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Author Fujita, Y. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B.
Title High-resolution study of T-z =+2 ->+1 Gamow-Teller transitions in the Ca-44(3He,t)Sc-44 reaction Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 88 Issue 1 Pages 014308 - 18pp
Keywords
Abstract In order to study the Gamow-Teller (GT) transitions from the T-z = +2 nucleus Ca-44 to the T-z = +1 nucleus Sc-44, where T-z is the z component of isospin T, we performed the (p, n)-type (He-3, t) charge-exchange (CE) reaction at 140 MeV/nucleon and the scattering angles 0 degrees and 2.5 degrees. An energy resolution of 28 keV, that was realized by applying matching techniques to the magnetic spectrometer system, allowed the study of fragmented states. The GT transition strengths, B(GT), were derived up to the excitation energy (E-x) of 13.7 MeV assuming the proportionality between cross sections and B(GT) values. The total sum of B(GT) values in discrete states was 3.7, which was 31% of the sum-rule-limit value of 12. Shell model calculations using the GXPF1J interaction could reproduce the gross features of the experimental B(GT) distribution, but not the fragmentation of the strength. By introducing the concepts of isospin, properties of isospin analogous transitions and states were investigated. (i) Assuming isospin symmetry, the T-z = +2 -> +1 and T-z = -2 -> -1 mirror GT transitions should have the same properties, where the latter can be studied in the beta decay of Cr-44 to V-44. First, we confirmed that the beta-decay half-life T-1/2 of Cr-44 can be reproduced using the B(GT) distribution from the Ca-44(He-3, t) measurement. Then, the 0 degrees, (3He, t) spectrum was modified to deduce the “beta-decay spectrum” and it was compared with the delayed-proton spectrum from the Cr-44 beta decay. The two spectra were mostly in agreement for the GT excitations, but suppression of the proton decay was found for the T = 2 isobaric analog state (IAS). (ii) Starting from the T = 2 ground state of 44Ca, the (3He, t) can excite GT states (state populated by GT transitions) with T = 1, 2, and 3. On the other hand, the Ca-44(p, p') reaction can excite spin-M1 states (states populated by spin-M1 transitions) with T = 2 and 3 that are analogous to the T = 2 and 3 GT states, respectively. By comparing the spectra from these two reactions, a T value of 2 is suggested for several GT states in the E-x = 11.5-13.7 MeV region. (iii) It has been suggested that the T = 2, J(pi) = 0(+) double isobaric analog state (DIAS) at 9.338 MeV in the T-z = 0 nucleus Ti-44 forms an isospin-mixed doublet with a subsidiary 0(+) state at 9.298 MeV. Since no corresponding state was found in the T-z = +1 nucleus Sc-44, we suggest T = 0 for the subsidiary state.
Address [Fujita, Y.; Fujita, H.] Osaka Univ, Dept Phys, Toyonaka, Osaka 5600043, Japan, Email: fujita@rcnp.osaka-u.ac.jp
Corporate Author Thesis
Publisher (up) 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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000321839100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1495
Permanent link to this record
 
 
Author Morales, A.I. et al; Algora, A.; Molina, F.; Rubio, B.
Title beta-delayed gamma-ray spectroscopy of Au-203,Au-204 and Pt200-202 Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 88 Issue 1 Pages 014319 - 12pp
Keywords
Abstract The beta decay of five heavy, neutron-rich nuclei, Pt-203,Pt-204 and Ir200-202, has been investigated following relativistic cold fragmentation reactions of lead projectiles using the FRS + RISING setup at GSI. This paper reports on the study of the low-lying states in the decay daughter nuclei Au-203,Au-204 and Pt200-202. The characteristic gamma rays for each nucleus have been determined using beta-delayed gamma-ray spectroscopy. Tentative level schemes, relative intensities, and apparent beta feedings are provided. These data are compared with shell-model calculations, which indicate a substantial contribution to the total beta strength from high-energy first-forbidden beta-decay transitions in this mass region.
Address [Morales, A. I.; Benlliure, J.; 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 (up) 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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000322113600003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1527
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 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 (up) 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
Permanent link to this record
 
 
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 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 (up) 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
Permanent link to this record
 
 
Author Karakoc, M. et al; Molina, F.
Title Gamow-Teller transitions in the A=40 isoquintet of relevance for neutrino captures in Ar-40 Type Journal Article
Year 2014 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 89 Issue 6 Pages 064313 - 7pp
Keywords
Abstract Background: The Gamow-Teller response of Ar-40 is important for the use of liquid argon as a medium for neutrino detection. An ambiguity about the Gamow-Teller strength for the excitation of 1(+) states at 2290 and 2730 keV in K-40 results in a significant uncertainty for neutrino capture rates. This ambiguity is caused by the large discrepancy observed between strengths extracted from Ar-40(p, n) charge-exchange data and the transition strengths for the analog transitions studied in the beta decay of Ti-40. Purpose: This study was aimed at resolving the ambiguity between the results from the Ar-40(p, n) charge-exchange and Ti-40 beta-decay data. Method: Shell-model calculations in the sd-pf shell with a new interaction (WBMB-C) were used to study differences between the structure of the transitions from Ar-40 and Ti-40. Distorted-wave Born approximation reaction calculations were used to investigate uncertainties in the extraction of Gamow-Teller strength from the Ar-40(p, n) data. New high-resolution data for the Ar-40(He-3,t) reaction were used to gain further insight into the charge-exchange reaction mechanism and to provide more information to test the validity of the shell-model calculations. Results: The shell-model calculations showed that interference between amplitudes associated with pf and sd components to the low-lying Gamow-Teller transitions, in combination with a difference in Coulomb energy shifts for Ar-40 and Ti-40, can produce the differences on the scale of those observed between the Ar-40 charge-exchange and Ti-40 beta-decay data. In combination with the difference in nuclear penetrability of the (p, n) and (He-3,t) probes, the different contributions from amplitudes associated with transitions in the pf and sd shells are likely also responsible for the observed discrepancy between the ratio of the cross sections for the low-lying 1(+) states in the Ar-40(p, n) and Ar-40(He-3,t) data. Conclusions: On the basis of this study, it is recommended to use Gamow-Teller strengths extracted from the Ar-40(p, n) data, not the Ti-40 beta-decay data, for the calculation of neutrino capture rates. Further theoretical studies are required to achieve a consistent quantitative description for the energy differences between low-lying 1(+) states in K-40 and Sc-40 and the experimentally observed Gamow-Teller strengths.
Address [Karakoc, M.; Boztosun, I.] Akdeniz Univ, Dept Phys, TR-07058 Antalya, Turkey, Email: zegers@nscl.msu.edu
Corporate Author Thesis
Publisher (up) 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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000338641500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1851
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 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 (up) 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 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 (up) 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 Molina, F. et al; Rubio, B.; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Gadea, A.; Tain, J.L.
Title T-z =-1 -> 0 beta decays of Ni-54, Fe-50, Cr-46, and Ti-42 and comparison with mirror (He-3,t) measurements Type Journal Article
Year 2015 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 91 Issue 1 Pages 014301 - 19pp
Keywords
Abstract We have studied the beta decay of the T-z = -1, f(7/2) shell nuclei Ni-54, Fe-50, Cr-46, and Ti-42 produced in fragmentation reactions. The proton separation energies in the daughter T-z = 0 nuclei are relatively large (approximate to 4-5 MeV) so studies of the. rays are essential. The experiments were performed at GSI as part of the Stopped-beam campaign with the RISING setup consisting of 15 Euroball Cluster Ge detectors. From the newly obtained high precision beta-decay half-lives, excitation energies, and beta branching ratios, we were able to extract Fermi and Gamow-Teller transition strengths in these beta decays. With these improved results it was possible to compare in detail the Gamow-Teller (GT) transition strengths observed in beta decay including a sensitivity limit with the strengths of the T-z = +1 to T-z = 0 transitions derived from high resolution (He-3,t) reactions on the mirror target nuclei at RCNP, Osaka. The accumulated B(GT) strength obtained from both experiments looks very similar although the charge exchange reaction provides information on a broader energy range. Using the “merged analysis” one can obtain a full picture of the B(GT) over the full Q(beta) range. Looking at the individual transitions some differences are observed, especially for the weak transitions. Their possible origins are discussed.
Address [Molina, F.; Rubio, B.; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Gadea, A.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: berta.rubio@ific.uv.es
Corporate Author Thesis
Publisher (up) 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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000347924300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2087
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 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 (up) 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 Orrigo, S.E.A. et al; Rubio, B.; Gelletly, W.; Agramunt, J.; Algora, A.; Molina, F.
Title beta decay of the exotic T-z =-2 nuclei Fe-48, Ni-52, and Zn-56 Type Journal Article
Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 93 Issue 4 Pages 044336 - 18pp
Keywords
Abstract The results of a study of the beta decays of three proton-rich nuclei with T-z = -2, namely Fe-48, Ni-52, and Zn-56, produced in an experiment carried out at GANIL, are reported. In all three cases we have extracted the half-lives and the total beta-delayed proton emission branching ratios. We have measured the individual beta-delayed protons and beta-delayed. rays and the branching ratios of the corresponding levels. Decay schemes have been determined for the three nuclei, and new energy levels are identified in the daughter nuclei. Competition between beta-delayed protons and. rays is observed in the de-excitation of the T = 2 isobaric analog states in all three cases. Absolute Fermi and Gamow-Teller transition strengths have been determined. The mass excesses of the nuclei under study have been deduced. In addition, we discuss in detail the data analysis taking as a test case Zn-56, where the exotic beta-delayed gamma-proton decay has been observed.
Address [Orrigo, S. E. A.; Rubio, B.; Gelletly, W.; 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 (up) 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:000374955500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2645
Permanent link to this record