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The second-phonon ( n ω = 2 ) wobbling band has been established in the nucleus 135Pr. Conclusive evidence for its wobbling nature comes from the Δ I = 1 , E2 character of the transitions between the new band and the previously identified transverse wobbler band ( n ω = 1 ) in this nucleus. Theoretical calculations in the framework of the quasiparticle triaxial rotor and triaxial projected shell models are found to be in good agreement with the experimental results.

Quasi-elastic scattering measurements have been performed using 16O and 24Mg projectiles off 90Zr at energies around the Coulomb barrier. Experimental data have been analyzed in the framework of coupled channels (CC) calculations using the code CCFULL. The quasi-elastic scattering excitation function and derived barrier distribution for 16O + 90Zr reaction are well reproduced by the CC calculations using the vibrational coupling strengths for 90Zr reported in the literature. Using these vibrational coupling strengths, a Bayesian analysis is carried out for 24Mg + 90Zr reaction. The β 2 and β 4 values for 24Mg are determined to be + 0.43 ± 0.02 and − 0.11 ± 0.02 , respectively. The β 2 parameter determined in the present work is in good agreement with results obtained using inelastic scattering probes. The hexadecapole deformation of 24Mg has been measured very precisely for the first time. Present results establish that quasi-elastic scattering could provide a useful probe to determine the ground state deformation of atomic nuclei.

"Why are the tin isotopes soft?" has remained, for the past decade, an open problem in nuclear structure physics: models which reproduce the isoscalar giant monopole resonance (ISGMR) in the "doubly-closed shell" nuclei, $^{90}$Zr and $^{208}$Pb, overestimate the ISGMR energies of the open-shell tin and cadmium nuclei, by as much as 1 MeV. In an effort to shed some light onto this problem, we present results of detailed studies of the ISGMR in the molybdenum nuclei, with the goal of elucidating where--and how--the softness manifests itself between $^{90}$Zr and the cadmium and tin isotopes. The experiment was conducted using the $^{94,96,98,100}$Mo($\alpha,\alpha^\prime$) reaction at $E_\alpha = 386$ MeV. A comparison of the results with relativistic, self-consistent Random-Phase Approximation calculations indicates that the ISGMR response begins to show softness in the molybdenum isotopes beginning with $A=92$., Comment: Accepted for publication to Physics Letters B