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Ca井手口 栄治*; Kib
di, T.*; Dowie, J. T. H.*; Hoang, T. H.*; Kumar Raju, M.*; 青井 考*; Mitchell, A. J.*; Stuchbery, A. E.*; 清水 則孝*; 宇都野 穣; et al.
Physical Review Letters, 128(25), p.252501_1 - 252501_6, 2022/06
被引用回数：2 パーセンタイル：46.35(Physics, Multidisciplinary)始状態と終状態のスピンパリティが
間の遷移は、電気単極遷移と呼ばれるガンマ線放出が禁止されている特殊な電磁遷移しか起こらない。状態は偶偶核の変形バンドのバンドヘッドであることから、電気単極遷移は古くから原子核の変形を知るための重要な手がかりとされてきた。その遷移の行列要素は通常、2準位模型によって始状態と終状態間の変形度の差と両者の混合の程度という2つの量で理解される。本研究では、Caの
から
へ遷移する寿命をオーストラリア国立大学にて測定した。これによって得られた電気単極遷移行列要素は比較的軽い原子核で知られている値よりも著しく小さいことがわかった。その電気単極遷移行列要素が抑制されるメカニズムとして、3つの変形した状態が混合することに伴う波動関数の打ち消しという、これまで考慮されてこなかった要因が重要であることが大規模殻模型計算の結果からわかった。
小松 遊矢*; 清水 亮太*; 佐藤 龍平*; Wilde, M.*; 西尾 和記*; 片瀬 貴義*; 松村 大樹; 齋藤 寛之*; 宮内 雅浩*; Adelman, J. R.*; et al.
Chemistry of Materials, 34(8), p.3616 - 3623, 2022/04
被引用回数：9 パーセンタイル：75.5(Chemistry, Physical)Here, we demonstrate such a highly repeatable photoinduced insulator-to-metal transition in yttrium oxyhydride (YO
H
) epitaxial thin films. The temperature (
) dependence of the electrical resistivity (
) of the films transforms from insulating to metallic (
) under ultraviolet laser illumination. The sample is heated (125 
C) under an Ar atmosphere to recover its original insulating state. The films recover their original metallic conductivity when subsequently subjected to ultraviolet laser illumination, showing repeatable photoinduced insulator-to-metal transition. First principles calculations show that the itinerant carriers originate from the variations in the charge states of the hydrogen atoms that occupy octahedral interstitial sites. This study indicates that tuning the site occupancy (octahedral/tetrahedral) of the hydrogen atoms exerts a significant effect on the photoresponse of metal hydrides.
Re渡邉 寛*; 渡辺 裕*; 平山 賀一*; Andreyev, A. N.; 橋本 尚志*; Kondev, F. G.*; Lane, G. J.*; Litvinov, Yu. A.*; Liu, J. J.*; 宮武 宇也*; et al.
Physics Letters B, 814, p.136088_1 - 136088_6, 2021/03
被引用回数：4 パーセンタイル：46.8(Astronomy & Astrophysics)The 
decay of 
Re
, which lies near the boundary between the regions of predicted prolate and oblate deformations, has been investigated using the KEK Isotope Separation System (KISS) in RIKEN Nishina Center. The ground state of Re has been assigned 
= 
based on the observed feedings and deduced log
values towards the 
and 
states in Os, which is known as a typical 
-soft nucleus. The shape transition from axial symmetry to axial asymmetry in the Re isotopes is discussed from the viewpoint of single-particle structure using the nuclear Skyrme-Hartree-Fock model.
Al-Shayeb, B.*; Sachdeva, R.*; Chen, L.-X.*; Ward, F.*; Munk, P.*; Devoto, A.*; Castelle, C. J.*; Olm, M. R.*; Bouma-Gregson, K.*; 天野 由記; et al.
Nature, 578(7795), p.425 - 431, 2020/02
被引用回数：220 パーセンタイル：99.5(Multidisciplinary Sciences)Phage typically have small genomes and depend on their bacterial hosts for replication. We generated metagenomic datasets from many diverse ecosystems and reconstructed hundreds of huge phage genomes, between 200 kbp and 716 kbp in length. Thirty four genomes were manually curated to completion, including the largest phage genomes yet reported. Expanded genetic repertoires include diverse and new CRISPR-Cas systems, tRNAs, tRNA synthetases, tRNA modification enzymes, initiation and elongation factors and ribosomal proteins. Phage CRISPR have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. Some phage repurpose bacterial systems for phage-defense to eliminate competing phage. We phylogenetically define seven major clades of huge phage from human and other animal microbiomes, oceans, lakes, sediments, soils and the built environment. We conclude that large gene inventories reflect a conserved biological strategy, observed across a broad bacterial host range and resulting in the distribution of huge phage across Earth's ecosystems.
-decay properties of 
FrGhys, L.*; Andreyev, A. N.; Huyse, M.*; Van Duppen, P.*; Antalic, S.*; Barzakh, A.*; Capponi, L.*; Cocolios, T. E.*; Cubiss, J.*; Derkx, X.*; et al.
Physical Review C, 100(5), p.054310_1 - 054310_13, 2019/11
被引用回数：12 パーセンタイル：77.09(Physics, Nuclear)The aim of this work was to investigate the -decay properties of Fr and daughter products. Neutron-deficient francium nuclei are produced at ISOLDE-CERN bombarding a UCx target with 1.4 GeV protons. Due to the very high statistics and the high beam purity, improved decay data for 
Fr and its daughters were obtained. The observation of crossover transitions positioned the isomeric high-spin level of 
At at an excitation energy of 265(3) keV. Half-life values of 4.47(5) s and 1.28(10) s were extracted for the ground state and isomeric state of At and 52(3) ms for the ground-state decay of 
Fr.
At revealed by in-source laser spectroscopyBarzakh, A. E.*; Cubiss, J. G.*; Andreyev, A. N.; Seliverstov, M. D.*; Andel, B.*; Antalic, S.*; Ascher, P.*; Atanasov, D.*; Beck, D.*; Biero
, J.*; et al.
Physical Review C, 99(5), p.054317_1 - 054317_9, 2019/05
被引用回数：12 パーセンタイル：77.09(Physics, Nuclear)Hyperfine-structure parameters and isotope shifts for the 795-nm atomic transitions in At have been measured at CERN-ISOLDE, using the in-source resonance-ionization spectroscopy technique. Magnetic dipole and electric quadrupole moments, and changes in the nuclear mean-square charge radii, have been deduced. A large inverse odd-even staggering in radii, which may be associated with the presence of octupole collectivity, has been observed. Namely, the radius of the odd-odd isotope 
At has been found to be larger than the average.
-decaying millisecond isomeric state in 
Cd
Jungclaus, A.*; Grawe, H.*; 西村 俊二*; Doornenbal, P.*; Lorusso, G.*; Simpson, G. S.*; S
derstrm, P.-A.*; 炭竃 聡之*; Taprogge, J.*; Xu, Z. Y.*; et al.
Physics Letters B, 772, p.483 - 488, 2017/09
被引用回数：8 パーセンタイル：55.37(Astronomy & Astrophysics)A new high-spin isomer in the neutron-rich nucleus Cd was populated in the projectile fission of a 
U beam at the Radioactive Isotope Beam Factory at RIKEN. A half-life of T
= 6.3(8) ms was measured for the new state which was tentatively assigned a spin/parity of (15
). The isomeric state decays via the emission of a 309-keV ray with 
multipolarity. The experimental results are compared to shell model calculations performed using state-of-the-art realistic effective interactions and to the neighbouring nucleus 
Cd. The comparison with calculations shows that adjustments of the pairing and multipole parts of the effective interaction derived from the CD-Bonn nucleon-nucleon potential are required in order to describe the properties of nuclei in the region around 
Sn.
Tl measured by in-source laser spectroscopyBarzakh, A.*; Andreyev, A. N.; Cocolios, T. E.*; de Groote, R. P.*; Fedorov, D. V.*; Fedosseev, V. N.*; Ferrer, R.*; Fink, D. A.*; Ghys, L.*; Huyse, M.*; et al.
Physical Review C, 95(1), p.014324_1 - 014324_12, 2017/01
被引用回数：26 パーセンタイル：86.67(Physics, Nuclear)Hyperfine structure and isotope shifts have been measured for the ground and isomeric states in the neutron deficient isotopes Tl using the 276.9 nm transition. The experiment has been performed at the CERN Isotope Separator On-Line facility using the in-source resonance-ionization laser spectroscopy technique. Spins for the ground states in 
Tl have been determined as 
= 1/2. Magnetic moments and changes in the nuclear mean-square charge radii have been deduced. By applying the additivity relation for magnetic moments of the odd-odd Tl nuclei the leading configuration assignments were confirmed. A deviation of magnetic moments for isomeric states in 
Tl from the trend of the heavier Tl nuclei is observed. The charge radii of the ground states of the isotopes Tl follow the trend for isotonic (spherical) lead nuclei. The noticeable difference in charge radii for ground and isomeric states of 
Tl has been observed, suggesting a larger deformation for the intruder-based 9/2
and 10 states compared to the ground states. An unexpected growth of the isomer shift for 
Tl has been found.
-delayed fission and decay of 
AtTruesdale, V. L.*; Andreyev, A. N.; Ghys, L.*; Huyse, M.*; Van Duppen, P.*; Sels, S.*; Andel, B.*; Antalic, S.*; Barzakh, A.*; Capponi, L.*; et al.
Physical Review C, 94(3), p.034308_1 - 034308_11, 2016/09
被引用回数：10 パーセンタイル：60.43(Physics, Nuclear)A nuclear-decay spectroscopy study of the neutron-deficient isotope At is reported where an isotopically pure beam was produced using the selective Resonance Ionization Laser Ion Source and On-Line Isotope Mass Separator (CERN). The fine-structure decay of At allowed the low-energy excited states in the daughter nucleus Bi to be investigated. A -delayed fission study of At was also performed. A mixture of symmetric and asymmetric fission-fragment mass distributions of the daughter isotope Po (populated by decay of At) was deduced based on the measured fission-fragment energies. A DF probability 
(At) = 9(1)
10
was determined.
decay of semi-magic 
Cd; Revision and extension of the level scheme of InJungclaus, A.*; Grawe, H.*; 西村 俊二*; Doornenbal, P.*; Lorusso, G.*; Simpson, G. S.*; Sderstrm, P. A.*; 炭竃 聡之*; Taprogge, J.*; Xu, Z. Y.*; et al.
Physical Review C, 94(2), p.024303_1 - 024303_8, 2016/08
被引用回数：18 パーセンタイル：77.39(Physics, Nuclear)The decay of the semi-magic nucleus Cd has been studied at the RIBF facility at the RIKEN Nishina Center. The high statistics of the present experiment allowed for a revision of the established level scheme of In and the observation of additional feeding to high lying core-excited states in In. The experimental results are compared to shell-model calculations employing a model space consisting of the full major 
neutron and 
proton shells, and good agreement is found.
-decay study of TlVan Beveren, C.*; Andreyev, A. N.; Barzakh, A. E.*; Cocolios, T. E.*; de Groote, R. P.*; Fedorov, D.*; Fedosseev, V. N.*; Ferrer, R.*; Ghys, L.*; Huyse, M.*; et al.
Journal of Physics G; Nuclear and Particle Physics, 43(2), p.025102_1 - 025102_22, 2016/02
被引用回数：11 パーセンタイル：63.13(Physics, Nuclear)-decay spectroscopy of Tl has been performed at the CERN isotope separator on-line (ISOLDE) facility. New fine-structure decays have been observed for both isotopes. -decay branching ratios of 0.089(19)
, 0.047(6) and 1.22(30) have been deduced for the (10), (7
) and (2) states respectively in 
Tl and a lower limit of 0.49 for the -decay branching ratio of 
Tl. A new half-life of 9.5(2) s for the (2) state in Tl and 1.9(1) s for the low-spin state in Tl has been deduced. Using - coincidence analysis, multiple rays were observed de-exciting levels in 
Au fed by Tl decays. The transitions connecting these low-lying states in Au are essential to sort the data and possibly identify bands from inbeam studies in these isotopes. Owing to the complex fine-structure decays and limited knowledge about the structure of the daughter nuclei, only partial level schemes could be constructed for both gold isotopes in the present work. Reduced -decay widths have been calculated and are compared with values obtained in neighboring odd-A and even-A thallium isotopes. Except for the allowed decay of the Tl (10) state, the other fine-structure decays observed in this study are hindered. This points to strong structural changes between parent thallium and daughter gold isotopes.
) intruder state in TlVan Beveren, C.*; Andreyev, A. N.; Barzakh, A.*; Cocolios, T. E.*; Fedorov, D.*; Fedosseev, V. N.*; Ferrer, R.*; Huyse, M.*; Kster, U.*; Lane, J. F. W.*; et al.
Physical Review C, 92(1), p.014325_1 - 014325_8, 2015/07
被引用回数：9 パーセンタイル：54.97(Physics, Nuclear)Decay spectroscopy of Tl has been performed at the CERN Isotope Separator On-Line (ISOLDE) facility. An excitation energy of 506.1(1) keV and a half-life of 47.1(7) ms of the intruder based (10) state have been extracted. The internal decay characteristics of this state are determined and discussed, extending the systematics of such states in the even-mass thallium nuclei below neutron midshell at N = 104. The retardation factors of the isomeric M2 and E3 transitions are deduced and compared with retardation factors in neighboring odd-mass and even-mass thallium isotopes. The new information is combined with a review of hindered and unhindered -decay data of 
Bi populating levels in daughter nuclei 
Tl and supports the interpretation of the intruder character of the (10) state in Tl.
decay of Cd and excited states in InTaprogge, J.*; Jungclaus, A.*; Grawe, H.*; 西村 俊二*; Doornenbal, P.*; Lorusso, G.*; Simpson, G. S.*; Sderstrm, P.-A.*; 炭竃 聡之*; Xu, Z. Y.*; et al.
Physical Review C, 91(5), p.054324_1 - 054324_11, 2015/05
被引用回数：24 パーセンタイル：82.61(Physics, Nuclear)The decay of Cd, produced in relativistic fission of a U beam, was studied at the RIKEN Nishina Center. From the -ray analysis, 31 excited states and 69 ray transitions were established in the level scheme of In, and compared with state-of-the-art shell-model calculations. It was found that the decay of Cd is dominated by Gamow teller transitions, but a non-negligible contribution to the decay is also made by first-forbidden transitions. To estimate the contribution of first-forbidden transitions is important for calculations of the -decay half-lives of nuclei in this region.
-decay half-lives of 110 neutron-rich nuclei across the 
=82 shell gap; Implications for the mechanism and universality of the astrophysical 
processLorusso, G.*; 西村 俊二*; Xu, Z. Y.*; Jungclaus, A.*; Shimizu, Y.*; Simpson, G. S.*; Sderstrm, P.-A.*; Watanabe, H.*; Browne, F.*; Doornenbal, P.*; et al.
Physical Review Letters, 114(19), p.192501_1 - 192501_7, 2015/05
被引用回数：164 パーセンタイル：97.96(Physics, Multidisciplinary)The -decay half-lives of 110 neutron-rich isotopes of the elements from Rb to Sn were measured at the RIBF Facility at RIKEN, Japan. The new data demonstrate the persistence of shell structure far from stability and have direct implications for the -process calculations. In particular, the new half-lives have a global impact on the calculated -process elemental abundances, and alleviate the underproduction of isotopes just above and below the A=130 peak, which in the past required the introduction of shell structure modifications. Reaction-network calculations based on the new data reinforce the notion that the r-process abundance pattern may result from the freeze-out of a (n,)
(,n) equilibrium.
Ni; Spectroscopy of the N=49 isotope 
ZnOrlandi, R.; M
cher, D.*; Raabe, R.*; Jungclaus, A.*; Pain, S. D.*; Bildstein, V.*; Chapman, R.*; De Angelis, G.*; Johansen, J. G.*; Van Duppen, P.*; et al.
Physics Letters B, 740, p.298 - 302, 2015/01
被引用回数：29 パーセンタイル：85.36(Astronomy & Astrophysics)Single-neutron states in Zn have been populated using the reaction Zn(d,p) at REX-Isolde, CERN. The analysis reveals that the lowest excited states in Zn lie at approximately 1 MeV, and involve neutron orbits above the N=50 shell gap. A 5/2 configuration was assigned to the 983-keV state. Comparison with large-scale shell model calculations supports a robust neutron N=50 shell closure for Ni. These data constitute an important step towards the understanding the magicity of Ni and the structure of nuclei in the region.
Cd
via the detection of internal conversion and Compton electronsTaprogge, J.*; Jungclaus, A.*; Grawe, H.*; 西村 俊二*; Xu, Z. Y.*; Doornenbal, P.*; Lorusso, G.*; N
cher, E.*; Simpson, G. S.*; Sderstrm, P.-A.*; et al.
Physics Letters B, 738, p.223 - 227, 2014/11
被引用回数：23 パーセンタイル：80.23(Astronomy & Astrophysics)The decay of an isomeric state in the neutron-rich nucleus Cd was observed via the detection of internal conversion and Compton electrons. This measurement provided the first experimental information on excited states in this nucleus. The isomer was populated in the projectile fission of a U beam at the RIBF facility at RIKEN. From the measured yields of rays and internal conversion electrons, E3 multipolarity was tentatively assigned to the isomeric transition. A half-life of 3.6(2) ms was determined for this new state which, by comparison with shell-model calculations, was tentatively assigned a spin of (21/2
).
Sn explored with the long-lived isomer in 
PdWatanabe, H.*; Lorusso, G.*; 西村 俊二*; Otsuka, T.*; Ogawa, K.*; Xu, Z. Y.*; 炭竃 聡之*; Sderstrm, P.-A.*; Doornenbal, P.*; Li, Z.*; et al.
Physical Review Letters, 113(4), p.042502_1 - 042502_6, 2014/07
被引用回数：24 パーセンタイル：76.91(Physics, Multidisciplinary)A new isomer with a half-life of 23.0(8) ms has been identified in Pd at 2406 keV excitation. The proposed spin and parity configuration is 10, with maximally aligned configuration of two 
neutron hole. -decay from the long-lived isomer was also observed to populated excited states at high spins in Ag. The small energy difference between the 10 and 7 isomers in Pd was interpreted in the frame of the monopole shift of the 1 neutron orbit. The effects of the monopole interaction on the evolution of single-neutron energies below Sn are discussed in terms of central and tensor forces.
proton-hole state in Sn and the shell structure along =82Taprogge, J.*; Jungclaus, A.*; Grawe, H.*; 西村 俊二*; Doornenbal, P.*; Lorusso, G.*; Simpson, G.*; Sderstrm, P.-A.*; 炭竃 聡之*; Xu, Z. Y.*; et al.
Physical Review Letters, 112(13), p.132501_1 - 132501_6, 2014/04
被引用回数：51 パーセンタイル：88.81(Physics, Multidisciplinary)A low-lying state in 
In, the one-proton hole nucleus with respect to double magic Sn, was observed by its decay to the beta emitting isomer. The new state, which was populated both in the beta decay of Cd and after beta-delayed neutron emission from Cd, was identified, at an excitation energy of 1353 keV, as the previously unknown single-hole state with respect to the Sn core. Exploiting this crucial new experimental information, shell-model calculations were performed to study the structure of experimentally inaccessible =82 isotones below Sn. The results evidence a surprising absence of proton subshell closures along the chain of =82 isotones. This finding bears consequences on the evolution of the =82 shell gap along the r-process path.
Rothe, S.*; Andreyev, A. N.*; Antalic, S.*; Borschevsky, A.*; Capponi, L.*; Cocolios, T. E.*; De Witte, H.*; Eliav, E.*; Fedorov, D. V.*; Fedosseev, V. N.*; et al.
Nature Communications (Internet), 4, p.1835_1 - 1835_6, 2013/05
被引用回数：83 パーセンタイル：94.59(Multidisciplinary Sciences)The radioactive element astatine exists only in trace amounts in nature. Its properties can therefore only be explored by study of smallest quantities of artificially produced isotopes or by performing theoretical calculations. One of the most important properties influencing the chemical behaviour is the energy required to remove one electron from the valence shell, referred to as the ionization potential (IP). Here we use laser spectroscopy to probe the optical spectrum of astatine near the ionization threshold. The observed series of Rydberg states allowed the deduction of the IP of the astatine atom for the first time. New ab initio calculations were performed to support the experimental result. The measured value of IP(At) serves as a benchmark for quantum chemistry calculations of the properties of astatine as well as for the theoretical prediction of the ionization potential of super-heavy element 117, the heaviest homologue of astatine.
-decay spectroscopy of the chain 
Tl
Au 
Ir 
Re
Andreyev, A. N.*; Liberati, V.*; Antalic, S.*; Ackermann, D.*; Barzakh, A.*; Bree, N.*; Cocolios, T. E.*; Diriken, J.*; Elseviers, J.*; Fedorov, D.*; et al.
Physical Review C, 87(5), p.054311_1 - 054311_8, 2013/05
被引用回数：16 パーセンタイル：70.21(Physics, Nuclear)-decay studies of Tl and its dahghter products Au and Ir were carried out in two complementary experiments at the mass separator ISOLDE (CERN) and velocity filter SHIP (GSI). The nucluesu Au has decay properties of half-life 207 ms and -decay energy 6433 keV. The ground state spins and parities for Au and Ir were determined to be 1/2.
