Recent studies of single-particle and collective degrees of freedom in nuclei above 132Sn

In a series of experiments with ¹³⁶Xe and ¹³⁸Ba beams and comparatively heavy targets, such as ¹⁰B and ¹³C, nuclei "north-northeast" of ¹³²Sn were studied with particle-gamma correlation techniques. The experimental setup included, as a crucial component, the Phoswich Wall, an auxiliary particle detector for the GRETA and Gammasphere gamma spectrometers. The presentation is primarily concerned with the results for the neutron-magic ¹³⁷Cs nucleus and the neutron number N = 83 ¹³⁹Ba case, which were populated by appropriate single-nucleon transfer reactions. The perhaps most important result of the ¹³⁷Cs study is the observation of all the single-proton states. The issue of expected changes, with increasing N, of the proton single-particle structure will be addressed. As for ¹³⁹Ba, new information related to the neutron i_13/2 "intruder" orbital (half-life of 13/2⁺₁, location of 13/2⁺₂ and 13/2⁺₃) is obtained and the implications are discussed. If time allows, other results will be presented: The outcome of a "save" Coulomb-excitation measurement for the ¹³⁶Xe projectile [improved B(E3; 3- → 0⁺) value] or/and the news from the ongoing analysis of a ²⁵²Cf-source experiment [high-spin transition quadrupole moments, Q_t ~ B(E2)^1/2, in ¹⁴⁴Ba and ¹⁴²Ba].