6533b7d5fe1ef96bd1264ff6

RESEARCH PRODUCT

Experimental study of isomeric intruder 12+ states in At197,203

M. J. MallaburnJari PartanenJanne PakarinenSanna StolzeMatti LeinoS. JuutinenMikael SandzeliusPhilippos PapadakisJuha SorriJuha UusitaloKalle AuranenDaniel CoxP. RahkilaF. Defranchi BissoUlrika JakobssonUlrika JakobssonPaul GreenleesO. NeuvonenR. JulinJoonas KonkiH. BadranC. ScholeyJan SarénAndrej HerzanA. LightfootT. Grahn

subject

Physics010308 nuclear & particles physics0103 physical sciencesState (functional analysis)Atomic physics010306 general physicsSpectroscopyGround state01 natural sciencesRecoil separator

description

A newly observed isomeric intruder ${\textonehalf{}}^{+}$ state $[{T}_{\textonehalf{}}=3.5(6)\phantom{\rule{0.16em}{0ex}}\mathrm{ms}]$ is identified in $^{203}\mathrm{At}$ using a gas-filled recoil separator and fusion-evaporation reactions. The isomer is depopulated through a cascade of $E3$ and mixed $M1/E2$ transitions to the ${9/2}^{\ensuremath{-}}$ ground state, and it is suggested to originate from the $\ensuremath{\pi}{({s}_{\textonehalf{}})}^{\ensuremath{-}1}$ configuration. In addition, the structures above the ${\textonehalf{}}^{+}$ state in $^{203}\mathrm{At}$ and $^{197}\mathrm{At}$ are studied using in-beam $\ensuremath{\gamma}$-ray spectroscopy, recoil-decay tagging, and recoil-isomer decay tagging methods. The ${\textonehalf{}}^{+}$ state is fed from ${3/2}^{+}$ and ${5/2}^{+}$ states, and the origin of these states are discussed.

https://doi.org/10.1103/physrevc.95.044311