Orateur
Description
Rapid shape transitions are predicted by the shell model calculations as a result of the nuclear shell structure significantly evolving in the neutron-rich region at the traditional magic numbers N=20 and 28. The energy ratios between the first 2+ and 4+ states in the even-even silicon isotopes from N=20 to 28 suggest a variety of collectivity evolving from vibrational, to possible triaxial, to rotational modes. The systematic behavior of the level schemes along the silicon isotopic chain suggests 38Si as the turning point in this transition. The lifetime measurements of 38Si and 36Si were performed at the National Superconducting Cyclotron Laboratory based on the Recoil-Distance Method using the Gamma-Ray Energy Tracking In-Beam Nuclear Array (GRETINA). The data was used to extract the B(E2) ratios for the yrast 2+ and 4+ states in 38Si and the yrast 4+ and 6+ states in 36Si. These ratios were then compared to theoretical models.
