Low lying spectroscopy of odd-odd $^{146}$Eu

TL;DR

This study investigates the low-lying energy states of $^{146}$Eu through gamma-ray spectroscopy and lifetime measurements, revealing modifications in level structure and providing insights into nuclear behavior with shell model calculations.

Contribution

It presents new lifetime measurements of specific energy levels in $^{146}$Eu and compares experimental results with shell model calculations, enhancing understanding of its nuclear structure.

Findings

Lifetimes of 3$^-$ and 2$^-$ states measured as 5.38 ps and 8.38 ps

Significant modifications observed in the level structure of $^{146}$Eu

Shell model calculations support experimental findings

Abstract

Electron Capture (EC) decay of $^{146}$Gd($\it{t_{1/2}}$ = 48d) to the low lying states of $^{146}$Eu has been studied using high-resolution $\gamma$ ray spectroscopy. The $^{146}$Gd activity was produced by ($\alpha$, 2n) reaction at E$_{\alpha}$ = 32 MeV using 93.8% enriched $^{144}$Sm target. The level structure has been considerably modified from the measurement of $\gamma$ ray singles, $\gamma\gamma$ coincidences and decay half lives. Lifetime measurement has been performed for the 3$^-$ (114.06 keV) and 2$^-$ (229.4 keV) levels of $^{146}$Eu using Mirror Symmetric Centroid Difference (MSCD) method with LaBr$_3$ (Ce) detectors. The lifetimes for these two states have been found to be 5.38 $\pm$ 2.36 ps and 8.38 $\pm$ 2.19 ps respectively. Shell model calculation has been performed using OXBASH code in order to interpret the results.