Conférences et séminaires » Séminaire du Dr David JENKINS
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New insights into shapes and structure in the mass 70 region.
Dr David JENKINS
(Université de YORK, UK)
le Jeudi 15 juin 2006 à 16 h00
Salle de Visioconférences - Bâtiment 25
IPHC, 23 rue du Loess, Strasbourg-Cronenbourg
The odd-odd N=Z nuclei form an excellent laboratory for study of the interplay of T=0 and T=1 states close to the ground state, as well as for searching for neutron-proton pairing. We have devised a new tagging methodology for studying these nuclei entitled recoil-beta tagging (RBT). Excited states in the odd-odd N=Z nuclei, 74Rb and 78Y were studied by correlating with their Fermi super-allowed beta decay at the focal plane of the RITU separator at the University of Jyväskylä. A double-sided silicon strip detector and planar germanium detector were used as an effective DE-E telescope for high energy positrons. Shape coexistence is also a known feature of this mass region, arising from the large shell gaps at oblate and prolate shape for N=Z=34 and 36. Recent work at GANIL has well established shape coexistence in the light Krypton isotopes. By contrast, the presence and origin of shape coexistence in the light Selenium isotopes is less clear. A recent Coulomb excitation measurement of an isobarically pure radioactive beam of 70Se at REX-ISOLDE has allowed the reorientation matrix element of the first 2+ state to be measured and a prolate shape inferred. These recent advances and their implications will be discussed.
Sandrine COURTIN :
Florent HAAS :