C. B. Hinke1 et al.
1 Physik Department E12, Technische Universität München, D-85748 Garching, Germany
The shell structure of atomic nuclei is associated with ‘magic numbers’ and originates in the nearly independent motion of neutrons and protons in a mean potential generated by all nucleons. During β+-decay, a proton transforms into a neutron in a previously not fully occupied orbital, emitting a positron–neutrino pair with either parallel or antiparallel spins, in a Gamow–Teller or Fermi transition, respectively. The transition probability, or strength, of a Gamow–Teller transition depends sensitively on the underlying shell structure and is usually distributed among many states in the neighbouring nucleus. Here we report measurements of the half-life and decay energy for the decay of 100Sn, the heaviest doubly magic nucleus with equal numbers of protons and neutrons. In the β-decay of 100Sn, a large fraction of the strength is observable because of the large decay energy. We determine the largest Gamow–Teller strength so far measured in allowed nuclear β-decay, establishing the ‘superallowed’ nature of this Gamow–Teller transition. The large strength and the low-energy states in the daughter nucleus, 100In, are well reproduced by modern, large-scale shell model calculations.
Nature Volume: 486, Pages: 341-345, Date published: 21 June 2012
DOI: 10.1038/nature11116
Ch. Hinke1, R. Krücken1, R. F Casten2, V. Werner2 and N. V. Zamfir3
1 Physik Department E12, Technische Universität München, D-85748, Garching, Germany
2 A.W. Wright Nuclear Structure Laboratory, Yale University, 06520, New Haven, CT, USA
3 National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania
The evolution of the structure of the gamma-vibrational band head 2+γ in well-deformed rare-earth nuclei is studied within the framework of RPA calculations using a quasiboson approximation based on the Nilsson model. The obtained evolution of the quasiparticle structure of the gamma-vibrational band head is shown to correlate well with the evolution of the same nuclei within the IBA symmetry triangle when described in the extended consistent-Q formalism. An empirical relation is presented that links the IBA parameter χ with the quasiparticle structure of the gamma-vibrational band head.
Eur. Phys. J. A 30, 357-367 (2006)
DOI: 10.1140/epja/i2006-10129-2
Spectroscopy of the doubly magic nucleus 100Sn and its decay
Hinke, Christoph B.
The investigation of the shell structure far from the valley of stability is a major task in modern nuclear structure physics. By fragmentation of a 1.0 A GeV 124Xe beam from the GSI accelerators 100Sn and neighbouring nuclei have been produced. The nuclei were stopped in an implantation detector with high spatial resolution in order to correlate implantations with succeeding decays. In this configuration the setup enabled us to do nearly 4Pi spectroscopy of the emitted gamma and particle decay radiation. In the thesis I focus on results of the decay spectroscopy of the doubly magic nucleus 100Sn which decays by a super Gamow Teller spin flip transition populating only a single final state in the daughter nucleus. New and more precise values of the half life, the beta endpoint energy and the Gamow Teller strength in the decay of 100Sn have been determined in order to address the question of the Gamow Teller quenching in 100Sn.
http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:91-diss-20100727-982004-1-1
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