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291 results on '"Lewitowicz, M."'

1. Complete set of bound negative-parity states in the neutron-rich 18N nucleus

Author

Ziliani, S., Ciemała, M., Crespi, F. C. L., Leoni, S., Fornal, B., Suzuki, T., Otsuka, T., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clément, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, Ł. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kimi, Y. -H., Kmiecik, M., Lemasson, A., Lewitowicz, M., Lenzi, S., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Müller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., and Zielinska, M.

Subjects
Nuclear Experiment
Abstract

High-resolution gamma-ray spectroscopy of 18N is performed with the Advanced GAmma Tracking Array AGATA, following deep-inelastic processes induced by an 18O beam on a 181Ta target. Six states are newly identified, which together with the three known excitations exhaust all negative-parity excited states expected in 18N below the neutron threshold. Spin and parities are proposed for all located states on the basis of decay branchings and comparison with large-scale shell-model calculations performed in the p-sd space, with the YSOX interaction. Of particular interest is the location of the 0^-_1 and 1^-_2 excitations, which provide strong constrains for cross-shell p-sd matrix elements based on realistic interactions, and help to simultaneously reproduce the ground and first-excited states in 16N and 18N, for the first time. Understanding the 18N structure may also have significant impact on neutron-capture cross-section calculations in r-process modeling including light neutron-rich nuclei.

Published
2021
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2. Accessing tens-to-hundreds femtoseconds nuclear state lifetimes with low-energy binary heavy-ion reactions

Author

Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y. -H., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., and Zielinska, M.

Subjects
Nuclear Experiment
Abstract

A novel Monte Carlo technique has been developed to determine lifetimes of excited states in the tens-to-hundreds femtoseconds range. The method is applied to low-energy heavy-ion binary reactions populating nuclei with complex velocity distributions. Its relevance is demonstrated in connection with the $^{18}$O(7.0 MeV/u) + $^{181}$Ta experiment, performed at GANIL with the AGATA+VAMOS+PARIS setup, to study neutron-rich O, C, N, ... nuclei. Excited states in $^{17}$O and $^{19}$O, with known lifetimes, are used to validate the method over the $\sim$20-400 fs lifetime-sensitivity range. Emphasis is given to the unprecedented position resolution provided by $\gamma$-tracking arrays, which turns out to be essential for reaching the required accuracy in Doppler-shift correction, at the basis of the detailed analysis of $\gamma$-ray lineshape and resulting state lifetime determination. The technique is anticipated to be an important tool for lifetime investigations in exotic neutron-rich nuclei, produced with intense ISOL-type beams.

Published
2020
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3. Testing ab initio nuclear structure in neutron-rich nuclei: lifetime measurements of second 2+ states in 16C and 20O

Author

Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., de France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., Atac, A., Barrientos, D., Birkenbach, B., Boston, A. J., Cederwall, B., Charles, L., Collado, J., Cullen, D. M., Desesquelles, P., Domingo-Pardo, C., Dudouet, J., Eberth, J., Gonzalez, V., Goupil, J., Harkness-Brennan, L. J., Hess, H., Judson, D. S., Jungclaus, A., Korten, W., Labiche, M., Lefevre, A., Menegazzo, R., Mengoni, D., Nyberg, J., Perez-Vidal, R. M., Podolyak, Zs., Pullia, A., Recchia, F., Reiter, P., Saillant, F., Salsac, M. D., Sanchis, E., Stezowski, O., Theisen, Ch., Valiente-Dobon, J. J., Holt, J. D., Menendez, J., Schwenk, A., and Simonis, J.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2+ state in neutron-rich 20O, tau(2+_2 ) = 150(+80-30) fs, and an estimate for the lifetime of the second 2+ state in 16C have been obtained, for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds femtoseconds range, by analyzing the Doppler-shifted gamma-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction 18O (7.0 MeV/u) + 181Ta. The requested sensitivity could only be reached owing to the excellent performances of the AGATA gamma-tracking array, coupled to the PARIS scintillator array and to the VAMOS++ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two- and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for 20O, and with the no-core shell model for 16C. The present measurement shows the power of electromagnetic observables, determined with high-precision gamma spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetimes measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense ISOL-type beams become available.

Published
2020
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4. High Precision Measurement of the $^{19}$Ne Half-life using real-time digital acquisition

Author

Fontbonne, C., Ujić, P., Santos, F. de Oliveira, Fléchard, X., Rotaru, F., Achouri, N. L., Alcindor, V. Girard, Bastin, B., Boulay, F., Briand, J. B., Sánchez-Benítez, A. M., Bouzomita, H., Borcea, C., Borcea, R., Blank, B., Carniol, B., Čeliković, I., Delahaye, P., Delaunay, F., Etasse, D., Fremont, G., de France, G., Fontbonne, J. M., Grinyer, G. F., Harang, J., Hommet, J., Jevremović, A., Lewitowicz, M., Martel, I., Mrazek, J., Parlog, M., Poincheval, J., Ramos, D., Spitaels, C., Stanoiu, M., Thomas, J. C., and Toprek, D.

Subjects
Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

The half-life of $^{19}$Ne has been measured using a real-time digital multiparametric acquisition system providing an accurate time-stamp and relevant information on the detectors signals for each decay event. An exhaustive offline analysis of the data gave unique access to experimental effects potentially biasing the measurement. After establishing the influence factors impacting the measurement such as after-pulses, pile-up, gain and base line fluctuations, their effects were accurately estimated and the event selection optimized. The resulting half-life, $17.2569\pm0.0019_{(stat)}\pm0.0009_{(syst)}$~s, is the most precise up to now for $^{19}$Ne. It is found in agreement with two recent precise measurements and not consistent with the most recent one [L.J. Broussard {\it et al.}, Phys. Rev. Lett. {\bf112}, 212301 (2014)] by 3.0 standard deviations. The full potential of the technique for nuclei with half-lives of a few seconds is discussed., Comment: 11 pages, 16 figures

Published
2017
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5. Nuclear structure studies of $^{24}$F

Author

Caceres, L., Lepailleur, A., Sorlin, O., Stanoiu, M., Sohler, D., Dombradi, Zs., Bogner, S. K., Brown, B. A., Hergert, H., Holt, J. D., Schwenk, A., Azaiez, F., Bastin, B., Borcea, C., Borcea, R., Bourgeois, C., Elekes, Z., Fülöp, Zs., Grévy, S., Gaudefroy, L., Grinyer, G. F., Guillemaud-Mueller, D., Ibrahim, F., Kerek, A., Krasznahorkay, A., Lewitowicz, M., Lukyanov, S. M., Mrazek, J., Negoita, F., De Oliveira, F., Penionzhkevich, Yu. -E., Podolyak, Zs., Porquet, M. G., Rotaru, F., Roussel-Chomaz, P., Saint-Laurent, M. G., Savajols, H., Sletten, G., Thomas, J. C., Timar, J., Timis, C., and Vajta, Zs.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The structure of the $^{24}$F nucleus has been studied at GANIL using the $\beta$ decay of $^{24}$O and the in-beam $\gamma$-ray spectroscopy from the fragmentation of projectile nuclei. Combining these complementary experimental techniques, the level scheme of $^{24}$F has been constructed up to 3.6 Mev by means of particle-$\gamma$ and particle-$\gamma\gamma$ coincidence relations. Experimental results are compared to shell-model calculations using the standard USDA and USDB interactions as well as ab-initio valence-space Hamiltonians calculated from the in-medium similarity renormalization group based on chiral two- and three-nucleon forces. Both methods reproduce the measured level spacings well, and this close agreement allows unidentified spins and parities to be consistently assigned., Comment: 5 figures, 2 tables

Published
2015

6. Probing Nuclear forces beyond the drip-line using the mirror nuclei $^{16}$N and $^{16}$F

Author

Stefan, I., Santos, F. de Oliveira, Sorlin, O., Davinson, T., Lewitowicz, M., Dumitru, G., Angélique, J. C., Angélique, M., Berthoumieux, E., Borcea, C., Borcea, R., Buta, A., Daugas, J. M., De Grancey, F., Fadil, M., Grévy, S., Kiener, J., Lefebvre-Schuhl, A., Lenhardt, M., Mrazek, J., Negoita, F., Pantelica, D., Pellegriti, M. G., Perrot, L., Ploszajczak, M., Roig, O., Laurent, M. G. Saint, Ray, I., Stanoiu, M., Stodel, C., Tatischeff, V., and Thomas, J. C.

Subjects
Nuclear Experiment
Abstract

Radioactive beams of $^{14}$O and $^{15}$O were used to populate the resonant states 1/2$^+$, 5/2$^+$ and $0^-,1^-,2^-$ in the unbound $^{15}$F and $^{16}$F nuclei respectively by means of proton elastic scattering reactions in inverse kinematics. Based on their large proton spectroscopic factor values, the resonant states in $^{16}$F can be viewed as a core of $^{14}$O plus a proton in the 2s$_{1/2}$ or 1d$_{5/2}$ shell and a neutron in 1p$_{1/2}$. Experimental energies were used to derive the strength of the 2s$_{1/2}$-1p$_{1/2}$ and 1d$_{5/2}$-1p$_{1/2}$ proton-neutron interactions. It is found that the former changes by 40% compared with the mirror nucleus $^{16}$N, and the second by 10%. This apparent symmetry breaking of the nuclear force between mirror nuclei finds explanation in the role of the large coupling to the continuum for the states built on an $\ell=0$ proton configuration., Comment: 6 pages, 3 figures, 2 tables, accepted for publication as a regular article in Physical Review C

Published
2014
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7. Excited states in the neutron-rich nucleus 25F

Author

Vajta, Zs., Stanoiu, M., Sohler, D., Jansen, G. R., Azaiez, F., Dombrádi, Zs., Sorlin, O., Brown, B. A., Belleguic, M., Borcea, C., Bourgeois, C., Dlouhy, Z., Elekes, Z., ülöp, Zs. F, Grévy, S., Guillemaud-Mueller, D., Hagen, G., Hjorth-Jensen, M., Ibrahim, F., Kerek, A., Krasznahorkay, A., Lewitowicz, M., Lukyanov, S. M., Mandal, S., Mayet, P., Mrázek, J., Negoita, F., Penionzhkevich, Yu. -E., Podolyák, Zs., Roussel-Chomaz, P., Saint-Laurent, M. G., Savajols, H., Sletten, G., Timár, J., Timis, C., and Yamamoto, A.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The structure of the nucleus 25F was investigated through in-beam {\gamma}-ray spectroscopy of the fragmentation of 26Ne and 27,28Na ion beams. Based on the particle-{\gamma} and particle-{\gamma}{\gamma} coincidence data, a level scheme was constructed and compared with shell model and coupled-cluster calculations. Some of the observed states were interpreted as quasi single-particle states built on top of the closed-shell nucleus 24O, while the others were described as states arising from coupling of a single proton to the 2+ core excitation of 24O., Comment: 8 pages, 4 figures and 1 table

Published
2014
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8. Production cross section measurements of radioactive isotopes by BigRIPS separator at RIKEN RI Beam Factory

Author

Suzuki, H., Kubo, T., Fukuda, N., Inabe, N., Kameda, D., Takeda, H., Yoshida, K., Kusaka, K., Yanagisawa, Y., Ohtake, M., Sato, H., Shimizu, Y., Baba, H., Kurokawa, M., Ohnishi, T., Tanaka, K., Tarasov, O. B., Bazin, D., Morrissey, D. J., Sherrill, B. M., Ieki, K., Murai, D., Iwasa, N., Chiba, A., Ohkoda, Y., Ideguchi, E., Go, S., Yokoyama, R., Fujii, T., Nishimura, D., Nishibata, H., Momota, S., Lewitowicz, M., DeFrance, G., Celikovic, I., and Steiger, K.

Subjects
Nuclear Experiment
Abstract

We have measured the production rates and production cross sections for a variety of radioactive isotopes which were produced from 124Xe, 48Ca, and 238U beams at an energy of 345 MeV/nucleon using the BigRIPS separator at the RIKEN Nishina Center RI Beam Factory (RIBF). Proton-rich isotopes with atomic numbers Z = 40 to 52 and neutron-rich isotopes with Z = 5 to 16 were produced by projectile fragmentation of the 124Xe and 48Ca beam on Be targets, respectively. Neutron-rich isotopes with Z = 20 to 59 were produced by in-flight fission of the 238U beam, in which both Be and Pb were used as production targets. The measured production rates and production cross sections were compared with those of the LISE++ calculations, and overall fairly good agreement has been obtained. Furthermore, in the measurements with the 124Xe beam, we have discovered four new isotopes on the proton-drip line, 85,86Ru and 81,82Mo, and obtained the clear evidence that 103Sb is particle unbound with an upper limit of 49 ns for the half-life. The measurements of projectile-fragment momentum distributions have been also performed with the 124Xe beam, in which the low-momentum tails of the distributions have been measured for the first time at the energy of 345 MeV/nucleon.

Published
2013
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9. Search for Superscreening effect in Superconductor

Author

Ujic, P., Santos, F. de Oliveira, Lewitowicz, M., Achouri, L., Assié, M., Bastin, B., Borcea, C., Borcea, R., Buta, A., Coc, A., De France, G., Kamalou, O., Kiener, J., Lepailleur, A., Meot, V., Pautrat, A., Laurent, M. G. Saint, Sorlin, O., Stanoiu, M., and Tatischef, V.

Subjects
Nuclear Experiment
Abstract

The decay of $^{19}$O($\beta^-$) and $^{19}$Ne($\beta^+$) implanted in niobium in its superconducting and metallic phase was measured using purified radioactive beams produced by the SPIRAL/GANIL facility. Half-lives and branching ratios measured in the two phases are consistent within one-sigma error bar. This measurement casts strong doubts on the predicted strong electron screening in superconductor, the so-called superscreening. The measured difference in screening potential energy is 110(90) eV for $^{19}$Ne and 400(320) eV for $^{19}$O. Precise determinations of the half-lives were obtained for $^{19}$O: 26.476(9) s and $^{19}$Ne: 17.254(5) s., Comment: 4 pages, 3 figures, accepted for publication in Physical Review Letters

Published
2012
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10. Spectroscopy of $^{26}$F

Author

Stanoiu, M., Sohler, D., Sorlin, O., Dombradi, Zs., Azaiez, F., Brown, B. A., Borcea, C., Bourgeois, C., Elekes, Z., Fülöp, Zs., Grévy, S., Guillemaud-Mueller, D., Ibrahim, F., Kerek, A., Krasznahorkay, A., Lewitowicz, M., Lukyanov, S. M., Mrazek, J., Negoita, F., Penionzhkevich, Yu. -E., Podolyak, Zs., Porquet, M. G., Roussel-Chomaz, P., Saint-Laurent, M. G., Savajols, H., Sletten, G., Timar, J., and Timis, C.

Subjects
Nuclear Experiment
Abstract

The structure of the weakly-bound $^{26}_{\;\;9}$F$_{17}$ odd-odd nucleus, produced from $^{27,28}$Na nuclei, has been investigated at GANIL by means of the in-beam $\gamma$-ray spectroscopy technique. A single $\gamma$-line is observed at 657(7) keV in $^{26}_{9}$F which has been ascribed to the decay of the excited J=$2^+$ state to the J=1$^+$ ground state. The possible presence of intruder negative parity states in $^{26}$F is also discussed., Comment: 3 pages, 1 figure, accepted for publication in Physical Review C

Published
2012
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11. The beta-decay of 22Al

Author

Achouri, N. L., Santos, F. de Oliveira, Lewitowicz, M., Blank, B., Aysto, J., Canchel, G., Czajkowski, S., Dendooven, P., Emsallem, A., Giovinazzo, J., Guillet, N., Jokinen, A., Laird, A. M., Longour, C., Perajarvi, K., Smirnova, N., Stanoiu, M., and Thomas, J. C.

Subjects
Nuclear Experiment
Abstract

In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22Al produced by the fragmentation of a 36Ar primary beam. A beta-decay half-life of 91.1 +- 0.5 ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of 4+ for the ground state of 22Al.

Published
2006
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12. New pathway to bypass the 15O waiting point

Author

Stefan, I., Santos, F. de Oliveira, Pellegriti, M. G., Dumitru, G., Angélique, J. C., Angélique, M., Berthoumieux, E., Buta, A., Borcea, R., Coc, A., Daugas, J. M., Davinson, T., Fadil, M., Grévy, S., Kiener, J., Lefebvre-Schuhl, A., Lenhardt, M., Lewitowicz, M., Negoita, F., Pantelica, D., Perrot, L., Roig, O., Laurent, M. G. Saint, Ray, I., Sorlin, O., Stanoiu, M., Stodel, C., Tatischeff, V., and Thomas, J. C.

Subjects
Nuclear Experiment
Abstract

We propose the sequential reaction process $^{15}$O($p$,$\gamma)(\beta^{+}$)$^{16}$O as a new pathway to bypass of the $^{15}$O waiting point. This exotic reaction is found to have a surprisingly high cross section, approximately 10$^{10}$ times higher than the $^{15}$O($p$,$\beta^{+}$)$^{16}$O. These cross sections were calculated after precise measurements of energies and widths of the proton-unbound $^{16}$F low lying states, obtained using the H($^{15}$O,p)$^{15}$O reaction. The large $(p,\gamma)(\beta^{+})$ cross section can be understood to arise from the more efficient feeding of the low energy wing of the ground state resonance by the gamma decay. The implications of the new reaction in novae explosions and X-ray bursts are discussed., Comment: submitted

Published
2006
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13. Beta-decay properties of $^{25}$Si and $^{26}$P

Author

Thomas, J. -C., Achouri, L., Aysto, J., Beraud, R., Blank, B., Canchel, G., Czajkowski, S., Dendooven, P., Ensallem, A., Giovinazzo, J., Guillet, N., Honkanen, J., Jokinen, A., Laird, A., Lewitowicz, M., Longour, C., Santos, F. De Oliveira, Perajarvi, K., and Stanoiu, M.

Subjects
Nuclear Experiment
Abstract

The $\beta$-decay properties of the neutron-deficient nuclei $^{25}$Si and $^{26}$P have been investigated at the GANIL/LISE3 facility by means of charged-particle and $\gamma$-ray spectroscopy. The decay schemes obtained and the Gamow-Teller strength distributions are compared to shell-model calculations based on the USD interaction. B(GT) values derived from the absolute measurement of the $\beta$-decay branching ratios give rise to a quenching factor of the Gamow-Teller strength of 0.6. A precise half-life of 43.7 (6) ms was determined for $^{26}$P, the $\beta$- (2)p decay mode of which is described.

Published
2004
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14. On the two-proton emission for Fe45 - a new type of radioactivity

Author

Giovinazzo, J., Blank, B., Chartier, M., Czajkowski, S., Fleury, A., Jimenez, M. J. Lopez, Pravikoff, M. S., Thomas, J. -C., Santos, F. De Oliveira, Lewitowicz, M., Maslov, V., Stanoiu, M., Grzywacz, R., Pfutzner, M., Borcea, C., and Brown, B. A.

Subjects
Nuclear Experiment
Abstract

In an experiment at the SISSI-LISE3 facility of GANIL, the decay of the proton drip-line nucleus Fe45 has been studied after projectile fragmentation of a Ni58 primary beam at 75 MeV/nucleon impinging on a natural nickel target. Fragment-implantation events have been correlated with radioactive decay events in a 16x16 pixel silicon strip detector on an event-by-event basis. The decay-energy spectrum of Fe45 implants shows a distinct peak at (1.06+/-0.04)MeV with a half-life of T1/2 = (4.7+3.4-1.4)ms. None of the events in this peak is in coincidence with beta particles which were searched for in a detector next to the implantation detector. For a longer correlation interval, daughter decays of the two-proton daughter Cr43 can be observed after Fe45 implantation. The decay energy for Fe45 agrees nicely with several theoretical predictions for two-proton emission. Barrier-penetration calculations slightly favour a di-proton emission picture over an emission of two individual protons and point thus to a He2 emission mode., Comment: 4 pages, 5 figures, sumitted to PRL

Published
2002
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15. First observation of 55,56Zn

Author

Giovinazzo, J., Blank, B., Borcea, C., Chartier, M., Czajkowski, S., de France, G., Grzywacz, R., Janas, Z., Lewitowicz, M., Santos, F. de Oliveira, Pf"utzner, M., Pravikoff, M. S., and Thomas, J. C.

Subjects
Nuclear Experiment
Abstract

In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich zinc isotopes 55,56Zn have been observed for the first time. The experiment was performed using a high-intensity 58Ni beam at 74.5 MeV/nucleon impinging on a nickel target. The identification of 55,56Zn opens the way to 54Zn, a good candidate for two-proton radioactivity according to theoretical predictions., Comment: 2 pages, 1 figure, accepted for publication in Eur. Phys. J. A

Published
2000
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16. Decay of proton-rich nuclei between 39Ti and 49Ni

Author

Giovinazzo, J., Blank, B., Borcea, C., Chartier, M., Czajkowski, S., de France, G., Grzywacz, R., Janas, Z., Lewitowicz, M., Santos, F. de Oliveira, Pf"utzner, M., Pravikoff, M. S., and Thomas, J. C.

Subjects
Nuclear Experiment
Abstract

Decay studies of very neutron-deficient nuclei ranging from 39Ti to 49Ni have been performed during a projectile fragmentation experiment at the GANIL/LISE3 separator. For all nuclei studied in this work, 39,40Ti, 42,43Cr, 46Mn, 45,46,47Fe and 49Ni, half-lives and decay spectra have been measured. In a few cases, gamma coincidence measurements helped to successfully identify the initial and final states of transitions. In these cases, partial decay scheme are proposed. For the most exotic isotopes, 39Ti, 42Cr, 45Fe and 49Ni, which are candidates for two-proton radioactivity from the ground state, no clear evidence of this process is seen in our spectra and we conclude rather on a delayed particle decay., Comment: 12 pages, 15 figures, submitted for publication in Eur. Phys. J. A

Published
2000
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17. One-neutron removal reactions on neutron-rich psd-shell nuclei

Author

Sauvan, E., Carstoiu, F., Orr, N. A., Angelique, J. C., Catford, W. N., Clarke, N. M., Mac Cormick, M., Curtis, N., Freer, M., Grevy, S., Brun, C. Le, Lewitowicz, M., Liegard, E., Marques, F. M., Roussel-Chomaz, P., Laurent, M. G. Saint, Shawcross, M., and Winfield, J. S.

Subjects
Nuclear Experiment
Abstract

A systematic study of high energy, one-neutron removal reactions on 23 neutron-rich, psd--shell nuclei (Z=5-9, A=12-25) has been carried out. The longitudinal momentum distributions of the core fragments and corresponding single-neutron removal cross sections are reported for reactions on a carbon target. Extended Glauber model calculations, weighted by the spectroscopic factors obtained from shell model calculations, are compared to the experimental results. Conclusions are drawn regarding the use of such reactions as a spectroscopic tool and spin-parity assignments are proposed for 15B, 17C, 19-21N, 21,23O, 23-25F. The nature of the weakly bound systems 14B and 15,17C is discussed., Comment: 11 pages + 2 figures

Published
2000
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18. Crossing the Dripline to 11N Using Elastic Resonance Scattering

Author

Markenroth, K., Axelsson, L., Baxter, S., Borge, M. J. G., Donzaud, C., Fayans, S., Fynbo, H. O. U., Goldberg, V. Z., Grevy, S., Guillemaud-Mueller, D., Jonson, B., Kallman, K. -M., Leenhardt, S., Lewitowicz, M., Lonnroth, T., Manngard, P., Martel, I., Mueller, A. C., Mukha, I., Nilsson, T., Nyman, G., Orr, N. A., Riisager, K., Rogachev, G. V., Saint-Laurent, M. -G., Serikov, I. N., Shul'gina, N. B., Sorlin, O., Steiner, M., Tengblad, O., Thoennessen, M., Tryggestad, E., Trzaska, W. H., Wenander, F., Winfield, J. S., and Wolski, R.

Subjects
Nuclear Experiment
Abstract

The level structure of the unbound nucleus 11N has been studied by 10C+p elastic resonance scattering in inverse geometry with the LISE3 spectrometer at GANIL, using a 10C beam with an energy of 9.0 MeV/u. An additional measurement was done at the A1200 spectrometer at MSU. The excitation function above the 10C+p threshold has been determined up to 5 MeV. A potential-model analysis revealed three resonance states at energies 1.27 (+0.18-0.05) MeV (Gamma=1.44 +-0.2 MeV), 2.01(+0.15-0.05) MeV, (Gamma=0.84 +-$0.2 MeV) and 3.75(+-0.05) MeV, (Gamma=0.60 +-0.05 MeV) with the spin-parity assignments I(pi) =1/2+, 1/2- and 5/2+, respectively. Hence, 11N is shown to have a ground state parity inversion completely analogous to its mirror partner, 11Be. A narrow resonance in the excitation function at 4.33 (+-0.05) MeV was also observed and assigned spin-parity 3/2-., Comment: 14 pages, 9 figures, twocolumn Accepted for publication in PRC

Published
2000
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19. The Halo of 14Be

Author

Labiche, M., Orr, N. A., Marques, F. M., Angelique, J. C., Axelsson, L., Benoit, B., Bergmann, U. C., Borge, M. J. G., Catford, W. N., Chappell, S. P. G., Clarke, N. M., Costa, G., Curtis, N., D'Arrigo, A., Brennand, E. de Goes, Dorvaux, O., Fazio, G., Freer, M., Fulton, B. R., Giardina, G., Grevy, S., Guillemaud-Mueller, D., Hanappe, F., Jones, B. Heusch K. L., Jonson, B., Brun, C. Le, Leenhardt, S., Lewitowicz, M., Lopez, M. J., Markenroth, K., Mueller, A. C., Nilsson, T., Ninane, A., Nyman, G., de Oliveira, F., Piqueras, I., Riisager, K., Laurent, M. G. Saint, Sarazin, F., Singer, S. M., Sorlin, O., and Stuttge, L.

Subjects
Nuclear Experiment
Abstract

The two-neutron halo nucleus 14Be has been investigated in a kinematically complete measurement of the fragments (12Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross-sections, neutron angular distributions and invariant mass spectra characteristic of a halo were observed and the electromagnetic (EMD) contributions deduced. Comparison with three-body model predictions indicate that the halo wavefunction contains a large 2s1/2^2 admixture. The EMD invariant mass spectrum exhibited a relatively narrow structure near threshold (Edecay=1.8+/-0.1 MeV, Gamma = 0.8+/-0.4 MeV) consistent with a soft-dipole excitation., Comment: 17 pages, 3 figures

Published
2000

20. On the discovery of doubly-magic $^{48}$Ni

Author

Blank, B., Chartier, M., Czajkowski, S., Giovinazzo, J., Pravikoff, M. S., Thomas, J. -C., de France, G., Santos, F. de Oliveira, Lewitowicz, M., Borcea, C., Grzywacz, R., Janas, Z., and Pfützner, M.

Subjects
Nuclear Experiment
Abstract

The paper reports on the first observation of doubly-magic Nickel-48 in an experimental at the SISSI/LISE3 facility of GANIL. Four Nickel-48 isotopes were identified. In addition, roughly 100 Nickel-49, 50 Iron-45, and 290 Chromium-42 isotopes were observed. This opens the possibility to search for two-proton emission from these nuclei., Comment: 4 pages, 3 figures, accepted for publication in Phys. Rev. Lett

Published
1999
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21. Needs for a Comprehensive European Plan to Acquire and Curate Nuclear Data

Author

Körner, G.-E., (0000-0001-8041-549X) Dimitriou, P., (0000-0002-7209-2499) Boeltzig, A., Garbil, R., (0000-0002-1942-2911) Leray, S., (0000-0002-1292-7239) Lewitowicz, M., (0000-0003-0486-6023) Widmann, E., Körner, G.-E., (0000-0001-8041-549X) Dimitriou, P., (0000-0002-7209-2499) Boeltzig, A., Garbil, R., (0000-0002-1942-2911) Leray, S., (0000-0002-1292-7239) Lewitowicz, M., and (0000-0003-0486-6023) Widmann, E.

Abstract

A Consultant’s Meeting was held at the IAEA to discuss the needs for a comprehensive European plan to acquire and curate nuclear data. Participants representing nuclear data groups, the nuclear physics community (NuPECC), and the existing funding agency (EURATOM), reviewed the status of nuclear data curation in Europe, including coordination, funding, and capacity building. A summary of the discussions as well as the list of recommendations and actions are included in this report.

Published
2023

22. γ decay to the ground state from the excitations above the neutron threshold in the 208Pb(p,p'γ) reaction at 85 MeV

Author

Wasilewska, B., Kmiecik, M., Ciemała, M., Maj, A., Crespi, F. C.L., Bracco, A., Harakeh, M. N., Bednarczyk, P., Bottoni, S., Brambilla, S., Camera, F., Ciepał, I., Cieplicka-Oryńczak, N., Csatlos, M., Fornal, B., Gaudilla, V., Grȩbosz, J., Isaak, J., Iskra, W., Jeżabek, M., Krasznahorkay, A. J., Kihel, S., Krzysiek, M., Lasko, P., Leoni, S., Lewitowicz, M., Łukasik, J., Matejska-Minda, M., Mazurek, K., Napiorkowski, P. J., Parol, W., Pawłowski, P., Qi, L. Q., Saxena, M., Schmitt, Ch, Sobolev, Y., Sowicki, B., Stanoiu, M., Tamii, A., Wieland, O., and Ziȩbliński, M.

Abstract

A new measurement of γ decay from the states above the neutron threshold in Pb208 has been performed at Cyclotron Centre Bronowice in Kraków, Poland. The main goal of the experiment was to observe the γ decay to the ground state from the isoscalar giant quadrupole resonance (ISGQR). To this day, the only published observation of this phenomenon dates back to the late 1980s, where γ decay to the ground state branching ratio was reported. At variance with the existing measurement using inelastic scattering of O17, here proton inelastic scattering is employed. In particular, data were obtained for Pb208(p,p′γ) at 85 MeV beam energy, where γ rays were measured for proton scattering angles 8.9∘, 10.7∘, 12.5∘, and 14.3∘. By applying a similar analysis method as in the previous experiment, the branching ratio of ISGQR gamma decay to the ground state was extracted from the data.

Published
2022

23. The (6+) isomer in 102Sn revisited: Neutron and proton effective charges close to the double shell closure

Author

Grawe, H., Straub, K., Faestermann, T., Górska, M., Hinke, C., Krücken, R., Nowacki, F., Böhmer, M., Boutachkov, P., Geissel, H., Gernhäuser, R., Gottardo, A., Grȩbosz, J., Kurz, N., Liu, Z., Maier, L., Pietri, S., Podolyák, Zs., Steiger, K., Weick, H., Wollersheim, H.J., Woods, P.J., Al-Dahan, N., Alkhomashi, N., Ataç, A., Blazhev, A., Braun, N., Čeliković, I., Davinson, T., Dillmann, I., Domingo-Pardo, C., Doornenbal, P., Farrelly, G., Farinon, F., de France, G., Gerl, J., Goel, N., Habermann, T., Hoischen, R., Janik, R., Karny, M., Kaşkaş, A., Kojouharov, I., Kröll, Th., Lewitowicz, M., Litvinov, Yu.A., Myalski, S., Nebel, F., Nishimura, S., Nociforo, C., Nyberg, J., Parikh, A., Procházka, A., Regan, P.H., Rigollet, C., Schaffner, H., Scheidenberger, C., Schwertel, S., Söderström, P.-A., Steer, S., Stolz, A., and Strmeň, P.

Published
2021
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24. Lifetime analysis of short-lived states in $^{17}$N

Author

Ziliani, S., Ciemała, M., Crespi, F. C.L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Oryńczak, N., Clément, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grȩbosz, J., Harakeh, M. N., Iskra, W., Jacquot, B., Karpov, A., Kicińska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Müller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, C., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Ziȩbliński, M., Zielińska, M., 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 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 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 Laue-Langevin (ILL), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Ziliani, S., Ciemala, M., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, C., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., and Research unit Nuclear & Hadron Physics

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

International audience; A recent extension of the Doppler-shift attenuation method to measure short lifetimes of states populated in low-energy binary reactions is applied to the case of 17N. The reliability of the technique is confirmed by measuring the lifetime of the 5515 keV 3/2− state, which is depopulated by two different γ rays. The method is used to measure the lifetime of the 5170 keV (9/2+) state in the same nucleus. Comparisons with large-scale shell-model predictions are given as well.

Published
2020

25. Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2+ state in C 16 and O 20

Author

Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, C., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., Atac, A., Barrientos, D., Birkenbach, B., Boston, A. J., Cederwall, B., Charles, L., Collado, J., Cullen, D. M., Desesquelles, P., Domingo-Pardo, C., Dudouet, J., Eberth, J., Gonzalez, V., Goupil, J., Harkness-Brennan, L. J., Hess, H., Judson, D. S., Jungclaus, A., Korten, W., Labiche, M., Lefevre, A., Menegazzo, R., Mengoni, D., Nyberg, J., Perez-Vidal, R. M., Podolyak, Z., Pullia, A., Recchia, F., Reiter, P., Saillant, F., Salsac, M. D., Sanchis, E., Stezowski, O., Theisen, C., Valiente-Dobon, J. J., Holt, J. D., Menendez, J., Schwenk, A., Simonis, J., Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, C., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., Atac, A., Barrientos, D., Birkenbach, B., Boston, A. J., Cederwall, B., Charles, L., Collado, J., Cullen, D. M., Desesquelles, P., Domingo-Pardo, C., Dudouet, J., Eberth, J., Gonzalez, V., Goupil, J., Harkness-Brennan, L. J., Hess, H., Judson, D. S., Jungclaus, A., Korten, W., Labiche, M., Lefevre, A., Menegazzo, R., Mengoni, D., Nyberg, J., Perez-Vidal, R. M., Podolyak, Z., Pullia, A., Recchia, F., Reiter, P., Saillant, F., Salsac, M. D., Sanchis, E., Stezowski, O., Theisen, C., Valiente-Dobon, J. J., Holt, J. D., Menendez, J., Schwenk, A., and Simonis, J.

Abstract

To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2+ state in neutron-rich O20,τ(22+)=150-30+80fs, and an estimate for the lifetime of the second 2+ state in C16 have been obtained for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds of femtoseconds range by analyzing the Doppler-shifted γ-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction O18(7.0MeV/u)+Ta181. The requested sensitivity could only be reached owing to the excellent performances of the Advanced γ-Tracking Array AGATA, coupled to the PARIS scintillator array and to the VAMOS++ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two-and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for O20 and with the no-core shell model for C16. The present measurement shows the power of electromagnetic observables, determined with high-precision γ spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetime measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense beams, produced by Isotope Separation On-Line (ISOL) techniques, become available.

Published
2020

26. The (6 ) Isomer in Sn revisited: Neutron and proton effective charges close to the double shell closure

Author

Grawe, H., Straub, K., Faestermann, T., Górska, M., Hinke, C., Krücken, R., Nowacki, F., Böhmer, M., Boutachkov, P., Geissel, H., Gernhäuser, R., Gottardo, A., Grȩbosz, J., Kurz, N., Liu, Z., Maier, L., Pietri, S., Podolyák, Zs., Steiger, K., Weick, H., Wollersheim, H.J., Woods, P.J., Al-Dahan, N., Alkhomashi, N., Ataç, A., Blazhev, A., Braun, N., Čeliković, I., Davinson, T., Dillmann, I., Domingo-Pardo, C., Doornenbal, P., Farrelly, G., Farinon, F., de France, G., Gerl, J., Goel, N., Habermann, T., Hoischen, R., Janik, R., Karny, M., Kaşkaş, A., Kojouharov, I., Kröll, Th., Lewitowicz, M., Litvinov, Yu.A., Myalski, S., Nebel, F., Nishimura, S., Nociforo, C., Nyberg, J., Parikh, A., Procházka, A., Regan, P.H., Rigollet, C., Schaffner, H., Scheidenberger, C., Schwertel, S., Söderström, P.A., Steer, S., Stolz, A., and Strmeň, P.

Abstract

In a high-energy fragmentation experiment at GSI an I=π(6+) isomer and its γ-decay are identified in $^{102}$Sn, the two-neutron neighbour of the doubly-magic $^{100}$Sn. Its half-life is measured to be T=1/2367(11) ns. The possible existence of further isomers is discussed in the framework of large-scale shell model (LSSM) calculations including up to five particle-hole excitations of the $^{100}$Sn core. From the precise B(E2; 6+→4+) strength and the recently remeasured value for B(E2; 8+→6+) in the two-proton hole neighbour $^{98}$Cd effective E2 polarization charges for protons and neutrons were inferred including LSSM corrections within the full N=4 0ħω space. The results are discussed in comparison to predicted and empirically determined effective operators.

Published
2021

27. Experimental approach to measure thick target neutron yields induced by heavy ions for shielding

Author

Trinh N.D., Fadil M., Lewitowicz M., Brouillard C., Clerc T., Damoy S., Desmezières V., Dessay E., Dupuis M., Grinyer G.F., Grinyer J., Jacquot B., Ledoux X., Madeline A., Menard N., Michel M., Morel V., Porée F., Rannou B., and Savalle A.

Subjects
Physics, QC1-999
Abstract

Double differential (angular and energy) neutron distributions were measured using an activation foil technique. Reactions were induced by impinging two low-energy heavy-ion beams accelerated with the GANIL CSS1 cyclotron: (36S (12 MeV/u) and 208Pb (6.25 MeV/u)) onto thick natCu targets. Results have been compared to Monte-Carlo calculations from two codes (PHITS and FLUKA) for the purpose of benchmarking radiation protection and shielding requirements. This comparison suggests a disagreement between calculations and experiment, particularly for high-energy neutrons.

Published
2017
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28. Complete set of bound negative-parity states in the neutron-rich $^{18}$N nucleus

Author

Ziliani, S., Ciema��a, M., Crespi, F. C. L., Leoni, S., Fornal, B., Suzuki, T., Otsuka, T., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Cl��ment, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, ��. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kimi, Y. -H., Kmiecik, M., Lemasson, A., Lewitowicz, M., Lenzi, S., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., M��ller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., 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 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), Institut Laue-Langevin (ILL), 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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

International audience; High-resolution γ-ray spectroscopy of N18 is performed with the Advanced GAmma Tracking Array, following deep-inelastic processes induced by an O18 beam on a Ta181 target. Six states are newly identified, which together with the three known excitations exhaust all negative-parity excited states expected in N18 below the neutron threshold. Spin and parities are proposed for all located states on the basis of decay branchings and comparison with large-scale shell-model calculations performed in the p-sd space, with the YSOX interaction. Of particular interest is the location of the 01− and 12− excitations, which provide strong constrains for cross-shell p-sd matrix elements based on realistic interactions and help to simultaneously reproduce the ground and first-excited states in N16 and N18, for the first time. Understanding the N18 structure may also have significant impact on neutron-capture cross-section calculations in r-process modeling including light neutron-rich nuclei.

Published
2021

29. Complete set of bound negative-parity states in the neutron-rich nucleus N-18

Author

Ziliani, S., Ciemala, M., Crespi, F. C. L., Leoni, S., Fornal, B., Suzuki, T., Otsuka, T., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., de France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I, Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Mueller-Gatermann, C., Nanal, V, Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch, Stanoiu, M., Stefan, I, Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Ziebliska, M., Ziliani, S., Ciemala, M., Crespi, F. C. L., Leoni, S., Fornal, B., Suzuki, T., Otsuka, T., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., de France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I, Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Mueller-Gatermann, C., Nanal, V, Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch, Stanoiu, M., Stefan, I, Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., and Ziebliska, M.

Abstract

High-resolution. -ray spectroscopy of N-18 is performed with the Advanced GAmma Tracking Array, following deep-inelastic processes induced by an O-18 beam on a Ta-181 target. Six states are newly identified, which together with the three known excitations exhaust all negative-parity excited states expected in N-18 below the neutron threshold. Spin and parities are proposed for all located states on the basis of decay branchings and comparison with large-scale shell-model calculations performed in the p-sd space, with the YSOX interaction. Of particular interest is the location of the 0(1)(-) and 1(2)(-) excitations, which provide strong constrains for cross-shell p-sd matrix elements based on realistic interactions and help to simultaneously reproduce the ground and first-excited states in N-16 and N-18, for the first time. Understanding the N-18 structure may also have significant impact on neutron-capture cross-section calculations in r-process modeling including light neutron-rich nuclei.

Published
2021

30. Accessing tens-to-hundreds femtoseconds nuclear state lifetimes with low-energy binary heavy-ion reactions

Author

Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y. -H., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Mueller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y. -H., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Mueller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., and Zielinska, M.

Abstract

A novel Monte Carlo technique has been developed to determine lifetimes of excited states in the tens-to-hundreds femtoseconds range in products of low-energy heavy-ion binary reactions, with complex velocity distributions. The method is based on a detailed study of Doppler-broadened gamma-ray lineshapes. Its relevance is demonstrated in connection with the 18O(7.0MeV/u)+181Ta experiment, performed at GANIL with the AGATA+VAMOS+PARIS setup, to study neutron-rich O, C, N, ... nuclei. Excited states in O-17 and O-19, with known lifetimes, are used to validate the method over the similar to 20-400fs lifetime-sensitivity range. Emphasis is given to the unprecedented position resolution provided by gamma-tracking arrays, which turns out to be essential for reaching the required accuracy in Doppler-shift correction. The technique is anticipated to be an important tool for lifetime investigations in exotic neutron-rich nuclei, produced with intense ISOL-type beams.

Published
2021

31. Lifetime analysis of short-lived states in N-17

Author

Ziliani, S., Ciemala, M., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Mueller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., Ziliani, S., Ciemala, M., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Mueller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., and Zielinska, M.

Abstract

A recent extension of the Doppler-shift attenuation method to measure short lifetimes of states populated in low-energy binary reactions is applied to the case of N-17. The reliability of the technique is confirmed by measuring the lifetime of the 5515 keV 3/2(-) state, which is depopulated by two different gamma rays. The method is used to measure the lifetime of the 5170 keV (9/2(+)) state in the same nucleus. Comparisons with large-scale shell-model predictions are given as well.

Published
2021

32. The (6(+)) isomer in Sn-102 revisited: Neutron and proton effective charges close to the double shell closure

Author

Grawe, H., Straub, K., Faestermann, T., Gorska, M., Hinke, C., Kruecken, R., Nowacki, F., Boehmer, M., Boutachkov, P., Geissel, H., Gernhaeuser, R., Gottardo, A., Grebosz, J., Kurz, N., Liu, Z., Maier, L., Pietri, S., Podolyak, Zs, Steiger, K., Weick, H., Wollersheim, H. J., Woods, P. J., Al-Dahan, N., Alkhomashi, N., Atac, A., Blazhev, A., Braun, N., Celikovic, I, Davinson, T., Dillmann, I, Domingo-Pardo, C., Doornenbal, P., Farrelly, G., Farinon, F., de France, G., Gerl, J., Goel, N., Habermann, T., Hoischen, R., Janik, R., Karny, M., Kaskas, A., Kojouharov, I, Kroell, Th, Lewitowicz, M., Litvinov, Yu A., Myalski, S., Nebel, F., Nishimura, S., Nociforo, C., Nyberg, J., Parikh, A., Prochazka, A., Regan, P. H., Rigollet, C., Schaffner, H., Scheidenberger, C., Schwertel, S., Soderstrom, P-A, Steer, S., Stolz, A., Strmen, P., Grawe, H., Straub, K., Faestermann, T., Gorska, M., Hinke, C., Kruecken, R., Nowacki, F., Boehmer, M., Boutachkov, P., Geissel, H., Gernhaeuser, R., Gottardo, A., Grebosz, J., Kurz, N., Liu, Z., Maier, L., Pietri, S., Podolyak, Zs, Steiger, K., Weick, H., Wollersheim, H. J., Woods, P. J., Al-Dahan, N., Alkhomashi, N., Atac, A., Blazhev, A., Braun, N., Celikovic, I, Davinson, T., Dillmann, I, Domingo-Pardo, C., Doornenbal, P., Farrelly, G., Farinon, F., de France, G., Gerl, J., Goel, N., Habermann, T., Hoischen, R., Janik, R., Karny, M., Kaskas, A., Kojouharov, I, Kroell, Th, Lewitowicz, M., Litvinov, Yu A., Myalski, S., Nebel, F., Nishimura, S., Nociforo, C., Nyberg, J., Parikh, A., Prochazka, A., Regan, P. H., Rigollet, C., Schaffner, H., Scheidenberger, C., Schwertel, S., Soderstrom, P-A, Steer, S., Stolz, A., and Strmen, P.

Abstract

In a high-energy fragmentation experiment at GSI an I-pi = (6(+)) isomer and its gamma-decay are identified in Sn-102, the two-neutron neighbour of the doubly-magic Sn-100. Its half-life is measured to be T-1/2 = 367(11) ns. The possible existence of further isomers is discussed in the framework of large-scale shell model (LSSM) calculations including up to five particle-hole excitations of the Sn-100 core. From the precise B(E2; 6(+) -> 4(+)) strength and the recently remeasured value for B(E2; 8(+) -> 6(+)) in the two-proton hole neighbour Cd-98 effective E2 polarization charges for protons and neutrons were inferred including LSSM corrections within the full N=4 0h omega space. The results are discussed in comparison to predicted and empirically determined effective operators. (C) 2021 The Author(s). Published by Elsevier B.V.

Published
2021

33. Spectroscopy of $^{99}\mathrm{Cd}$ and $^{101}\mathrm{In}$ from ${\beta}$ decays of $^{99}\mathrm{In}$ and $^{101}\mathrm{Sn}$

Author

PARK, J., KRÜCKEN, R., BLAZHEV, A., LUBOS, D., GERNHÄUSER, R., LEWITOWICZ, M., NISHIMURA, S., AHN, D.S., BABA, H., BLANK, B., BOUTACHKOV, P., BROWNE, F., ČELIKOVIĆ, I., DE FRANCE, G., DOORNENBAL, P., FAESTERMANN, T., FANG, Y., FUKUDA, N., GIOVINAZZO, J., GOEL, N., GÓRSKA, M., GRAWE, H., ILIEVA, S., INABE, N., ISOBE, T., JUNGCLAUS, A., KAMEDA, D., KIM, G.D., KIM, Y.K., KOJOUHAROV, I., KUBO, T., KURZ, N., KWON, Y.K., LORUSSO, G., MOSCHNER, K., MURAI, D., NISHIZUKA, I., PATEL, Z., RAJABALI, M.M., RICE, S., SAKURAI, H., SCHAFFNER, H., SHIMIZU, Y., SINCLAIR, L., SÖDERSTRÖM, P.A., STEIGER, K., SUMIKAMA, T., SUZUKI, H., TAKEDA, H., WANG, Z., WATANABE, H., WU, J., XU, Z.Y., Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre 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), TRIUMF, 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 Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Astrophysics::High Energy Astrophysical Phenomena, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure
Abstract

International audience; We report on new γ-ray spectroscopy results from β decays of In99 and Sn101. 30 new γ rays were observed following the β decay of In99, and inconsistencies in the literature with respect to the γ rays following the β decay of Sn101 were addressed with two confirmed cases and two new transitions. The experimental γ-ray energies, intensities, and coincidence relationships are discussed with shell model calculations, where theoretical β-decay branching ratios from the parent nuclei and γ-ray cascades of excited states from the daughter nuclei were combined to generate hypothetical βγ spectra and βγγ coincidence matrices. The most intense β-delayed γ-ray branches in both Cd99 and In101 were well reproduced with this approach, and several γ rays were assigned to new excited states based on their good agreement with shell model predictions. (APS)

Published
2020

34. Spectroscopy of Cd 99 and in 101 from β decays of in 99 and Sn 101

Author

Park, J., Krücken, R., Blazhev, A., Lubos, D., Gernhäuser, R., Lewitowicz, M., Nishimura, S., Ahn, D.S., Baba, H., Blank, B., Boutachkov, P., Browne, F., Celikovic, I., De France, G., Doornenbal, P., Faestermann, T., Fang, Y., Fukuda, N., Giovinazzo, J., Goel, N., Górska, M., Grawe, H., Ilieva, S., Inabe, N., Isobe, T., Jungclaus, Andrea, Kameda, D., Kim, G.D., Kim, Y.K., Kojouharov, I., Kubo, T., Kurz, N., Kwon, Y.K., Lorusso, G., Moschner, K., Murai, D., Nishizuka, I., Patel, Z., Rajabali, M.M., Rice, S., Sakurai, H., Schaffner, H., Shimizu, Y., Sinclair, L., Söderström, P.A., Steiger, K., Sumikama, T., Suzuki, H., Takeda, H., RIKEN Nishina Center for Accelerator-Based Science, University of Tokyo, Ministry of Education, Science and Technology (South Korea), National Research Foundation of Korea, Japan Society for the Promotion of Science, German Research Foundation, Federal Ministry of Education and Research (Germany), Ministerio de Economía y Competitividad (España), Natural Sciences and Engineering Research Council of Canada, and French-Japanese International Associated Laboratory for Nuclear Structure Problems

Abstract

11 pags., 10 figs., 3 tabs., We report on new γ-ray spectroscopy results from β decays of In99 and Sn101. 30 new γ rays were observed following the β decay of In99, and inconsistencies in the literature with respect to the γ rays following the β decay of Sn101 were addressed with two confirmed cases and two new transitions. The experimental γ-ray energies, intensities, and coincidence relationships are discussed with shell model calculations, where theoretical β-decay branching ratios from the parent nuclei and γ-ray cascades of excited states from the daughter nuclei were combined to generate hypothetical βγ spectra and βγγ coincidence matrices. The most intense β-delayed γ-ray branches in both Cd99 and In101 were well reproduced with this approach, and several γ rays were assigned to new excited states based on their good agreement with shell model predictions., The authors would like to thank the personnel at the RIKEN Nishina Center for providing the exotic radioactive isotope beam with record intensities. This experiment was performed at RI Beam Factory operated by RIKEN Nishina Center and CNS, University of Tokyo. We acknowledge the EUROBALL Owners Committee for loaning the germanium detectors and the PreSpec Collaboration for the readout electronics of the cluster detectors of EURICA. Support for the WAS3ABi setup was provided by the Rare Isotope Science Project, funded by the Ministry of Education, Science and Technology (MEST) and National Research Foundation (NRF) of Korea, as well as KAKENHI (Grant No. 25247045) of Japan Society for the Promotion of Science (JSPS). This work was supported by the Institute for Basic Science (IBS-R031-D1). The authors acknowledge also the support of the DFG cluster of excellence “Origin and Structure of the Universe,” German BMBF under Contracts No. 05P15PKFNA and No. 05P19PKFNA, and the Spanish Ministerio de Economía y Competitividad via Project No. FPA2017-84756-C4-2-P. Part of the research was funded by the Natural Sciences and Engineering Research Council (NSERC) of Canada and also supported by FJNSP LIA (French-Japanese International Associated Laboratory for Nuclear Structure Problems)

Published
2020

35. Testing $ab initio$ nuclear structure in neutron-rich nuclei: lifetime measurements of second 2$^+$ states in $^{16}$C and $^{20}$O

Author

Ciemala, M., Ziliani, S., Crespi, F.C.L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clément, E., Coelli, S., Dorvaux, O., Erturk, S., de France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M.N., Iskra, L.W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S.M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D.R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., Atac, A., Barrientos, D., Birkenbach, B., Boston, A.J., Cederwall, B., Charles, L., Collado, J., Cullen, D.M., Desesquelles, P., Domingo-Pardo, C., Dudouet, J., Eberth, J., Gonzalez, V., Goupil, J., Harkness-Brennan, L.J., Hess, H., Judson, D.S., Jungclaus, A., Korten, W., Labiche, M., Lefevre, A., Menegazzo, R., Mengoni, D., Nyberg, J., Perez-Vidal, R.M., Podolyak, Zs., Pullia, A., Recchia, F., Reiter, P., Saillant, F., Salsac, M.D., Sanchis, E., Stezowski, O., Theisen, Ch., Valiente-Dobon, J.J., Holt, J.D., Menendez, J., Schwenk, A., Simonis, J., 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 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), 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), Institut Laue-Langevin (ILL), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Institut de Physique Nucléaire de Lyon (IPNL), 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), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), ILL, 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), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Nuclear Theory (nucl-th), nucl-th, Nuclear Theory, Nuclear Physics - Theory, Starke Wechselwirkung und exotische Kerne – Abteilung Blaum, 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

To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2+ state in neutron-rich O20,τ(22+)=150−30+80fs, and an estimate for the lifetime of the second 2+ state in C16 have been obtained for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds of femtoseconds range by analyzing the Doppler-shifted γ-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction O18(7.0MeV/u)+Ta181. The requested sensitivity could only be reached owing to the excellent performances of the Advanced γ-Tracking Array AGATA, coupled to the PARIS scintillator array and to the VAMOS++ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two- and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for O20 and with the no-core shell model for C16. The present measurement shows the power of electromagnetic observables, determined with high-precision γ spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetime measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense beams, produced by Isotope Separation On-Line (ISOL) techniques, become available. To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2+ state in neutron-rich 20O, tau(2+_2 ) = 150(+80-30) fs, and an estimate for the lifetime of the second 2+ state in 16C have been obtained, for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds femtoseconds range, by analyzing the Doppler-shifted gamma-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction 18O (7.0 MeV/u) + 181Ta. The requested sensitivity could only be reached owing to the excellent performances of the AGATA gamma-tracking array, coupled to the PARIS scintillator array and to the VAMOS++ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two- and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for 20O, and with the no-core shell model for 16C. The present measurement shows the power of electromagnetic observables, determined with high-precision gamma spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetimes measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense ISOL-type beams become available.

Published
2020

36. Spectroscopy of Cd 99 and in 101 from β decays of in 99 and Sn101

Author

Park, J, Krücken, R, Blazhev, A, Lubos, D, Gernhäuser, R, Lewitowicz, M, Nishimura, S, Ahn, D S, Baba, H, Blank, B, Boutachkov, P, Browne, F, Čeliković, Igor T., de France, G., Doornenbal, P, Faestermann, T, Fang, Y, Fukuda, N, Giovinazzo, J, Goel, N, Górska, M, Grawe, H, Ilieva, S, Inabe, N, Isobe, T, Jungclaus, A, Kameda, D, Kim, G. D., Kim, Y.-K., Kojouharov, I, Kubo, T, Kurz, N, Kwon, Y K, Lorusso, G, Moschner, K, Murai, D, Nishizuka, I, Patel, Z, Rajabali, M M, Rice, S, Sakurai, H, Schaffner, H, Shimizu, Y, Sinclair, L, Söderström, P.-A., Steiger, K, Sumikama, T, Suzuki, H, Takeda, H, Wang, Z, Watanabe, H, Wu, J, Xu, Z Y, Park, J, Krücken, R, Blazhev, A, Lubos, D, Gernhäuser, R, Lewitowicz, M, Nishimura, S, Ahn, D S, Baba, H, Blank, B, Boutachkov, P, Browne, F, Čeliković, Igor T., de France, G., Doornenbal, P, Faestermann, T, Fang, Y, Fukuda, N, Giovinazzo, J, Goel, N, Górska, M, Grawe, H, Ilieva, S, Inabe, N, Isobe, T, Jungclaus, A, Kameda, D, Kim, G. D., Kim, Y.-K., Kojouharov, I, Kubo, T, Kurz, N, Kwon, Y K, Lorusso, G, Moschner, K, Murai, D, Nishizuka, I, Patel, Z, Rajabali, M M, Rice, S, Sakurai, H, Schaffner, H, Shimizu, Y, Sinclair, L, Söderström, P.-A., Steiger, K, Sumikama, T, Suzuki, H, Takeda, H, Wang, Z, Watanabe, H, Wu, J, and Xu, Z Y

Abstract

We report on new γ-ray spectroscopy results from β decays of In99 and Sn101. 30 new γ rays were observed following the β decay of In99, and inconsistencies in the literature with respect to the γ rays following the β decay of Sn101 were addressed with two confirmed cases and two new transitions. The experimental γ-ray energies, intensities, and coincidence relationships are discussed with shell model calculations, where theoretical β-decay branching ratios from the parent nuclei and γ-ray cascades of excited states from the daughter nuclei were combined to generate hypothetical βγ spectra and βγγ coincidence matrices. The most intense β-delayed γ-ray branches in both Cd99 and In101 were well reproduced with this approach, and several γ rays were assigned to new excited states based on their good agreement with shell model predictions.

Published
2020

37. Spectroscopy of Cd-99 and In-101 from beta decays of In-99 and Sn-101

Author

Park, J., Kruecken, R., Blazhev, A., Lubos, D., Gernhaeuser, R., Lewitowicz, M., Nishimura, S., Ahn, D. S., Baba, H., Blank, B., Boutachkov, P., Browne, F., Celikovic, I, de France, G., Doornenbal, P., Faestermann, T., Fang, Y., Fukuda, N., Giovinazzo, J., Goel, N., Gorska, M., Grawe, H., Ilieva, S., Inabe, N., Isobe, T., Jungclaus, A., Kameda, D., Kim, G. D., Kim, Y-K, Kojouharov, I, Kubo, T., Kurz, N., Kwon, Y. K., Lorusso, G., Moschner, K., Murai, D., Nishizuka, I, Patel, Z., Rajabali, M. M., Rice, S., Sakurai, H., Schaffner, H., Shimizu, Y., Sinclair, L., Soderstrom, P-A, Steiger, K., Sumikama, T., Suzuki, H., Takeda, H., Wang, Z., Watanabe, H., Wu, J., Xu, Z. Y., Park, J., Kruecken, R., Blazhev, A., Lubos, D., Gernhaeuser, R., Lewitowicz, M., Nishimura, S., Ahn, D. S., Baba, H., Blank, B., Boutachkov, P., Browne, F., Celikovic, I, de France, G., Doornenbal, P., Faestermann, T., Fang, Y., Fukuda, N., Giovinazzo, J., Goel, N., Gorska, M., Grawe, H., Ilieva, S., Inabe, N., Isobe, T., Jungclaus, A., Kameda, D., Kim, G. D., Kim, Y-K, Kojouharov, I, Kubo, T., Kurz, N., Kwon, Y. K., Lorusso, G., Moschner, K., Murai, D., Nishizuka, I, Patel, Z., Rajabali, M. M., Rice, S., Sakurai, H., Schaffner, H., Shimizu, Y., Sinclair, L., Soderstrom, P-A, Steiger, K., Sumikama, T., Suzuki, H., Takeda, H., Wang, Z., Watanabe, H., Wu, J., and Xu, Z. Y.

Abstract

We report on new gamma-ray spectroscopy results from beta decays of In-99 and Sn-101. 30 new gamma rays were observed following the beta decay of In-99, and inconsistencies in the literature with respect to the gamma rays following the beta decay of Sn-101 were addressed with two confirmed cases and two new transitions. The experimental gamma-ray energies, intensities, and coincidence relationships are discussed with shell model calculations, where theoretical beta-decay branching ratios from the parent nuclei and gamma-ray cascades of excited states from the daughter nuclei were combined to generate hypothetical beta gamma spectra and beta gamma gamma coincidence matrices. The most intense beta-delayed gamma-ray branches in both Cd-99 and In-101 were well reproduced with this approach, and several gamma rays were assigned to new excited states based on their good agreement with shell model predictions.

Published
2020

38. Study of ground and excited state decays in N ≈ Z Ag nuclei

Author

Moschner K., Blazhev A., Warr N., Boutachkov P., Davies P., Wadsworth R., Ameil F., Baba H., Bäck T., Dewald M., Doornenbal P., Faestermann T., Gengelbach A., Gerl J., Gernhäuser R., Go S., Górska M., Grawe H., Gregor E., Hotaka H., Isobe T., Jenkins D. G., Jolie J., Jung H. S., Kojouharov I., Kurz N., Lewitowicz M., Lorusso G., Merchan E., Naqvi F., Nishibata H., Nishimura D., Nishimura S., Pietralla N., Schaffner H., Söderström P.-A., Steiger K., Sumikama T., Taprogge J., Thöle P., Watanabe H., Werner V., Xu Z. Y., Yagi A., Yoshinaga K., and Zhu Y.

Subjects
Physics, QC1-999
Abstract

A decay spectroscopy experiment was performed within the EURICA campaign at RIKEN in 2012. It aimed at the isomer and particle spectroscopy of excited states and ground states in the mass region below the doubly magic 100Sn. The N = Z nuclei 98In, 96Cd and 94Ag were of particular interest for the present study. Preliminary results on the neutron deficient nuclei 93Ag and 94Ag are presented. In 94Ag a more precise value for the half-life of the ground state’s superallowed Fermi transition was deduced. In addition the energy spectra of the mentioned decay could be reproduced through precise Geant4 simulations of the used active stopper SIMBA. This will enable us to extract Qβ values from the measured data. The decay of 93Ag is discussed based on the observed implantation-decay correlation events.

Published
2015
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39. Measurement of the \(\gamma \) Decay from the Energy Region of the Pygmy Dipole States Excited in the \(^{208}\)Pb\((p,p'\gamma )\) Reaction at CCB

Author

Wasilewska, B., primary, Kmiecik, M., additional, Ciemała, M., additional, Maj, A., additional, Łukasik, J., additional, Pawłowski, P., additional, Sowicki, B., additional, Ziębliński, M., additional, Grębosz, J., additional, Crespi, F.C.L., additional, Bednarczyk, P., additional, Bracco, A., additional, Brambilla, S., additional, Ciepał, I., additional, Cieplicka-Oryńczak, N., additional, Fornal, B., additional, Guguła, K., additional, Harakeh, M.N., additional, Jeżabek, M., additional, Kicińska-Habior, M., additional, Krzysiek, M., additional, Kulessa, P., additional, Lewitowicz, M., additional, Matejska-Minda, M., additional, Mazurek, K., additional, Napiorkowski, P., additional, Schmitt, Ch., additional, and Sobolev, Y., additional

Published
2020
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40. Spectroscopy of Neutron-rich Nitrogen Isotopes with AGATA+PARIS+VAMOS

Author

Ziliani, S., primary, Ciemała, M., additional, Crespi, F.C.L., additional, Leoni, S., additional, Fornal, B., additional, Maj, A., additional, Bednarczyk, P., additional, Benzoni, G., additional, Bracco, A., additional, Boiano, C., additional, Bottoni, S., additional, Brambilla, S., additional, Bast, M., additional, Beckers, M., additional, Braunroth, T., additional, Camera, F., additional, Cieplicka-Oryńczak, N., additional, Clément, E., additional, Coelli, S., additional, Dorvaux, O., additional, Erturk, S., additional, de France, G., additional, Fransen, C., additional, Goldkuhle, A., additional, Grębosz, J., additional, Harakeh, M.N., additional, Iskra, Ł.W., additional, Jacquot, B., additional, Karpov, A., additional, Kicińska-Habior, M., additional, Kim, Y., additional, Kmiecik, M., additional, Lemasson, A., additional, Lenzi, S.M., additional, Lewitowicz, M., additional, Li, H., additional, Matea, I., additional, Mazurek, K., additional, Michelagnoli, C., additional, Matejska-Minda, M., additional, Million, B., additional, Müller-Gatermann, C., additional, Nanal, V., additional, Napiorkowski, P., additional, Napoli, D.R., additional, Palit, R., additional, Rejmund, M., additional, Schmitt, Ch., additional, Stanoiu, M., additional, Stefan, I., additional, Vardaci, E., additional, Wasilewska, B., additional, Wieland, O., additional, Ziębliński, M., additional, and Zielińska, M., additional

Published
2020
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41. Short-range Lifetime Measurements for Deep-inelastic Reaction Products: the \(^{19}\)O Test Case

Author

Ciemała, M., primary, Ziliani, S., additional, Crespi, F., additional, Leoni, S., additional, Fornal, B., additional, Maj, A., additional, Bednarczyk, P., additional, Benzoni, G., additional, Bracco, A., additional, Boiano, C., additional, Bottoni, S., additional, Brambilla, S., additional, Bast, M., additional, Beckers, M., additional, Braunroth, T., additional, Camera, F., additional, Cieplicka-Oryńczak, N., additional, Clément, E., additional, Dorvaux, O., additional, Erturk, S., additional, de France, G., additional, Fransen, C., additional, Goldkuhle, A., additional, Grębosz, J., additional, Harakeh, M.N., additional, Iskra, Ł.W., additional, Jacquot, B., additional, Karpov, A., additional, Kicińska-Habior, M., additional, Kim, Y., additional, Kmiecik, M., additional, Lemasson, A., additional, Lenzi, S.M., additional, Lewitowicz, M., additional, Li, H., additional, Matea, I., additional, Mazurek, K., additional, Michelagnoli, C., additional, Matejska-Minda, M., additional, Million, B., additional, Müller-Gatermann, C., additional, Nanal, V., additional, Napiorkowski, P., additional, Napoli, D.R., additional, Palit, R., additional, Rejmund, M., additional, Schmitt, Ch., additional, Stanoiu, M., additional, Stefan, I., additional, Vardaci, E., additional, Wasilewska, B., additional, Wieland, O., additional, Zielińska, M., additional, and Ziębliński, M., additional

Published
2020
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42. Improved Value for the Gamow-Teller Strength of the Sn 100 Beta Decay

Author

Lubos, D., Park, J., Faestermann, T., Gernhäuser, R., Krücken, R., Lewitowicz, M., Nishimura, S., Sakurai, H., Ahn, D.S., Baba, H., Blank, B., Blazhev, A., Boutachkov, P., Browne, F., Celikovic, I., De France, G., Doornenbal, P., Fang, Y., Fukuda, N., Giovinazzo, J., Goel, N., Górska, M., Ilieva, S., Inabe, N., Isobe, T., Jungclaus, Andrea, Kameda, D., Kim, Y. K., Kojouharov, I., Kubo, T., Kurz, N., Kwon, Y. K., Lorusso, G., Moschner, K., Murai, D., Nishizuka, I., Patel, Z., Rajabali, M. M., Rice, S., Schaffner, H., Shimizu, Y., Sinclair, L., Söderström, P. A., Steiger, K., Sumikama, T., Suzuki, H., Takeda, H., Wang, Z., Warr, N., RIKEN Nishina Center for Accelerator-Based Science, University of Tokyo, German Research Foundation, Federal Ministry of Science, Research and Economy (Germany), Ministry of Education, Science and Technology (South Korea), National Research Foundation of Korea, Natural Sciences and Engineering Research Council of Canada, and Ministerio de Ciencia, Innovación y Universidades (España)

Abstract

6 pags., 4 figs., A record number of Sn100 nuclei was detected and new isotopic species toward the proton dripline were discovered at the RIKEN Nishina Center. Decay spectroscopy was performed with the high-efficiency detector arrays WAS3ABi and EURICA. Both the half-life and the β-decay end point energy of Sn100 were measured more precisely than the literature values. The value and the uncertainty of the resulting strength for the pure 0+→1+ Gamow-Teller decay was improved to BGT=4.4-0.7+0.9. A discrimination between different model calculations was possible for the first time, and the level scheme of In100 is investigated further., This work was carried out at the RIBF operated by RIKEN Nishina Center, RIKEN and CNS, University of Tokyo. It was supported and financed by the DFG cluster of excellence “Origin and Structure of the Universe,” the German BMBF under Contracts No. 05P12WOFNF and No. 05P15PKFNA, the Hanns-Seidel-Stiftung, and the RIKEN IPA Programme. We wish to acknowledge the EURICA RIBF09 collaboration as well as the support on the WAS3ABi setup from the Rare Isotope Science Project, funded by the Ministry of Education, Science and Technology and National Research Foundation of Korea KAKENHI (Grant No. 25247045). Part of the research was also funded by the Natural Sciences and Engineering Research Council of Canada, supported by FJNSP LIA (French-Japanese International Associated Laboratory for Nuclear Structure Problems) and by the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P.

Published
2019

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

Author

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

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

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

Published
2019

44. Toward the limit of nuclear binding on the N=Z line : Spectroscopy of Cd 96

Author

Davies, P. J., Park, J., Grawe, H., Wadsworth, R., Gernhäuser, R., Krücken, R., Nowacki, F., Ahn, D. S., Ameil, F., Baba, H., Bäck, T., Blank, B., Blazhev, A., Boutachkov, P., Browne, F., Čeliković, I., Dewald, M., Doornenbal, P., Faestermann, T., Fang, Y., De France, G., Fukuda, N., Gengelbach, A., Gerl, J., Giovinazzo, J., Go, S., Goel, N., Górska, M., Gregor, E., Hotaka, H., Ilieva, S., Inabe, N., Isobe, T., Jenkins, D. G., Jolie, J., Jung, H. S., Jungclaus, A., Kameda, D., Kim, G. D., Kim, Y. K., Kojouharov, I., Kubo, T., Kurz, N., Lewitowicz, M., Lorusso, G., Lubos, D., Maier, L., Merchan, E., Moschner, K., Murai, D., Naqvi, F., Nishibata, H., Nishimura, D., Nishimura, S., Nishizuka, I., Patel, Z., Pietralla, N., Rajabali, M. M., Rice, S., Sakurai, H., Schaffner, H., Shimizu, Y., Sinclair, L. F., Söderström, P. A., Steiger, K., Sumikama, T., Suzuki, H., Takeda, H., Taprogge, J., Thöle, P., Valder, S., Wang, Z., Warr, N., Watanabe, H., Werner, V., Wu, J., Xu, Z. Y., Yagi, A., Yoshinaga, K., and Zhu, Y.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

A γ-decaying isomeric state (τ1/2=197-17+19 ns) has been identified in Cd96, which is one α particle away from the last known bound N=Z nucleus, Sn100. Comparison of the results with shell-model calculations has allowed a tentative experimental level scheme to be deduced and the isomer to be interpreted as a medium-spin negative-parity spin trap based on the coupling of isoscalar (T=0) and isovector (T=1) neutron-proton pairs. The data also suggest evidence for the population of a 9+ T=1 state, which is predicted by shell-model calculations to be yrast. Such a low-lying T=1 state, which is unknown in lighter mass even-even self-conjugate nuclei, can also be interpreted in terms of the coupling of T=0 and T=1 neutron-proton pairs.

Published
2019

45. Toward the limit of nuclear binding on the N=Z line: Spectroscopy of Cd 96

Author

Davies, P.J., Park, J., Grawe, H., Wadsworth, R., Gernhäuser, R., Krücken, R., Nowacki, F., Ahn, D.S., Ameil, F., Baba, H., Bäck, T., Blank, B., Blazhev, A., Boutachkov, P., Browne, F., Celikovic, I., Dewald, M., Doornenbal, P., Faestermann, T., Fang, Y., De France, G., Fukuda, N., Gengelbach, A., Gerl, J., Giovinazzo, J., Go, S., Goel, N., Górska, M., Gregor, E., Hotaka, H., Ilieva, S., Inabe, N., Isobe, T., Jenkins, D.G., Jolie, J., Jung, H. S., Jungclaus, Andrea, Kameda, D., Kim, G.D., Kim, Y.K., Kojouharov, I., Kubo, T., Kurz, N., Lewitowicz, M., Lorusso, G., Lubos, D., Maier, L., Merchan, E., Moschner, K., Taprogge, J., Federal Ministry of Education and Research (Germany), Science and Technology Facilities Council (UK), Natural Sciences and Engineering Research Council of Canada, Department of Energy (US), and Ministerio de Economía y Competitividad (España)

Abstract

6 pags., 5 figs., A γ-decaying isomeric state (τ1/2=197-17+19 ns) has been identified in Cd96, which is one α particle away from the last known bound N=Z nucleus, Sn100. Comparison of the results with shell-model calculations has allowed a tentative experimental level scheme to be deduced and the isomer to be interpreted as a medium-spin negative-parity spin trap based on the coupling of isoscalar (T=0) and isovector (T=1) neutron-proton pairs. The data also suggest evidence for the population of a 9+ T=1 state, which is predicted by shell-model calculations to be yrast. Such a low-lying T=1 state, which is unknown in lighter mass even-even self-conjugate nuclei, can also be interpreted in terms of the coupling of T=0 and T=1 neutron-proton pairs., This work was partially supported by the German BMBF Grants No. 05P12PKFNE and No. 05P15RDFN1, the UK STFC under Grants No. ST/J000124/1 and No. ST/L005727/1, the Natural Sciences and Engineering Research Council (NSERC) of Canada, the U.S. DOE Grant No. DE-FG02-91ER40609, KAKENHI under Grant No. 25247045, and the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014-57196-C5-4-P.

Published
2019

46. Toward the limit of nuclear binding on the $N=Z$ line: Spectroscopy of $^{96}$Cd

Author

Davies, P.J., Park, J., Grawe, H., Wadsworth, R., Gernhäuser, R., Krücken, R., Nowacki, F., Ahn, D.S., Ameil, F., Baba, H., Bäck, T., Blank, B., Blazhev, A., Boutachkov, P., Browne, F., Celikovic, I., Dewald, M., Doornenbal, P., Faestermann, T., Fang, Y., De France, G., Fukuda, N., Gengelbach, A., Gerl, J., Giovinazzo, J., Go, S., Goel, N., Górska, M., Gregor, E., Hotaka, H., Ilieva, S., Inabe, N., Isobe, T., Jenkins, D.G., Jolie, J., Jung, H.S., Jungclaus, A., Kameda, D., Kim, G.D., Kim, Y.-K., Kojouharov, I., Kubo, T., Kurz, N., Lewitowicz, M., Lorusso, G., Lubos, D., Maier, L., Merchan, E., Moschner, K., Murai, D., Naqvi, F., Nishibata, H., Nishimura, D., Nishimura, S., Nishizuka, I., Patel, Z., Pietralla, N., Rajabali, M.M., Rice, S., Sakurai, H., Schaffner, H., Shimizu, Y., Sinclair, L.F., Söderström, P.-A., Steiger, K., Sumikama, T., Suzuki, H., Takeda, H., Taprogge, J., Thöle, P., Valder, S., Wang, Z., Warr, N., Watanabe, H., Werner, V., Wu, J., Xu, Z.Y., Yagi, A., Yoshinaga, K., Zhu, Y., Université de Strasbourg (UNISTRA), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), 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 Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and 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, Nuclear Structure
Abstract

International audience; A γ -decaying isomeric state (τ1/2 = 197$^{+19}_{−17}$ ns) has been identified in 96Cd, which is one α particle away from the last known bound N = Z nucleus, 100Sn. Comparison of the results with shell-model calculations has allowed a tentative experimental level scheme to be deduced and the isomer to be interpreted as a medium-spin negativeparity spin trap based on the coupling of isoscalar (T = 0) and isovector (T = 1) neutron-proton pairs. The data also suggest evidence for the population of a 9+ T = 1 state, which is predicted by shell-model calculations to be yrast. Such a low-lying T = 1 state, which is unknown in lighter mass even-even self-conjugate nuclei, can also be interpreted in terms of the coupling of T = 0 and T = 1 neutron-proton pairs.

Published
2019

47. Properties of γ-decaying isomers in the Sn 100 region populated in fragmentation of a Xe 124 beam

Author

Häfner, G., Moschner, K., Blazhev, A., Boutachkov, P., Davies, P. J., Wadsworth, R., Ameil, F., Baba, H., Bäck, T., Dewald, M., Doornenbal, P., Faestermann, T., Gengelbach, A., Gerl, J., Gernhaüser, R., Go, S., Górska, M., Grawe, H., Gregor, E., Hotaka, H., Isobe, T., Jenkins, D. G., Jolie, J., Jung, H. S., Kojouharov, I., Kurz, N., Lewitowicz, M., Lorusso, G., Lozeva, R., Merchan, E., Naqvi, F., Nishibata, H., Nishimura, D., Nishimura, S., Pietralla, N., Schaffner, H., Söderström, P. A., Steiger, K., Sumikama, T., Taprogge, J., Thöle, P., Watanbe, H., Warr, N., Werner, V., Xu, Z. Y., Yagi, A., Yoshinaga, K., Zhu, Y., RIKEN Nishina Center for Accelerator-Based Science, University of Tokyo, Federal Ministry of Education and Research (Germany), Department of Energy (US), Japan Society for the Promotion of Science, Science and Technology Facilities Council (UK), and Bonn-Cologne Graduate School of Physics and Astronomy

Subjects
Physics::Accelerator Physics, Nuclear Experiment
Abstract

9 pags., 6 figs., 2 tabs., A systematic study was performed of microsecond γ-decaying isomers around Sn100 produced in a fragmentation reaction of a Xe124 beam at 345 MeV/u at the Radioactive Ion Beam Factory of the RIKEN Nishina Center in Saitama, Japan. Half-lives of isomeric states in that region were remeasured allowing us to improve the currently available experimental information. Reduced transition probabilities were deduced and compared to shell-model calculations in various model spaces. The recently reported low-energy transitions in Rh92 and Ag96 were remeasured with improved precision. Additionally, experimental information on isomeric ratios, including five new ones, were extracted and compared to a previous experimental study and the sharp cutoff model of fragmentation reaction., This work was carried out at the RIBF operated by the RIKEN Nishina Center, RIKEN and CNS, University of Tokyo. We acknowledge the EUROBALL Owners Committee for the loan of germanium detectors and the PreSpec Collaboration for the readout electronics of cluster detectors. This work was partly supported by the German BMBF under Contracts No. 05P12PKFNE and No. 05P15PKFNA, the U.S. Department of Energy under Grant No. DE-FG02-91ER40609, JSPS KAKENHI Grant No. KAKENHI 25247045, and the UK STFC under Grants No. ST/J000124/1, No. ST/L005727/1, and No. ST/P003885/1. G.H. was supported by the Bonn-Cologne Graduate School of Physics and Astronomy.

Published
2019

48. New and comprehensive $\beta$- and $\beta{p}$-decay spectroscopy results in the vicinity of $^{100}\mathrm{Sn}$

Author

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

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

International audience; A decay spectroscopy experiment on proton-rich nuclei in the vicinity of the doubly magic Sn100 was carried out at RIKEN Nishina Center. More than 20 nuclei with 43≤Z≤50 and N≤51, produced by fragmentation reactions were investigated via analyses of β-decay, βp-decay, and subsequent γ-ray data. Owing to higher statistics, the precision on the half-lives of many of the ground states and isomers was improved. β-decay endpoint energies of 11 states in 8 nuclei were measured for the first time, and the corresponding QEC and excitation energies were generally consistent with various mass models. Many β-delayed proton emission branching ratios were measured either for the first time or with higher precision compared to literature values, and some of them differed by more than 2σ. Many of the large discrepancies were associated with nuclei with long-lived isomeric states, highlighting large systematic uncertainties involved in these measurements. Twenty-five new γ rays were observed, and ten new states are proposed with unambiguous excitation energies, spins, and parities. Most of the energies of the excited states were consistent within 300 keV or 20%, whichever was greater, compared to shell model predictions in the proton/neutron (p1/2,g9/2) model space assuming a Sr76 core. A signature of a new (1/2−) isomer in Cd97 with T1/2=0.73(7) s was found, in good agreement with shell model predictions.

Published
2019

49. Properties of gamma-decaying isomers in the Sn-100 region populated in fragmentation of a Xe-124 beam

Author

Haefner, G., Moschner, K., Blazhev, A., Boutachkov, P., Davies, P. J., Wadsworth, R., Ameil, F., Baba, H., Back, T., Dewald, M., Doornenbal, P., Faestermann, T., Gengelbach, Aila, Gerl, J., Gernhaeuser, R., Go, S., Gorska, M., Grawe, H., Gregor, E., Hotaka, H., Isobe, T., Jenkins, D. G., Jolie, J., Jung, H. S., Kojouharov, I, Kurz, N., Lewitowicz, M., Lorusso, G., Lozeva, R., Merchan, E., Naqvi, F., Nishibata, H., Nishimura, D., Nishimura, S., Pietralla, N., Schaffner, H., Soderstrom, P-A, Steiger, K., Sumikama, T., Taprogge, J., Thoele, P., Watanbe, H., Warr, N., Werner, V, Xu, Z. Y., Yagi, A., Yoshinaga, K., Zhu, Y., Haefner, G., Moschner, K., Blazhev, A., Boutachkov, P., Davies, P. J., Wadsworth, R., Ameil, F., Baba, H., Back, T., Dewald, M., Doornenbal, P., Faestermann, T., Gengelbach, Aila, Gerl, J., Gernhaeuser, R., Go, S., Gorska, M., Grawe, H., Gregor, E., Hotaka, H., Isobe, T., Jenkins, D. G., Jolie, J., Jung, H. S., Kojouharov, I, Kurz, N., Lewitowicz, M., Lorusso, G., Lozeva, R., Merchan, E., Naqvi, F., Nishibata, H., Nishimura, D., Nishimura, S., Pietralla, N., Schaffner, H., Soderstrom, P-A, Steiger, K., Sumikama, T., Taprogge, J., Thoele, P., Watanbe, H., Warr, N., Werner, V, Xu, Z. Y., Yagi, A., Yoshinaga, K., and Zhu, Y.

Abstract

A systematic study was performed of microsecond gamma-decaying isomers around Sn-100 produced in a fragmentation reaction of a Xe-124 beam at 345 MeV/u at the Radioactive Ion Beam Factory of the RIKEN Nishina Center in Saitama, Japan. Half-lives of isomeric states in that region were remeasured allowing us to improve the currently available experimental information. Reduced transition probabilities were deduced and compared to shell-model calculations in various model spaces. The recently reported low-energy transitions in Rh-92 and Ag-96 were remeasured with improved precision. Additionally, experimental information on isomeric ratios, including five new ones, were extracted and compared to a previous experimental study and the sharp cutoff model of fragmentation reaction.

Published
2019
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50. Properties of γ-decaying Isomers in the 100Sn Region Revisited

Author

Haefner, G., Moschner, K., Blazhev, A., Boutachkov, P., Davies, P. J., Wadsworth, R., Ameil, F., Baba, H., Back, T., Dewald, M., Doornenbal, P., Faestermann, T., Gengelbach, Aila, Gerl, J., Gernhaeuser, R., Go, S., Gorska, M., Grawe, H., Gregor, E., Hotaka, H., Isobe, T., Jenkins, D. G., Jolie, J., Jung, H. S., Kojouharov, I, Kurz, N., Lewitowicz, M., Lorusso, G., Merchan, E., Naqvi, F., Nishibata, H., Nishimura, D., Nishimura, S., Pietralla, N., Schaffner, H., Soderstrom, P-A, Steiger, K., Sumikama, T., Taprogge, J., Thoele, P., Watanabe, H., Warr, N., Werner, V, Xu, Z. Y., Yagi, A., Yoshinagai, K., Zhui, Y., Haefner, G., Moschner, K., Blazhev, A., Boutachkov, P., Davies, P. J., Wadsworth, R., Ameil, F., Baba, H., Back, T., Dewald, M., Doornenbal, P., Faestermann, T., Gengelbach, Aila, Gerl, J., Gernhaeuser, R., Go, S., Gorska, M., Grawe, H., Gregor, E., Hotaka, H., Isobe, T., Jenkins, D. G., Jolie, J., Jung, H. S., Kojouharov, I, Kurz, N., Lewitowicz, M., Lorusso, G., Merchan, E., Naqvi, F., Nishibata, H., Nishimura, D., Nishimura, S., Pietralla, N., Schaffner, H., Soderstrom, P-A, Steiger, K., Sumikama, T., Taprogge, J., Thoele, P., Watanabe, H., Warr, N., Werner, V, Xu, Z. Y., Yagi, A., Yoshinagai, K., and Zhui, Y.

Abstract

The study of nuclei in the region around the N = Z doubly-magic nucleus 100Sn has been of long standing interest for the nuclear structure and nuclear astrophysics. Recently, Park et al. have reported on properties of γ-decaying isomers and isomeric ratios in the vicinity of 100Sn. That experiment was performed at the Radioactive Ion Beam Factory (RIBF) of the RIKEN Nishina Center in Japan as a part of the EURICA campaign. Neutron-deficient nuclei were produced in a fragmentation reaction of a 124Xe primary beam on a 9Be target at an energy of 345 MeV/A. Secondary ions were separated and identified in the BigRIPS fragment separator and implanted in the silicon detector array WAS3ABi. The data presented here were obtained in another experiment performed at the RIBF using the same reaction but slightly different separator settings. New results of ratios of isomeric population and half-lives of γ-decaying isomers populated in the experiment are presented., Wos title: PROPERTIES OF gamma-DECAYING ISOMERS IN THE Sn-100 REGION REVISITED

Published
2019
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