$E0$ transition strength in stable Ni isotopes

TL;DR

This study measures $E0$, $M1$, and $E2$ transition strengths between low-lying states in stable Ni isotopes using multiple experimental techniques, revealing consistently large $E0$ strengths in these nuclei.

Contribution

It provides new experimental data on $E0$, $M1$, and $E2$ transition strengths in stable Ni isotopes, combining different spectroscopic methods for comprehensive analysis.

Findings

Large $E0$ transition strengths between $2^+$ states in Ni isotopes

Consistent $E0$ strengths between $0^+$ states with previous results

Complementary use of proton, neutron scattering, and electron spectroscopy

Abstract

Excited states in $^{58,60,62}$Ni were populated via inelastic proton scattering at the Australian National University as well as via inelastic neutron scattering at the University of Kentucky Accelerator Laboratory. The Super-e electron spectrometer and the CAESAR Compton-suppressed HPGe array were used in complementary experiments to measure conversion coefficients and $\delta(E2/M1)$ mixing ratios, respectively, for a number of $2^+ \rightarrow 2^+$ transitions. The data obtained were combined with lifetimes and branching ratios to determine $E0$, $M1$, and $E2$ transition strengths between $2^+$ states. The $E0$ transition strengths between $0^+$ states were measured using internal conversion electron spectroscopy and compare well to previous results from internal pair formation spectroscopy. The $E0$ transition strengths between the lowest-lying $2^+$ states were found to be consistently large for the isotopes studied.