arXiv subjects

E. Kleis

Publications and source records attributed to E. Kleis.

2 recordsLinked to original sources

arXiv2025

Lifetime of the $4^+_1$ state of $^{132}$Te

The evolution of the collectivity of tellurium isotopes from mid-shell towards $N=82$ is currently based mainly on properties of the first excited $2^+$ states. To extend structural information in this isotopic chain, in particular with respect to the balance of microscopic, seniority-type and collective excitations, electric quadrupole transition strengths from $4^+$ states need to be considered. An experiment was performed to determine the $4_1^+$ lifetime of $^{132}$Te via the recoil-distance Doppler-shift method at the University of Cologne tandem accelerator. The isotope of interest was populated in the two neutron-transfer reaction $^{130}$Te($^{18}$O,$^{16}$O)$^{132}$Te$^*$. The $E2$ decay transition strength has been determined to be $B(E2; 4^+_1\rightarrow 2^+_1) = 9.3(10)\, \text{W.u.}$ and compares favourably to shell model calculations.

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arXiv2025

Revised $B(E2; 2^{+}_{1} \rightarrow 0^{+}_{1})$ value in the semi-magic nucleus $^{210}$Pb

The lifetime of the $2^+_1$ state of $^{210}$Pb was measured in the $^{208}$Pb($^{18}$O, $^{16}$O)$^{210}$Pb two-neutron transfer reaction by $\gamma$-ray spectroscopy employing the recoil-distance Doppler-shift method. The extracted absolute $B(E2)$$\downarrow$ value of ${119\;^{+\;9}_{-\;8}\;\hspace{-0pt}\,\text{e}^2\text{fm}^4}$ is consistent with previously reported measurements, but with significantly improved precision. The available experimental data for the $2^+_1$-$4^+_1$-$6^+_1$-$8^+_1$ multiplet are compared with shell-model calculations based on the well-established Kuo-Herling interaction. The new $B(E2)$$\downarrow$ value agrees well with the shell-model prediction, providing evidence that the properties of the $2^+_1$ and $8^+_1$ states of $^{210}$Pb can be consistently described together within the nuclear shell-model framework.

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