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Chen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; Tsunoda, Yusuke*; Otsuka, Takaharu*; Chazono, Yoshiki*; Hagen, G.*; Holt, J. D.*; et al.
Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08
Gamma decays were observed in Ca and
Ca following quasi-free one-proton knockout reactions from
Sc. For
Ca, a
ray transition was measured to be 1456(12) keV, while for
Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the
decays. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for
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
and
orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic
Ca and potentially drives the dripline of Ca isotopes to
Ca or even beyond.
Pohl, T.*; Sun, Y. L.*; Obertelli, A.*; Lee, J.*; Gmez-Ramos, M.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Cai, B. S.*; Yuan, C. X.*; Brown, B. A.*; et al.
Physical Review Letters, 130(17), p.172501_1 - 172501_8, 2023/04
Times Cited Count:2 Percentile:94.39(Physics, Multidisciplinary)We report on the first proton-induced single proton- and neutron-removal reactions from the neutron deficient O nucleus with large Fermi-surface asymmetry at
100 MeV/nucleon. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively.
Ao, N.*; Zhang, H.*; Xu, H. H.*; Wu, S. C.*; Liu, D.*; Xu, P. G.; Su, Y. H.; Kang, Q. H.*; Kang, G. Z.*
Engineering Fracture Mechanics, 281, p.109166_1 - 109166_14, 2023/03
Times Cited Count:0 Percentile:0.01(Mechanics)Jiang, X.*; Hattori, Takanori; Xu, X.*; Li, M.*; Yu, C.*; Yu, D.*; Mole, R.*; Yano, Shinichiro*; Chen, J.*; He, L.*; et al.
Materials Horizons, 10(3), p.977 - 982, 2023/03
Times Cited Count:1 Percentile:79.28(Chemistry, Multidisciplinary)As a promising environment-friendly alternative to current vapor-compression refrigeration, solid-state refrigeration based on the barocaloric effect has been attracting world wide attention. Generally, both phases in which a barocaloric effect occurs are present at ambient pressure. Here, instead, we demonstrate that KPF exhibits a colossal barocaloric effect due to the creation of a high-pressure rhombohedral phase. The phase diagram is constructed based on pressure-dependent calorimetric, Raman scattering, and neutron diffraction measurements. The present study is expected to provide an alternative routine to colossal barocaloric effects through the creation of a high-pressure phase.
Zhang, H.*; Wu, S. C.*; Ao, N.*; Zhang, J. W.*; Li, H.*; Zhou, L.*; Xu, P. G.; Su, Y. H.
International Journal of Fatigue, 166, p.107296_1 - 107296_11, 2023/01
Times Cited Count:0 Percentile:0.01(Engineering, Mechanical)Elekes, Z.*; Juhsz, M. M.*; Sohler, D.*; Sieja, K.*; Yoshida, Kazuki; Ogata, Kazuyuki*; Doornenbal, P.*; Obertelli, A.*; Achouri, N. L.*; Baba, Hidetada*; et al.
Physical Review C, 106(6), p.064321_1 - 064321_10, 2022/12
Times Cited Count:0 Percentile:0.02(Physics, Nuclear)The low-lying level structure of V and
V was investigated for the first time. The neutron knockout reaction and inelastic proton scattering were applied for
V while the neutron knock-out reaction provided the data for
V. Four and five new transitions were determined for
V and
V, 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 (
,
) excitation cross sections for
V were analyzed by the coupled-channels formalism assuming quadrupole plus hexadecapole deformations. Due to the role of the hexadecapole deformation,
V could not be unambiguously placed on the island of inversion.
Enciu, M.*; Liu, H. N.*; Obertelli, A.*; Doornenbal, P.*; Nowacki, F.*; Ogata, Kazuyuki*; Poves, A.*; Yoshida, Kazuki; Achouri, N. L.*; Baba, Hidetada*; et al.
Physical Review Letters, 129(26), p.262501_1 - 262501_7, 2022/12
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)The one-neutron knockout from Ca was performed at
230 MeV/nucleon combined with prompt
spectroscopy. The momentum distributions corresponding to the removal of
and
neutrons were measured. The cross sections are consistent with a shell closure at the neutron number
, found as strong as at
and
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
and
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
orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number.
Xu, X.*; Odaira, Takumi*; Xu, S.*; Hirata, Kenji*; Omori, Toshihiro*; Ueki, Kosuke*; Ueda, Kyosuke*; Narushima, Takayuki*; Nagasako, Makoto*; Kainuma, Ryosuke*; et al.
Advanced Materials & Processes, 180(7), p.35 - 37, 2022/10
Xu, S.*; Odaira, Takumi*; Sato, Shunsuke*; Xu, X.*; Omori, Toshihiro*; Harjo, S.; Kawasaki, Takuro; Seiner, H.*; Zoubkov, K.*; Murakami, Yasukazu*; et al.
Nature Communications (Internet), 13, p.5307_1 - 5307_8, 2022/09
Times Cited Count:3 Percentile:50.12(Multidisciplinary Sciences)Odaira, Takumi*; Xu, S.*; Hirata, Kenji*; Xu, X.*; Omori, Toshihiro*; Ueki, Kosuke*; Ueda, Kyosuke*; Narushima, Takayuki*; Nagasako, Makoto*; Harjo, S.; et al.
Advanced Materials, 34(27), p.2202305_1 - 2202305_11, 2022/07
Times Cited Count:3 Percentile:55.05(Chemistry, Multidisciplinary)Walter, H.*; Colonna, M.*; Cozma, D.*; Danielewicz, P.*; Ko, C. M.*; Kumar, R.*; Ono, Akira*; Tsang, M. Y. B*; Xu, J.*; Zhang, Y.-X.*; et al.
Progress in Particle and Nuclear Physics, 125, p.103962_1 - 103962_90, 2022/07
Times Cited Count:32 Percentile:96.94(Physics, Nuclear)Transport models are the main method to obtain physics information on the nuclear equation of state and in-medium properties of particles from low to relativistic-energy heavy-ion collisions. The Transport Model Evaluation Project (TMEP) has been pursued to test the robustness of transport model predictions to reach consistent conclusions from the same type of physical model. To this end, calculations under controlled conditions of physical input and set-up were performed by the various participating codes. These included both calculations of nuclear matter in a periodic box, which test individual ingredients of a transport code, and calculations of complete collisions of heavy ions. Over the years, five studies were performed within this project. They show, on one hand, that in box calculations the differences between the codes can be well understood and a convergence of the results can be reached. These studies also highlight the systematic differences between the two families of transport codes, known under the names of Boltzmann-Uehling-Uhlenbeck (BUU) and Quantum Molecular Dynamics (QMD) type codes. On the other hand, there still exist substantial differences when these codes are applied to real heavy-ion collisions. The results of transport simulations of heavy-ion collisions will have more significance if codes demonstrate that they can verify benchmark calculations such as the ones studied in these evaluations.
Koiwai, Takuma*; Wimmer, K.*; Doornenbal, P.*; Obertelli, A.*; Barbieri, C.*; Duguet, T.*; Holt, J. D.*; Miyagi, Takayuki*; Navrtil, P.*; Ogata, Kazuyuki*; et al.
Physics Letters B, 827, p.136953_1 - 136953_7, 2022/04
Times Cited Count:2 Percentile:69.47(Astronomy & Astrophysics)no abstracts in English
Yan, S. Q.*; Li, X. Y.*; Nishio, Katsuhisa; Lugaro, M.*; Li, Z. H.*; Makii, Hiroyuki; Pignatari, M.*; Wang, Y. B.*; Orlandi, R.; Hirose, Kentaro; et al.
Astrophysical Journal, 919(2), p.84_1 - 84_7, 2021/10
Times Cited Count:1 Percentile:11.75(Astronomy & Astrophysics)Linh, B. D.*; Corsi, A.*; Gillibert, A.*; Obertelli, A.*; Doornenbal, P.*; Barbieri, C.*; Chen, S.*; Chung, L. X.*; Duguet, T.*; Gmez-Ramos, M.*; et al.
Physical Review C, 104(4), p.044331_1 - 044331_16, 2021/10
Times Cited Count:3 Percentile:56.39(Physics, Nuclear)no abstracts in English
Browne, F.*; Chen, S.*; Doornenbal, P.*; Obertelli, A.*; Ogata, Kazuyuki*; Utsuno, Yutaka; Yoshida, Kazuki; Achouri, N. L.*; Baba, Hidetada*; Calvet, D.*; et al.
Physical Review Letters, 126(25), p.252501_1 - 252501_7, 2021/06
Times Cited Count:8 Percentile:76.2(Physics, Multidisciplinary)Direct proton-knockout reactions of Sc were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of
Ca were investigated through
-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological inter-nucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of
Sc, valence proton removals populated predominantly the ground-state of
Ca. This counter-intuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.
Juhsz, M. M.*; Elekes, Z.*; Sohler, D.*; Utsuno, Yutaka; Yoshida, Kazuki; Otsuka, Takaharu*; Ogata, Kazuyuki*; Doornenbal, P.*; Obertelli, A.*; Baba, Hidetada*; et al.
Physics Letters B, 814, p.136108_1 - 136108_8, 2021/03
Times Cited Count:3 Percentile:56.39(Astronomy & Astrophysics)The nuclear structure of Ar was studied by the (
,2
) reaction using
-ray spectroscopy for the bound and unbound states. Comparing the results to our shell-model calculations, two bound and six unbound states were established. The low cross sections populating the two bound states of
Ar could be interpreted as a clear signature for the presence of significant sub-shell closures at neutron numbers 32 and 34 in argon isotopes.
Hao, Y. Q.*; Wo, H. L.*; Gu, Y. M.*; Zhang, X. W.*; Gu, Y. Q.*; Zheng, S. Y.*; Zhao, Y.*; Xu, G. Y.*; Lynn, J. W.*; Nakajima, Kenji; et al.
Science China; Physics, Mechanics & Astronomy, 64(3), p.237411_1 - 237411_6, 2021/03
Times Cited Count:3 Percentile:48.43(Physics, Multidisciplinary)Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.
Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02
Times Cited Count:31 Percentile:96.37(Physics, Multidisciplinary)A quasifree (,
) experiment was performed to study the structure of the Borromean nucleus
B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for
and
orbitals, and a surprisingly small percentage of 9(2)% was determined for
. Our finding of such a small
component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in
B. The present work gives the smallest
- or
-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of
or
orbitals is not a prerequisite for the occurrence of a neutron halo.
Corts, M. L.*; Rodriguez, W.*; Doornenbal, P.*; Obertelli, A.*; Holt, J. D.*; Men
ndez, J.*; Ogata, Kazuyuki*; Schwenk, A.*; Shimizu, Noritaka*; Simonis, J.*; et al.
Physical Review C, 102(6), p.064320_1 - 064320_9, 2020/12
Times Cited Count:9 Percentile:75.29(Physics, Nuclear)Low-lying excited states in the = 32 isotope
Ar were investigated by in-beam
-ray spectroscopy following proton- and neutron-knockout, multinucleon 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
coincidences was compared to shell-model calculations in the
model space and to
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.
Lokotko, T.*; Leblond, S.*; Lee, J.*; Doornenbal, P.*; Obertelli, A.*; Poves, A.*; Nowacki, F.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Authelet, G.*; et al.
Physical Review C, 101(3), p.034314_1 - 034314_7, 2020/03
Times Cited Count:8 Percentile:75.29(Physics, Nuclear)The structures of the neutron-rich Co isotopes were investigated via (
) knockout reactions at the Radioactive Isotope Beam Factory, RIKEN. Level schemes were reconstructed using the
coincidence technique, with tentative spin-parity assignments based on the measured inclusive and exclusive cross sections. Comparison with shell-model calculations suggests coexistence of spherical and deformed shapes at low excitation energies in the
Co isotopes.