664 articles – 6755 Notices  [english version]
 HAL : in2p3-00712670, version 2
 arXiv : 1206.6572
 Physical Review Letters 109 (2012) 092503
 Versions disponibles : v1 (28-06-2012) v2 (05-07-2012)
 Unveiling the intruder deformed 0$^+_2$ state in $^{34}$Si
 (2012)
 The 0$^+_2$ state in $^{34}$Si has been populated at the {\sc Ganil/Lise3} facility through the $\beta$-decay of a newly discovered 1$^+$ isomer in $^{34}$Al of 26(1)~ms half-life. The simultaneous detection of $e^+e^-$ pairs allowed the determination of the excitation energy E(0$^+_2$)=2719(3)~keV and the half-life T$_{1/2}$=19.4(7)~ns, from which an electric monopole strength of $\rho^2$(E0)=13.0(0.9)$\times$10$^{-3}$ was deduced. The 2$^+_1$ state is observed to decay both to the 0$^+_1$ ground state and to the newly observed 0$^+_2$ state (via a 607(2)~keV transition) with a ratio R(2$^+_1$$\rightarrow0^+_1/2^+_1$$\rightarrow$0$^+_2$)=1380(717). Gathering all information, a weak mixing with the 0$^+_1$ and a large deformation parameter of $\beta$=0.29(4) are found for the 0$^+_2$ state, in good agreement with shell model calculations using a new {\sc sdpf-u-mix} interaction allowing \textit{np-nh} excitations across the $N=20$ shell gap.
 Thème(s) : Physique/Physique Nucléaire Expérimentale
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 in2p3-00712670, version 2 http://hal.in2p3.fr/in2p3-00712670 oai:hal.in2p3.fr:in2p3-00712670 Contributeur : Michel Lion <> Déposé pour le compte de : Stéphane Grévy <> Soumis le : Jeudi 5 Juillet 2012, 10:07:06 Dernière modification le : Jeudi 30 Août 2012, 10:05:27