The electric quadrupole channel of the 7.8 eV ${}^{229}\mathrm{Th}$ transition

Abstract

The unique isomeric transition at 7.8 eV in ${}^{229}\mathrm{Th}$ has a magnetic dipole ($M1$) and an electric quadrupole ($E2$) multipole mixing. So far, the $E2$ component has been widely disregarded. Here, we investigate the nuclear physics nature and the impact of the $E2$ decay channel for the nuclear coupling to the atomic shell based on the newest theoretical predictions for the corresponding reduced nuclear transition probabilities. Our results show that the contribution of the $E2$ channel is dominant or at least of the same order of magnitude for internal conversion or electronic bridge transitions involving the atomic orbitals $7p$, $6d$ and $5f$. Notable exceptions are the internal conversion of the $7s$ electron and the electronic bridge between the electronic states $7s$ and $7p$, for which the $M1$ component dominates by two to three orders of magnitude. Caution is therefore advised when considering isomeric excitation or decay via nuclear coupling to the atomic shell, as the involved orbitals determine which multipole transition component dominates.

References in corpus (10)

• Direct detection of the 229Th nuclear clock transition
• Laser spectroscopic characterization of the nuclear clock isomer ${}^{229m}$Th
• Proposal for a Nuclear Gamma-Ray Laser of Optical Range
• Lifetime measurement of the ${}^{229}$Th nuclear isomer
• Excitation of the isomeric ^{229m}Th nuclear state via an electronic bridge process in ^{229}Th^+
• Nuclear clocks based on resonant excitation of gamma-transitions
• Nuclear collective motion with a coherent coupling interaction between quadrupole and octupole modes
• Coherence-enhanced optical determination of the ${}^{229}$Th isomeric transition
• Laser-induced electronic bridge for characterization of the ${}^{229\mathrm{m}}\mathrm{Th}\to {}^{229\mathrm{g}}\mathrm{Th}$ nuclear transition with a tunable optical laser
• Internal conversion from excited electronic states of ${}^{229}\mathrm{T}h$ ions

Cited by in corpus (15)

• Energy of the ${}^{229}$Th nuclear clock transition
• Electronic bridge excitation in highly charged Th-229 ions
• Nuclear excitation of the ${}^{229}$Th isomer via defect states in doped crystals
• The ${}^{229}$Th isomer: prospects for a nuclear optical clock
• Nuclear charge radii of ${}^{229}$Th from isotope and isomer shifts
• The theory of direct laser excitation of nuclear transitions
• Excitation of the ${}^{229}$Th nucleus via a two-photon electronic transition
• Resonant electronic-bridge excitation of the U-235 nuclear transition in ions with chaotic spectra
• Driven electronic bridge processes via defect states in ${}^{229}$Th-doped crystals
• ${}^{229}$Th Nuclear Spectroscopy in an Opaque Material: Laser-Based Conversion Electron Mössbauer Spectroscopy of ${}^{229}$ThO${}_2$
• Theory of internal conversion of the thorium-229 nuclear isomer in solid-state hosts
• Collective effects in ${}^{229}$Th-doped crystals
• Solid-State ${}^{229}\mathrm{Th}$ Nuclear Laser with Two-Photon Pumping
• Internal conversion of the low energy ${}^{229m}$Th isomer in the Thorium anion
• Studies of thorium and ytterbium ion trap loading from laser ablation for gravity monitoring with nuclear clocks