Radiative lifetime and energy of the low-energy isomeric level in $^{229}$Th
Radiative lifetime and energy of the low-energy isomeric level in $^{229}$Th
复制标题
$^{229}$Th 中低能异构能级的辐射寿命和能量
DOI：
--
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
E. Hudson
中科院分区：
文献类型：
--
作者：
E. Tkalya;Christian Schneider;Justin Jeet;E. Hudson
We estimate the range of the radiative lifetime and energy of the anomalous, low-energy $3/{2}^{+}(7.8ifmmodepmelse extpmfi{}0.5$ eV) state in the $^{229}mathrm{Th}$ nucleus. Our phenomenological calculations are based on the available experimental data for the intensities of $M1$ and $E2$ transitions between excited levels of the $^{229}mathrm{Th}$ nucleus in the ${K}^{ensuremath{pi}}[N{n}_{Z}mathrm{ensuremath{Lambda}}]=5/{2}^{+}[633]$ 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, $0.66ifmmode imeselse exttimesfi{}{10}^{6}{ ext{s}phantom{
ule{4.pt}{0ex}} ext{eV}}^{3}/{ensuremath{omega}}^{3}ensuremath{le}ensuremath{ au}ensuremath{le}2.2ifmmode imeselse exttimesfi{}{10}^{6}{ ext{s}phantom{
ule{4.pt}{0ex}} ext{eV}}^{3}/{ensuremath{omega}}^{3}$, where the transition lifetime $ensuremath{ au}$ as a function of transition energy $ensuremath{omega}$ should lie at roughly the 95% confidence level. Together with the result of Beck et al. [LLNL-PROC-415170 (2009)], we establish a favored area where 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.
We estimate the range of the radiative lifetime and energy of the anomalous, low-energy $3/{2}^{+}(7.8ifmmodepmelse extpmfi{}0.5$ eV) state in the $^{229}mathrm{Th}$ nucleus. Our phenomenological calculations are based on the available experimental data for the intensities of $M1$ and $E2$ transitions between excited levels of the $^{229}mathrm{Th}$ nucleus in the ${K}^{ensuremath{pi}}[N{n}_{Z}mathrm{ensuremath{Lambda}}]=5/{2}^{+}[633]$ 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, $0.66ifmmode imeselse exttimesfi{}{10}^{6}{ ext{s}phantom{
ule{4.pt}{0ex}} ext{eV}}^{3}/{ensuremath{omega}}^{3}ensuremath{le}ensuremath{ au}ensuremath{le}2.2ifmmode imeselse exttimesfi{}{10}^{6}{ ext{s}phantom{
ule{4.pt}{0ex}} ext{eV}}^{3}/{ensuremath{omega}}^{3}$, where the transition lifetime $ensuremath{ au}$ as a function of transition energy $ensuremath{omega}$ should lie at roughly the 95% confidence level. Together with the result of Beck et al. [LLNL-PROC-415170 (2009)], we establish a favored area where 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.