Study of quadrupole correlations in the ${}^{106,108}Sn$ isotopes via lifetimes measurements.

underline Siciliano M., Goasduff A., Valiente-Dobón J.J., Pérez-Vidal R.M., Bazzacco D., Alahari N., Benzoni G., Braunroth T., Cieplicka N., Crespi F.C.L., Clement E., Doncel M., Ertürk S., Fransen C., Gadea A., Georgiev G., Goldkuhle A., Jakobsson U., Jaworski G., John P.R., Kuti I., Lemasson A., Li H., Marchi T., Mengoni D., Michelagnoli C., Mijatovic T., Müller-Gatermann C., Napoli D.R., Nyberg J., Palacz M., Rejmund M., Saygi B., Sohler D., Szilner S., Testov D.
  Mercoledì 28/09   10:00 - 13:00   Edificio Psicologia 2 - Aula 3F   I - Fisica nucleare e subnucleare
The robustness of the proton shell closure $Z=50$ has been studied when $N=50$ is approached: both the excitation energy of the $2^{+}$ states and the reduced transition probabilities provide a clear evidence of the shell evolution along the whole Sn isotopic chain. The systematic of the first $2^{+}$ state excitation energy is rather constant, but the information on $B(E2; 2^{+}\rightarrow 0^{+})$ for the neutron-deficient Sn isotopes suffer from large experimental uncertainties which makes the interpretation of the shell evolution controversial. During the AGATA campaign at GANIL, ${}^{106-108}Sn$ were populated via a multi-nucleon transfer reaction in order to measure the $B(E2; 2^{+}\rightarrow 0^{+})$.