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arXiv · 1509.09101

Radiative lifetime and energy of the low-energy isomeric level in $^{229}$Th

E. V. Tkalya·Christian Schneider·Justin Jeet·Eric R. Hudson
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Abstract

We estimate the range of the radiative lifetime and energy of the anomalous, low-energy $3/2^+(7.8 \pm 0.5$ eV) state in the $^{229}$Th nucleus. Our phenomenological calculations are based on the available experimental data for the intensities of $M1$ and $E2$ transitions between excited levels of the $^{229}$Th nucleus in the $K^π[Nn_ZΛ]=5/2^+[633]$ and $3/2^+[631]$ rotational bands. We also discuss the influence of certain branching coefficients, which affect the currently accepted measured energy of the isomeric state. From this work, we establish a favored region where the transition lifetime and energy should lie at roughly the 90% confidence level. We also suggest new nuclear physics measurements, which would significantly reduce the ambiguity in the present data.

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E. V. Tkalya, Christian Schneider, Justin Jeet, Eric R. Hudson. 2015-09-30. Radiative lifetime and energy of the low-energy isomeric level in $^{229}$Th. https://doi.org/10.1103/physrevc.92.054324

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