| 11. |
- Ekman, Jörgen, et al.
(författare)
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Unusual Isospin-Breaking and Isospin-mixing Effects in the A=35 Mirror Nuclei
- 2004
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Ingår i: Physical Review Letters. - 1079-7114. ; 92:13
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Tidskriftsartikel (refereegranskat)abstract
- Excited states have been studied in Ar-35 following the O-16(Mg-24,1alpha1n)Ar-35 fusion-evaporation reaction at 60 MeV using the Ge-detector array GASP. A comparison with the mirror nucleus Cl-35 shows two remarkable features: (i) A surprisingly large energy difference for the 13/2(-) states, in which the hitherto overlooked electromagnetic spin-orbit term is shown to play a major role, and (ii) a very different decay pattern for the 7/2(-) states, which provides direct evidence of isospin mixing.
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| 12. |
- Fahlander, Claes, et al.
(författare)
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Excited States in 103Sn: Neutron Single-particle Energies with Respect to 100Sn
- 2001
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813 .- 1089-490X. ; 63:2
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Tidskriftsartikel (refereegranskat)abstract
- Gamma-ray lines from Sn-103 have been identified for the first time using EUROBALL and ancillary detectors. The level scheme of Sn-103 has been established by means of particle-gated gamma gamma coincidences. The energy spacing between the g(7/2) and d(5/2) neutron single-particle orbitals is determined from the excited states in Sn-103.
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| 13. |
- Formicola, A, et al.
(författare)
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Astrophysical S-factor of 14N(p,γ)15O
- 2004
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 591:1-2, s. 61-68
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Tidskriftsartikel (refereegranskat)abstract
- We report on a new measurement of the 14N(p,γ) 15O capture cross section at Ep=140 to 400 keV using the 400 kV LUNA accelerator facility at the Laboratori Nazionali del Gran Sasso (LNGS). The uncertainties have been reduced with respect to previous measurements and their analysis. We have analyzed the data using the R-matrix method and we find that the ground state transition accounts for about 15% of the total S-factor. The main contribution to the S-factor is given by the transition to the 6.79 MeV state. We find a total S(0)=1.7±0.2 keVb, in agreement with recent extrapolations. The result has important consequences for the solar neutrino spectrum as well as for the age of globular clusters. © 2004 Elsevier B.V. All rights reserved.
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| 14. |
- Imbriani, G., et al.
(författare)
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The bottleneck of CNO burning and the age of Globular Clusters
- 2004
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 420:2, s. 625-629
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Tidskriftsartikel (refereegranskat)abstract
- The transition between the Main Sequence and the Red Giant Branch in low mass stars is powered by the onset of CNO burning, whose bottleneck is 14N(p, γ) 15O. The LUNA collaboration has recently improved the low energy measurements of the cross section of this key reaction. We analyse the impact of the revised reaction rate on the estimate of the Globular Cluster ages, as derived from the turnoff luminosity. We found that the age of the oldest Globular Clusters should be increased by about 0.7-1 Gyr with respect to the current estimates.
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| 15. |
- Johannesson, Kerstin, 1955, et al.
(författare)
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Hybrid fitness seems not to be an explanation for the partial reproductive isolation between ecotypes of Galician Littorina saxatilis
- 2000
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Ingår i: Journal of Molluscan Studies. - 0260-1230. ; 66, s. 149-156
-
Tidskriftsartikel (refereegranskat)abstract
- Partial reproductive isolation between closely related groups of organisms is suggested to be of central importance during speciation. Galician populations of Littorina saxatilis are phenotypically differentiated into an upper-shore and a lower-shore morph. These mate assortatively in the mid-shore: zone of overlap, and genetic assessment shows an impeded gene flow between the parental morphs. The traditional explanation as to why assortative mating occurs is that reproductive isolation is reinforced due to hybrid unfitness. Earlier studies have, however, not found hybrids to be less viable. Likewise, growth and migratory behaviours are merely intermediate between those of the parental morphs. In the present study we compared male and female fertility components of the parental morphs and the hybrids to test hypotheses of decreased hybrid fertility. The results showed that hybrid males were as fertile as other males, and hybrid females did not produce fewer embryos, nor aborted embryos at a higher rate, than the parental morphs.
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| 16. |
- Lagergren, K, et al.
(författare)
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Coexistence of superdeformed shapes in Er-154
- 2001
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 8702:2
-
Tidskriftsartikel (refereegranskat)abstract
- A new superdeformed rotational band has been observed in Er-154 using the Euroball Ge detector array. The new band and the one previously observed can be understood as based on coexisting superdeformed structures at prolate and triaxial shapes, respectively. The observation resolves long-standing difficulties in the theoretical interpretation of superdeformed states in Er-154.
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| 17. |
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| 18. |
- Lieder, RM, et al.
(författare)
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Development of gamma-ray tracking detectors
- 2001
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Ingår i: ACTA PHYSICA POLONICA B. - : ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS. - 0587-4254. ; 32:9, s. 2395-2401
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The next generation of 4 pi arrays for high-precision gamma -ray spectroscopy AGATA will consist of gamma -ray tracking detectors. They represent high-fold segmented Ge detectors and a front-end electronics, based on digital signal processing techniques,
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| 19. |
- Lieder, RM, et al.
(författare)
-
Gamma-ray tracking arrays
- 2001
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Ingår i: PROGRESS IN PARTICLE AND NUCLEAR PHYSICS. - : ELSEVIER SCIENCE BV. - 0146-6410. ; 46, s. 399-407
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The next generation of 4 pi arrays for high-precision gamma -ray spectroscopy will involve "gamma -ray tracking front-end on digital signal processing techniques, which allows to extract energy, timing and spatial information on the interactions of a gamm
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| 20. |
- Lieder, R. M., et al.
(författare)
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Development of magnetic rotation in light Gd nuclei; study of Gd-142
- 2002
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 13:3, s. 297-305
-
Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Gd-142 have been populated by means of the Ru-99(Ti-48, 2p3n) reaction at 2-10 MeV and investigated with the gamma-spectrometer EUROBALL III and the charged-particle detector array ISIS. The features of four dipole bands have been determined and compared with tilted-axis cranking model calculations indicating that they are magnetic rotational bands. A transition from regular to irregular bands has been found approaching N = 82 demonstrating that this is a general phenomenon in nuclei near a double-shell closure.
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