Fast-timing measurements of nuclear lifetimes in the Z ~ 50 region

Abstract

The neutron–deficient region around the Z=50 major shell closure provides fertile grounds for nuclear structure studies, as single–particle degrees of freedom compete with collective phenomena to form several of the observed spectroscopic properties. This work reports on the progress and the preliminary results of a recent experiment performed at IFIN–HH, in Magurele, Romania, focused around the measurement of lifetimes of excited states in neutron–deficient Te isotopes, by means of the Fast Electronic Scintillation Timing (FEST, or fast–timing) technique. A ¹¹B beam of E_lab = 35 MeV impinging on a 5 mg/cm^{2 nat}Ag target was used to populate excited states in ^115−120Te. The γ rays de-exciting these levels were detected by the ROSPHERE array, in its mixed 15 HPGe + 10 LaBr₃(Ce) detector configuration. Additionally, the SORCERER particle detector array was coupled to ROSPHERE, enabling the study of p-γ and p-γ-γ coincident events. The combination of experimental findings and theoretical predictions from several models, including the newly developed proxy-SU(3), is anticipated to offer valuable insights into the dynamic shape evolution of the investigated isotopes.