Search

Your search keyword '"Lehr, C."' showing total 584 results
Start Over Author "Lehr, C."

Refine your results

584 results on '"Lehr, C."'

1. Spectroscopy of deeply bound orbitals in neutron-rich Ca isotopes

Author

Li, P. J., Lee, J., Doornenbal, P., Chen, S., Wang, S., Obertelli, A., Chazono, Y., Holt, J. D., Hu, B. S., Ogata, K., Utsuno, Y., Yoshida, K., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Château, F., Chiga, N., Corsi, A., Cortés, M. L., Delbart, A., Gheller, J-M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Liu, H. N., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Boretzky, K., Caesar, C., Chung, L. X., Flavigny, F., Franchoo, S., Gasparic, I., Gerst, R. -B., Gibelin, J., Hahn, K. I., Kahlbow, J., Kim, D., Koiwai, T., Kondo, Y., Körper, D., Koseoglou, P., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Miki, K., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Schindler, F., Simon, H., Söderström, P-A., Sohler, D., Takeuchi, S., Toernqvist, H., Tscheuschner, J., Vaquero, V., Wagner, V., Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The calcium isotopes are an ideal system to investigate the evolution of shell structure and magic numbers. Although the properties of surface nucleons in calcium have been well studied, probing the structure of deeply bound nucleons remains a challenge. Here, we report on the first measurement of unbound states in $^{53}$Ca and $^{55}$Ca, populated from \ts{54,56}Ca($p,pn$) reactions at a beam energy of around 216 MeV/nucleon at the RIKEN Radioactive Isotopes Beam Factory. The resonance properties, partial cross sections, and momentum distributions of these unbound states were analyzed. Orbital angular momentum $l$ assignments were extracted from momentum distributions based on calculations using the distorted wave impulse approximation (DWIA) reaction model. The resonances at excitation energies of 5516(41)\,keV in $^{53}$Ca and 6000(250)\,keV in $^{55}$Ca indicate a significant $l$\, =\,3 component, providing the first experimental evidence for the $\nu 0f_{7/2}$ single-particle strength of unbound hole states in the neutron-rich Ca isotopes. The observed excitation energies and cross-sections point towards extremely localized and well separated strength distributions, with some fragmentation for the $\nu 0f_{7/2}$ orbital in $^{55}$Ca. These results are in good agreement with predictions from shell-model calculations using the effective GXPF1Bs interaction and \textit{ab initio} calculations and diverge markedly from the experimental distributions in the nickel isotones at $Z=28$., Comment: 13 pages, 7 figures

Published
2024
Full Text
View/download PDF

2. Level Structures of $^{56,58}$Ca Cast Doubt on a doubly magic $^{60}$Ca

Author

Chen, S., Browne, F., Doornenbal, P., Lee, J., Obertelli, A., Tsunoda, Y., Otsuka, T., Chazono, Y., Hagen, G., Holt, J. D., Jansen, G. R., Ogata, K., Shimizu, N., Utsuno, Y., Yoshida, K., Achouri, N. L., Baba, H., Calvet, D., Château, F., Chiga, N., Corsi, A., Cortés, M. L., Delbart, A., Gheller, J. -M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Liu, H. N., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gasparic, I., Gerst, R. -B., Gibelin, J., Hahn, K. I., Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Söderström, P. -A., Sohler, D., Takeuchi, S., Törnqvist, H., Vaquero, V., Wagner, V., Wang, S., Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Gamma decays were observed in $^{56}$Ca and $^{58}$Ca following quasi-free one-proton knockout reactions from $^{57,59}$Sc beams at $\approx 200$ MeV/nucleon. For $^{56}$Ca, a $\gamma$ ray transition was measured to be 1456(12) keV, while for $^{58}$Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the $2^+_1 \rightarrow 0^+_{gs}$ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for $2^+_1$ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the $N$ = 34 shell. Its constituents, the $0f_{5/2}$ and $0g_{9/2}$ orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic $^{60}$Ca and potentially drives the dripline of Ca isotopes to $^{70}$Ca or even beyond., Comment: 8 pages, 3 figures

Published
2023
Full Text
View/download PDF

3. A First Glimpse at the Shell Structure beyond $^{54}$Ca: Spectroscopy of $^{55}$K, $^{55}$Ca, and $^{57}$Ca

Author

Koiwai, T., Wimmer, K., Doornenbal, P., Obertelli, A., Barbieri, C., Duguet, T., Holt, J. D., Miyagi, T., Navrátil, P., Ogata, K., Shimizu, N., Somà, V., Utsuno, Y., Yoshida, K., Achouri, N. L., Baba, H., Browne, F., f, D. Calvet, Château, F., Chen, S., Chiga, N., Corsi, A., Cortés, M. L., Delbart, A., Gheller, J. -M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Liu, H. N., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo v, S., Gasparic, I., Gerst, R. -B., Gibelin, J., Hahn, K. I., Kim, D., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Söderström, P-A., Sohler, D., Takeuchi, S., Toernqvist, H., Vaquero, V., Wagner, V., Wang, S., Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Subjects
Nuclear Experiment
Abstract

States in the $N=35$ and 37 isotopes $^{55,57}$Ca have been populated by direct proton-induced nucleon removal reactions from $^{56,58}$Sc and $^{56}$Ca beams at the RIBF. In addition, the $(p,2p)$ quasi-free single-proton removal reaction from $^{56}$Ca was studied. Excited states in $^{55}$K, $^{55}$Ca, and $^{57}$Ca were established for the first time via in-beam $\gamma$-ray spectroscopy. Results for the proton and neutron removal reactions from $^{56}$Ca to states in $^{55}$K and $^{55}$Ca for the level energies, excited state lifetimes, and exclusive cross sections agree well with state-of-the-art theoretical calculations using different approaches. The observation of a short-lived state in $^{57}$Ca suggests a transition in the calcium isotopic chain from single-particle dominated states at $N=35$ to collective excitations at $N=37$., Comment: accepted Phys. Lett. B

Published
2022
Full Text
View/download PDF

4. Investigation of the ground-state spin inversion in the neutron-rich 47,49Cl isotopes

Author

Linh, B. D., Corsi, A., Gillibert, A., Obertelli, A., Doornenbal, P., Barbieri, C., Chen, S., Chung, L. X., Duguet, T., Gómez-Ramos, M., Holt, J. D., Moro, A., Navrátil, P., Ogata, K., Phuc, N. T. T., Shimizu, N., Somà, V., Utsuno, Y., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Château, F., Chiga, N., Cortés, M. L., Delbart, A., Gheller, J. -M., Giganon, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Liu, H. N., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Flavigny, F., Franchoo, S., Gašparić, I., Gerst, R. -B., Gibelin, J., Hahn, K. I., Khai, N. T., Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Sohler, D., Söderström, P. -A., Takeuchi, S., Ton, N. D., Törnqvist, H., Vaquero, V., Wagner, V., Wang, H., Werner, V., Xu, X., Yamada, Y., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

A first gamma-ray study of 47,49Cl spectroscopy was performed at the Radioactive Isotope Beam Factory with 50Ar projectiles at 217 MeV/nucleon, impinging on the liquid hydrogen target of the MINOS device. Prompt de-excitation gamma-rays were measured with the NaI(Tl) array DALI2+. Through the one-proton knockout reaction 50Ar(p,2p), a spin assignment could be determined for the low-lying states of 49Cl from the momentum distribution obtained with the SAMURAI spectrometer. A spin-parity J = 3/2+ is deduced for the ground state of 49Cl, similar to the recently studied N = 32 isotope 51K.

Published
2021
Full Text
View/download PDF

5. Unveiling the Two-Proton Halo Character of 17Ne: Exclusive Measurement of Quasi-free Proton-Knockout Reactions

Author

Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernandez, P. Diaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D. H. H., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Bleis, T. Le, Lemmon, R., Litvinov, Yu. A., Loeher, B., Mahata, K., Marganiec-Galazka, J., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Suemmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Subjects
Nuclear Experiment
Abstract

The proton drip-line nucleus 17Ne is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the 17Ne(p,2p)16F->15O+p quasi-free one-proton knockout reaction has been performed at GSI at around 500 MeV/nucleon beam energy. All particles resulting from the scattering process have been detected. The relevant reconstructed quantities are the angles of the two protons scattered in quasi-elastic kinematics, the decay of 16F into 15O (including gamma decays from excited states) and a proton, as well as the 15O+p relative-energy spectrum and the 16F momentum distributions. The latter two quantities allow an independent and consistent determination of the ratio of l=0 and l=2 motion of the valence protons in 17Ne. With a resulting relatively small l=0 component of only around 35(3)%, it is concluded that 17Ne exhibits a rather modest halo character only. The quantitative agreement of the two values deduced from the energy spectrum and the momentum distributions supports the theoretical treatment of the calculation of momentum distributions after quasi-free knockout reactions at high energies by taking into account distortions based on the Glauber theory. Moreover, the experimental data allow the separation of valence-proton knockout and knockout from the 15O core. The latter process contributes with 11.8(3.1) mb around 40% to the total proton-knockout cross section of 30.3(2.3) mb, which explains previously reported contradicting conclusions derived from inclusive cross sections., Comment: 7 pages, 5 figures

Published
2021
Full Text
View/download PDF

6. $\boldsymbol{N=32}$ shell closure below calcium: Low-lying structure of $^{50}$Ar

Author

Cortés, M. L., Rodriguez, W., Doornenbal, P., Obertelli, A., Holt, J. D., Menéndez, J., Ogata, K., Schwenk, A., Shimizu, N., Simonis, J., Utsuno, Y., Yoshida, K., Achouri, L., Baba, H., Browne, F., Calvet, D., Château, F., Chen, S., Chiga, N., Corsi, A., Delbart, A., Gheller, J-M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Liu, H. N., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gašparić, I., Gerst, R. -B., Gibelin, J., Hahn, K. I., Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Söderström, P. -A., Sohler, D., Takeuchi, S., Toernqvist, H., Vaquero, V., Wagner, V., Wang, S., Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Subjects
Nuclear Experiment
Abstract

Low-lying excited states in the $N=32$ isotope $^{50}$Ar were investigated by in-beam $\gamma$-ray spectroscopy following proton- and neutron-knockout, multi-nucleon removal, and proton inelastic scattering at the RIKEN Radioactive Isotope Beam Factory. The energies of the two previously reported transitions have been confirmed, and five additional states are presented for the first time, including a candidate for a 3$^-$ state. The level scheme built using $\gamma\gamma$ coincidences was compared to shell-model calculations in the $sd-pf$ model space, and to ab initio predictions based on chiral two- and three-nucleon interactions. Theoretical proton- and neutron-knockout cross sections suggest that two of the new transitions correspond to $2^+$ states, while the previously proposed $4^+$ state could also correspond to a $2^+$ state., Comment: Accepted for Phys. Rev. C

Published
2020
Full Text
View/download PDF

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

Author

Cortés, M. L., Rodriguez, W., Doornenbal, P., Obertelli, A., Holt, J. D., Lenzi, S. M., Menéndez, J., Nowacki, F., Ogata, K., Poves, A., Rodríguez, T. R., Schwenk, A., Simonis, J., Stroberg, S. R., Yoshida, K., Achouri, L., Baba, H., Browne, F., Calvet, D., Château, F., Chen, S., Chiga, N., Corsi, A., Delbart, A., Gheller, J-M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Liu, H. N., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gašparić, I., Gerst, R. -B., Gibelin, J., Hahn, K. I., Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Sohler, D., Söderström, P. -A., Takeuchi, S., Toernqvist, H., Vaquero, V., Wagner, V., Wang, S., Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Excited states in the $N=40$ isotone $^{62}$Ti were populated via the $^{63}$V$(p,2p)$$^{62}$Ti reaction at $\sim$200~MeV/u at the Radioactive Isotope Beam Factory and studied using $\gamma$-ray spectroscopy. The energies of the $2^+_1 \rightarrow 0^{+}_{\mathrm{gs}}$ and $4^+_1 \rightarrow 2^+_1$ transitions, observed here for the first time, indicate a deformed $^{62}$Ti ground state. These energies are increased compared to the neighboring $^{64}$Cr and $^{66}$Fe isotones, suggesting a small decrease of quadrupole collectivity. The present measurement is well reproduced by large-scale shell-model calculations based on effective interactions, while ab initio and beyond mean-field calculations do not yet reproduce our findings. The shell-model calculations for $^{62}$Ti show a dominant configuration with four neutrons excited across the $N=40$ gap. Likewise, they indicate that the $N=40$ island of inversion extends down to $Z=20$, disfavoring a possible doubly magic character of the elusive $^{60}$Ca.

Published
2019
Full Text
View/download PDF

8. Study of multi-neutron systems with SAMURAI spectrometer

Author

Yang, Z. H., Marqués, F. M., Achouri, N. L., Ahn, D. S., Aumann, T., Baba, H., Beaumel, D., Böhmer, M., Boretzky, K., Caamaño, M., Chen, S., Chiga, N., Cortés, M. L., Cortina, D., Doornenbal, P., Douma, C. A., Dufter, F., Feng, J., Fernández-Domínguez, B., Elekes, Z., Forsberg, U., Fujino, T., Fukuda, N., Gašparić, I., Ge, Z., Gernhäuser, R., Gheller, J. M., Gibelin, J., Gillibert, A., Godoy, B. M., Halász, Z., Harada, T., Harakeh, M. N., Hirayama, A., Huang, S. W., Inabe, N., Isobe, T., Kahlbow, J., Kalantar-Nayestanaki, N., Kim, D., Kim, S., Knösel, M. A., Kobayashi, T., Kondo, Y., Koseoglou, P., Kubota, Y., Kuti, I., Lehr, C., Li, P. J., Liu, Y., Maeda, Y., Masuoka, S., Matsumoto, M., Mayer, J., Miki, H., Miwa, M., Murray, I., Nakamura, T., Obertelli, A., Orr, N., Otsu, H., Panin, V., Park, S., Parlog, M., Paschalis, S., Potlog, M., Reichert, S., Revel, A., Rossi, D., Saito, A., Sasano, M., Sato, H., Scheit, H., Schindler, F., Shimada, T., Shimizu, Y., Shimoura, S., Stefan, I., Storck, S., Stuhl, L., Suzuki, H., Symochko, D., Takeda, H., Takeuchi, S., Tanaka, J., Togano, Y., Tomai, T., Tscheuschner, H. T. Törnqvsit. J., Uesaka, T., Wagner, V., Wimmer, K., Yamada, H., Yang, B., Yang, L., Yasuda, Y., Yoneda, K., Zanetti, L., and Zenihiro, J.

Subjects
Nuclear Experiment
Abstract

The tetraneutron has been drawing the attention of the nuclear physics community for decades, but a firm conclusion on its existence and properties is still far from being reached despite many experimental and theoretical efforts. New measurements have recently been performed at RIBF with the SAMURAI spectrometer by applying complementary reaction probes, which will help to pin down the properties of this four-neutron system., Comment: 5 pages, 2 figures, conference proceedings of XXII International Conference on Few-Body Problems in Physics (FB22), Caen, France, July 2018

Published
2019

9. Diverse mechanisms in proton knockout reactions from the Borromean nucleus 17Ne

Author

Wamers, F., Lehr, C., Marganiec-Gałązka, J., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernández, P. Díaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Le Bleis, T., Lemmon, R., Litvinov, Yu. A., Mahata, K., Müntz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Sümmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Published
2023
Full Text
View/download PDF

10. How Robust is the N = 34 Subshell Closure? First Spectroscopy of $^{52}$Ar

Author

Liu, H. N., Obertelli, A., Doornenbal, P., Bertulani, C. A., Hagen, G., Holt, J. D., Jansen, G. R., Morris, T. D., Schwenk, A., Stroberg, R., Achouri, N., Baba, H., Browne, F., Calvet, D., Château, F., Chen, S., Chiga, N., Corsi, A., Cortés, M. L., Delbart, A., Gheller, J. -M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gašparić, I., Gerst, R. -B., Gibelin, J., Hahn, K. I., Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Sohler, D., Söderström, P. -A., Takeuchi, S., Törnqvist, H., Vaquero, V., Wagner, V., Wang, S., Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

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

Published
2018
Full Text
View/download PDF

11. Observation of a correlated free four-neutron system

Author

Duer, M., Aumann, T., Gernhäuser, R., Panin, V., Paschalis, S., Rossi, D. M., Achouri, N. L., Ahn, D., Baba, H., Bertulani, C. A., Böhmer, M., Boretzky, K., Caesar, C., Chiga, N., Corsi, A., Cortina-Gil, D., Douma, C. A., Dufter, F., Elekes, Z., Feng, J., Fernández-Domínguez, B., Forsberg, U., Fukuda, N., Gasparic, I., Ge, Z., Gheller, J. M., Gibelin, J., Gillibert, A., Hahn, K. I., Halász, Z., Harakeh, M. N., Hirayama, A., Holl, M., Inabe, N., Isobe, T., Kahlbow, J., Kalantar-Nayestanaki, N., Kim, D., Kim, S., Kobayashi, T., Kondo, Y., Körper, D., Koseoglou, P., Kubota, Y., Kuti, I., Li, P. J., Lehr, C., Lindberg, S., Liu, Y., Marqués, F. M., Masuoka, S., Matsumoto, M., Mayer, J., Miki, K., Monteagudo, B., Nakamura, T., Nilsson, T., Obertelli, A., Orr, N. A., Otsu, H., Park, S. Y., Parlog, M., Potlog, P. M., Reichert, S., Revel, A., Saito, A. T., Sasano, M., Scheit, H., Schindler, F., Shimoura, S., Simon, H., Stuhl, L., Suzuki, H., Symochko, D., Takeda, H., Tanaka, J., Togano, Y., Tomai, T., Törnqvist, H. T., Tscheuschner, J., Uesaka, T., Wagner, V., Yamada, H., Yang, B., Yang, L., Yang, Z. H., Yasuda, M., Yoneda, K., Zanetti, L., Zenihiro, J., and Zhukov, M. V.

Published
2022
Full Text
View/download PDF

12. A foam model highlights the differences of the macro- and microrheology of respiratory horse mucus

Author

Gros, A., Torge, A., Schaefer, U. F., Schneider, M., Lehr, C. M., and Wagner, C.

Subjects
Condensed Matter - Soft Condensed Matter, Condensed Matter - Materials Science, Physics - Biological Physics, Quantitative Biology - Biomolecules
Abstract

Native horse mucus is characterized with micro- and macrorheology and compared to hydroxyethylcellulose (HEC) gel as a model. Both systems show comparable viscoelastic properties on the microscale and for the HEC the macrorheology is in good agreement with the microrheology. For the mucus, the viscoelastic moduli on the macroscale are several orders of magnitude larger than on the microscale. Large amplitude oscillatory shear experiments show that the mucus responds nonlinearly at much smaller deformations than HEC. This behavior fosters the assumption that the mucus has a foam like structure on the microscale compared to the typical mesh like structure of the HEC, a model that is supported by cryogenic-scanning-electron-microscopy (CSEM) images. These images allow also to determine the relative amount of volume that is occupied by the pores and the scaffold. Consequently, we can estimate the elastic modulus of the scaffold. We conclude that this particular foam like microstructure should be considered as a key factor for the transport of particulate matter which plays a central role in mucus function with respect to particle penetration. The mesh properties composed of very different components are responsible for macroscopic and microscopic behavior being part of particles fate after landing., Comment: Accepted for publication in the Journal of the Mechanical Behavior of Biomedical Materials

Published
2017

13. A new Time-of-flight detector for the R3B setup

Author

Heil, M., Kelić-Heil, A., Bott, L., Almusidi, T., Alvarez-Pol, H., Atar, L., Atkins, L., Aumann, T., Benlliure, J., Boretzky, K., Brückner, B., Cabanelas, P., Caesar, C., Casarejos, E., Cederkall, J., Chulkov, L., Corsi, A., Dueñas, J., Erbacher, P., Rodriguez, S. Escribano, Falduto, A., Feijoo, M., Frotscher, A., Frühauf, J., Gašparić, I., Borge, M. J. G., Gerbig, J., Gernhäuser, R., Gilbert, M., Glorius, J., Gnoffo, B., Göbel, K., Caamaño, D. Gonzalez, Grein, A., Hartig, A.-L., Heggen, H., Heine, M., Heinz, A., Holl, M., Homm, I., Horvat, A., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kamenyero, A., Khodaparast, A., Kiselev, O., Klenze, P., Knösel, M., Koch, K., Körper, D., Kröll, T., Kurtulgil, D., Kurz, N., Löher, B., Langer, C., Lehr, C., Litvinov, Y., Liu, H., Morales, S. Murillo, Nácher, E., Nilsson, T., Park, J., Paschalis, S., Pellegri, L., Perea, A., Petri, M., Pohl, T., Ponnath, L., Popočovski, R., Reifarth, R., Rhee, H.-B., Sanchez, J. L. Rodriguez, Rossi, D., Sürder, C., Sánchez-Benítez, A. M., Savran, D., Scheit, H., Simon, H., Slavkovská, Z., Storck-Dutine, S., Sun, Y., Törnqvist, H. T., Tanaka, J., Tengblad, O., Thomas, B., Varga, L., Volknandt, M., Wagner, V., Wamers, F., and Zanetti, L.

Published
2022
Full Text
View/download PDF

14. Study of Multi-neutron Systems with SAMURAI Spectrometer

Author

Yang, Z. H., Marqués, F. M., Achouri, N. L., Ahn, D. S., Aumann, T., Baba, H., Beaumel, D., Böhmer, M., Boretzky, K., Caamaño, M., Chen, S., Chiga, N., Cortés, M. L., Cortina, D., Doornenbal, P., Douma, C. A., Dufter, F., Feng, J., Fernández-Domínguez, B., Elekes, Z., Forsberg, U., Fujino, T., Fukuda, N., Gašparić, I., Ge, Z., Gernhäuser, R., Gheller, J. M., Gibelin, J., Gillibert, A., Godoy, B. M., Halász, Z., Harada, T., Harakeh, M. N., Hirayama, A., Huang, S. W., Inabe, N., Isobe, T., Kahlbow, J., Kalantar-Nayestanaki, N., Kim, D., Kim, S., Knösel, M. A., Kobayashi, T., Kondo, Y., Koseoglou, P., Kubota, Y., Kuti, I., Lehr, C., Li, P. J., Liu, Y., Maeda, Y., Masuoka, S., Matsumoto, M., Mayer, J., Miki, H., Miwa, M., Murray, I., Nakamura, T., Obertelli, A., Orr, N. A., Otsu, H., Panin, V., Park, S., Parlog, M., Paschalis, S., Potlog, M., Reichert, S., Revel, A., Rossi, D., Saito, A., Sasano, M., Sato, H., Scheit, H., Schindler, F., Shimada, T., Shimizu, Y., Shimoura, S., Stefan, I., Storck, S., Stuhl, L., Suzuki, H., Symochko, D., Takeda, H., Takeuchi, S., Tanaka, J., Togano, Y., Tomai, T., Törnqvsit, H. T., Tscheuschner, J., Uesaka, T., Wagner, V., Wimmer, K., Yamada, H., Yang, B., Yang, L., Yasuda, Y., Yoneda, K., Zanetti, L., Zenihiro, J., Orr, N. A., editor, Ploszajczak, M., editor, Marqués, F. M., editor, and Carbonell, J., editor

Published
2020
Full Text
View/download PDF

15. Experimental study of ⁴n with ⁸He(p,2p) reaction

Author

Huang, S. W., Yang, H., Marqués, F. M., Achouri, N. L., Ahn, D. S., Aumann, T., Baba, H., Beaumel, D., Böhmer, M., Boretzky, K., Caamaño, M., Chen, S., Chiga, N., Cortés, M. L., Cortina, D., Doornenbal, P., Douma, C. A., Dufter, F., Feng, J., Fernández-Domínguez, B., Elekes, Z., Forsberg, U., Fujino, T., Fukuda, N., Gašparić, I., Ge, Z., Gernhäuser, R., Gheller, J. M., Gibelin, J., Gillibert, A., Godoy, B. M., Halász, Z., Harada, T., Harakeh, M. N., Hirayama, A., Inabe, N., Isobe, T., Kahlbow, J., Kalantar-Nayestanaki, N., Kim, D., Kim, S., Knösel, M. A., Kobayashi, T., Kondo, Y., Koseoglou, P., Kubota, Y., Kuti, I., Lehr, C., Li, P. J., Liu, Y., Maeda, Y., Masuoka, S., Matsumoto, M., Mayer, J., Miki, H., Miwa, M., Murray, I., Nakamura, T., Obertelli, A., Orr, N., Otsu, H., Panin, V., Park, S., Parlog, M., Paschalis, S., Potlog, M., Reichert, S., Revel, A., Rossi, D., Saito, A., Sasano, M., Sato, H., Scheit, H., Schindler, F., Shimada, T., Shimizu, Y., Shimoura, S., Stefan, I., Storck, S., Stuhl, L., Suzuki, H., Symochko, D., Takeda, H., Takeuchi, S., Tanaka, J., Togano, Y., Tomai, T., Törnqvsit, H. T., Tscheuschner, J., Uesaka, T., Wagner, V., Wimmer, K., Yamada, H., Yang, B., Yang, L., Yasuda, Y., Yoneda, K., Zanetti, L., Zenihiro, J., Elidiano, T., Lenain, C., Huang, S. W., Yang, H., Marqués, F. M., Achouri, N. L., Ahn, D. S., Aumann, T., Baba, H., Beaumel, D., Böhmer, M., Boretzky, K., Caamaño, M., Chen, S., Chiga, N., Cortés, M. L., Cortina, D., Doornenbal, P., Douma, C. A., Dufter, F., Feng, J., Fernández-Domínguez, B., Elekes, Z., Forsberg, U., Fujino, T., Fukuda, N., Gašparić, I., Ge, Z., Gernhäuser, R., Gheller, J. M., Gibelin, J., Gillibert, A., Godoy, B. M., Halász, Z., Harada, T., Harakeh, M. N., Hirayama, A., Inabe, N., Isobe, T., Kahlbow, J., Kalantar-Nayestanaki, N., Kim, D., Kim, S., Knösel, M. A., Kobayashi, T., Kondo, Y., Koseoglou, P., Kubota, Y., Kuti, I., Lehr, C., Li, P. J., Liu, Y., Maeda, Y., Masuoka, S., Matsumoto, M., Mayer, J., Miki, H., Miwa, M., Murray, I., Nakamura, T., Obertelli, A., Orr, N., Otsu, H., Panin, V., Park, S., Parlog, M., Paschalis, S., Potlog, M., Reichert, S., Revel, A., Rossi, D., Saito, A., Sasano, M., Sato, H., Scheit, H., Schindler, F., Shimada, T., Shimizu, Y., Shimoura, S., Stefan, I., Storck, S., Stuhl, L., Suzuki, H., Symochko, D., Takeda, H., Takeuchi, S., Tanaka, J., Togano, Y., Tomai, T., Törnqvsit, H. T., Tscheuschner, J., Uesaka, T., Wagner, V., Wimmer, K., Yamada, H., Yang, B., Yang, L., Yasuda, Y., Yoneda, K., Zanetti, L., Zenihiro, J., Elidiano, T., and Lenain, C.

Abstract

The tetraneutron has attracted the attention of nuclear physicists during the past decades, but there is still no unambiguous confirmation of its existence or non-existence. A new experiment based on ⁸He(p,2p)⁷H{t+⁴ n} reaction, with direct detection of the four neutrons, has been carried out at RIBF, which can hopefully help to draw a definite conclusion on the tetraneutron system.

Published
2024

16. Experimental Study of 4n by Directly Detecting the Decay Neutrons

Author

Huang, S. W., Yang, Z. H., Marqués, F. M., Achouri, N. L., Ahn, D. S., Aumann, T., Baba, H., Beaumel, D., Böhmer, M., Boretzky, K., Caamaño, M., Chen, S., Chiga, N., Cortés, M. L., Cortina, D., Doornenbal, P., Douma, C. A., Dufter, F., Feng, J., Fernández-Domínguez, B., Elekes, Z., Forsberg, U., Fujino, T., Fukuda, N., Gašparić, I., Ge, Z., Gernhäuser, R., Gheller, J. M., Gibelin, J., Gillibert, A., Halász, Z., Harada, T., Harakeh, M. N., Hirayama, A., Inabe, N., Isobe, T., Kahlbow, J., Kalantar-Nayestanaki, N., Kim, D., Kim, S., Kiyotake, S., Kobayashi, T., Kondo, Y., Koseoglou, P., Kubota, Y., Kuti, I., Lehr, C., Lenain, C., Li, P. J., Liu, Y., Maeda, Y., Masuoka, S., Matsumoto, M., Matta, A., Mayer, J., Miki, H., Miwa, M., Monteagudo, B., Murray, I., Nakamura, T., Obertelli, A., Orr, N. A., Otsu, H., Panin, V., Park, S., Parlog, M., Paschalis, S., Potlog, M., Reichert, S., Revel, A., Rossi, D., Saito, A., Sasano, M., Sato, H., Scheit, H., Schindler, F., Shimada, T., Shimizu, Y., Shimoura, S., Simon, H., Stefan, I., Storck, S., Stuhl, L., Suzuki, H., Symochko, D., Takeda, H., Takeuchi, S., Tanaka, J., Togano, Y., Tomai, T., Törnqvist, H. T., Tronchin, E., Tscheuschner, J., Uesaka, T., Wagner, V., Wimmer, K., Yamada, H., Yang, B., Yang, L., Yasuda, Y., Yoneda, K., Zanetti, L., and Zenihiro, J.

Published
2021
Full Text
View/download PDF

17. Study of Multi-neutron Systems with SAMURAI Spectrometer

Author

Yang, Z. H., primary, Marqués, F. M., additional, Achouri, N. L., additional, Ahn, D. S., additional, Aumann, T., additional, Baba, H., additional, Beaumel, D., additional, Böhmer, M., additional, Boretzky, K., additional, Caamaño, M., additional, Chen, S., additional, Chiga, N., additional, Cortés, M. L., additional, Cortina, D., additional, Doornenbal, P., additional, Douma, C. A., additional, Dufter, F., additional, Feng, J., additional, Fernández-Domínguez, B., additional, Elekes, Z., additional, Forsberg, U., additional, Fujino, T., additional, Fukuda, N., additional, Gašparić, I., additional, Ge, Z., additional, Gernhäuser, R., additional, Gheller, J. M., additional, Gibelin, J., additional, Gillibert, A., additional, Godoy, B. M., additional, Halász, Z., additional, Harada, T., additional, Harakeh, M. N., additional, Hirayama, A., additional, Huang, S. W., additional, Inabe, N., additional, Isobe, T., additional, Kahlbow, J., additional, Kalantar-Nayestanaki, N., additional, Kim, D., additional, Kim, S., additional, Knösel, M. A., additional, Kobayashi, T., additional, Kondo, Y., additional, Koseoglou, P., additional, Kubota, Y., additional, Kuti, I., additional, Lehr, C., additional, Li, P. J., additional, Liu, Y., additional, Maeda, Y., additional, Masuoka, S., additional, Matsumoto, M., additional, Mayer, J., additional, Miki, H., additional, Miwa, M., additional, Murray, I., additional, Nakamura, T., additional, Obertelli, A., additional, Orr, N. A., additional, Otsu, H., additional, Panin, V., additional, Park, S., additional, Parlog, M., additional, Paschalis, S., additional, Potlog, M., additional, Reichert, S., additional, Revel, A., additional, Rossi, D., additional, Saito, A., additional, Sasano, M., additional, Sato, H., additional, Scheit, H., additional, Schindler, F., additional, Shimada, T., additional, Shimizu, Y., additional, Shimoura, S., additional, Stefan, I., additional, Storck, S., additional, Stuhl, L., additional, Suzuki, H., additional, Symochko, D., additional, Takeda, H., additional, Takeuchi, S., additional, Tanaka, J., additional, Togano, Y., additional, Tomai, T., additional, Törnqvsit, H. T., additional, Tscheuschner, J., additional, Uesaka, T., additional, Wagner, V., additional, Wimmer, K., additional, Yamada, H., additional, Yang, B., additional, Yang, L., additional, Yasuda, Y., additional, Yoneda, K., additional, Zanetti, L., additional, and Zenihiro, J., additional

Published
2020
Full Text
View/download PDF

18. Problems from the workshop on 'Automorphisms of Curves' (Leiden, August, 2004)

Author

Bouw, I., Chinburg, T., Cornelissen, G., Gasbarri, C., Glass, D., Lehr, C., Matignon, M., Oort, F., Pries, R., and Wewers, S.

Subjects
Mathematics - Algebraic Geometry, Mathematics - Number Theory, 14H37
Abstract

Contents: Rational functions with given monodromy on generic curves (I. Bouw & S. Wewers); Can deformation rings of group representations not be local complete intersections? (T. Chinburg); Lifting an automorphism group to finite characteristic (G. Cornelissen); Flat connections and representations of the fundamental group in characteristic p>0 (C. Gasbarri) Questions on p-torsion of hyperelliptic curves (D. Glass & R. Pries); Automorphisms of curves and stable reduction (C. Lehr & M. Matignon); p-groups as automorphism groups of curves in characteristic p; Lifting Galois covers of smooth curves (M. Matignon); Abelian varieties isogenous to a Jacobian (F. Oort); Minimal maximal number of automorphisms of curves (F. Oort), Comment: 47 pages; edited by G. Cornelissen and F. Oort

Published
2004

19. Level structures of 56,58Ca cast doubt on a doubly magic 60Ca

Author

Chen, S., primary, Browne, F., additional, Doornenbal, P., additional, Lee, J., additional, Obertelli, A., additional, Tsunoda, Y., additional, Otsuka, T., additional, Chazono, Y., additional, Hagen, G., additional, Holt, J.D., additional, Jansen, G.R., additional, Ogata, K., additional, Shimizu, N., additional, Utsuno, Y., additional, Yoshida, K., additional, Achouri, N.L., additional, Baba, H., additional, Calvet, D., additional, Château, F., additional, Chiga, N., additional, Corsi, A., additional, Cortés, M.L., additional, Delbart, A., additional, Gheller, J.-M., additional, Giganon, A., additional, Gillibert, A., additional, Hilaire, C., additional, Isobe, T., additional, Kobayashi, T., additional, Kubota, Y., additional, Lapoux, V., additional, Liu, H.N., additional, Motobayashi, T., additional, Murray, I., additional, Otsu, H., additional, Panin, V., additional, Paul, N., additional, Rodriguez, W., additional, Sakurai, H., additional, Sasano, M., additional, Steppenbeck, D., additional, Stuhl, L., additional, Sun, Y.L., additional, Togano, Y., additional, Uesaka, T., additional, Wimmer, K., additional, Yoneda, K., additional, Aktas, O., additional, Aumann, T., additional, Chung, L.X., additional, Flavigny, F., additional, Franchoo, S., additional, Gasparic, I., additional, Gerst, R.-B., additional, Gibelin, J., additional, Hahn, K.I., additional, Kim, D., additional, Koiwai, T., additional, Kondo, Y., additional, Koseoglou, P., additional, Lehr, C., additional, Linh, B.D., additional, Lokotko, T., additional, MacCormick, M., additional, Moschner, K., additional, Nakamura, T., additional, Park, S.Y., additional, Rossi, D., additional, Sahin, E., additional, Söderström, P.-A., additional, Sohler, D., additional, Takeuchi, S., additional, Törnqvist, H., additional, Vaquero, V., additional, Wagner, V., additional, Wang, S., additional, Werner, V., additional, Xu, X., additional, Yamada, H., additional, Yan, D., additional, Yang, Z., additional, Yasuda, M., additional, and Zanetti, L., additional

Published
2023
Full Text
View/download PDF

20. Diverse mechanisms in proton knockout reactions from the Borromean nucleus $$^{17}\text {Ne}$$

Author

Wamers, F., primary, Lehr, C., additional, Marganiec-Gałązka, J., additional, Aksouh, F., additional, Aksyutina, Yu., additional, Alvarez-Pol, H., additional, Atar, L., additional, Aumann, T., additional, Beceiro-Novo, S., additional, Bertulani, C. A., additional, Boretzky, K., additional, Borge, M. J. G., additional, Caesar, C., additional, Chartier, M., additional, Chatillon, A., additional, Chulkov, L. V., additional, Cortina-Gil, D., additional, Fernández, P. Díaz, additional, Emling, H., additional, Ershova, O., additional, Fraile, L. M., additional, Fynbo, H. O. U., additional, Galaviz, D., additional, Geissel, H., additional, Heil, M., additional, Holl, M., additional, Johansson, H. T., additional, Jonson, B., additional, Karagiannis, C., additional, Kiselev, O. A., additional, Kratz, J. V., additional, Kulessa, R., additional, Kurz, N., additional, Langer, C., additional, Lantz, M., additional, Le Bleis, T., additional, Lemmon, R., additional, Litvinov, Yu. A., additional, Mahata, K., additional, Müntz, C., additional, Nilsson, T., additional, Nociforo, C., additional, Ott, W., additional, Panin, V., additional, Paschalis, S., additional, Perea, A., additional, Plag, R., additional, Reifarth, R., additional, Richter, A., additional, Riisager, K., additional, Rodriguez-Tajes, C., additional, Rossi, D., additional, Savran, D., additional, Scheit, H., additional, Schrieder, G., additional, Schrock, P., additional, Simon, H., additional, Stroth, J., additional, Sümmerer, K., additional, Tengblad, O., additional, Weick, H., additional, and Wimmer, C., additional

Published
2023
Full Text
View/download PDF

21. Level Structures of $^{56,58}$Ca Cast Doubt on a doubly magic $^{60}$Ca

Author

Chen, S, Browne, F, Doornenbal, P, Lee, J, Obertelli, A, Tsunoda, Y, Otsuka, T, Chazono, Y, Hagen, G, Holt, J.D, Jansen, G.R, Ogata, K, Shimizu, N, Utsuno, Y, Yoshida, K, Achouri, N.L, Baba, H, Calvet, D, Château, F, Chiga, N, Corsi, A, Cortés, M.L, Delbart, A, Gheller, J.-M, Giganon, A, Gillibert, A, Hilaire, C, Isobe, T, Kobayashi, T, Kubota, Y, Lapoux, V, Liu, H.N, Motobayashi, T, Murray, I, Otsu, H, Panin, V, Paul, N, Rodriguez, W, Sakurai, H, Sasano, M, Steppenbeck, D, Stuhl, L, Sun, Y.L, Togano, Y, Uesaka, T, Wimmer, K, Yoneda, K, Aktas, O, Aumann, T, Chung, L.X, Flavigny, F, Franchoo, S, Gasparic, I, Gerst, R.-B, Gibelin, J, Hahn, K.I, Kim, D, Koiwai, T, Kondo, Y, Koseoglou, P, Lehr, C, Linh, B.D, Lokotko, T, Maccormick, M, Moschner, K, Nakamura, T, Park, S.Y, Rossi, D, Sahin, E, Söderström, P.-A, Sohler, D, Takeuchi, S, Törnqvist, H, Vaquero, V, Wagner, V, Wang, S, Werner, V, Xu, X, Yamada, H, Yan, D, Yang, Z, Yasuda, M, Zanetti, L, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Laboratoire Kastler Brossel (LKB [Collège de France]), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear Theory (nucl-th), [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, FOS: Physical sciences, Shell evolution, Nuclear Experiment (nucl-ex), Nuclear Experiment, Ray spectroscopy
Abstract

Gamma decays were observed in $^{56}$Ca and $^{58}$Ca following quasi-free one-proton knockout reactions from $^{57,59}$Sc beams at $\approx 200$ MeV/nucleon. For $^{56}$Ca, a $\gamma$ ray transition was measured to be 1456(12) keV, while for $^{58}$Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the $2^+_1 \rightarrow 0^+_{gs}$ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for $2^+_1$ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the $N$ = 34 shell. Its constituents, the $0f_{5/2}$ and $0g_{9/2}$ orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic $^{60}$Ca and potentially drives the dripline of Ca isotopes to $^{70}$Ca or even beyond., Comment: 8 pages, 3 figures

Published
2023
Full Text
View/download PDF

23. Diverse mechanisms in proton knockout reactions from the Borromean nucleus Ne-17

Author

Wamers, F., Lehr, C., Marganiec-Galazka, J., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernandez, P. Diaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, Mattias, Le Bleis, T., Lemmon, R., Litvinov, Yu. A., Mahata, K., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Suemmerer, K., Tengblad, O., Weick, H., Wimmer, C., Wamers, F., Lehr, C., Marganiec-Galazka, J., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernandez, P. Diaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, Mattias, Le Bleis, T., Lemmon, R., Litvinov, Yu. A., Mahata, K., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Suemmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Abstract

Nucleon knockout experiments using beryllium or carbon targets reveal a strong dependence of the quenching factors, i.e., the ratio (Rs) of theoretical to the experimental spectroscopic factors (C2S), on the proton-neutron asymmetry in the nucleus under study. However, this dependence is greatly reduced when a hydrogen target is used. To understand this phenomenon, exclusive H-1(Ne-17, 2p F-16) and inclusive C-12(Ne-17, 2p 1(6)F)X, 1(2)C(Ne-17, F-16)X as well as 1H(Ne-17,(16) F)X(X-denotes undetected reaction products) reactions with F-16 in the ground and excited states were anal- ysed. The longitudinal momentum distribution of F-16 and the correlations between the detached protons were studied. In the case of the carbon target, there is a significant deviation from the predictions of the eikonal model. The eikonal approximation was used to extract spectroscopic factor values (CS)-S-2. The experimental (CS)-S-2 value obtained with C target is markedly lower than that for H target. This is interpreted as rescattering due to simultaneous nucleon knockout from both reaction partners, Ne-17 and C-12.

Published
2023
Full Text
View/download PDF

24. Diverse mechanisms in proton knockout reactions from the Borromean nucleus 17Ne

Author

Chalmers University of Technology, Federal Ministry of Education and Research (Germany), Helmholtz International Center for FAIR, Swedish Research Council, Ministerio de Ciencia e Innovación (España), Department of Energy (US), Jonson, B. [0000-0002-9697-9115], Wamers, F., Lehr, C., Marganiec-Gałązka, J., Aksouh, F., Aksyutina, Yu, Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., García Borge, María José, Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernández, P. Díaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O.U., Galaviz, D., Geissel, H., Heil, M., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Le Bleis, T., Lemmon, R., Litvinov, Yu A., Mahata, K., Müntz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, Ángel, Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Sümmerer, K., Tengblad, Olof, Weick, H., Wimmer, C., Chalmers University of Technology, Federal Ministry of Education and Research (Germany), Helmholtz International Center for FAIR, Swedish Research Council, Ministerio de Ciencia e Innovación (España), Department of Energy (US), Jonson, B. [0000-0002-9697-9115], Wamers, F., Lehr, C., Marganiec-Gałązka, J., Aksouh, F., Aksyutina, Yu, Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., García Borge, María José, Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernández, P. Díaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O.U., Galaviz, D., Geissel, H., Heil, M., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Le Bleis, T., Lemmon, R., Litvinov, Yu A., Mahata, K., Müntz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, Ángel, Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Sümmerer, K., Tengblad, Olof, Weick, H., and Wimmer, C.

Abstract

Nucleon knockout experiments using beryllium or carbon targets reveal a strong dependence of the quenching factors, i.e., the ratio (R s) of theoretical to the experimental spectroscopic factors (C 2S), on the proton-neutron asymmetry in the nucleus under study. However, this dependence is greatly reduced when a hydrogen target is used. To understand this phenomenon, exclusive 1H (17Ne , 2p16F) and inclusive 12C(17Ne,2p16F)X , 12C (17Ne , 16F) X as well as 1H (17Ne , 16F) X (X-denotes undetected reaction products) reactions with 16F in the ground and excited states were analysed. The longitudinal momentum distribution of 16F and the correlations between the detached protons were studied. In the case of the carbon target, there is a significant deviation from the predictions of the eikonal model. The eikonal approximation was used to extract spectroscopic factor values C 2S . The experimental C 2S value obtained with C target is markedly lower than that for H target. This is interpreted as rescattering due to simultaneous nucleon knockout from both reaction partners, 17Ne and 12C .

Published
2023

26. Level structures of Ca cast doubt on a doubly magic Ca

Author

Chen, S., Browne, F., Doornenbal, P., Lee, J., Obertelli, A., Tsunoda, Y., Otsuka, T., Chazono, Y., Hagen, G., Holt, J.D., Jansen, G.R., Ogata, K., Shimizu, N., Utsuno, Y., Yoshida, K., Achouri, N.L., Baba, H., Calvet, D., Château, F., Chiga, N., Corsi, A., Cortés, M.L., Delbart, A., Gheller, J.M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Liu, H.N., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y.L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L.X., Flavigny, F., Franchoo, S., Gasparic, I., Gerst, R.B., Gibelin, J., Hahn, K.I., Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lehr, C., Linh, B.D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S.Y., Rossi, D., Sahin, E., Söderström, P.A., Sohler, D., Takeuchi, S., Törnqvist, H., Vaquero, V., Wagner, V., Wang, S., Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Abstract

Gamma decays were observed in $^{56}$Ca and $^{58}$Ca following quasi-free one-proton knockout reactions from $^{57,59}$Sc beams at ≈200 MeV/nucleon. For $^{56}$Ca, a γ ray transition was measured to be 1456(12) keV, while for $^{58}$Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 21+→0gs+ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 21+ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 0f5/2 and 0g9/2 orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic $^{60}$Ca and potentially drives the dripline of Ca isotopes to $^{70}$Ca or even beyond.

Published
2023

30. Extended p 3 / 2 Neutron Orbital and the N = 32 Shell Closure in 52 Ca

Author

Enciu, M., Liu, H. N., Obertelli, A., Doornenbal, P., Nowacki, F., Ogata, K., Poves, A., Yoshida, K., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Château, F., Chen, S., Chiga, N., Corsi, A., Cortés, M. L., Delbart, A., Gheller, J.-M., Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V., Motobayashi, T., Murray, I., Otsu, H., Panin, V., Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y .L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gasparic, I., Gerst, R.-B., Gibelin, J., Hahn, K. I., Kim, D., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Li, P. J., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Söderström, P.-A., Sohler, D., Takeuchi, S., Toernqvist, H., Vaquero, Victor, Wagner, V., Wang, Li, Werner, V., Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., Zanetti, L., RIKEN Nishina Center for Accelerator-Based Science, German Research Foundation, Fundamental Research Funds for the Central Universities (China), Japan Society for the Promotion of Science, Ministerio de Ciencia e Innovación (España), Ministry of Science and Technology of Vietnam, National Research, Development and Innovation Office (Hungary), Federal Ministry of Science, Research and Economy (Germany), European Commission, Enciu, M., and Liu, H. N.

Abstract

7 pags., 3 figs., 1 tab., The one-neutron knockout from ^{52}Ca in inverse kinematics onto a proton target was performed at ∼230 MeV/nucleon combined with prompt γ spectroscopy. Exclusive quasifree scattering cross sections to bound states in ^{51}Ca and the momentum distributions corresponding to the removal of 1f_{7/2} and 2p_{3/2} neutrons were measured. The cross sections, interpreted within the distorted-wave impulse approximation reaction framework, are consistent with a shell closure at the neutron number N=32, found as strong as at N=28 and N=34 in Ca isotopes from the same observables. The analysis of the momentum distributions leads to a difference of the root-mean-square radii of the neutron 1f_{7/2} and 2p_{3/2} orbitals of 0.61(23) fm, in agreement with the modified-shell-model prediction of 0.7 fm suggesting that the large root-mean-square radius of the 2p_{3/2} orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number., We are grateful for the support of the RIKEN Nishina Center accelerator staff in the delivery of the primary beam and the BigRIPS team for preparing the secondary beams.We thank Y. Chazono for the 48Caðp; pnÞ knockout triple differential cross section calculations. M. E., H. N. L., A. O., T. A., I. G., C. L., D. R., H. T., V. W., and L. Z. acknowledge the support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project No. 279384907–SFB 1245. H. N. L. is supported by the Fundamental Research Funds for the Central Universities. K. O. acknowledges the support by Grants-in-Aid for Scientific Research from the JSPS (No. JP21H00125). A. P. is funded by Grant No. CEX2020-001007-S funded by MCIN/AEI/10.13039/ 501100011033 and PGC-2018-94583. Y. T. acknowledges the support from the JSPS Grant-in-Aid for Scientific Research Grants No. JP21H01114. B. D. L. and L. X. C. acknowledge support from the Vietnam Ministry of Science and Technology under Grant No. ĐTCB.01/21/VKHKTHN. D. S. acknowledges the National Research, Development and Innovation Fund of Hungary via project No. K128947. F. B. was supported by the RIKEN Special Postdoctoral Researcher Program. V. W. acknowledges the BMBF Grants No. 05P21RDFN1 and No. 05P21RDFN9. The development of M. I. N. O. S. has been supported by the European Research Council through the ERC Grant No. MINOS-258567.

Published
2022

31. Extended p3/2 Neutron Orbital and the N=32 Shell Closure in Ca52

Author

Enciu, M., primary, Liu, H. N., additional, Obertelli, A., additional, Doornenbal, P., additional, Nowacki, F., additional, Ogata, K., additional, Poves, A., additional, Yoshida, K., additional, Achouri, N. L., additional, Baba, H., additional, Browne, F., additional, Calvet, D., additional, Château, F., additional, Chen, S., additional, Chiga, N., additional, Corsi, A., additional, Cortés, M. L., additional, Delbart, A., additional, Gheller, J-M., additional, Giganon, A., additional, Gillibert, A., additional, Hilaire, C., additional, Isobe, T., additional, Kobayashi, T., additional, Kubota, Y., additional, Lapoux, V., additional, Motobayashi, T., additional, Murray, I., additional, Otsu, H., additional, Panin, V., additional, Paul, N., additional, Rodriguez, W., additional, Sakurai, H., additional, Sasano, M., additional, Steppenbeck, D., additional, Stuhl, L., additional, Sun, Y. L., additional, Togano, Y., additional, Uesaka, T., additional, Wimmer, K., additional, Yoneda, K., additional, Aktas, O., additional, Aumann, T., additional, Chung, L. X., additional, Flavigny, F., additional, Franchoo, S., additional, Gasparic, I., additional, Gerst, R.-B., additional, Gibelin, J., additional, Hahn, K. I., additional, Kim, D., additional, Kondo, Y., additional, Koseoglou, P., additional, Lee, J., additional, Lehr, C., additional, Li, P. J., additional, Linh, B. D., additional, Lokotko, T., additional, MacCormick, M., additional, Moschner, K., additional, Nakamura, T., additional, Park, S. Y., additional, Rossi, D., additional, Sahin, E., additional, Söderström, P.-A., additional, Sohler, D., additional, Takeuchi, S., additional, Toernqvist, H., additional, Vaquero, V., additional, Wagner, V., additional, Wang, S., additional, Werner, V., additional, Xu, X., additional, Yamada, H., additional, Yan, D., additional, Yang, Z., additional, Yasuda, M., additional, and Zanetti, L., additional

Published
2022
Full Text
View/download PDF

36. A first glimpse at the shell structure beyond Ca-54: Spectroscopy of K-55, Ca-55, and Ca-57

Author

Koiwai, T, Wimmer, K, Doornenbal, P, Obertelli, A, Barbieri, C, Duguet, T, Holt, JD, Miyagi, T, Navratil, P, Ogata, K, Shimizu, N, Soma, V, Utsuno, Y, Yoshida, K, Achouri, NL, Baba, H, Browne, F, Calvet, D, Chateau, F, Chen, S, Chiga, N, Corsi, A, Cortes, ML, Delbart, A, Gheller, J-M, Giganon, A, Gillibert, A, Hilaire, C, Isobe, T, Kobayashi, T, Kubota, Y, Lapoux, V, Liu, HN, Motobayashi, T, Murray, I, Otsu, H, Panin, V, Paul, N, Rodriguez, W, Sakurai, H, Sasano, M, Steppenbeck, D, Stuhl, L, Sun, YL, Togano, Y, Uesaka, T, Yoneda, K, Aktas, O, Aumann, T, Chung, LX, Flavigny, F, Franchoo, S, Gasparic, I, Gerst, R-B, Gibelin, J, Hahn, K, Kim, D, Kondo, Y, Koseoglou, P, Lee, J, Lehr, C, Linh, BD, Lokotko, T, MacCormick, M, Moschner, K, Nakamura, T, Park, SY, Rossi, D, Sahin, E, Soderstrom, P-A, Sohler, D, Takeuchi, S, Toernqvist, H, Vaquero, V, Wagner, V, Wang, S, Werner, V, Xu, X, Yamada, H, Yan, D, Yang, Z, Yasuda, M, and Zanetti, L

Subjects
MODEL, Science & Technology, Physics, Nuclear, gamma-ray spectroscopy, Physics, Physical Sciences, SCATTERING, Shell evolution, Astronomy & Astrophysics, MASSES, Physics, Particles & Fields, Radioactive beams
Abstract

ispartof: PHYSICS LETTERS B vol:827 status: published

Published
2022

37. Unveiling the two-proton halo character of 17Ne : Exclusive measurement of quasi-free proton-knockout reactions

Author

Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu, Álvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J.G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Díaz Fernández, P., Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O.U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D. H.H., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Le Bleis, T., Lemmon, R., Litvinov, Yu A., Löher, B., Mahata, K., Marganiec-Galązka, J., Müntz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Sümmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Abstract

The proton drip-line nucleus 17Ne is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the 17Ne(p,2p)16F→15⁎O+p quasi-free one-proton knockout reaction has been performed at GSI at around 500 MeV/nucleon beam energy. All particles resulting from the scattering process have been detected. The relevant reconstructed quantities are the angles of the two protons scattered in quasi-elastic kinematics, the decay of 16F into 15O (including γ decays from excited states) and a proton, as well as the 15O+p relative-energy spectrum and the 16F momentum distributions. The latter two quantities allow an independent and consistent determination of the fractions of l=0 and l=2 motion of the valence protons in 17Ne. With a resulting relatively small l=0 component of only around 35(3)%, it is concluded that 17Ne exhibits a rather modest halo character only. The quantitative agreement of the two values deduced from the energy spectrum and the momentum distributions supports the theoretical treatment of the calculation of momentum distributions after quasi-free knockout reactions at high energies by taking into account distortions based on the Glauber theory. Moreover, the experimental data allow the separation of valence-proton knockout and knockout from the 15O core. The latter process contributes with 11.8(3.1) mb around 40% to the total proton-knockout cross section of 30.3(2.3) mb, which explains previously reported contradicting conclusions derived from inclusive cross sections.

Published
2022

38. Unveiling the two-proton halo character of Ne-17 : Exclusive measurement of quasi-free proton-knockout reactions

Author

Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu, Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. , V, Cortina-Gil, D., Diaz Fernandez, P., Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D. H. H., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. , V, Kulessa, R., Kurz, N., Langer, C., Lantz, Mattias, Le Bleis, T., Lemmon, R., Litvinov, Yu A., Loeher, B., Mahata, K., Marganiec-Galazka, J., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V, Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Suemmerer, K., Tengblad, O., Weick, H., Wimmer, C., Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu, Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. , V, Cortina-Gil, D., Diaz Fernandez, P., Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D. H. H., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. , V, Kulessa, R., Kurz, N., Langer, C., Lantz, Mattias, Le Bleis, T., Lemmon, R., Litvinov, Yu A., Loeher, B., Mahata, K., Marganiec-Galazka, J., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V, Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Suemmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Abstract

The proton drip-line nucleus Ne-17 is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the Ne-17(p, 2p)F-16* -> O-15+p quasi-free one-proton knockout reaction has been performed at GSI at around 500MeV/nucleon beam energy. All particles resulting from the scattering process have been detected. The relevant reconstructed quantities are the angles of the two protons scattered in quasi-elastic kinematics, the decay of F-16 into O-15 (including gamma decays from excited states) and a proton, as well as the O-15+p relative-energy spectrum and the F-16 momentum distributions. The latter two quantities allow an independent and consistent determination of the fractions of l = 0 and l = 2 motion of the valence protons in Ne-17. With a resulting relatively small l = 0 component of only around 35(3)%, it is concluded that Ne-17 exhibits a rather modest halo character only. The quantitative agreement of the two values deduced from the energy spectrum and the momentum distributions supports the theoretical treatment of the calculation of momentum distributions after quasi-free knockout reactions at high energies by taking into account distortions based on the Glauber theory. Moreover, the experimental data allow the separation of valence-proton knockout and knockout from the O-15 core. The latter process contributes with 11.8(3.1) mb around 40% to the total proton-knockout cross section of 30.3(2.3) mb, which explains previously reported contradicting conclusions derived from inclusive cross sections. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).

Published
2022
Full Text
View/download PDF

39. A first glimpse at the shell structure beyond Ca-54: Spectroscopy of K-55, Ca-55, and Ca-57

Author

Koiwai, T., Wimmer, K., Doornenbal, P., Obertelli, A., Barbieri, C., Duguet, T., Holt, J. D., Miyagi, T., Navratil, P., Ogata, K., Shimizu, N., Soma, V, Utsuno, Y., Yoshida, K., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Chateau, F., Chen, S., Chiga, N., Corsi, A., Cortes, M. L., Delbart, A., Gheller, J-M, Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V, Liu, H. N., Motobayashi, T., Murray, I, Otsu, H., Panin, V, Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gasparic, I, Gerst, R-B, Gibelin, J., Hahn, K., I, Kim, D., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Soderstrom, P-A, Sohler, D., Takeuchi, S., Toernqvist, H., Vaquero, V., Wagner, V, Wang, S., Werner, V, Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., Zanetti, L., Koiwai, T., Wimmer, K., Doornenbal, P., Obertelli, A., Barbieri, C., Duguet, T., Holt, J. D., Miyagi, T., Navratil, P., Ogata, K., Shimizu, N., Soma, V, Utsuno, Y., Yoshida, K., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Chateau, F., Chen, S., Chiga, N., Corsi, A., Cortes, M. L., Delbart, A., Gheller, J-M, Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V, Liu, H. N., Motobayashi, T., Murray, I, Otsu, H., Panin, V, Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gasparic, I, Gerst, R-B, Gibelin, J., Hahn, K., I, Kim, D., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Soderstrom, P-A, Sohler, D., Takeuchi, S., Toernqvist, H., Vaquero, V., Wagner, V, Wang, S., Werner, V, Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Abstract

States in the N = 35 and 37 isotopes Ca-55,Ca-57 have been populated by direct proton-induced nucleon removal reactions from Sc-56,Sc-58 and Ca-56 beams at the RIBF. In addition, the (p, 2p) quasi-free single-proton removal reaction from Ca-56 was studied. Excited states in K-55, Ca-55, and Ca-57 were established for the first time via in-beam gamma-ray spectroscopy. Results for the proton and neutron removal reactions from Ca-56 to states in K-55 and Ca-55 for the level energies, excited state lifetimes, and exclusive cross sections agree well with state-of-the-art theoretical calculations using different approaches. The observation of a short-lived state in Ca-57 suggests a transition in the calcium isotopic chain from single-particle dominated states at N = 35 to collective excitations at N = 37. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).

Published
2022

40. Extended p3/2 Neutron Orbital and the N=32 Shell Closure in 52Ca

Author

Enciu, M., Liu, H. N., Obertelli, A., Doornenbal, P., Nowacki, F., Ogata, K., Poves, A., Yoshida, K., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Chateau, F., Chen, S., Chiga, N., Corsi, A., Cortes, M. L., Delbart, A., Gheller, J-M, Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V, Motobayashi, T., Murray, I, Otsu, H., Panin, V, Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gasparic, I, Gerst, R-B, Gibelin, J., Hahn, K., I, Kim, D., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Li, P. J., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Soderstrom, P-A, Sohler, D., Takeuchi, S., Toernqvist, H., Vaquero, V., Wagner, V, Wang, S., Werner, V, Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., Zanetti, L., Enciu, M., Liu, H. N., Obertelli, A., Doornenbal, P., Nowacki, F., Ogata, K., Poves, A., Yoshida, K., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Chateau, F., Chen, S., Chiga, N., Corsi, A., Cortes, M. L., Delbart, A., Gheller, J-M, Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V, Motobayashi, T., Murray, I, Otsu, H., Panin, V, Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Flavigny, F., Franchoo, S., Gasparic, I, Gerst, R-B, Gibelin, J., Hahn, K., I, Kim, D., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Li, P. J., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Soderstrom, P-A, Sohler, D., Takeuchi, S., Toernqvist, H., Vaquero, V., Wagner, V, Wang, S., Werner, V, Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Abstract

The one-neutron knockout from 52Ca in inverse kinematics onto a proton target was performed at similar to 230 MeV/nucleon combined with prompt 7 spectroscopy. Exclusive quasifree scattering cross sections to bound states in 51Ca and the momentum distributions corresponding to the removal of 1f7=2 and 2p3=2 neutrons were measured. The cross sections, interpreted within the distorted-wave impulse approximation reaction framework, are consistent with a shell closure at the neutron number N = 32, found as strong as at N = 28 and N = 34 in Ca isotopes from the same observables. The analysis of the momentum distributions leads to a difference of the root-mean-square radii of the neutron 1f7=2 and 2p3=2 orbitals of 0.61(23) fm, in agreement with the modified-shell-model prediction of 0.7 fm suggesting that the large root-mean-square radius of the 2p3=2 orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number.

Published
2022

41. Southwestern boundary of the N=40 island of inversion: First study of low-lying bound excited states in 59V and 61V

Author

Elekes, Z., Juhasz, M. M., Sohler, D., Sieja, K., Yoshida, K., Ogata, K., Doornenbal, P., Obertelli, A., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Chateau, F., Chen, S., Chiga, N., Corsi, A., Cortes, M. L., Delbart, A., Gheller, J-M, Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V, Liu, H. N., Motobayashi, T., Murray, I, Otsu, H., Panin, V, Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Dombradi, Zs, Flavigny, F., Franchoo, S., Gasparic, I, Gerst, R-B, Gibelin, J., Hahn, K., I, Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Soderstrom, P-A, Takeuchi, S., Tornqvist, H., Vaquero, V., Wagner, V, Wang, S., Werner, V, Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., Zanetti, L., Elekes, Z., Juhasz, M. M., Sohler, D., Sieja, K., Yoshida, K., Ogata, K., Doornenbal, P., Obertelli, A., Achouri, N. L., Baba, H., Browne, F., Calvet, D., Chateau, F., Chen, S., Chiga, N., Corsi, A., Cortes, M. L., Delbart, A., Gheller, J-M, Giganon, A., Gillibert, A., Hilaire, C., Isobe, T., Kobayashi, T., Kubota, Y., Lapoux, V, Liu, H. N., Motobayashi, T., Murray, I, Otsu, H., Panin, V, Paul, N., Rodriguez, W., Sakurai, H., Sasano, M., Steppenbeck, D., Stuhl, L., Sun, Y. L., Togano, Y., Uesaka, T., Wimmer, K., Yoneda, K., Aktas, O., Aumann, T., Chung, L. X., Dombradi, Zs, Flavigny, F., Franchoo, S., Gasparic, I, Gerst, R-B, Gibelin, J., Hahn, K., I, Kim, D., Koiwai, T., Kondo, Y., Koseoglou, P., Lee, J., Lehr, C., Linh, B. D., Lokotko, T., MacCormick, M., Moschner, K., Nakamura, T., Park, S. Y., Rossi, D., Sahin, E., Soderstrom, P-A, Takeuchi, S., Tornqvist, H., Vaquero, V., Wagner, V, Wang, S., Werner, V, Xu, X., Yamada, H., Yan, D., Yang, Z., Yasuda, M., and Zanetti, L.

Abstract

The low-lying level structure of 59V and 61V was investigated for the first time. The neutron knockout reaction and inelastic proton scattering were applied for 61V while the neutron knock-out reaction provided the data for 59V. Four and five new transitions were determined for 59V and 61V, respectively. Based on the comparison to our shell-model calculations using the Lenzi-Nowacki-Poves-Sieja (LNPS) interaction, three of the observed ?? rays for each isotope could be placed in the level scheme and assigned to the decay of the first 11/2??? and 9/2??? levels. The (p, p') excitation cross sections for 61V were analyzed by the coupled-channels formalism assuming quadrupole plus hexadecapole deformations. Due to the role of the hexadecapole deformation, 61V could not be unambiguously placed on the island of inversion.

Published
2022

42. Unveiling the Two-Proton Halo Character of 17Ne: Exclusive Measurement of Quasi-free Proton-Knockout Reactions

Author

Federal Ministry of Education and Research (Germany), Helmholtz International Center for FAIR, Technische Universität Darmstadt, Swedish Research Council, Russian Foundation for Basic Research, Ministerio de Ciencia e Innovación (España), Department of Energy (US), National Science Foundation (US), Aumann, T. [0000-0003-1660-9294], Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C.A., Boretzky, K., García Borge, María José, Caesar, C., Chartier, M., Chatillon, A., Chulkov, L.V., Cortina-Gil, D., Diaz Fernandez, P., Emling, H., Ershova, O., Fraile, Luis M., Fynbo, H.O.U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D.H.H., Holl, M., Johansson, H.T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Bleis, T. Le, Lemmon, R., Litvinov, Yu. A., Loeher, B., Mahata, K., Marganiec-Galazka, J., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, Ángel, Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, R., Simon, H., Stroth, J., Suemmerer, K., Tengblad, Olof, Weick, H., Wimmer, C., Federal Ministry of Education and Research (Germany), Helmholtz International Center for FAIR, Technische Universität Darmstadt, Swedish Research Council, Russian Foundation for Basic Research, Ministerio de Ciencia e Innovación (España), Department of Energy (US), National Science Foundation (US), Aumann, T. [0000-0003-1660-9294], Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C.A., Boretzky, K., García Borge, María José, Caesar, C., Chartier, M., Chatillon, A., Chulkov, L.V., Cortina-Gil, D., Diaz Fernandez, P., Emling, H., Ershova, O., Fraile, Luis M., Fynbo, H.O.U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D.H.H., Holl, M., Johansson, H.T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Bleis, T. Le, Lemmon, R., Litvinov, Yu. A., Loeher, B., Mahata, K., Marganiec-Galazka, J., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, Ángel, Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, R., Simon, H., Stroth, J., Suemmerer, K., Tengblad, Olof, Weick, H., and Wimmer, C.

Abstract

The proton drip-line nucleus 17Ne is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the 17Ne(p,2p)16F->15O+p quasi-free one-proton knockout reaction has been performed at GSI at around 500 MeV/nucleon beam energy. All particles resulting from the scattering process have been detected. The relevant reconstructed quantities are the angles of the two protons scattered in quasi-elastic kinematics, the decay of 16F into 15O (including gamma decays from excited states) and a proton, as well as the 15O+p relative-energy spectrum and the 16F momentum distributions. The latter two quantities allow an independent and consistent determination of the ratio of l=0 and l=2 motion of the valence protons in 17Ne. With a resulting relatively small l=0 component of only around 35(3)%, it is concluded that 17Ne exhibits a rather modest halo character only. The quantitative agreement of the two values deduced from the energy spectrum and the momentum distributions supports the theoretical treatment of the calculation of momentum distributions after quasi-free knockout reactions at high energies by taking into account distortions based on the Glauber theory. Moreover, the experimental data allow the separation of valence-proton knockout and knockout from the 15O core. The latter process contributes with 11.8(3.1) mb around 40% to the total proton-knockout cross section of 30.3(2.3) mb, which explains previously reported contradicting conclusions derived from inclusive cross sections.

Published
2022

49. A first glimpse at the shell structure beyond 54Ca: Spectroscopy of 55K, 55Ca, and 57Ca

Author

Koiwai, T., primary, Wimmer, K., additional, Doornenbal, P., additional, Obertelli, A., additional, Barbieri, C., additional, Duguet, T., additional, Holt, J.D., additional, Miyagi, T., additional, Navrátil, P., additional, Ogata, K., additional, Shimizu, N., additional, Somà, V., additional, Utsuno, Y., additional, Yoshida, K., additional, Achouri, N.L., additional, Baba, H., additional, Browne, F., additional, Calvet, D., additional, Château, F., additional, Chen, S., additional, Chiga, N., additional, Corsi, A., additional, Cortés, M.L., additional, Delbart, A., additional, Gheller, J.-M., additional, Giganon, A., additional, Gillibert, A., additional, Hilaire, C., additional, Isobe, T., additional, Kobayashi, T., additional, Kubota, Y., additional, Lapoux, V., additional, Liu, H.N., additional, Motobayashi, T., additional, Murray, I., additional, Otsu, H., additional, Panin, V., additional, Paul, N., additional, Rodriguez, W., additional, Sakurai, H., additional, Sasano, M., additional, Steppenbeck, D., additional, Stuhl, L., additional, Sun, Y.L., additional, Togano, Y., additional, Uesaka, T., additional, Yoneda, K., additional, Aktas, O., additional, Aumann, T., additional, Chung, L.X., additional, Flavigny, F., additional, Franchoo, S., additional, Gasparic, I., additional, Gerst, R.-B., additional, Gibelin, J., additional, Hahn, K.I., additional, Kim, D., additional, Kondo, Y., additional, Koseoglou, P., additional, Lee, J., additional, Lehr, C., additional, Linh, B.D., additional, Lokotko, T., additional, MacCormick, M., additional, Moschner, K., additional, Nakamura, T., additional, Park, S.Y., additional, Rossi, D., additional, Sahin, E., additional, Söderström, P.-A., additional, Sohler, D., additional, Takeuchi, S., additional, Toernqvist, H., additional, Vaquero, V., additional, Wagner, V., additional, Wang, S., additional, Werner, V., additional, Xu, X., additional, Yamada, H., additional, Yan, D., additional, Yang, Z., additional, Yasuda, M., additional, and Zanetti, L., additional

Published
2022
Full Text
View/download PDF

50. Unveiling the two-proton halo character of Ne: Exclusive measurement of quasi-free proton-knockout reactions

Author

Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu., Álvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C.A., Boretzky, K., Borge, M.J.G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L.V., Cortina-Gil, D., Díaz Fernández, P., Emling, H., Ershova, O., Fraile, L.M., Fynbo, H.O.U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D.H.H., Holl, M., Johansson, H.T., Jonson, B., Karagiannis, C., Kiselev, O.A., Kratz, J.V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Le Bleis, T., Lemmon, R., Litvinov, Yu.A., Löher, B., Mahata, K., Marganiec-Galązka, J., Müntz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Sümmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Abstract

The proton drip-line nucleus $^{17}$Ne is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the $^{17}$Ne(p,2p)16F→15⁎O+p quasi-free one-proton knockout reaction has been performed at GSI at around 500 MeV/nucleon beam energy. All particles resulting from the scattering process have been detected. The relevant reconstructed quantities are the angles of the two protons scattered in quasi-elastic kinematics, the decay of $^{16}$F into $^{15}$O (including γ decays from excited states) and a proton, as well as the $^{15}$O+p relative-energy spectrum and the $^{16}$F momentum distributions. The latter two quantities allow an independent and consistent determination of the fractions of l=0 and l=2 motion of the valence protons in $^{17}$Ne. With a resulting relatively small l=0 component of only around 35(3)%, it is concluded that $^{17}$Ne exhibits a rather modest halo character only. The quantitative agreement of the two values deduced from the energy spectrum and the momentum distributions supports the theoretical treatment of the calculation of momentum distributions after quasi-free knockout reactions at high energies by taking into account distortions based on the Glauber theory. Moreover, the experimental data allow the separation of valence-proton knockout and knockout from the $^{15}$O core. The latter process contributes with 11.8(3.1) mb around 40% to the total proton-knockout cross section of 30.3(2.3) mb, which explains previously reported contradicting conclusions derived from inclusive cross sections.

Published
2022

Catalog

Books, media, physical & digital resources
See catalog results