Speaker
Description
The M1 scissors mode in deformed atomic nuclei depicts the collective vibration of the proton and neutron systems with respect to each other. There have been suggestions that the M1 scissors mode may explain discrepancies between theoretical calculations using the Hauser-Feshbach theory and evaluated data of radiative neutron captures for many applications ranging from nuclear technology to nuclear astrophysics. In a recent Letter [Phys. Rev. Lett. 129, 042502 (2022)], we reported microscopic many-body calculations indicating that rotational bands based on scissors vibrations exhibit systematic splitting between neighboring spin states (ΔI = 2 bifurcation) in which the magnitude of the moment of inertia oscillates between states having even and odd spins. We showed that this unexpected result is caused by self-organization of the deformed proton and neutron bodies in the scissors motion, which is further amplified by the Kπ=1+ two-quasiparticle configurations near the scissors states. We proposed that the puzzling excited state found above the 1+ scissors state in 156Gd [Phys. Rev. Lett. 118, 212502 (2017)] is the first evidence of this effect, and predicted that bifurcation may generally appear in all other scissors rotational bands of deformed nuclei, and possibly in other systems exhibiting collective scissors vibrations. In order to confirm the bifurcation feature, it is crucial to identify experimentally the excited states with Iπ ≥ 3+ in the scissors rotational bands.
