Speaker
Description
Octupole deformation in Barium isotopes has been experimentally established up to $N$=90 [1,2], with more recent evidence extending this behavior up to $N$=94. Symmetry-conserving configuration mixing (SCCM) calculations confirm an evolution toward increasingly quadrupole-deformed shapes accompanied by sustained octupole correlations in this region[3].
New spectroscopic information was obtained using the GRIFFIN spectrometer on neutron-rich $^{148}$Ba isotope following the $\beta$-decay from $^{148}$Cs. Particular attention is given to a tentative $(3-)$ state, whose structure is re-examined in light of the new data. The observed decay patterns suggest that this assignment may involve a more complex configuration, potentially reflecting mixing between states of different character. Additionally, gamma-ray transitions are investigated with the aim to further refine the level scheme.
Ongoing analysis aims to clarify the nature of this state and its role in the emerging picture of octupole collectivity. The results are discussed in the context of isotopic and isotonic systematics, providing insight into the evolution of quadrupole deformation and octupole correlations in this mass region.
References
[1] B. Bucher et al., Phys. Rev. Lett. 116, 112503 (2016)
[2] B. Bucher et al., Phys. Rev. Lett. 118, 152504 (2017)
[3] R. Lică et al., Phys. Rev. C 97, 024305 (2018)