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Author Phong, V.H. et al; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Morales, A.I.; Rubio, B.; Tain, J.L.; Tarifeño-Saldivia, A.; Tolosa-Delgado, A.
Title Beta-Delayed One and Two Neutron Emission Probabilities South-East of Sn-132 and the Odd-Even Systematics in r-Process Nuclide Abundances Type Journal Article
Year 2022 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 129 Issue 18 Pages 172701 - 7pp
Keywords
Abstract The beta-delayed one- and two-neutron emission probabilities (P-1n and P-2n) of 20 neutron-rich nuclei with N >= 82 have been measured at the RIBF facility of the RIKEN Nishina Center. P-1n of Ag-130;131, Cd-133;134, In-135;136, and (138;13)9Sn were determined for the first time, and stringent upper limits were placed on P-2n for nearly all cases. beta-delayed two-neutron emission (beta 2n) was unambiguously identified in Cd-133 and In-135;136, and their P-2n were measured. Weak beta 2n was also detected from Sn-137;138. Our results highlight the effect of the N = 82 and Z = 50 shell closures on beta-delayed neutron emission probability and provide stringent benchmarks for newly developed macroscopic-microscopic and self-consistent global models with the inclusion of a statistical treatment of neutron and. emission. The impact of our measurements on r-process nucleosynthesis was studied in a neutron star merger scenario. Our P-1n and P-2n have a direct impact on the
Address [Phong, V. H.; Nishimura, S.; Lorusso, G.; Liu, J.; Nishimura, N.; Ahn, D. S.; Baba, H.; Fukuda, N.; Go, S.; Ha, J.; Isobe, T.; Kiss, G. G.; Kubono, S.; Matsui, K.; Sakurai, H.; Shimizu, Y.; Sumikama, T.; Suzuki, H.; Takeda, H.] RIKEN, Nishina Ctr, Wako, Saitama 3510198, Japan, Email: phong@ribf.riken.jp;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000910940600006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5458
Permanent link to this record
 
 
Author Goigoux, T. et al; Algora, A.; Guadilla, V.; Montaner-Piza, A.; Morales, A.I.; Orrigo, S.E.A.; Rubio, B.; Gelletly, W.
Title Two-Proton Radioactivity of Kr-67 Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 117 Issue 16 Pages 162501 - 6pp
Keywords
Abstract In an experiment with the BigRIPS separator at the RIKEN Nishina Center, we observed two-proton (2p) emission from Kr-67. At the same time, no evidence for 2p emission of Ge-59 and Se-63, two other potential candidates for this exotic radioactivity, could be observed. This observation is in line with Q value predictions which pointed to Kr-67 as being the best new candidate among the three for two-proton radioactivity. Kr-67 is only the fourth 2p ground-state emitter to be observed with a half-life of the order of a few milliseconds. The decay energy was determined to be 1690(17) keV, the 2p emission branching ratio is 37(14)%, and the half-life of Kr-67 is 7.4(30) ms.
Address [Goigoux, T.; Ascher, P.; Blank, B.; Gerbaux, M.; Giovinazzo, J.; Grevy, S.; Nieto, T. Kurtukian; Magron, C.] Univ Bordeaux, Ctr Etud Nucl Bordeaux Gradignan, IN2P3, UMR CNRS 5797, Chemin Solarium, F-33175 Gradignan, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000385641900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2831
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Author Morales, A.I.; Algora, A.; Molina, F.; Rubio, B.
Title Half-Life Systematics across the N=126 Shell Closure: Role of First-Forbidden Transitions in the beta Decay of Heavy Neutron-Rich Nuclei Type Journal Article
Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 113 Issue 2 Pages 022702 - 5pp
Keywords
Abstract This Letter reports on a systematic study of beta-decay half-lives of neutron-rich nuclei around doubly magic Pb-208. The lifetimes of the 126-neutron shell isotone Pt-204 and the neighboring Ir200-202, Pt-203, Au-204 are presented together with other 19 half-lives measured during the “stopped beam” campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden beta strength reveal significant deviations for most of the nuclei with N < 126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during beta decay back to stability.
Address [Morales, A. I.; Benlliure, J.; Kurtukian-Nieto, T.; Verma, S.; Casarejos, E.; Alvarez-Pol, H.; Estevez-Aguado, M. E.] Univ Santiago de Compostela, E-15782 Santiago De Compostela, Spain, Email: anaisabel.morales@mi.infn.it
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000341315100007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1913
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Author IDS Collaboration (Heideman, J. et al); Algora, A.; Morales, A.I.
Title Evidence of nonstatistical neutron emission following beta decay near doubly magic Sn-132 Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (down) 108 Issue 2 Pages 024311 - 9pp
Keywords
Abstract Models of the beta-delayed neutron emission (beta n) assume that neutrons are emitted statistically via an intermediate compound nucleus post beta decay. Evidence to the contrary was found in an In-134 beta-decay experiment carried out at ISOLDE CERN. Neutron emission probabilities from the unbound states in Sn-134 to known low-lying, single-particle states in Sn-133 were measured. The neutron energies were determined using the time-of-flight technique, and the subsequent decay of excited states in Sn-133 was studied using gamma-ray detectors. Individual beta n probabilities were determined by correlating the relative intensities and energies of neutrons and gamma rays. The experimental data disagree with the predictions of representative statistical models which are based upon the compound nucleus postulate. Our results suggest that violation of the compound nucleus assumption may occur in beta-delayed neutron emission. This impacts the neutron-emission probabilities and other properties of nuclei participating in the r-process. A model of neutron emission, which links the observed neutron emission probabilities to nuclear shell effects, is proposed.
Address [Heideman, J.; Grzywacz, R.; Xu, Z. Y.; Madurga, M.; Halverson, C.; King, T. T.; Singh, M.; Yokoyama, R.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:001053419100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5620
Permanent link to this record
 
 
Author Xu, Z.Y. et al; Algora, A.; Morales, A.I.
Title Beta-delayed neutron spectroscopy of 133In Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (down) 108 Issue 1 Pages 014314 - 9pp
Keywords
Abstract The decay properties of 133In were studied in detail at the ISOLDE Decay Station. The implementation of the Resonance Ionization Laser Ion Source allowed separate measurements of its 9/2+ ground state (133gIn) and 1/2- isomer (133mIn). With the use of & beta;-delayed neutron and & gamma; spectroscopy, the decay strengths above the neutron separation energy were quantified in this neutron-rich nucleus for the first time. The allowed Gamow-Teller transition 9/2+ & RARR; 7/2+ was located at 5.93 MeV in the 133gIn decay with a log ft = 4.7(1). In addition, several neutron-unbound states were populated at lower excitation energies by the first-forbidden decays of 133g,mIn. We assigned spins and parities to those neutron-unbound states based on the & beta;-decay selection rules, the log ft values, and systematics.
Address [Xu, Z. Y.; Madurga, M.; Grzywacz, R.; King, T. T.; Halverson, C.; Heideman, J.; Singh, M.; Yokoyama, R.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:001062056700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5757
Permanent link to this record
 
 
Author Yokoyama, R. et al; Tain, J.L.; Algora, A.; Agramunt, J.; Domingo-Pardo, C.; Morales, A.I.; Rubio, B.; Tolosa-Delgado, A.
Title β-delayed neutron emissions from N > 50 gallium isotopes Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (down) 108 Issue 6 Pages 064307 - 15pp
Keywords
Abstract beta-delayed gamma-neutron spectroscopy has been performed on the decay of A=84 to 87 gallium isotopes at the RI-beam Factory at the RIKEN Nishina Center using a high-efficiency array of 3He neutron counters (BRIKEN). beta-2n-gamma events were measured in the decays of all of the four isotopes for the first time, which is direct evidence for populating the excited states of two-neutron daughter nuclei. Detailed decay schemes with the gamma branching ratios were obtained for these isotopes, and the neutron emission probabilities (P-xn) were updated from the previous study. Hauser-Feshbach statistical model calculations were performed to understand the experimental branching ratios. We found that the P-1n and P-2n values are sensitive to the nuclear level densities of 1n daughter nuclei and showed that the statistical model reproduced the P-2n/P-1n ratio better when experimental levels plus shell-model level densities fit by the Gilbert-Cameron formula were used as the level-density input. We also showed the neutron and gamma branching ratios are sensitive to the ground-state spin of the parent nucleus. Our statistical model analysis suggested J <= 3 for the unknown ground-state spin of the odd-odd nucleus Ga-86, from the I gamma(4(+)-> 2(+))/I-gamma(2(+)-> 0(+)) ratio of Ga-84 and the P-2n/P-1n ratio. These results show the necessity of detailed understanding of the decay scheme, including data from neutron spectroscopy, in addition to gamma measurements of the multineutron emitters.
Address [Yokoyama, R.; Grzywacz, R.; Rasco, B. C.; Brewer, N.; Heideman, J.; King, T. T.; Madurga, M.; Singh, M.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA, Email: yokoyama@cns.s.u-tokyo.ac.jp
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:001159167500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5939
Permanent link to this record
 
 
Author Pedersen, L.G. et al; Morales, A.I.
Title First spectroscopic study of odd-odd 78Cu Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (down) 107 Issue 4 Pages 044301 - 10pp
Keywords
Abstract Nuclei in the vicinity of 78Ni are important benchmarks for nuclear structure, which can reveal changes in the shell structure far from stability. Spectroscopy of the odd-odd isotope 78Cu was performed for the first time in an experiment with the EURICA setup at the Radioactive Isotope Beam Factory at RIKEN Nishina Center. Excited states in the neutron-rich isotope were populated following the beta decay of 78Ni produced by in-flight fission and and separated by the BigRIPS separator. A level scheme based on the analysis of γ−γ coincidences is presented. Tentative spin and parity assignments were made when possible based on the β-decay feeding intensities and γ-decay properties of the excited states. Time correlations between β and γ decay show clear indications of an isomeric state with a half-life of 3.8(4) ms. Large-scale Monte Carlo shell-model calculations were performed using the A3DA-m interaction and a valence space comprising the full fp shell and the 1g9/2 and 2d5/2 orbitals for both protons and neutrons. The comparison of the experimental results with the shell-model calculations allows interpreting the excited states in terms of spin multiplets arising from the proton-neutron interaction. The results provide further insight into the evolution of the proton single-particle orbitals as a function of neutron number, and quantitative information about the proton-neutron interaction outside the doubly magic 78Ni core.
Address [Pedersen, L. G.; Sahin, E.; Gorgen, A.; Garrote, F. L. Bello; Modamio, V.] Univ Oslo, Dept Phys, NO-0316 Oslo, Norway, Email: l.g.pedersen@fys.uio.no;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000998180300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5572
Permanent link to this record
 
 
Author Wu, J. et al; Algora, A.; Agramunt, J.; Morales, A.I.; Orrigo, S.E.A.; Tain, J.L.; Tarifeño-Saldivia, A.; Tolosa-Delgado, A.
Title First observation of isomeric states in 111Zr, 113Nb, and 115Mo Type Journal Article
Year 2022 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (down) 106 Issue 6 Pages 064328 - 5pp
Keywords
Abstract Isomeric states in the neutron-rich nuclei 111Zr [T1/2 = 0.10(7) μs], 113Nb [T1/2 = 0.7(4) μs], 115Mo [T1/2 = 46(3) μs] were first identified at the Radioactive Ion Beam Factory (RIBF) of RIKEN by using in-flight fission and fragmentation of a 238U beam at an energy of 345 MeV/u. This is a brief report of the gamma transitions de -exciting from isomeric states and half-lives measurements, which provides the first spectroscopy in the nuclear region of prolate-to-oblate shape-phase transition around mass A approximate to 110.
Address [Wu, J.] Brookhaven Natl Lab, Natl Nucl Data Ctr, Upton, NY 11973 USA, Email: jwu2@bnl.gov
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000906391600002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5452
Permanent link to this record
 
 
Author Orrigo, S.E A. et al; Rubio, B.; Gelletly, W.; Aguilera, P.; Algora, A.; Morales, A.I.; Agramunt, J.; Guadilla, V.; Montaner-Piza, A.
Title beta decay of the very neutron-deficient Ge-60 and Ge-62 nuclei Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (down) 103 Issue 1 Pages 014324 - 12pp
Keywords
Abstract We report here the results of a study of the beta decay of the proton-rich Ge isotopes, Ge-60 and Ge-62, produced in an experiment at the RIKEN Nishina Center. We have improved our knowledge of the half-lives of Ge-62 [73.5(1) ms] and Ge-60 [25.0(3) ms] and its daughter nucleus, Ga-60 [69.4(2) ms]. We measured individual beta-delayed proton and gamma emissions and their related branching ratios. Decay schemes and absolute Fermi and Gamow-Teller transition strengths have been determined. The mass excesses of the nuclei under study have been deduced. A total beta-delayed proton-emission branching ratio of 67(3)% has been obtained for Ge-60. New information has been obtained on the energy levels populated in Ga-60 and on the 1/2(-) excited state in the beta p daughter Zn-59. We extracted a ground state-to-ground state feeding of 85.3(3)% for the decay of Ge-62. Eight new y lines have been added to the deexcitation of levels populated in the Ga-62 daughter.
Address [Orrigo, S. E. A.; Rubio, B.; Gelletly, W.; Aguilera, P.; Algora, A.; Morales, A., I; Agramunt, J.; Guadilla, V; Montaner-Piza, A.] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain, Email: sonja.orrigo@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000613141500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4716
Permanent link to this record
 
 
Author Escrig, S. et al; Morales, A.I.
Title Persistence of the Z=28 shell gap in A=75 isobars: Identification of a possible (1/2(-)) μs isomer in Co-75 and beta decay to Ni-75 Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume (down) 103 Issue 6 Pages 064328 - 12pp
Keywords
Abstract Background: The evolution of shell structure around doubly magic exotic nuclei is of great interest in nuclear physics and astrophysics. In the 'southwest' region of Ni-78, the development of deformation might trigger a major shift in our understanding of explosive nucleosynthesis. To this end, new spectroscopic information on key close-lying nuclei is very valuable. Purpose: We intend to measure the isomeric and beta decay of Co-75, with one-proton and two-neutron holes relative to Ni-78, to access new nuclear structure information in Co-75 and its beta-decay daughters Ni-75 and Ni-74. Methods: The nucleus Co-75 is produced in relativistic in-flight fission reactions of U-238 at the Radioactive Ion Beam Factory in the RIKEN Nishina Center. Its isomeric and f decay are studied exploiting the BigRIPS and EURICA setups. Results: We obtain partial beta-decay spectra for Ni-75 and Ni-74, and report a new isomeric transition in Co-75. The energy [E-gamma = 1914(2) keV] and half-life [t(1/2) = 13(6) μs] of the delayed gamma ray lend support for the existence of aJ(pi) = (1/2(-)) isomeric state at 1914(2) keV. A comparison with PFSDG-U shell-model calculations provides a good account for the observed states in Ni-75, but the first calculated 1/2(-) level in Co-75, a prolate K = 1/2 state, is predicted about 1 MeV below the observed (1/2(-)) level. Conclusions: The spherical-like structure of the lowest-lying excited states in Ni-75 is proved. In the case of Co-75, the results suggest that the dominance of the spherical configurations over the deformed ones might be stronger than expected below Ni-78. Further experimental efforts to discern the nature of the J(pi) = (1/2(-)) isomer are necessary.
Address [Escrig, S.; Morales, A., I] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain, Email: Samuel.Escrig@csic.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000669040500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4887
Permanent link to this record