Probing the order-to-chaos region in superdeformed 151Tb and 196Pb nuclei with continuum gamma-transitions

TL;DR

This study investigates gamma-decay in superdeformed nuclei 151Tb and 196Pb during warm rotation, revealing enhanced B(E1) strength possibly linked to octupole vibrations, through experimental data and Monte Carlo simulations.

Contribution

It provides new experimental data and a microscopic simulation approach that highlights the role of low-energy B(E1) enhancement and octupole vibrations in superdeformed nuclear decay.

Findings

Enhanced B(E1) strength at low excitation energy.

Agreement between simulation and data only with B(E1) enhancement.

Evidence suggesting octupole vibrations in superdeformed nuclei.

Abstract

The gamma-decay associated with the warm rotation of the superdeformed (SD) nuclei 151Tb and 196Pb has been measured with the EUROBALL IV array. Several independent quantities provide a stringent test of the population and decay dynamics in the SD well. A Monte Carlo simulation of the gamma-decay based on microscopic calculations gives remarkable agreement with the data only assuming a large enhancement of the B(E1) strength at low excitation energy, which may be related to the evidence for octupole vibrations in both mass regions.