The role of triaxiality for the coexistence and evolution of shapes in light krypton isotopes

Shape coexistence and evolution in neutron-deficient krypton isotopes

“…This confirms the prolate character of the upper members of the yrast line [37][38][39][40] but casts doubt on the designation of the ground state as the band head [41]. In fact, both experimental evidences [5,11] and theoretical calculations (ours as well as others' [20,42] (14) keV [41], the deduced angular frequency would decline a little before increasing steadily with angular momentum, which does not often occur in well-deformed nuclei. Some authors are inclined to take the excited 0 + 2 state instead as the band head of the prolate band [9], which seems to make more sense in light of our calculation.…”

“…It has been indicated that the γ degree of freedom might be of some importance in reproducing theoretically the observed phenomenon of shape coexistence and evolution in neutron-deficient krypton isotopes [18][19][20]. In particular, beyond-mean-field studies adopting the Gogny D1S force [20] can give a correct description only if triaxiality is included; otherwise, a dominance of oblate shape in the ground states would occur, similar to the results obtained by the studies that make use of the Skyrme interaction but are limited to axial symmetry [18].…”

“…In particular, beyond-mean-field studies adopting the Gogny D1S force [20] can give a correct description only if triaxiality is included; otherwise, a dominance of oblate shape in the ground states would occur, similar to the results obtained by the studies that make use of the Skyrme interaction but are limited to axial symmetry [18]. However, within the framework of the present work, although the equilibrium deformations seem to be soft in the γ direction, especially for 72 Kr (see Fig.…”

Shape mixing dynamics in the low-lying states of proton-rich Kr isotopes

“…We have furthermore shown that the rotational motion plays an important role for the growth of localization of the vibrational wave functions in the (β, γ) deformation space. [3,4] and the result of the HFB-based GCM (GOA) calculation [17].…”

“…It is well known that the ignorance of the time-odd components in the IB masses breaks the self-consistency of the theory [29,30]. Nevertheless, even in recent microscopic studies by means of the 5D quadrupole collective Hamiltonian [17,31,32,33,34], the IB cranking masses are still used at least for vibrational inertial functions. In this study, we use the pairing-plus-quadrupole (P+Q) force model [35,36] including the quadrupole-pairing force and take into account the contributions from the time-odd components of the mean field to the vibrational and rotational masses.…”