Superallowed Gamow-Teller decay of the doubly magic nucleus 100Sn
2012 (English)In: Nature, ISSN 0028-0836, Vol. 486, no 7403, 341-345 p.Article in journal (Refereed) Published
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 beta(+)-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 Sn-100, the heaviest doubly magic nucleus with equal numbers of protons and neutrons. In the beta-decay of Sn-100, 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 beta-decay, establishing the 'superallowed' nature of this Gamow-Teller transition. The large strength and the low-energy states in the daughter nucleus, In-100, are well reproduced by modern, large-scale shell model calculations.
Place, publisher, year, edition, pages
2012. Vol. 486, no 7403, 341-345 p.
IdentifiersURN: urn:nbn:se:uu:diva-178596DOI: 10.1038/nature11116ISI: 000305466800032OAI: oai:DiVA.org:uu-178596DiVA: diva2:542521