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Author Tain, J.L. et al; Valencia, E.; Algora, A.; Agramunt, J.; Rubio, B.; Estevez, E.; Jordan, M.D.
Title Enhanced gamma-Ray Emission from Neutron Unbound States Populated in beta Decay Type Journal Article
Year 2015 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 115 Issue 6 Pages 062502 - 5pp
Keywords
Abstract Total absorption spectroscopy is used to investigate the beta-decay intensity to states above the neutron separation energy followed by gamma-ray emission in Br-87,Br-88 and Rb-94. Accurate results are obtained thanks to a careful control of systematic errors. An unexpectedly large. intensity is observed in all three cases extending well beyond the excitation energy region where neutron penetration is hindered by low neutron energy. The gamma branching as a function of excitation energy is compared to Hauser-Feshbach model calculations. For Br-87 and Br-88 the gamma branching reaches 57% and 20%, respectively, and could be explained as a nuclear structure effect. Some of the states populated in the daughter can only decay through the emission of a large orbital angular momentum neutron with a strongly reduced barrier penetrability. In the case of neutron-rich Rb-94 the observed 4.5% branching is much larger than the calculations performed with standard nuclear statistical model parameters, even after proper correction for fluctuation effects on individual transition widths. The difference can be reconciled by introducing an enhancement of 1 order of magnitude in the photon strength to neutron strength ratio. An increase in the photon strength function of such magnitude for very neutron-rich nuclei, if it proves to be correct, leads to a similar increase in the (n, gamma) cross section that would have an impact on r process abundance calculations.
Address [Tain, J. L.; Valencia, E.; Algora, A.; Agramunt, J.; Rubio, B.; Estevez, E.; Jordan, M. D.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: tain@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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000359059100002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2319
Permanent link to this record
 
 
Author IGISOL Collaboration (Zakari-Issoufou, A.A. et al); Algora, A.; Tain, J.L.; Valencia, E.; Agramunt, J.; Estevez, E.; Gelletly, W.; Jordan, M.D.; Molina, F.; Perez-Cerdan, A.B.; Rubio, B.
Title Total Absorption Spectroscopy Study of Rb-92 Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape Type Journal Article
Year 2015 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 115 Issue 10 Pages 102503 - 6pp
Keywords
Abstract The antineutrino spectra measured in recent experiments at reactors are inconsistent with calculations based on the conversion of integral beta spectra recorded at the ILL reactor. Rb-92 makes the dominant contribution to the reactor antineutrino spectrum in the 5-8 MeV range but its decay properties are in question. We have studied Rb-92 decay with total absorption spectroscopy. Previously unobserved beta feeding was seen in the 4.5-5.5 region and the GS to GS feeding was found to be 87.5(25)%. The impact on the reactor antineutrino spectra calculated with the summation method is shown and discussed.
Address [Zakari-Issoufou, A. -A.; Fallot, M.; Porta, A.; Bui, V. M.; Cormon, S.; Estienne, M.; Briz, J. A.; Cucoanes, A.; Shiba, T.] Univ Nantes, Ecole Mines Nantes, SUBATECH, CNRS,IN2P3, F-44307 Nantes, France, Email: porta@subatech.in2p3.fr
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:000360603500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2375
Permanent link to this record
 
 
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
Permanent link to this record
 
 
Author Grodner, E. et al; Gadea, A.; Algora, A.; Agramunt, J.; Domingo-Pardo, C.; Molina, F.; Rubio, B.
Title Hindered Gamow-Teller Decay to the Odd-Odd N = Z Ga-62: Absence of Proton-Neutron T=0 Condensate in A=62 Type Journal Article
Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 113 Issue 9 Pages 092501 - 5pp
Keywords
Abstract Search for a new kind of superfluidity built on collective proton-neutron pairs with aligned spin is performed studying the Gamow-Teller decay of the T = 1, J(pi) = 0(+) ground state of Ge-62 into excited states of the odd-odd N = Z nucleus Ga-62. The experiment is performed at GSI Helmholtzzentrum fur Shwerionenforshung with the Ge-62 ions selected by the fragment separator and implanted in a stack of Si-strip detectors, surrounded by the RISING Ge array. A half-life of T-1/2 = 2 82.9(14) ms is measured for the Ge-62 ground state. Six excited states of Ga-62, populated below 2.5 MeV through Gamow-Teller transitions, are identified. Individual Gamow-Teller transition strengths agree well with theoretical predictions of the interacting shell model and the quasiparticle random phase approximation. The absence of any sizable low-lying Gamow-Teller strength in the reported beta-decay experiment supports the hypothesis of a negligible role of coherent T = 0 proton-neutron correlations in Ga-62.
Address [Grodner, E.] Univ Warsaw, Fac Phys, Warsaw, Poland
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:000341292800008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1919
Permanent link to this record
 
 
Author Fujita, Y. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B.
Title Observation of Low- and High-Energy Gamow-Teller Phonon Excitations in Nuclei Type Journal Article
Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 112 Issue 11 Pages 112502 - 5pp
Keywords
Abstract Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The nuclear GT excitations were studied for the mass number A = 42, 46, 50, and 54 “f-shell” nuclei in (He-3, t) charge-exchange reactions. In the Ca-42 -> Sc-42 reaction, most of the GT strength is concentrated in the lowest excited state at 0.6 MeV, suggesting the existence of a low-energy GT phonon excitation. As A increases, a high-energy GT phonon excitation develops in the 6-11 MeV region. In the Fe-54 -> Co-54 reaction, the high-energy GT phonon excitation mainly carries the GT strength. The existence of these two GT phonon excitations are attributed to the 2 fermionic degrees of freedom in nuclei.
Address [Fujita, Y.; Fujita, H.; Adachi, T.; Fujita, K.; Hatanaka, K.; Hirota, K.; Ishikawa, D.; Matsubara, H.; Nakanishi, K.; Okamura, H.; Ong, H. J.; Shimizu, Y.; Suzuki, T.; Tameshige, Y.; Tamii, A.; Uchida, M.; Wakasa, T.; Yosoi, M.; Zenihiro, J.] Osaka Univ, Nucl Phys Res Ctr, Ibaraki, Osaka 5670047, Japan, Email: fujita@rcnp.osaka-u.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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000332925900009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1729
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Author Orrigo, S.E.A. et al; Rubio, B.; Agramunt, J.; Algora, A.; Molina, F.
Title Observation of the beta-Delayed gamma-Proton Decay of Zn-56 and its Impact on the Gamow-Teller Strength Evaluation Type Journal Article
Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 112 Issue 22 Pages 222501 - 5pp
Keywords
Abstract We report the observation of a very exotic decay mode at the proton drip line, the beta-delayed gamma-proton decay, clearly seen in the beta decay of the T-z = -2 nucleus Zn-56. Three gamma-proton sequences have been observed after the beta decay. Here this decay mode, already observed in the sd shell, is seen for the first time in the f p shell. Both. and proton decays have been taken into account in the estimation of the Fermi and Gamow-Teller strengths. Evidence for fragmentation of the Fermi strength due to strong isospin mixing is found.
Address [Orrigo, S. E. A.; Rubio, B.; Agramunt, J.; Algora, A.; Molina, F.] Univ Valencia, CSIC, Inst Fis Corpuscular, 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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000336909200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1817
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Author Guastalla, G. et al; Algora, A.; Domingo-Pardo, C.
Title Coulomb Excitation of Sn-104 and the Strength of the Sn-100 Shell Closure Type Journal Article
Year 2013 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 110 Issue 17 Pages 172501 - 5pp
Keywords
Abstract A measurement of the reduced transition probability for the excitation of the ground state to the first 2(+) state in Sn-104 has been performed using relativistic Coulomb excitation at GSI. Sn-104 is the lightest isotope in the Sn chain for which this quantity has been measured. The result is a key point in the discussion of the evolution of nuclear structure in the proximity of the doubly magic nucleus Sn-100. The value B(E2; 0(+) -> 2(+)) = 0.10(4) e(2)b(2) is significantly lower than earlier results for Sn-106 and heavier isotopes. The result is well reproduced by shell model predictions and therefore indicates a robust N = Z = 50 shell closure.
Address Tech Univ Darmstadt, Inst Kernphys, Darmstadt, Germany
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:000317915200008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1423
Permanent link to this record
 
 
Author Gottardo, A. et al; Gadea, A.; Algora, A.
Title New Isomers in the Full Seniority Scheme of Neutron-Rich Lead Isotopes: The Role of Effective Three-Body Forces Type Journal Article
Year 2012 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 109 Issue 16 Pages 162502 - 5pp
Keywords
Abstract The neutron-rich lead isotopes, up to Pb-216, have been studied for the first time, exploiting the fragmentation of a primary uranium beam at the FRS-RISING setup at GSI. The observed isomeric states exhibit electromagnetic transition strengths which deviate from state-of-the-art shell-model calculations. It is shown that their complete description demands the introduction of effective three-body interactions and two-body transition operators in the conventional neutron valence space beyond Pb-208.
Address [Gottardo, A.; Valiente-Dobon, J. J.; de Angelis, G.; Napoli, D. R.; Sahin, E.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: andrea.gottardo@lnl.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:000309860900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1182
Permanent link to this record
 
 
Author Fallot, M.; Cormon, S.; Estienne, M.; Algora, A.; Bui, V.M.; Cucoanes, A.; Elnimr, M.; Giot, L.; Jordan, D.; Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A.; Tain, J.L.; Yermia, F.; Zakari-Issoufou, A.A.
Title New Antineutrino Energy Spectra Predictions from the Summation of Beta Decay Branches of the Fission Products Type Journal Article
Year 2012 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 109 Issue 20 Pages 202504 - 5pp
Keywords
Abstract In this Letter, we study the impact of the inclusion of the recently measured beta decay properties of the Tc-102;104;105;106;107, Mo-105, and Nb-101 nuclei in an updated calculation of the antineutrino energy spectra of the four fissible isotopes U-235,U-238 and Pu-239,Pu-241. These actinides are the main contributors to the fission processes in pressurized water reactors. The beta feeding probabilities of the above-mentioned Tc, Mo, and Nb isotopes have been found to play a major role in the gamma component of the decay heat of Pu-239, solving a large part of the gamma discrepancy in the 4-3000 s range. They have been measured by using the total absorption technique, insensitive to the pandemonium effect. The calculations are performed by using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of U-235, Pu-239,Pu-241, and, in particular, U-238 for which no measurement has been published yet. We conclude that new total absorption technique measurements are mandatory to improve the reliability of the predicted spectra.
Address [Fallot, M.; Cormon, S.; Estienne, M.; Bui, V. M.; Cucoanes, A.; Elnimr, M.; Giot, L.; Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A.; Yermia, F.; Zakari-Issoufou, A. -A.] Univ Nantes, Ecole Mines Nantes, CNRS, IN2P3,SUBATECH, F-44307 Nantes, 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:000310991700009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1250
Permanent link to this record
 
 
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