Identification of new isomers in ${}^{228}$Ac : Impact on dark matter searches

K. W. Kim, G. Adhikari, E. Barbosa de Souza +50

We report the identification of metastable isomeric states of ${}^{228}$Ac at 6.28 keV, 6.67 keV and 20.19 keV, with lifetimes of an order of 100 ns. These states are produced by the…