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Author  |
Fujita, H. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B. |
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Title |
Experimental study of Gamow-Teller transitions via the high-energy-resolution O-18(He-3, t)F-18 reaction: Identification of the low-energy “super” -Gamow-Teller state |
Type |
Journal Article |
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Year |
2019 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
100 |
Issue |
3 |
Pages |
034618 - 13pp |
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Keywords |
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Abstract |
Using the high-resolution O-18(He-3, t)F-18 reaction at 0 degrees and at 140 MeV/nucleon, Gamow-Teller (GT) transitions were studied. A high energy resolution of 31 keV was achieved by applying dispersion matching techniques. The main part of the observed GT transition strength is concentrated in the transition to the F-18 ground state (g.s.). The absolute values of the reduced GT transition strengths, B(GT), were derived up to E-x = 12 MeV assuming proportionality between the B(GT) values and the reaction cross sections at 0 degrees. The B(GT) value obtained from the beta decay of F-18 (g.s.) -> O-18 (g.s.) was used to determine the proportionality constant. A total B(GT) of 4.06(5) was found and 76(1)% of the strength is concentrated to the ground state of F-18. The obtained B(GT) values were compared with those from the O-18(p, n) F-18 reaction and the mirror symmetric beta(+) decay of Ne-18 -> F-18. The candidates for 1(+) states with isospin T = 1 were identified by comparison with the O-18(p, p') data. The results of shell-model and quasiparticle-random-phase approximation calculations suggest constructive contributions of various configurations to the F-18 ground state, suggesting that this state is the low-energy super GT state. |
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Address |
[Fujita, H.; Fujita, Y.; Adachi, T.; Hatanaka, K.; Hirota, K.; Ishikawa, D.; Matsubara, H.; Okamura, H.; Ong, H. J.; Susoy, G.; Suzuki, T.; Tamii, A.; Zenihiro, J.] Osaka Univ, Res Ctr Nucl Phys, Ibaraki, Osaka 5670047, Japan, Email: hfujita@rcnp.osaka-u.ac.jp |
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Publisher |
Amer Physical Soc |
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English |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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ISSN |
2469-9985 |
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Notes |
WOS:000488259800004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4165 |
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Author |
Fujita, Y. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B. |
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Title |
Observation of Low- and High-Energy Gamow-Teller Phonon Excitations in Nuclei |
Type |
Journal Article |
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Year |
2014 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
112 |
Issue |
11 |
Pages |
112502 - 5pp |
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Keywords |
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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. |
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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 |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Conference |
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Notes |
WOS:000332925900009 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1729 |
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Author |
Fujita, Y. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B. |
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Title |
High-resolution study of T-z =+2 ->+1 Gamow-Teller transitions in the Ca-44(3He,t)Sc-44 reaction |
Type |
Journal Article |
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Year |
2013 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
88 |
Issue |
1 |
Pages |
014308 - 18pp |
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Keywords |
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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. |
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Address |
[Fujita, Y.; Fujita, H.] Osaka Univ, Dept Phys, Toyonaka, Osaka 5600043, Japan, Email: fujita@rcnp.osaka-u.ac.jp |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000321839100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1495 |
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Author |
Fujita, Y.; Rubio, B.; Adachi, T.; Blank, B.; Fujita, H.; Gelletly, W.; Molina, F.; Orrigo, S.E.A. |
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Title |
Gamow-Teller excitations studied by weak and strong interactions |
Type |
Journal Article |
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Year |
2015 |
Publication |
Acta Physica Polonica B |
Abbreviated Journal |
Acta Phys. Pol. B |
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Volume |
46 |
Issue |
3 |
Pages |
657-668 |
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Keywords |
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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. |
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Address |
[Fujita, Y.; Adachi, T.; Fujita, H.] Osaka Univ, Nucl Phys Res Ctr, Ibaraki, Osaka 5670047, Japan |
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Corporate Author |
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Publisher |
Wydawnictwo Uniwersytetu Jagiellonskiego |
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English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0587-4254 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000353565500047 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2220 |
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Author |
Fujita, Y.; Rubio, B.; Molina, F.; Adachi, T.; Fujita, H.; Blank, B.; Ganioglu, E.; Gelletly, W.; Orrigo, S.E.A. |
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Title |
The Tz = ±1 → 0 and ±2 →±1 Mirror Gamow–Teller transitions in pf-shell nuclei |
Type |
Journal Article |
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Year |
2016 |
Publication |
Acta Physica Polonica B |
Abbreviated Journal |
Acta Phys. Pol. B |
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Volume |
47 |
Issue |
3 |
Pages |
867-881 |
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Keywords |
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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. |
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Address |
[Fujita, Y.; Adachi, T.; Fujita, H.] Osaka Univ, RCNP, Ibaraki, Osaka 5670047, Japan |
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Corporate Author |
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Thesis |
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Publisher |
Wydawnictwo Uniwersytetu Jagiellonskiego |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0587-4254 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000373495500033 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2626 |
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