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Author (up) 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 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 (up) Fujita, Y.; Rubio, B.; Gelletly, W.
Title Spin-isospin excitations probed by strong, weak and electro-magnetic interactions Type Journal Article
Year 2011 Publication Progress in Particle and Nuclear Physics Abbreviated Journal Prog. Part. Nucl. Phys.
Volume 66 Issue 3 Pages 549-606
Keywords Gamow-Teller transitions; beta decay; Charge-exchange reactions; Isospin symmetry; High resolution; Proton-rich nuclei
Abstract Gamow-Teller (GT) transitions are the most common weak interaction processes of spin-isospin (sigma tau) type in atomic nuclei. They are of interest not only in nuclear physics but also in astrophysics; they play an important role in supernovae explosions and nucleosynthesis. The direct study of weak decay processes, however, gives relatively limited information about GT transitions and the states excited via GT transitions (GT states); beta decay can only access states at excitation energies lower than the decay Q-value, and neutrino-induced reactions have very small cross-sections. However, one should note that beta decay has a direct access to the absolute GT transition strengths B(GT) from a study of half-lives, Q(beta)-values and branching ratios. They also provide information on GT transitions in nuclei far-from-stability. Studies of M1 gamma transitions provide similar information. In contrast, the complementary charge-exchange (CE) reactions, such as the (p, n) or ((3)He, t) reactions at intermediate beam energies and 0 degrees, can selectively excite GT states up to high excitation energies in the final nucleus. It has been found empirically that there is a close proportionality between the cross-sections at 0 degrees and the transition strengths B(GT) in these CE reactions. Therefore, CE reactions are useful tools to study the relative values of B(GT) strengths up to high excitation energies. In recent ((3)He, t) measurements, one order-of-magnitude improvement in the energy resolution has been achieved. This has made it possible to make one-to-one comparisons of GT transitions studied in CE reactions and beta decays. Thus GT strengths in ((3)He, t) reactions can be normalised by the beta-decay values. In addition, comparisons with closely related M1 transitions studied in gamma decay or electron inelastic scattering [(e, e')1, and furthermore with “spin” M I transitions that can be studied by proton inelastic scattering [(p, p')[ have now been made possible. In these comparisons, the isospin quantum number T and associated symmetry structure in the same mass A nuclei (isobars) play a key role. Isospin symmetry can extend our scope even to the structures of unstable nuclei that are far from reach at present unstable beam factories.
Address [Fujita, Y] Osaka Univ, Dept Phys, Osaka 5600043, Japan, Email: fujita@rcnp.osaka-u.ac.jp
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 0146-6410 ISBN Medium
Area Expedition Conference
Notes WOS:000292473100003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 692
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Author (up) 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 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
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Author (up) 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 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
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Author (up) 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 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