions in the $^{238}\mathrm {U}+{^{238}}$U System Studied with the VAMOS$+$AGATA$+$ID-Fix

Author: Utepov, A, Ackermann, D, Stodel, C, Lemasson, A, Ramos, D, Rejmund, M, Clement, E, Jacquot, B, Piot, J, Ducret, J.E, Caceres, L, Savajols, H, Chakma, R, Heinz, S, Kindler, B, Lommel, B, Korichi, A, Lopez-Martens, A, Hauschild, K, Sulignano, B, Theisen, C, Vandebrouck, M, Rey-Herme, E, Gadea, A, Corradi, L, Fioretto, E, Galtarossa, F, Szilner, S, Mijatović, T, Fougères, C, Seweryniak, D, Kim, Y.H, Cho, Y, Son, Y, Matejska-Minda, M, Dorvaux, O, Forge, M, Kessaci, K, Gall, B, Marini, P, Million, B, 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), Université de Caen Normandie (UNICAEN), Normandie Université (NU), 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), 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), 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), Laboratoire de Physique des Deux Infinis Bordeaux (LP2I - Bordeaux), and Université de Bordeaux (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract: International audience; The measurement of the production cross sections of exotic neutronrich heavy nuclei, in the uranium region, in the vicinity of the N = 152 deformed shell gap was carried out via multinucleon transfer reactions of 238U + 238U at 7.193 and 6.765 MeV/A using the VAMOS++ magnetic spectrometer coupled to the AGATA and ID-Fix photon detection arrays. This article reports on the status of the VAMOS++ data analysis and results on the population of the strongest (±1n) transfer channels observed from the decay of long-lived products after irradiation.
Published: 2023

12. First observation of high-K isomeric states in Md-249 and Md-251

Author: Goigoux, T, Theisen, Ch, Sulignano, B, Airiau, M, Auranen, K, Badran, H, Briselet, R, Calverley, T, Cox, D, Dechery, F, Bisso, F Defranchi, Drouart, A, Favier, Z, Gall, B, Grahn, T, Greenlees, PT, Hauschild, K, Herzan, A, Herzberg, R-D, Jakobsson, U, Julin, R, Juutinen, S, Konki, J, Leino, M, Lightfoot, A, Lopez-Martens, A, Mistry, A, Nieminen, P, Pakarinen, J, Papadakis, P, Partanen, J, Peura, P, Rahkila, P, Rey-Herme, E, Rubert, J, Ruotsalainen, P, Sandzelius, M, Saren, J, Scholey, C, Sorri, J, Stolze, S, Uusitalo, J, Vandebrouck, M, Ward, A, Zielinska, M, Jachimowicz, P, Kowal, M, and Skalski, J
Published: 2021

13. Coulomb and nuclear excitations of $^{70}$Zn and $^{68}$Ni at intermediate energy

Author: Calinescu, S., Sorlin, O., Matea, I., Carstoiu, F., Dao, D., Nowacki, F., de Angelis, G., Astabatyan, R., Bagchi, S., Borcea, C., Borcea, R., C��ceres, L., Ciem��la, M., Cl��ment, E., Dombr��di, Z., Franchoo, S., Gottardo, A., Gr��vy, S., Guerin, H., Harakeh, M. N., Harca, I. M., Kamalou, O., Kmiecik, M., Krasznahorkay, A., Krzysiek, M., Kuti, I., Lepailleur, A., Lukyanov, S., Maj, A., Maslov, V., Mazurek, K., Morfouace, P., Mrazek, J., Negoita, F., Niikura, M., Olivier, L., Penionzhkevich, Y., Perrot, L., Petrone, C., Podoly��k, Z., Rigollet, C, Roger, T., Rotaru, F., Sohler, D., Stanoiu, M., Stefan, I., Stuhl, L., Thomas, J. C., Vajta, Z., Vandebrouck, M., Wieland, O., 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), 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), 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), 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)-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), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear Theory (nucl-th), Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: International audience; The reduced transition probabilities $B(E2; 0^+_{g.s.}\rightarrow2_1^+,2^+_2)$ in $^{70}$Zn and the full $B(E2; 0^+_{g.s.}\rightarrow2^+)$ strength up to S$_n$=7.79 MeV in $^{68}$Ni have been determined at the LISE/GANIL facility using the Coulomb-excitation technique at intermediate beam energy on a $^{208}$Pb target. The $\gamma$ rays emitted in-flight were detected with an array of 46 BaF$_2$ crystals. The angles of the deflected nuclei were determined in order to disentangle and extract the Coulomb and nuclear contributions to the excitation of the 2$^+$ states. The measured $B(E2; 0^+_{g.s.}\rightarrow2_1^+)$ of 1432(124) e$^2$fm$^4$ for $^{70}$Zn falls in the lower part of the published values which clustered either around 1600 or above 2000 e$^2$fm$^4$, while the $B(E2; 0^+_{g.s.}\rightarrow2^+_2)$ of 53(7) e$^2$fm$^4$ agrees very well with the two published values. The relatively low $B(E2; 0^+_{g.s.}\rightarrow2_1^+)$ of 301(38) e$^2$fm$^4$ for $^{68}$Ni agrees with previous studies and confirms a local magicity at $Z=28, N=40$. Combining the results of the low-energy spectra of $^{68}$Ni and $^{70}$Zn and their shell-model interpretations, it is interesting to notice that four different shapes (spherical, oblate, prolate and triaxial) are present. Finally, a summed $E2$ strength of only about 150 e$^2$fm$^4$ has been found experimentally at high excitation energy, likely due to proton excitations across the $Z=28$ gap. The experimental distribution of this high-energy $E2$ excitation agrees with SM calculations, but its strength is about two times weaker.
Published: 2021

14. Low-lying single-particle structure of C and the = 14 Sub-shell Closure

Author: Pereira-López, X., Fernández-Domínguez, B., Delaunay, F., Achouri, N.L., Orr, N.A., Catford, W.N., Assié, M., Bailey, S., Bastin, B., Blumenfeld, Y., Borcea, R., Caamaño, M., Caceres, L., Clément, E., Corsi, A., Curtis, N., Deshayes, Q., Farget, F., Fisichella, M., de France, G., Franchoo, S., Freer, M., Gibelin, J., Gillibert, A., Grinyer, G.F., Hammache, F., Kamalou, O., Knapton, A., Kokalova, T., Lapoux, V., Lay, J.A., Le Crom, B., Leblond, S., Lois-Fuentes, J., Marqués, F.M., Matta, A., Morfouace, P., Moro, A.M., Otsuka, T., Pancin, J., Perrot, L., Piot, J., Pollacco, E., Ramos, D., Rodríguez-Tajes, C., Roger, T., Rotaru, F., Sénoville, M., de Séréville, N., Smith, R., Sorlin, O., Stanoiu, M., Stefan, I., Stodel, C., Suzuki, D., Suzuki, T., Thomas, J.C., Timofeyuk, N., Vandebrouck, M., Walshe, J., and Wheldon, C.
Abstract: The first investigation of the single-particle structure of the bound states of $^{17}$C, via the d(16C,p) transfer reaction, has been undertaken. The measured angular distributions confirm the spin-parity assignments of 1/2+ and 5/2+ for the excited states located at 217 and 335 keV, respectively. The spectroscopic factors deduced for these states exhibit a marked single-particle character, in agreement with shell model and particle-core model calculations, and combined with their near degeneracy in energy provide clear evidence for the absence of the N=14 sub-shell closure. The very small spectroscopic factor found for the 3/2+ ground state is consistent with theoretical predictions and indicates that the ν1d3/2 strength is carried by unbound states. With a dominant ℓ=0 valence neutron configuration and a very low separation energy, the 1/2+ excited state is a one-neutron halo candidate.
Published: 2020

15. Probing the Z = 6 spin-orbit shell gap with (p,2p) quasi-free scattering reactions

Author: Syndikus, I, Petri, M, Macchiavelli, AO, Paschalis, S, Bertulani, CA, Aumann, T, Alvarez-Pol, H, Atar, L, Beceiro-Novo, S, Benlliure, J, Boillos, JM, Boretzky, K, Borge, MJG, Brown, BA, Caamaño, M, Caesar, C, Casarejos, E, Catford, W, Cederkall, J, Chakraborty, S, Chulkov, LV, Cortina-Gil, D, Cravo, E, Crespo, R, Pramanik, U Datta, Dillmann, I, Fernández, P Díaz, Elekes, Z, Enders, J, Farinon, F, Fraile, LM, Galaviz, D, Geissel, H, Gernhäuser, R, Golubev, P, Göbel, K, Heil, M, Heine, M, Heinz, A, Henriques, A, Holl, M, Johansson, HT, Jonson, B, Kalantar-Nayestanaki, N, Kanungo, R, Kelic-Heil, A, Kröll, T, Kurz, N, Langer, C, Le Bleis, T, Machado, J, Marganiec-Gałązka, J, Nacher, E, Nilsson, T, Nociforo, C, Panin, V, Perea, A, Pietri, SB, Plag, R, Rahaman, A, Reifarth, R, Revel, A, Ribeiro, G, Rigollet, C, Rossi, DM, Savran, D, Scheit, H, Simon, H, Sorlin, O, Tengblad, O, Togano, Y, Vandebrouck, M, Volkov, V, Wamers, F, Wheldon, C, Wilson, GL, Winfield, JS, Weick, H, Woods, P, Yakorev, D, Zhukov, M, Zilges, A, Zuber, K, and Collaboration, R3B
Subjects: Particle and Plasma Physics, Molecular, Nuclear, Atomic, Nuclear & Particles Physics, Mathematical Physics, Astronomical and Space Sciences
Abstract: The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z=6 spin-orbit shell gap towards the neutron dripline. To do so, we employed NA(p,2p)CA−1 quasi-free scattering reactions to measure the proton component of the 21+ state of 16,18,20C. The experimental findings support the notion of a moderate reduction of the proton 1p1/2−1p3/2 spin-orbit splitting, at variance to recent claims for a prevalent Z=6 magic number towards the neutron dripline.
Published: 2020

16. In-beam gamma-ray and electron spectroscopy of Md-249,Md-251

Author: Briselet, R, Theisen, Ch, Sulignano, B, Airiau, M, Auranen, K, Cox, DM, Dechery, F, Drouart, A, Favier, Z, Gall, B, Goigoux, T, Grahn, T, Greenlees, PT, Hauschild, K, Herzan, A, Herzberg, R-D, Jakobsson, U, Julin, R, Juutinen, S, Konki, J, Leino, M, Lopez-Martens, A, Mistry, A, Nieminen, P, Pakarinen, J, Papadakis, P, Peura, P, Rey-Herme, E, Rahkila, P, Rubert, J, Ruotsalainen, P, Sandzelius, M, Saren, J, Scholey, C, Sorri, J, Stolze, S, Uusitalo, J, Vandebrouck, M, Ward, A, Zielinska, M, Bally, B, Bender, M, and Ryssens, W
Published: 2020

17. Halo Structure of the Neutron-Dripline Nucleus ¹⁹B

Author: Cook, K. J., Nakamura, T., Kondo, Y., Hagino, K., Ogata, K., Saito, A. T., Achouri, N. L., Aumann, T., Baba, H., Delaunay, F., Deshayes, Q., Doornenbal, P., Fukuda, N., Gibelin, J., Hwang, J. W., Inabe, N., Isobe, T., Kameda, D., Kanno, D., Kim, S., Kobayashi, N., Kobayashi, T., Kubo, T., Leblond, S., Lee, J., Marqués, F. M., Minakata, R., Motobayashi, T., Muto, K., Murakami, T., Murai, D., Nakashima, T., Nakatsuka, N., Navin, A., Nishi, S., Ogoshi, S., Orr, N. A., Otsu, H., Sato, H., Satou, Y., Shimizu, Y., Suzuki, H., Takahashi, K., Takeda, H., Takeuchi, S., Tanaka, R., Togano, Y., Tsubota, J., Tuff, A. G., Vandebrouck, M., and Yoneda, K.
Subjects: Nuclear Theory, Nuclear Experiment
Abstract: The heaviest bound isotope of boron ¹⁹B has been investigated using exclusive measurements of its Coulomb dissociation, into ¹⁷B and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys) e² fm² for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that ¹⁹B has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation., コンパクトな新奇中性子対の新たな証拠を発見 --不安定核ビームを用いた実験と少数系理論により実現--. 京都大学プレスリリース. 2020-06-22.
Published: 2020

18. In-beam gamma-ray and electron spectroscopy of $^{249,251}$Md

Author: Briselet, R., Theisen, Ch., Sulignano, B., Airiau, M., Auranen, K., Cox, D.M., Déchery, F., Drouart, A., Favier, Z., Gall, B., Goigoux, T., Grahn, T., Greenlees, P.T., Hauschild, K., Herzan, A., Herzberg, R.-D., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lopez-Martens, A., Mistry, A., Nieminen, P., Pakarinen, J., Papadakis, P., Peura, P., Rahkila, P., Rey-Herme, E., Rubert, J., Ruotsalainen, P., Sandzelius, M., Sarén, J., Scholey, C., Sorri, J., Stolze, S., Uusitalo, J., Vandebrouck, M., Ward, A., Zielínska, M., Bally, B., Bender, M., Ryssens, W., 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), Université de Strasbourg (UNISTRA)-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), Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), 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)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: Nuclear Theory (nucl-th), nucl-th, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, Nuclear Physics - Theory, FOS: Physical sciences, Nuclear Physics - Experiment, ddc:530, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, Nuclear Structure, Nuclear Experiment
Abstract: The odd-Z Md251 nucleus was studied using combined γ-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the [521]1/2− configuration, another rotational structure has been identified using γ-γ coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a [514]7/2− single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of ≃60% was well reproduced by simulating a set of unresolved excited bands. Moreover, a detailed analysis of the intensity profile as a function of the angular momentum provided a method for deriving the orbital gyromagnetic factor, namely gK=0.69−0.16+0.19 for the ground-state band. The odd-Z Md249 was studied using γ-ray in-beam spectroscopy. Evidence for octupole correlations resulting from the mixing of the Δl=Δj=3 [521]3/2− and [633]7/2+ Nilsson orbitals were found in both Md249,251. A surprising similarity of the Md251 ground-state band transition energies with those of the excited band of Lr255 has been discussed in terms of identical bands. Skyrme-Hartree-Fock-Bogoliubov calculations were performed to investigate the origin of the similarities between these bands. The odd-$Z$ $^{251}$Md nucleus was studied using combined $\gamma$-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the $[521]1/2^-$ configuration, another rotational structure has been identified using $\gamma$-$\gamma$ coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a $[514]7/2^-$ single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of $\simeq$ 60% was well reproduced by simulating a set of unresolved excited bands. Moreover, a detailed analysis of the intensity profile as a function of the angular momentum provided a method for deriving the orbital gyromagnetic factor, namely $g_K = 0.69^{+0.19}_{-0.16}$ for the ground-state band. The odd-$Z$ $^{249}$Md was studied using $\gamma$-ray in-beam spectroscopy. Evidence for octupole correlations resulting from the mixing of the $\Delta l = \Delta j = 3$ $[521]3/2^-$ and $[633]7/2^+$ Nilsson orbitals were found in both $^{249,251}$Md. A surprising similarity of the $^{251}$Md ground-state band transition energies with those of the excited band of $^{255}$Lr has been discussed in terms of identical bands. Skyrme-Hartree-Fock-Bogoliubov calculations were performed to investigate the origin of the similarities between these bands.
Published: 2020

19. Stability of the heaviest elements: K isomer in No-250

Author: Kallunkathariyil, J, Sulignano, B, Greenlees, PT, Khuyagbaatar, J, Theisen, Ch, Auranen, K, Badran, H, Bisso, F, Brionnet, P, Briselet, R, Drouart, A, Favier, Z, Goigoux, T, Grahn, T, Hauschild, K, Herzan, A, Hessberger, FP, Jakobsson, U, Julin, R, Juutinen, S, Konki, J, Leino, M, Lightfoot, A, Pakarinen, J, Papadakis, P, Partanen, J, Peura, P, Rahkila, P, Rezynkina, K, Ruotsalainen, P, Sandzelius, M, Saren, J, Scholey, C, Siciliano, M, Sorri, J, Stolze, S, Svirikhin, AI, Uusitalo, J, Vandebrouck, M, Ward, A, Wraith, C, and Zielinska, M
Published: 2020

20. Halo Structure of the Neutron-Dripline Nucleus $^{19}$B

Author: Cook, K.J., Nakamura, T., Kondo, Y., Hagino, K., Ogata, K., Saito, A.T., Achouri, N.L., Aumann, T., Baba, H., Delaunay, F., Deshayes, Q., Doornenbal, P., Fukuda, N., Gibelin, J., Hwang, J.W., Inabe, N., Isobe, T., Kameda, D., Kanno, D., Kim, S., Kobayashi, N., Kobayashi, T., Kubo, T., Leblond, S., Lee, J., Marqués, F.M., Minakata, R., Motobayashi, T., Muto, K., Murakami, T., Murai, D., Nakashima, T., Nakatsuka, N., Navin, A., Nishi, S., Ogoshi, S., Orr, N.A., Otsu, H., Sato, H., Satou, Y., Shimizu, Y., Suzuki, H., Takahashi, K., Takeda, H., Takeuchi, S., Tanaka, R., Togano, Y., Tsubota, J., Tuff, A.G., Vandebrouck, M., Yoneda, K., 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), 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), 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), 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)-Centre National de la Recherche Scientifique (CNRS), 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: Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Nuclear Physics
Abstract: International audience; The heaviest bound isotope of boron B19 has been investigated using exclusive measurements of its Coulomb dissociation, into B17 and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys) e2 fm2 for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that B19 has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.
Published: 2020

21. Signature of a possible $��$-cluster state in $N=Z$ doubly-magic $^{56}$Ni

Author: Bagchi, S., Akimune, H., Gibelin, J., Harakeh, M. N., Kalantar-Nayestanaki, N., Achouri, N. L., Bastin, B., Boretzky, K., Bouzomita, H., Caama��o, M., C��ceres, L., Damoy, S., Delaunay, F., Fern��ndez-Dom��nguez, B., Fujiwara, M., Garg, U., Grinyer, G. F., Kamalou, O., Khan, E., Krasznahorkay, A., Lhoutellier, G., Libin, J. F., Lukyanov, S., Mazurek, K., Najafi, M. A., Pancin, J., Penionzkhevich, Y., Perrot, L., Raabe, R., Rigollet, C., Roger, T., Sambi, S., Savajols, H., Senoville, M., Stodel, C., Suen, L., Thomas, J. C., Vandebrouck, M., and Van de Walle, J.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: An inelastic $��$-scattering experiment on the unstable $N=Z$, doubly-magic $^{56}$Ni nucleus was performed in inverse kinematics at an incident energy of 50 A.MeV at GANIL. High multiplicity for $��$-particle emission was observed within the limited phase-space of the experimental setup. This observation cannot be explained by means of the statistical-decay model. The ideal classical gas model at $kT$ = 0.4 MeV reproduces fairly well the experimental momentum distribution and the observed multiplicity of $��$ particles corresponds to an excitation energy around 96 MeV. The method of distributed $m��$-decay ensembles is in agreement with the experimental results if we assume that the $��$-gas state in $^{56}$Ni exists at around $113^{+15}_{-17}$ MeV. These results suggest that there may exist an exotic state consisting of many $��$ particles at the excitation energy of $113^{+15}_{-17}$ MeV., Accepted for publication in the European Physical Journal A
Published: 2020
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22. In-beam γ-ray and electron spectroscopy of Md249,251

Author: Briselet, R., Theisen, Ch., Sulignano, B., Airiau, M., Auranen, K., Cox, D. M., Déchery, F., Drouart, A., Favier, Z., Gall, B., Goigoux, T., Grahn, T., Greenlees, P. T., Hauschild, K., Herzan, A., Herzberg, R.-D., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lopez-Martens, A., Mistry, A., Nieminen, P., Pakarinen, J., Papadakis, P., Peura, P., Rey-Herme, E., Rahkila, P., Rubert, J., Ruotsalainen, P., Sandzelius, M., Sarén, J., Scholey, C., Sorri, J., Stolze, S., Uusitalo, J., Vandebrouck, M., Ward, A., Zielińska, M., Bally, B., Bender, M., and Ryssens, W.
Subjects: electromagnetic transitions, spektroskopia, nuclear spin and parity, collective levels, ydinfysiikka
Abstract: The odd-Z 251Md nucleus was studied using combined γ-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the [521]1/2− configuration, another rotational structure has been identified using γ−γ coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a [514]7/2− single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of ≃60% was well reproduced by simulating a set of unresolved excited bands. Moreover, a detailed analysis of the intensity profile as a function of the angular momentum provided a method for deriving the orbital gyromagnetic factor, namely gK=0.69+0.19−0.16 for the ground-state band. The odd-Z 249Md was studied using γ-ray in-beam spectroscopy. Evidence for octupole correlations resulting from the mixing of the Δl=Δj=3 [521]3/2− and [633]7/2+ Nilsson orbitals were found in both 249,251Md. A surprising similarity of the 251Md ground-state band transition energies with those of the excited band of 255Lr has been discussed in terms of identical bands. Skyrme-Hartree-Fock-Bogoliubov calculations were performed to investigate the origin of the similarities between these bands. peerReviewed
Published: 2020

23. Stability of the heaviest elements: $K$ isomer in $^{250}\mathrm{No}$

Author: Kallunkathariyil, J., Sulignano, B., Greenlees, P.T., Khuyagbaatar, J., Theisen, Ch., Auranen, K., Badran, H., Bisso, F., Brionnet, P., Briselet, R., Drouart, A., Favier, Z., Goigoux, T., Grahn, T., Hauschild, K., Herzan, A., Heßberger, F.P., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lightfoot, A., Pakarinen, J., Papadakis, P., Partanen, J., Peura, P., Rahkila, P., Rezynkina, K., Ruotsalainen, P., Sandzelius, M., Saren, J., Scholey, C., Siciliano, M., Sorri, J., Stolze, S., Svirikhin, A.I., Uusitalo, J., Vandebrouck, M., Ward, A., Wraith, C., Zielińska, M., 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), 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), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Experiment, Nuclear Structure
Abstract: International audience; Decay spectroscopy of $^{250}\mathrm{No}$ has been performed using digital electronics and pulse-shape analysis of the fast nuclear decays for the first time. Previous studies of $^{250}\mathrm{No}$ reported two distinct fission decay lifetimes, related to the direct fission of the ground state and to the decay of an isomeric state but without the possibility to determine if the isomeric state decayed directly via fission or via internal electromagnetic transitions to the ground state. The data obtained in the current experiment allowed the puzzle to finally be resolved, attributing the shorter half-life of $t_{1/2}=3.8 \pm 0.3 \mu s$ to the ground state and the longer half-life $t_{1/2}=34.9^{+3.9}_{-3.2} \mu s$ to the decay of an isomeric state. $^{250}\mathrm{No}$ becomes, thus, one of a very few examples of very heavy nuclei with an isomeric state living considerably longer than its ground state. This phenomenon has important consequences for the nuclear-structure models aiming to determine the borders of the island of stability of superheavy elements.
Published: 2020

24. Structure of Si 33 and the magicity of the N=20 gap at Z=14

Author: Jongile, S., Lemasson, A., Sorlin, O., Wiedeking, M., Papka, P., Bazin, D., Borcea, C., Borcea, R., Gade, A., Iwasaki, H., Khan, E., Lepailleur, A., Mutschler, A., Nowacki, F., Recchia, F., Roger, T., Rotaru, F., Stanoiu, M., Stroberg, S. R., Tostevin, J. A., Vandebrouck, M., Weisshaar, D., and Wimmer, K.
Published: 2020

25. In-beam γ-ray and electron spectroscopy of ²⁴⁹,²⁵¹Md

Author: Briselet, R. (R.), Theisen, C. (Ch), Sulignano, B. (B.), Airiau, M. (M.), Auranen, K. (K.), Cox, D. M. (D. M.), Dechery, F. (F.), Drouart, A. (A.), Favier, Z. (Z.), Gall, B. (B.), Goigoux, T. (T.), Grahn, T. (T.), Greenlees, P. T. (P. T.), Hauschild, K. (K.), Herzan, A. (A.), Herzberg, R.-D. (R-D), Jakobsson, U. (U.), Julin, R. (R.), Juutinen, S. (S.), Konki, J. (J.), Leino, M. (M.), Lopez-Martens, A. (A.), Mistry, A. (A.), Nieminen, P. (P.), Pakarinen, J. (J.), Papadakis, P. (P.), Peura, P. (P.), Rey-Herme, E. (E.), Rahkila, P. (P.), Rubert, J. (J.), Ruotsalainen, P. (P.), Sandzelius, M. (M.), Saren, J. (J.), Scholey, C. (C.), Sorri, J. (J.), Stolze, S. (S.), Uusitalo, J. (J.), Vandebrouck, M. (M.), Ward, A. (A.), Zielinska, M. (M.), Bally, B. (B.), Bender, M. (M.), and Ryssens, W. (W.)
Abstract: The odd-Z ²⁵¹Md nucleus was studied using combined γ-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the [521]1/2⁻ configuration, another rotational structure has been identified using γ−γ coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a [514]7/2⁻ single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of ≃60% was well reproduced by simulating a set of unresolved excited bands. Moreover, a detailed analysis of the intensity profile as a function of the angular momentum provided a method for deriving the orbital gyromagnetic factor, namely $g_{K}=0.69^{+0.19}_{−0.16}$ for the ground-state band. The odd-Z ²⁴⁹Md was studied using γ-ray in-beam spectroscopy. Evidence for octupole correlations resulting from the mixing of the Δl=Δj=3 [521]3/2⁻ and [633]7/2⁺ Nilsson orbitals were found in both ²⁴⁹,²⁵¹Md. A surprising similarity of the²⁵¹Md ground-state band transition energies with those of the excited band of ²⁵⁵Lr has been discussed in terms of identical bands. Skyrme-Hartree-Fock-Bogoliubov calculations were performed to investigate the origin of the similarities between these bands.
Published: 2020

26. Stability of the heaviest elements : K isomer in 250No

Author: Kallunkathariyil, J., Sulignano, B., Greenlees, P. T., Khuyagbaatar, J., Theisen, Ch., Auranen, K., Badran, H., Bisso, F., Brionnet, P., Briselet, R., Drouart, A., Favier, Z., Goigoux, T., Grahn, T., Hauschild, K., Herzan, A., Heßberger, F. P., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lightfoot, A., Pakarinen, J., Papadakis, P., Partanen, J., Peura, P., Rahkila, P., Rezynkina, K., Ruotsalainen, P., Sandzelius, M., Saren, J., Scholey, C., Siciliano, M., Sorri, J., Stolze, S., Svirikhin, A. I., Uusitalo, J., Vandebrouck, M., Ward, A., Wraith, C., and Zielińska, M.
Subjects: isomer decays, ydinfysiikka, nuclear structure and decays
Abstract: Decay spectroscopy of 250No has been performed using digital electronics and pulse-shape analysis of the fast nuclear decays for the first time. Previous studies of 250No reported two distinct fission decay lifetimes, related to the direct fission of the ground state and to the decay of an isomeric state but without the possibility to determine if the isomeric state decayed directly via fission or via internal electromagnetic transitions to the ground state. The data obtained in the current experiment allowed the puzzle to finally be resolved, attributing the shorter half-life of t1/2 = 3.8 ± 0.3 μs to the ground state and the longer half-life t1/2 = 34.9+3.9 −3.2 μs to the decay of an isomeric state. 250No becomes, thus, one of a very few examples of very heavy nuclei with an isomeric state living considerably longer than its ground state. This phenomenon has important consequences for the nuclear-structure models aiming to determine the borders of the island of stability of superheavy elements. peerReviewed
Published: 2020

27. Towards day one experiments at the S3 Low Energy Branch

Author: Lecesne, N., Ackermann, D., Authier, M., Boumard, F., Caceres, L., Cam, J-F., Damoy, S., Delahaye, P., Desrue, P., Drouart, A., Duchesne, P., Ferrer, R., Fléchard, X., Franchoo, S., Gangnant, P., Goigoux, T., Groote, R. de, Kraemer, S., Leroy, R., Lory, J., Lutton, F., Merrer, Y., Moore, I., Osmond, B., Piot, J., Pochon, O., Retailleau, B.M., Romans, J., Savajols, H., Traykov, E., Uusitalo, J., Vandamme, C., Vandebrouck, M., Bergh, P. Van den, Duppen, P. Van, Verlinde, M., Verstraelen, E., Wend, K., 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-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), Instituut voor Kern- en Stralingsfysica (K.U. LEUVEN), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), University of Jyväskylä (JYU), KU Leuven, Instituut voor Kern- en Stralingsfysica, 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), Johannes Gutenberg - Universität Mainz (JGU), 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), 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), and Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU)
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2019

28. Production cross section and decay study of Es-243 and Md-249

Author: Briselet, R, Theisen, Ch, Vandebrouck, M, Marchix, A, Airiau, M, Auranen, K, Badran, H, Boilley, D, Calverley, T, Cox, D, Dechery, F, Bisso, F Defranchi, Drouart, A, Gall, B, Goigoux, T, Grahn, T, Greenlees, PT, Hauschild, K, Herzan, A, Herzberg, RD, Jakobsson, U, Julin, R, Juutinen, S, Konki, J, Leino, M, Lightfoot, A, Lopez-Martens, A, Mistry, A, Nieminen, P, Pakarinen, J, Papadakis, P, Partanen, J, Peura, P, Rahkila, P, Rubert, J, Ruotsalainen, P, Sandzelius, M, Saren, J, Scholey, C, Sorri, J, Stolze, S, Sulignano, B, Uusitalo, J, Ward, A, Zielinska, M, University of Helsinki, University of Jyväskylä, and University of Helsinki, Laboratory of Radiochemistry
Subjects: 114 Physical sciences
Abstract: In the study of the odd-Z, even-N nuclei Es-243 and Md-249, performed at the University of Jyvaskyla, the fusion-evaporation reactions Au-197(Ca-48, 2n)Es-243 and Tl-203(Ca-48, 2n) Md-249 have been used for the first time. Fusion-evaporation residues were selected and detected using a gas-filled separator coupled with its focal-plane spectrometer. For Es-243, the recoil decay correlation analysis yielded a half-life of 24 +/- 3 s and a maximum production cross section of 37 +/- 10 nb. In the same way, a half-life of 26 +/- 1 s, an alpha-branching ratio of 75 +/- 5%, and a maximum production cross section of 300 +/- 80 nb were determined for Md-249. The decay properties of Es-245, the daughter of Md-249, were also measured: an alpha-branching ratio of 54 +/- 7% and a half-life of 65 +/- 6 s. Experimental cross sections were compared to the results of calculations performed using the KEWPIE2 statistical fusion-evaporation code.
Published: 2019

29. Production cross section and decay study of $^{243}$Es and $^{249}$Md

Author: Briselet, R., Theisen, Ch., Vandebrouck, M., Marchix, A., Airiau, M., Auranen, K., Badran, H., Boilley, D., Calverley, T., Cox, D., Déchery, F., Defranchi Bisso, F., Drouart, A., Gall, B., Goigoux, T., Grahn, T., Greenlees, P.T., Hauschild, K., Herzan, A., Herzberg, R.D., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lightfoot, A., Lopez-Martens, A., Mistry, A., Nieminen, P., Pakarinen, J., Papadakis, P., Partanen, J., Peura, P., Rahkila, P., Rubert, J., Ruotsalainen, P., Sandzelius, M., Saren, J., Scholey, C., Sorri, J., Stolze, S., Sulignano, B., Uusitalo, J., Ward, A., Zielińska, M., 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), Université de Caen Normandie (UNICAEN), Normandie Université (NU), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-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), 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: ydinreaktiot, alpha decay, Nuclear Reactions, FOS: Physical sciences, low and intermediate energy heavy-ion reactions, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: In the study of the odd-$Z$, even-$N$ nuclei $^{243}$Es and $^{249}$Md, performed at the University of Jyv\"askyl\"a, the fusion-evaporation reactions $^{197}$Au($^{48}$Ca,2$n$)$^{243}$Es and $^{203}$Tl($^{48}$Ca,2$n$)$^{249}$Md have been used for the first time. Fusion-evaporation residues were selected and detected using the RITU gas-filled separator coupled with the focal-plane spectrometer GREAT. For $^{243}$Es, the recoil decay correlation analysis yielded a half-life of $24 \pm 3$s, and a maximum production cross section of $37 \pm 10$ nb. In the same way, a half-life of $26 \pm 1$ s, an $\alpha$ branching ratio of 75 $\pm$ 5%, and a maximum production cross section of 300 $\pm$ 80 nb were determined for $^{249}$Md. The decay properties of $^{245}$Es, the daughter of $^{249}$Md, were also measured: an $\alpha$ branching ratio of 54 $\pm$ 7% and a half-life of 65 $\pm$ 6 s. Experimental cross sections were compared to the results of calculations performed using the KEWPIE2 statistical fusion-evaporation code.
Published: 2019

30. Nuclear moments of the low-lying isomeric 1 State of Al: Investigation on the neutron 1 1 Excitation Across = 20 in the Island of Inversion

Author: Xu, Z.Y., Heylen, H., Asahi, K., Boulay, F., Daugas, J.M., de Groote, R.P., Gins, W., Kamalou, O., Koszorús, Á., Lykiardopoulou, M., Mertzimekis, T.J., Neyens, G., Nishibata, H., Otsuka, T., Orset, R., Poves, A., Sato, T., Stodel, C., Thomas, J.C., Tsunoda, N., Utsuno, Y., Vandebrouck, M., and Yang, X.F.
Abstract: The nuclear g factor and quadrupole moment (Qs) have been measured for the low-lying isomeric 1+ state of $^{34}$Al, using the β-detected nuclear magnetic resonance (β-NMR) and quadrupole resonance (β-NQR) methods. Spin-polarized $^{34}$Al isotopes were produced in a one-neutron pickup reaction induced by a $^{36}$S beam on a $^{9}$Be target at a kinetic energy of 77.5 MeV/nucleon, and were collected with the LISE fragment separator at GANIL. The measured g factor (|g| in a range of 1.757±0.014) and quadrupole moment (|Qs|=38(5) mb) are in good agreement with shell-model calculations using effective interactions. The similarity between the g factor of 34mAl and that of $^{32}$Al confirms a dominant neutron 2p1h configuration π(d5/2)−1⊗ν(d3/2)−1(f7/2)2 of 34mAl. In addition, the enhanced quadrupole moment of 34mAl relative to that of $^{32}$Al suggests that the neutron 1p1h excitation across the N=20 shell gap introduces extra nucleon–nucleon correlation and deformation.
Published: 2018

31. Quasifree (p, pN) scattering of light neutron-rich nuclei near N=14

Author: Diaz Fernandez, P, Alvarez-Pol, H, Crespo, R, Cravo, E, Atar, L, Deltuva, A, Aumann, T, Avdeichikov, V, Beceiro-Novo, S, Bemmerer, D, Benlliure, J, Bertulani, CA, Boillos, JM, Boretzky, K, Borge, MJG, Caamano, M, Cabanelas, P, Caesar, C, Casarejos, E, Catford, W, Cederkall, J, Chartier, M, Chulkov, LV, Cortina-Gil, D, Pramanik, U Datta, Dillmann, I, Elekes, Z, Enders, J, Ershova, O, Estrade, A, Farinon, F, Fernandez-Dominguez, B, Fraile, LM, Freer, M, Galaviz, D, Geissel, H, Gernhaeuser, R, Golubev, P, Goebel, K, Hagdahl, J, Heftrich, T, Heil, M, Heine, M, Heinz, A, Henriques, A, Holl, M, Hufnagel, A, Ignatov, A, Johansson, HT, Jonson, B, Jurciukonis, D, Kalantar-Nayestanaki, N, Kanungo, R, Kelic-Heil, A, Knyazev, A, Kroell, T, Kurz, N, Labiche, M, Langer, C, Le Bleis, T, Lemmon, R, Lindberg, S, Machado, J, Marganiec, J, Moro, AM, Movsesyan, A, Nacher, E, Najafi, A, Nikolskii, E, Nilsson, T, Nociforo, C, Panin, V, Paschalis, S, Perea, A, Petri, M, Pietras, B, Pietri, S, Plag, R, Reifarth, R, Ribeiro, G, Rigollet, C, Rossi, D, Roeder, M, Savran, D, Scheit, H, Simon, H, Sorlin, O, Syndikus, I, Taylor, JT, Tengblad, O, Thies, R, Togano, Y, Vandebrouck, M, Velho, P, Volkov, V, Wagner, A, Wamers, F, Weick, H, Wheldon, C, Wilson, G, Winfield, JS, Woods, P, Yakorev, D, Zhukov, M, Zilges, A, Zuber, K, and Collaboration, R3B
Published: 2018

32. Quasifree (p, 2p) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength

Author: Atar, L, Paschalis, S, Barbieri, C, Bertulani, CA, Diaz Fernandez, P, Holl, M, Najafi, MA, Panin, V, Alvarez-Pol, H, Aumann, T, Avdeichikov, V, Beceiro-Novo, S, Bemmerer, D, Benlliure, J, Boillos, JM, Boretzky, K, Borge, MJG, Caamano, M, Caesar, C, Casarejos, E, Catford, W, Cederkall, J, Chartier, M, Chulkov, L, Cortina-Gil, D, Cravo, E, Crespo, R, Dillmann, I, Elekes, Z, Enders, J, Ershova, O, Estrade, A, Farinon, F, Fraile, LM, Freer, M, Galaviz Redondo, D, Geissel, H, Gernhaeuser, R, Golubev, P, Goebel, K, Hagdahl, J, Heftrich, T, Heil, M, Heine, M, Heinz, A, Henriques, A, Hufnagel, A, Ignatov, A, Johansson, HT, Jonson, B, Kahlbow, J, Kalantar-Nayestanaki, N, Kanungo, R, Kelic-Heil, A, Knyazev, A, Kroell, T, Kurz, N, Labiche, M, Langer, C, Le Bleis, T, Lemmon, R, Lindberg, S, Machado, J, Marganiec-Galazka, J, Movsesyan, A, Nacher, E, Nikolskii, EY, Nilsson, T, Nociforo, C, Perea, A, Petri, M, Pietri, S, Plag, R, Reifarth, R, Ribeiro, G, Rigollet, C, Rossi, DM, Roeder, M, Savran, D, Scheit, H, Simon, H, Sorlin, O, Syndikus, I, Taylor, JT, Tengblad, O, Thies, R, Togano, Y, Vandebrouck, M, Velho, P, Volkov, V, Wagner, A, Wamers, F, Weick, H, Wheldon, C, Wilson, GL, Winfield, JS, Woods, P, Yakorev, D, Zhukov, M, Zilges, A, Zuber, K, and Collaboration, R3B
Subjects: Nuclear Theory, Nuclear Experiment
Abstract: Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R3B/LAND setup with incident beam energies in the range of 300–450 MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type AO(p,2p)A−1N have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.
Published: 2018

33. Structure of $^{13}$Be studied in proton knockout from $^{14}$B

Author: Ribeiro, G., Nácher, E., Tengblad, O., Díaz Fernández, P., Aksyutina, Y., Alvarez-Pol, H., Atar, L., Aumann, T., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Caesar, C., Casarejos, E., Catford, W., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Datta Pramanik, U., Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Kurz, N., Kröll, T., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Movsesyan, A., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Rigollet, C., Riisager, K., Rossi, D., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I., Taylor, J. T., Thies, R., Velho, P., Wagner, A., Wamers, F., Vandebrouck, M., Weick, H., Wheldon, C., Wilson, G., Wimmer, C., Winfield, J. S., Woods, P., Zhukov, M. V., Zilges, A., Zuber, K., 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), R$^3$B, 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: radioactive beams, nuclear structure, Nuclear Theory, Aucun, 13Be, Nuclear Reactions, unbound nuclei, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: Physical review / C 98(2), 024603 (2018). doi:10.1103/PhysRevC.98.024603, Published by Inst., Woodbury, NY
Published: 2018

34. Structure of Be13 studied in proton knockout from B14

Author: Ribeiro, G., Nácher, E., Tengblad, O., Díaz Fernández, P., Aksyutina, Y., Alvarez-Pol, H., Atar, L., Aumann, T., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Caesar, C., Casarejos, E., Catford, W., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Datta Pramanik, U., Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Kurz, N., Kröll, T., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Movsesyan, A., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Rigollet, C., Riisager, K., Rossi, D., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I., Taylor, J. T., Thies, R., Velho, P., Wagner, A., Wamers, F., Vandebrouck, M., Weick, H., Wheldon, C., Wilson, G., Wimmer, C., Winfield, J. S., Woods, P., Zhukov, M. V., Zilges, A., and Zuber, K.
Subjects: ddc
Published: 2018

35. Quasi-free (p,pN) scattering of light neutron-rich nuclei around N = 14

Author: Diaz Fernandez, P., Alvarez-Pol, H., Crespo, R., Cravo, E., Atar, L., Deltuva, A., Aumann, T., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Cabanelas, P., Caesar, C., Casarejos, E., Catford, W., Cederkall, J., Chartier, M., Chulkov, L. V., Cortina-Gil, D., Datta Pramanik, U., Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fernandez-Dominguez, B., Fraile, L. M., Freer, M., Galaviz, D., Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Jurciukonis, D., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Moro, A. M., Movsesyan, A., Nacher, E., Najafi, A., Nikolskii, E., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, A., Petri, M., Pietras, B., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Rossi, D., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I., Taylor, J. T., Tengblad, O., Thies, R., Togano, Y., Vandebrouck, M., Velho, P., Volkov, V., Wagner, A., Wamers, F., Weick, H., Wheldon, C., Wilson, G., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.
Subjects: quasi-free scattering reactions radioactive beams single-particle, Nuclear Experiment
Abstract: In this work we investigate for the first time the quasi-free scattering reactions (p,pn) and (p,2p) simultaneously for the same projectile in inverse and complete kinematics for radioactive beams with the aim to study the evolution of single-particle properties from N = 14 to N = 15.
Published: 2018

36. Quasifree ($p$, $2p$) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength

Author: Atar, Leyla, Paschalis, Stefanos, Barbieri, C., Bertulani, C. A., Fernández, P. Díaz, Holl, M., Najafi, M.A, Panin, V., Alvarez-Pol, H., Aumann, T., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Boillos, J.M., Boretzky, K., Borge, M. J. G., Caamaño, M., Caesar, C., Casarejos, E., Catford, W., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L.M, Freer, M., Redondo, D. Galaviz, Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Hufnagel, A., Ignatov, A., Johansson, H.T, Jonson, B, Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J., Marganiec-Gałązka, J., Movsesyan, A., Nacher, E., Nikolskii, E.Y., Nilsson, T., Nociforo, C., Perea, A., Petri, Marina, Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Rossi, D.M., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I., Taylor, J. T., Tengblad, O, Thies, R., Togano, Y., Vandebrouck, M., Velho, P., Volkov, V., Wagner, A., Wamers, F., Weick, H., Wheldon, C., Wilson, G.L., Winfield, J.S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., Zuber, K, 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), 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), 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), 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), Helmholtz Centre for Heavy Ion Research, Department of Energy (US), National Science Foundation (US), Ministerio de Economía y Competitividad (España), Science and Technology Facilities Council (UK), Federal Ministry of Education and Research (Germany), University of Leicester, and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, ddc:550, Aucun, Nuclear Experiment
Abstract: 7 pags., 4 figs., tab., Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the (RB)-B-3/LAND setup with incident beam energies in the range of 300-450 MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type O-A(p,2p)NA-1 have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry., This work was supported by the German Federal Ministry for Education and Research (BMBF project 05P15RDFN1), and through the GSI-TU Darmstadt cooperation agreement. The work of C. B., W. C., and G.W. was supported by the United Kingdom Science and Technology Facilities Council (STFC) under Grants No. ST/L005743/1 and No. ST/P005314/1. SCGF calculations were performed at the DiRAC Complexity system of the University of Leicester (BIS National E-1023 infrastructure capital Grant No. ST/K000373/1 and STFC 1024 Grant No. ST/K0003259/1). C. A. B. acknowledges support by the U.S. DOE Grant No. DE-FG02- 08ER41533 and the U.S. NSF Grant No. 1415656. L. M. F. acknowledges funding from MINECO FPA2015-65035-P project.
Published: 2018

37. Nuclear moments of the low-lying isomeric 1+ state of 34Al: Investigation on the neutron 1p1h excitation across N = 20 in the island of inversion

Author: Xu, Z.Y. Heylen, H. Asahi, K. Boulay, F. Daugas, J.M. de Groote, R.P. Gins, W. Kamalou, O. Koszorús, Á. Lykiardopoulou, M. Mertzimekis, T.J. Neyens, G. Nishibata, H. Otsuka, T. Orset, R. Poves, A. Sato, T. Stodel, C. Thomas, J.C. Tsunoda, N. Utsuno, Y. Vandebrouck, M. Yang, X.F.
Subjects: Nuclear Theory, Nuclear Experiment
Abstract: The nuclear g factor and quadrupole moment (Qs) have been measured for the low-lying isomeric 1+ state of 34Al, using the β-detected nuclear magnetic resonance (β-NMR) and quadrupole resonance (β-NQR) methods. Spin-polarized 34Al isotopes were produced in a one-neutron pickup reaction induced by a 36S beam on a 9Be target at a kinetic energy of 77.5 MeV/nucleon, and were collected with the LISE fragment separator at GANIL. The measured g factor (|g| in a range of 1.757±0.014) and quadrupole moment (|Qs|=38(5) mb) are in good agreement with shell-model calculations using effective interactions. The similarity between the g factor of 34mAl and that of 32Al confirms a dominant neutron 2p1h configuration π(d5/2)−1⊗ν(d3/2)−1(f7/2)2 of 34mAl. In addition, the enhanced quadrupole moment of 34mAl relative to that of 32Al suggests that the neutron 1p1h excitation across the N=20 shell gap introduces extra nucleon–nucleon correlation and deformation. © 2018 The Author(s)
Published: 2018

38. Quasifree ($p,pN$) scattering of light neutron-rich nuclei near $N=14$

Author: Díaz Fernández, P., Alvarez-Pol, H., Crespo, R., Cravo, E., Atar, L., Deltuva, A., Aumann, T., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C.A., Boillos, J.M., Boretzky, K., Borge, M.J.G., Caamaño, M., Cabanelas, P., Caesar, C., Casarejos, E., Catford, W., Cederkäll, J., Chartier, M., Chulkov, L.V., Cortina-Gil, D., Datta Pramanik, U., Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estradé, A., Farinon, F., Fernández-Domínguez, B., Fraile, L.M., Freer, M., Galaviz, D., Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Johansson, H.T., Jonson, B., Jurčiukonis, D., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Moro, A.M., Movsesyan, A., Nacher, E., Najafi, A., Nikolskii, E., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, A., Petri, M., Pietras, B., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Rossi, D., Röder, M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Syndikus, I., Taylor, J.T., Tengblad, O., Thies, R., Togano, Y., Vandebrouck, M., Velho, P., Volkov, V., Wagner, A., Wamers, F., Weick, H., Wheldon, C., Wilson, G., Winfield, J.S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., Zuber, K., 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), 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: Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: International audience; Background: For many years, quasifree scattering reactions in direct kinematics have been extensively used to study the structure of stable nuclei, demonstrating the potential of this approach. The RB3 collaboration has performed a pilot experiment to study quasifree scattering reactions in inverse kinematics for a stable C12 beam. The results from that experiment constitute the first quasifree scattering results in inverse and complete kinematics. This technique has lately been extended to exotic beams to investigate the evolution of shell structure, which has attracted much interest due to changes in shell structure if the number of protons or neutrons is varied. Purpose: In this work we investigate for the first time the quasifree scattering reactions (p,pn) and (p,2p) simultaneously for the same projectile in inverse and complete kinematics for radioactive beams with the aim to study the evolution of single-particle properties from N=14 to N=15. Method: The structure of the projectiles O23, O22, and N21 has been studied simultaneously via (p,pn) and (p,2p) quasifree knockout reactions in complete inverse kinematics, allowing the investigation of proton and neutron structure at the same time. The experimental data were collected at the R3B-LAND setup at GSI at beam energies of around 400 MeV/u. Two key observables have been studied to shed light on the structure of those nuclei: the inclusive cross sections and the corresponding momentum distributions. Conclusions: The knockout reactions (p,pn) and (p,2p) with radioactive beams in inverse kinematics have provided important and complementary information for the study of shell evolution and structure. For the (p,pn) channels, indications of a change in the structure of these nuclei moving from N=14 to N=15 have been observed, i.e., from the 0d5/2 shell to the 1s1/2. This supports previous observations of a subshell closure at N=14 for neutron-rich oxygen isotopes and its weakening for the nitrogen isotopes.
Published: 2018

39. First observation of $^{20}$B and $^{21}$B

Author: Leblond, S., Marqués, F.M., Gibelin, J., Orr, N.A., Kondo, Y., Nakamura, T., Bonnard, J., Michel, N., Achouri, N.L., Aumann, T., Baba, H., Delaunay, F., Deshayes, Q., Doornenbal, P., Fukuda, N., Hwang, J.W., Inabe, N., Isobe, T., Kameda, D., Kanno, D., Kim, S., Kobayashi, N., Kobayashi, T., Kubo, T., Lee, J., Minakata, R., Motobayashi, T., Murai, D., Murakami, T., Muto, K., Nakashima, T., Nakatsuka, N., Navin, A., Nishi, S., Ogoshi, S., Otsu, H., Sato, H., Satou, Y., Shimizu, Y., Suzuki, H., Takahashi, K., Takeda, H., Takeuchi, S., Tanaka, R., Togano, Y., Tuff, A.G., Vandebrouck, M., Yoneda, K., 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), 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 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 Theory (nucl-th), Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Phase Diagram of QCD, Quark-Gluon Plasma, FOS: Physical sciences, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Nuclear Physics
Abstract: The most neutron-rich boron isotopes 20B and 21B have been observed for the first time following proton removal from 22N and 22C at energies around 230 MeV/nucleon. Both nuclei were found to exist as resonances which were detected through their decay into 19B and one or two neutrons. Two-proton removal from 22N populated a prominent resonance-like structure in 20B at around 2.5 MeV above the one-neutron decay threshold, which is interpreted as arising from the closely spaced 1-,2- ground-state doublet predicted by the shell model. In the case of proton removal from 22C, the 19B plus one- and two-neutron channels were consistent with the population of a resonance in 21B 2.47+-0.19 MeV above the two-neutron decay threshold, which is found to exhibit direct two-neutron decay. The ground-state mass excesses determined for 20,21B are found to be in agreement with mass surface extrapolations derived within the latest atomic-mass evaluations., Comment: Accepted for publication in Physical Review Letters. Supplemental Material at http://link.aps.org/supplemental/10.1103/PhysRevLett.121.262502
Published: 2018

40. Structure of $^{13}$Be studied in proton knockout from $^{14}$B

Author: Ribeiro, G., Nácher, E., Bemmerer, D., Benlliure, J., Bertulani, C. A., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Caesar, C., Casarejos, E., Catford, W., Tengblad, O., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Datta Pramanik, U., Dillmann, I., Elekes, Z., Enders, J., Díaz Fernández, P., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Gernhäuser, R., Golubev, P., Aksyutina, Y., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Hufnagel, A., Ignatov, A., Alvarez-Pol, H., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Kurz, N., Kröll, T., Labiche, M., Langer, C., Le Bleis, T., Atar, L., Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Movsesyan, A., Nilsson, T., Nociforo, C., Panin, V., Paschalis, S., Perea, A., Aumann, T., Petri, M., Pietri, S., Plag, R., Reifarth, R., Rigollet, C., Riisager, K., Rossi, D., Röder, M., Savran, D., Scheit, H., Avdeichikov, V., Simon, H., Sorlin, O., Syndikus, I., Taylor, J. T., Thies, R., Velho, P., Wagner, A., Wamers, F., Vandebrouck, M., Weick, H., Beceiro-Novo, S., Wheldon, C., Wilson, G., Wimmer, C., Winfield, J. S., Woods, P., Zhukov, M. V., Zilges, A., Zuber, K., and R3B Collaboration
Subjects: ddc:530
Published: 2018

41. Effective proton-neutron interaction near the drip line from unbound states in F-25,F-26

Author: Vandebrouck, M, Lepailleur, A, Sorlin, O, Aumann, T, Caesar, C, Holl, M, Panin, V, Wamers, F, Stroberg, SR, Holt, JD, Santos, FDO, Alvarez-Pol, H, Atar, L, Avdeichikov, V, Beceiro-Novo, S, Bemmerer, D, Benlliure, J, Bertulani, CA, Bogner, SK, Boillos, JM, Boretzky, K, Borge, MJG, Caamano, M, Casarejos, E, Catford, W, Cederkall, J, Chartier, M, Chulkov, L, Cortina-Gil, D, Cravo, E, Crespo, R, Pramanik, UD, Diaz Fernandez, P, Dillmann, I, Elekes, Z, Enders, J, Ershova, O, Estrade, A, Farinon, F, Fraile, LM, Freer, M, Galaviz, D, Geissel, H, Gernhaeuser, R, Gibelin, J, Golubev, P, Goebel, K, Hagdahl, J, Heftrich, T, Heil, M, Heine, M, Heinz, A, Henriques, A, Hergert, H, Hufnagel, A, Ignatov, A, Johansson, HT, Jonson, B, Kahlbow, J, Kalantar-Nayestanaki, N, Kanungo, R, Kelic-Heil, A, Knyazev, A, Kroll, T, Kurz, N, Labiche, M, Langer, C, Le Bleis, T, Lemmon, R, Lindberg, S, Machado, J, Marganiec, J, Marques, FM, Movsesyan, A, Nacher, E, Najafi, M, Nikolskii, E, Nilsson, T, Nociforo, C, Paschalis, S, Perea, A, Petri, M, Pietri, S, Plag, R, Reifarth, R, Ribeiro, G, Rigollet, C, Roeder, M, Rossi, D, Savran, D, Scheit, H, Schwenk, A, Simon, H, Syndikus, I, Taylor, JT, Tengblad, O, Thies, R, Togano, Y, Velho, P, Volkov, V, Wagner, A, Weick, H, Wheldon, C, Wilson, G, Winfield, JS, Woods, P, Yakorev, D, Zhukov, M, Zilges, A, Zuber, K, and Collaboration, R
Published: 2017

42. Effective proton-neutron interaction near the drip line from unbound states in 25,26 F

Author: Vandebrouck, M., Lepailleur, A., Sorlin, O, Aumann, T., Caesar, C., Holl, M., Panin, V., Wamers, F., Stroberg, S. R., Holt, J. D., De Oliveira Santos, F., Alvarez-Pol, H., Atar, L., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Bogner, S. K., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamaño, M., Casarejos, E., Catford, W, Cederkäll, J., Chartier, M., Chulkov, L. V., Cortina-Gil, D, Cravo, E., Crespo, R., Datta Pramanik, U., Díaz Fernández, P., Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estradé, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz, D., Geissel, H, Gernhäuser, R., Gibelin, J., Golubev, P., Göbel, K., Hagdahl, J., Paschalis, S., and Petri, M.
Subjects: Nuclear Theory, Nuclear Experiment
Abstract: Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The F26 nucleus, composed of a deeply bound π0d5/2 proton and an unbound ν0d3/2 neutron on top of an O24 core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a Jπ=11+-41+ multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The Jπ=11+,21+,41+ bound states have been determined, and only a clear identification of the Jπ=31+ is missing. Purpose: We wish to complete the study of the Jπ=11+-41+ multiplet in F26, by studying the energy and width of the Jπ=31+ unbound state. The method was first validated by the study of unbound states in F25, for which resonances were already observed in a previous experiment. Method: Radioactive beams of Ne26 and Ne27, produced at about 440AMeV by the fragment separator at the GSI facility were used to populate unbound states in F25 and F26 via one-proton knockout reactions on a CH2 target, located at the object focal point of the R3B/LAND setup. The detection of emitted γ rays and neutrons, added to the reconstruction of the momentum vector of the A-1 nuclei, allowed the determination of the energy of three unbound states in F25 and two in F26. Results: Based on its width and decay properties, the first unbound state in F25, at the relative energy of 49(9) keV, is proposed to be a Jπ=1/2- arising from a p1/2 proton-hole state. In F26, the first resonance at 323(33) keV is proposed to be the Jπ=31+ member of the Jπ=11+-41+ multiplet. Energies of observed states in F25,26 have been compared to calculations using the independent-particle shell model, a phenomenological shell model, and the ab initio valence-space in-medium similarity renormalization group method. Conclusions: The deduced effective proton-neutron interaction is weakened by about 30-40% in comparison to the models, pointing to the need for implementing the role of the continuum in theoretical descriptions or to a wrong determination of the atomic mass of F26.
Published: 2017

43. Effective proton-neutron interaction near the drip line from unbound states in $^{25,26}$F

Author: Vandebrouck, M., Lepailleur, A., Sorlin, O., Aumann, T., Caesar, C., Holl, M., Panin, V., Wamers, F., Stroberg, S. R., Holt, J. D., de Oliveira Santos, F., Alvarez-Pol, H., Atar, L., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Bogner, S. K., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamaño, M., Casarejos, E., Catford, W., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Datta Pramanik, U., Díaz Fernández, P., Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estradé, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz, D., Geissel, H., Gernhäuser, R., Gibelin, J., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M. (Marcel), Heinz, A., Henriques, A., Hergert, H., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Le Bleis, T., Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Marqués, F. M., Movsesyan, A., Nacher, E., Najafi, M., Nikolskii, E., Nilsson, T., Nociforo, C., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Röder, M., Rossi, D., Savran, D., Scheit, H., Schwenk, A., Simon, H., Syndikus, I., Taylor, J. T., Tengblad, O., Thies, R., Togano, Y., Velho, P., Volkov, V., Wagner, A., Weick, H., Wheldon, C., Wilson, G., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., Zuber, K., Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), R3B Collaboration, 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)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 21.10.-k, Nuclear Theory, Aucun, Coulomb dissociation radioactive beam, FOS: Physical sciences, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, 27.30.+t, 25.60.-t, 29.30.Hs
Abstract: Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The $^{26}$F nucleus, composed of a deeply bound $\pi0d\_{5/2}$ proton and an unbound $\nu0d\_{3/2}$ neutron on top of an $^{24}$O core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The $J^{\pi} = 1^{+}\_1, 2^{+}\_1,4^{+}\_1$ bound states have been determined, and only a clear identification of the $J^{\pi} =3^{+}\_1$ is missing.Purpose: We wish to complete the study of the $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet in $^{26}$F, by studying the energy and width of the $J^{\pi} =3^{+}\_1$ unbound state. The method was firstly validated by the study of unbound states in $^{25}$F, for which resonances were already observed in a previous experiment.Method: Radioactive beams of $^{26}$Ne and $^{27}$Ne, produced at about $440A$\,MeV by the FRagment Separator at the GSI facility, were used to populate unbound states in $^{25}$F and $^{26}$F via one-proton knockout reactions on a CH$\_2$ target, located at the object focal point of the R$^3$B/LAND setup. The detection of emitted $\gamma$-rays and neutrons, added to the reconstruction of the momentum vector of the $A-1$ nuclei, allowed the determination of the energy of three unbound states in $^{25}$F and two in $^{26}$F. Results: Based on its width and decay properties, the first unbound state in $^{25}$F is proposed to be a $J^{\pi} = 1/2^-$ arising from a $p\_{1/2}$ proton-hole state. In $^{26}$F, the first resonance at 323(33)~keV is proposed to be the $J^{\pi} =3^{+}\_1$ member of the $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet. Energies of observed states in $^{25,26}$F have been compared to calculations using the independent-particle shell model, a phenomenological shell-model, and the ab initio valence-space in-medium similarity renormalization group method.Conclusions: The deduced effective proton-neutron interaction is weakened by about 30-40\% in comparison to the models, pointing to the need of implementing the role of the continuum in theoretical descriptions, or to a wrong determination of the atomic mass of $^{26}$F., Comment: 14 pages, 7 figures, 3 tables, submitted to PRC
Published: 2017

44. Corrigendum to 'Single-neutron knockout from $^{20}$C and the structure of $^{20}$C' [Phys. Lett. B 769 (2017) 503–508]

Author: Hwang, J. W., Kim, S., Delaunay, F., Doornenbal, P., Fukuda, N., Inabe, N., Isobe, T., Kameda, D., Kanno, D., Kobayashi, N., Kobayashi, T., Kubo, T., Satou, Y., Leblond, S., Lee, J., Marqués, F. M., Minakata, R., Motobayashi, T., Murai, D., Murakami, T., Muto, K., Nakashima, T., Nakatsuka, N., Orr, N. A., Navin, A., Nishi, S., Ogoshi, S., Otsu, H., Sato, H., Shimizu, Y., Suzuki, H., Takahashi, K., Takeda, H., Takeuchi, S., Kondo, Y., Tanaka, R., Togano, Y., Tuff, A. G., Vandebrouck, M., Yoneda, K., Nakamura, T., Gibelin, J., Achouri, N. L., Aumann, T., and Baba, H.
Subjects: ddc:530
Abstract: Physics letters / B 774, 723 - (2017). doi:10.1016/j.physletb.2017.08.072, Published by North-Holland Publ., Amsterdam
Published: 2017
Full Text: View/download PDF

45. Single-neutron knockout from $^{20}\textrm{C}$ and the structure of $^{19}\textrm{C}$

Author: Hwang, J.W., Kim, S., Satou, Y., Orr, N.A., Kondo, Y., Nakamura, T., Gibelin, J., Achouri, N.L., Aumann, T., Baba, H., Delaunay, F., Doornenbal, P., Fukuda, N., Inabe, N., Isobe, T., Kameda, D., Kanno, D., Kobayashi, N., Kobayashi, T., Kubo, T., Leblond, S., Lee, J., Marqués, F.M., Minakata, R., Motobayashi, T., Murai, D., Murakami, T., MUTO, K., Nakashima, T., Nakatsuka, N., Navin, A., Nishi, S., Ogoshi, S., Otsu, H., Sato, H., Shimizu, Y., Suzuki, H., Takahashi, K., Takeda, H., Takeuchi, S., Tanaka, R., Togano, Y., Tuff, A.G., Vandebrouck, M., Yoneda, K., Laboratoire de physique corpusculaire de Caen ( LPCC ), Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Ecole 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 ), 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 ), 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), 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), 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), 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)-Centre National de la Recherche Scientifique (CNRS), 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: Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, Heavy-ion knockout, Shell evolution, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Theory (nucl-th), Invariant mass spectroscopy, Nuclear Experiment (nucl-ex), [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, [ PHYS.NUCL ] Physics [physics]/Nuclear Theory [nucl-th]
Abstract: The low-lying unbound level structure of the halo nucleus $^{19}\textrm{C}$ has been investigated using single-neutron knockout from $^{20}\textrm{C}$ on a carbon target at 280 MeV/nucleon. The invariant mass spectrum, derived from the momenta of the forward going beam velocity $^{18}\textrm{C}$ fragment and neutrons, was found to be dominated by a very narrow near threshold ($E_\textrm{rel}$ = 0.036(1) MeV) peak. Two less strongly populated resonance-like features were also observed at $E_\textrm{rel}$ = 0.84(4) and 2.31(3) MeV, both of which exhibit characteristics consistent with neutron $p$-shell hole states. Comparisons of the energies, measured cross sections and parallel momentum distributions to the results of shell-model and eikonal reaction calculations lead to spin-parity assignments of $5/2^+_1$ and $1/2^-_1$ for the levels at $E_x$ = 0.62(9) and 2.89(10) MeV with $S_n$ = 0.58(9) MeV. Spectroscopic factors were also deduced and found to be in reasonable accord with shell-model calculations. The valence neutron configuration of the $^{20}\textrm{C}$ ground state is thus seen to include, in addition to the known $1s^2_{1/2}$ component, a significant $0d^2_{5/2}$ contribution. The level scheme of $^{19}\textrm{C}$, including significantly the $1/2^-_1$ cross-shell state, is well accounted for by the YSOX shell-model interaction developed from the monopole-based universal interaction., Physics Letters B, in press
Published: 2017

46. Effective proton-neutron interaction near the drip line from unbound states in F-25,F-26

Author: Vandebrouck, M., Lepailleur, A., Álvarez-Pol, H., Benlliure, J., Boillos, J.M., García Borge, María José, Caamaño, M., Casarejos, E., Cortina-Gil, D., Fraile, L.M., Galaviz, D., Nácher, Enrique, Perea, Ángel, Ribeiro, Guillermo, Tengblad, Olof, Zuber, K., National Research Council of Canada, Natural Sciences and Engineering Research Council of Canada, National Science Foundation (US), European Research Council, European Commission, German Research Foundation, Federal Ministry of Education and Research (Germany), Ministerio de Economía y Competitividad (España), Fundação para a Ciência e a Tecnologia (Portugal), Ohio Supercomputer Center, Michigan State University, Helmholtz International Center for FAIR, State of Hesse, and Department of Energy (US)
Abstract: M. Vandebrouck et al. -- 13 pags., 7 figs., 3 tabs., Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The F-26 nucleus, composed of a deeply bound pi 0d(5/2) proton and an unbound v0d(3/2) neutron on top of an O-24 core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a J(pi) = 1(1)(+) - 4(1)(+) multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The J(pi) = 1(1)(+), 2(1)(+), 4(1)(+) bound states have been determined, and only a clear identification of the J(pi) = 3(1)(+) is missing. Purpose: We wish to complete the study of the J(pi) = 1(1)(+) - 4(1)(+) multiplet in F-26, by studying the energy and width of the J(pi) = 3(1)(+) unbound state. The method was first validated by the study of unbound states in F-25, for which resonances were already observed in a previous experiment. Method: Radioactive beams of Ne-26 and Ne-27, produced at about 440AMeV by the fragment separator at the GSI facility were used to populate unbound states in F-25 and F-26 via one-proton knockout reactions on a CH2 target, located at the object focal point of the (RB)-B-3/LAND setup. The detection of emitted. rays and neutrons, added to the reconstruction of the momentum vector of the A - 1 nuclei, allowed the determination of the energy of three unbound states in F-25 and two in F-26. Results: Based on its width and decay properties, the first unbound state in F-25, at the relative energy of 49(9) keV, is proposed to be a J(pi) = 1/ 2(-) arising from a p1/2 proton- hole state. In F-26, the first resonance at 323(33) keV is proposed to be the J(pi) = 3(1)(+) member of the J(pi) = 1(1)(+) - 4(1)(+) multiplet. Energies of observed states in F-25,F-26 have been compared to calculations using the independent-particle shell model, a phenomenological shell model, and the ab initio valence-space in-medium similarity renormalization group method. Conclusions: The deduced effective proton- neutron interaction is weakened by about 30-40% in comparison to the models, pointing to the need for implementing the role of the continuum in theoretical descriptions or to a wrong determination of the atomic mass of F-26, TRIUMF receives funding via a contribution through the National Research Council of Canada. This work was supported in part by NSERC, the NUCLEI SciDAC Collaboration under the US Department of Energy Grants No. DE-SC0008533 and No. DE-SC0008511, the National Science Foundation under Grant No. PHY-1404159, the European Research Council Grant No. 307986 STRONGINT, the Deutsche Forschungsgesellschaft under Grant No. SFB 1245, and the BMBF under Contracts No. 05P15RDFN1 and No. 05P15WOFNA. This work has also been supported by the Spanish MINECO via Projects No. FPA2013-41267-P, No. FPA2015-64969-P, and No. FPA2015-65035-P and by the Portuguese FCT, Project No. PTDC/FIS/103902/2008. Computations were performed with an allocation of computing resources at the Jülich Supercomputing Center, Ohio Supercomputer Center (OSC), and the Michigan State University High Performance Computing Center (HPCC)/Institute for Cyber-Enabled Research (iCER). C. A. Bertulani acknowledges support fromUS DOE Grant No.DE-FG02-08ER41533 and the US NSF Grant No. 1415656. M. Petri acknowledges support from the Helmholtz International Center for FAIR within the framework of the LOEWE program launched by the State of Hesse
Published: 2017

47. Study of the 26Al(n,p)26Mg and 26Al(n,α)23Na reactions using the 27Al(p,p')27Al inelastic scattering reaction

Author: Benamara, S., De Séréville, N., Adsley, P., Laird, A. M., Hammache, F., Stefan, I., Roussel, P., Ancelin, S., Assié, M., Barton, C., Coc, A., Diget, C., Deloncle, I., Fox, S., Guillot, J., Hamadache, C., Kiener, J., Le Crom, B., Lefebvre, L., Lefebfre-Schuhl, A., Marquinez Duran, G., Mavilla, G., Morfouace, P., Mutschler, A., Nsangu, C. T., Perrot, L., Oulebsir, N., Sánchez-Benítez, M., Suzuki, D., Tatischeff, V., and Vandebrouck, M.
Abstract: 26Al was the first cosmic radioactivity ever detected in the galaxy as well as one of the first extinct radioactivity observed in refractory phases of meteorites. Its nucleosynthesis in massive stars is still uncertain mainly due to the lack of nuclear information concerning the 26Al(n,p)26Mg and 26 Al(n,α)23Na reactions. We report on a single and coincidence measurement of the 27Al(p,p')27Al(p)26Mg and 27Al(p,p')27Al(α)23Na reactions performed at the Orsay TANDEM facility aiming at the spectroscopy study of 27Al above the neutron threshold. Fourteen states are observed for the first time within 350 keV above the 26Al+n threshold.
Published: 2016

48. Proton-neutron interaction towards the drip line from the study of 26F unboud states

Author: Vandebrouck, M., Lion, Michel, Grand Accélérateur National d'Ions Lourds (GANIL), 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: [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2016

49. Isoscalar response of 68Ni to 88. Locations of breakup in reactions of light nuclei astrophysics using radioactive beams α-particle & deuteron probes

Author: Vandebrouck, M., Lion, Michel, Grand Accélérateur National d'Ions Lourds (GANIL), 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: [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2016

50. Spectroscopy of $^{28}$Na: shell evolution toward the drip line

Author: Lepailleur, A., Wimmer, K., Mutschler, A., Sorlin, O., Bader, V., Bancroft, C., Barofsky, D., Bastin, B., Baugher, T., Bazin, Dominique, Bildstein, V., Borcea, C., Borcea, R., Brown, B.A., Caceres, L., Gade, A., Gaudefroy, L., Grévy, S., Grinyer, G.F., Iwasaki, H., Khan, E., Kröll, T., Langer, C., Lemasson, A., Llidoo, O., Lloyd, J., Negoita, F., de Oliveira Santos, Francois, Perdikakis, G., Recchia, F., Redpath, T., Roger, T., Rotaru, F., Saenz, S., Saint-Laurent, M.G., Smalley, D., Sohler, D., Stanoiu, M., Stroberg, S.R., Thomas, J.C., Vandebrouck, M., Weisshaar, D., Westerberg, A., 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), 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), 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 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), GANILEXP, 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), 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 Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 21.60.Cs, FOS: Physical sciences, 23.20.Lv, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 27.30.+t, Nuclear Experiment
Abstract: Excited states in $^{28}$Na have been studied using the $\beta$-decay of implanted $^{28}$Ne ions at GANIL/LISE as well as the in-beam $\gamma$-ray spectroscopy at the NSCL/S800 facility. New states of positive (J$^{\pi}$=3,4$^+$) and negative (J$^{\pi}$=1-5$^-$) parity are proposed. The former arise from the coupling between 0d$\_{5/2}$ protons and a 0d$\_{3/2}$ neutron, while the latter are due to couplings with 1p$\_{3/2}$ or 0f$\_{7/2}$ neutrons. While the relative energies between the J$^{\pi}$=1-4$^+$ states are well reproduced with the USDA interaction in the N=17 isotones, a progressive shift in the ground state binding energy (by about 500 keV) is observed between $^{26}$F and $^{30}$Al. This points to a possible change in the proton-neutron 0d$\_{5/2}$-0d$\_{3/2}$ effective interaction when moving from stability to the drip line. The presence of J$^{\pi}$=1-4$^-$ negative parity states around 1.5 MeV as well as of a candidate for a J$^{\pi}$=5$^-$ state around 2.5 MeV give further support to the collapse of the N=20 gap and to the inversion between the 0f$\_{7/2}$ and 1p$\_{3/2}$ levels below Z=12. These features are discussed in the framework of Shell Model and EDF calculations, leading to predicted negative parity states in the low energy spectra of the $^{26}$F and $^{25}$O nuclei., Comment: Exp\'erience GANIL/LISE et NSCL/S800
Published: 2015

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