Spectroscopy of Neutron-Rich 168,170Dy: Yrast Band Evolution Close to the NpNn Valence Maximum

TL;DR

This study investigates the structure and evolution of the yrast bands in neutron-rich dysprosium isotopes 168Dy and 170Dy, using advanced spectroscopic techniques and theoretical calculations to understand collectivity near the NpNn valence maximum.

Contribution

It extends the known yrast band of 168Dy up to 10+ and provides tentative evidence for transitions in 170Dy, combining experimental data with Total Routhian Surface calculations.

Findings

Confirmed the 2+ and 4+ states in 168Dy

Extended the yrast band of 168Dy to 10+

Identified a tentative transition in 170Dy

Abstract

The yrast sequence of the neutron-rich dysprosium isotope 168Dy has been studied using multi-nucleon transfer reactions following collisions between a 460-MeV 82Se beam and a 170Er target. The reaction products were identified using the PRISMA magnetic spectrometer and the gamma rays detected using the CLARA HPGe-detector array. The 2+ and 4+ members of the previously measured ground state rotational band of 168Dy have been confirmed and the yrast band extended up to 10+. A tentative candidate for the 4+ to 2+ transition in 170Dy was also identified. The data on these nuclei and on the lighter even-even dysprosium isotopes are interpreted in terms of Total Routhian Surface calculations and the evolution of collectivity in the vicinity of the proton-neutron valence product maximum is discussed.