Orateur
Description
Coexistence between spherical and deformed shapes is largely found in and near semi-magic or doubly-magic nuclei.
The region between the doubly-magic $^{48}$Ca and $^{56}$Ni nuclei is predicted to present phenomena of shape coexistence, although experimental information on E0 and E2 transition strengths connecting deformed and spherical configurations remains rather limited. In $^{52}$Cr ($Z=24$, $N=28$), a recent measurement of the $X(E0/E2)$ ratio between the deformed 0$_2^+$ state and the spherical 0$_1^+$ and 2$_1^+$ states suggests that sizeable E0 strengths are indeed present. However, the determination of the $\rho^2$(E0) value--crucial to characterizing the nature of shape coexistence in this nucleus--requires a measurement of the lifetime of the excited state.
A lifetime measurement of $^{52}$Cr was carried out at the Legnaro National Laboratories using the $\gamma$-ray tracking array AGATA, coupled to the charged-particle detector SPIDER, with the nucleus of interest populated via a two-neutron transfer reaction. We will present the status of the ongoing analysis together with preliminary results concerning the 4$^{+}_{1}$ state.
