Speaker
Description
In the light Sn isotopes, a systematic deviation between the B(E2; $2_1^+ \to 0_{g.s.}^+)$ values and state-of-the-art theoretical calculations has been observed, and such a discrepancy becomes even more significant when comparing predictions and experimental results for the B(E2; $4_1^+ \to 2_1^+)$ strengths.
Recent works have indicated the importance of the $4_1^+ \to 2_1^+$ transitions to clarify the electromagnetic structure of nuclei around $^{100}$Sn.
However, the presence of low-lying isomers prevents the direct measurement of reduced transition probabilities between these states, particularly for the light even-mass Sn isotopes.
In this regard, the neighboring odd-mass Sn isotopes provide an alternative solution to investigate the electromagnetic properties of low-lying excited states in this region.
Similarly, additional information can be obtained from the study of Sb nuclei, which are one proton above the $Z=50$ shell closure.
The systematic study of electromagnetic properties in both Sn and Sb isotopic chains is crucial to explore the robustness of the $Z=50$ shell closure and investigate the nuclear interaction in proximity of the doubly-magic self-conjugate $^{100}$Sn.
To accomplish this objective we propose to measure the lifetime of low-lying states in the $^{107,109,111}$Sn and $^{111,113}$Sb, especially the $2_1^+$- and $4_1^+$-core coupled states (i.e. $9/2^+$, $11/2^+$ and $13/2^+$).
The nuclei of interest will be populated via a multi-nucleon transfer reaction by using a 784-MeV $^{112}$Sn beam impinging on a $^{92}$Mo target and the lifetime of the excited states will be measured via the recoil-distance Doppler-shift technique using the dedicated plunger setup.
The emitted $\gamma$ rays will be detected by the AGATA array and the beam-like reaction products will be identified by the PRISMA spectrometer.
