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Author Fujita, Y.; Rubio, B.; Adachi, T.; Blank, B.; Fujita, H.; Gelletly, W.; Molina, F.; Orrigo, S.E.A.
Title Gamow-Teller excitations studied by weak and strong interactions Type Journal Article
Year 2015 Publication Acta Physica Polonica B Abbreviated Journal Acta Phys. Pol. B
Volume 46 Issue 3 Pages 657-668
Keywords
Abstract (down) Studying weak nuclear responses, especially the Gamow-Teller (GT) transitions starting from stable as well as unstable nuclei, provide crucial and critical information on nuclear structure. Therefore, the study of GT transitions is a key issue in nuclear physics and also nuclear-astrophysics. Under the assumption of isospin symmetry, it is expected that the structure of mirror nuclei and the GT transitions starting from their ground states are identical. We have studied the corresponding GT transitions starting from T-z = +/- 1 and +/- 2 p f -shell nuclei, respectively, by means of hadronic (He-3,t) charge-exchange reactions and mirror beta decays. The results on GT strength distributions measured in beta decays and (He-3,t) reactions performed at an intermediate incident energy of 140 MeV/nucleon and 0 degrees are compared. The combined results help provide an understanding of nuclear structure of nuclei far-from-stability.
Address [Fujita, Y.; Adachi, T.; Fujita, H.] Osaka Univ, Nucl Phys Res Ctr, Ibaraki, Osaka 5670047, Japan
Corporate Author Thesis
Publisher Wydawnictwo Uniwersytetu Jagiellonskiego Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0587-4254 ISBN Medium
Area Expedition Conference
Notes WOS:000353565500047 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2220
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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 (down) 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
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Author Denis Bacelar, A.M. et al; Algora, A.; Molina, F.; Rubio, B.
Title The population of metastable states as a probe of relativistic-energy fragmentation reactions Type Journal Article
Year 2013 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 723 Issue 4-5 Pages 302-306
Keywords
Abstract (down) Isomeric ratios have been measured for high-spin states in Po-198,200,206,208(84), At-208,209,210,211(85), Rn-210,211,212,213,214(86), Fr-208,211,212,213,214(87), Ra-210,211,212,214,215(88), and Ac-215(89) following the projectile fragmentation of a 1 AGeV U-238 beam by a Be-9 target at GSI Helmholtzzentrum fur Schwerionenforschung. The fragments were separated in the fragment separator (FRS) and identified by means of energy loss and time-of-flight techniques. They were brought to rest at the centre of the RISING gamma-ray detector array and intensities of gamma rays emitted in the decay of isomeric states with half-lives between 100 ns and 40 μs and spin values up to 55/2 (h) over bar were used to obtain the corresponding isomeric ratios. The data are compared to theoretical isomeric ratios calculated in the framework of the abrasion-ablation model. Large experimental enhancements are obtained for high-spin isomers in comparison to expected values.
Address [Bacelar, A. M. Denis; Bruce, A. M.; Lalkovski, S.] Univ Brighton, Sch Comp Engn & Math, Brighton BN2 4GJ, E Sussex, England, Email: alison.bruce@brighton.ac.uk
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000320745400005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1502
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Author Ganioglu, E. et al; Rubio, B.; Algora, A.; Estevez-Aguado, E.; Molina, F.
Title High-resolution study of Gamow-Teller transitions in the Ti-48(He-3,t)V-48 reaction Type Journal Article
Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 93 Issue 6 Pages 064326 - 10pp
Keywords
Abstract (down) In this work we have studied T-z = +2 -> +1, Gamow-Teller (GT) transitions in the Ti-48(He-3, t)V-48 chargeexchange reaction at 140 MeV/nucleon and 0 degrees at the Research Center for Nuclear Physics, Osaka. From the high-resolution facility, consisting of a high-dispersion beamline and the Grand Raiden spectrometer, the spectrum had an energy resolution of 21 keV, among the best achieved. Individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy of 12 MeV. The total sum of the B(GT) strength observed in discrete states was 4.0, which is 33% of the sum-rule-limit value of 12. The results were compared with the results of shell-model calculations carried out with the GXPF1J interaction. The measured B(GT) distribution was also compared with that obtained in the (He-3, t) charge-exchange reaction on Ti-47. On the assumption of isospin symmetry the beta spectrum of the T-z = -2 nucleus Fe-48 was deduced from the observed spectrum in the Ti-48(He-3, t)V-48 reaction and this predicted spectrum was compared with the measured one.
Address [Ganioglu, E.; Susoy, G.] Istanbul Univ, Dept Phys, TR-34134 Istanbul, Turkey, Email: ganioglu@istanbul.edu.tr
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:000378818000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2740
Permanent link to this record
 

 
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 (down) 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 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 Ganioglu, E. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B.
Title High-resolution study of Gamow-Teller transitions in the Ti-47(He-3, t)V-47 reaction Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 87 Issue 1 Pages 014321 - 12pp
Keywords
Abstract (down) Given the importance of Gamow-Teller (GT) transitions in nuclear structure and astrophysical nuclear processes, we have studied T-z = +3/2 -> +1/2, GT transitions starting from the Ti-47 nucleus in the (He-3, t) charge-exchange reaction at 0 degrees and at an intermediate incident energy of 140 MeV/nucleon. The experiments were carried out at the Research Center for Nuclear Physics (RCNP), Osaka, using the high-resolution facility with a high-dispersion beam line and the Grand-Raiden spectrometer. With an energy resolution of 20 keV, individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy (E-x) of 12.5 MeV. The GT strength was widely distributed from low excitation energy up to 12.5 MeV, where we had to stop the analysis because of the high level density. The distribution of the GT strengths was compared with the results of shell model calculations using the GXPF1 interaction. The calculations could reproduce the experimental GT distributions well. The GT transitions from the ground state of Ti-47 and the M1 transitions from the isobaric analog state in V-47 to the same low-lying states in V-47 are analogous. It was found that the ratios of GT transition strengths to the ground state, the 0.088-MeV state, and the 0.146-MeV state are similar to the ratios of the strengths of the analogous M1 transitions from the isobaric analog state (IAS) to these states. The measured distribution of the GT strengths was also compared with those starting from the T-z = +3/2 nucleus K-41 to the T-z = +1/2 nucleus Ca-41.
Address [Ganioglu, E.; Susoy, G.] Istanbul Univ, Dept Phys, TR-34134 Istanbul, Turkey, Email: ganioglu@istanbul.edu.tr;
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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000313548700005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1308
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 (down) 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
Permanent link to this record
 

 
Author Fujita, Y.; Rubio, B.; Molina, F.; Adachi, T.; Fujita, H.; Blank, B.; Ganioglu, E.; Gelletly, W.; Orrigo, S.E.A.
Title The Tz = ±1 → 0 and ±2 →±1 Mirror Gamow–Teller transitions in pf-shell nuclei Type Journal Article
Year 2016 Publication Acta Physica Polonica B Abbreviated Journal Acta Phys. Pol. B
Volume 47 Issue 3 Pages 867-881
Keywords
Abstract (down) Gamow-Teller (GT) transitions are the most common weak-interaction processes in the Universe. They play important roles in various processes of nucleosynthesis, for example, in the rapid proton-capture process (rp-process). In the pf-shell region, the rp-process runs through neutron-deficient nuclei with T-z = -2, -1, and 0 mainly by means of GT and Fermi transitions, where T-z is the z component of isospin T defined by T-z = (N = Z)/2. Under the assumption of isospin symmetry, mirror nuclei with reversed Z and N numbers, and thus with opposite signs of T-z, have the same structure. Therefore, symmetry is also expected for the GT transitions starting from and ending up in mirror nuclei. We have been studying the T-z = -2 -> -1 and -1 -> 0 GT transitions in beta decays, while those from stable T-z = +2 and +1 nuclei by means of hadronic (He-3; t) charge-exchange (CE) reactions. The results from these studies are compared in order to examine the mirror-symmetry structure in nuclei. In addition, these results are combined for the better understanding of GT transitions in the pf-shell region.
Address [Fujita, Y.; Adachi, T.; Fujita, H.] Osaka Univ, RCNP, Ibaraki, Osaka 5670047, Japan
Corporate Author Thesis
Publisher Wydawnictwo Uniwersytetu Jagiellonskiego Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0587-4254 ISBN Medium
Area Expedition Conference
Notes WOS:000373495500033 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2626
Permanent link to this record
 

 
Author Al-Dahan, N. et al; Algora, A.; Molina, F.; Rubio, B.
Title Multiple beta(-) decaying states in Re-194: Shape evolution in neutron-rich osmium isotopes Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 85 Issue 3 Pages 034301 - 9pp
Keywords
Abstract (down) beta decays from heavy, neutron-rich nuclei with A similar to 190 have been investigated following their production via the relativistic projectile fragmentation of an E/A = 1 GeV Pb-208 primary beam on a similar to 2.5 g/cm(2) Be-9 target. The reaction products were separated and identified using the GSI FRagment Separator (FRS) and stopped in the RISING active stopper. gamma decays were observed and correlated with these secondary ions on an event-by-event basis such that gamma-ray transitions following from both internal (isomeric) and beta decays were recorded. A number of discrete, beta-delayed gamma-ray transitions associated with beta decays from Re-194 to excited states in Os-194 have been observed, including previously reported decays from the yrast I-pi = (6(+)) state. Three previously unreported gamma-ray transitions with energies 194, 349, and 554 keV are also identified; these transitions are associated with decays from higher spin states in Os-194. The results of these investigations are compared with theoretical predictions from Nilsson multi-quasiparticle (MQP) calculations. Based on lifetime measurements and the observed feeding pattern to states in Os-194, it is concluded that there are three beta(-)-decaying states in Re-194.
Address [Al-Dahan, N.] Univ Kerbala, Coll Sci, Dept Phys, Kerbala, Iraq, Email: p.regan@surrey.ac.uk
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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000301113800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 932
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 (down) 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 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