The 02+ state in 34Si has been populated at the {\sc Ganil/Lise3} facility through the β-decay of a newly discovered 1+ isomer in 34Al of 26(1) ms half-life. The simultaneous detection of e+e− pairs allowed the determination of the excitation energy E(02+)=2719(3) keV and the half-life T1/2=19.4(7) ns, from which an electric monopole strength of ρ2(E0)=13.0(0.9)×10−3 was deduced. The 21+ state is observed to decay both to the 01+ ground state and to the newly observed 02+ state (via a 607(2) keV transition) with a ratio R(21+→01+/21+→02+)=1380(717). Gathering all information, a weak mixing with the 01+ and a large deformation parameter of β=0.29(4) are found for the 02+ 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.
@article{arxiv.1206.6572,
title = {Unveiling the intruder deformed 0$^+_2$ state in $^{34}$Si},
author = {F. Rotaru and F. Negoita and S. Grévy and J. Mrazek and S. Lukyanov and F. Nowacki and A. Poves and O. Sorlin and C. Borcea and R. Borcea and A. Buta and L. Caceres and S. Calinescu and R. Chevrier and Zs. Dombradi and J. M. Daugas and D. Lebhertz and Y. Penionzhkevich and C. Petrone and D. Sohler and M. Stanoiu and J. C. Thomas},
journal= {arXiv preprint arXiv:1206.6572},
year = {2012}
}
Comments
5 pages, 3 figures, accepted for publication in Physical Review Letters