Thomas-Ehrman effect in a three-body model: ${}^{16}$Ne case

Abstract

The dynamic mechanism of the Thomas-Ehrman shift is studied in three-cluster systems by example of ${}^{16}$Ne and ${}^{16}$C isobaric mirror partners. We predict configuration mixings for $0^{+}$ and $2^{+}$ states in ${}^{16}$Ne and ${}^{16}$C. Large isospin symmetry breaking on the level of wave function component weights is demonstrated for these states and discussed as three-body mechanism of Thomas-Ehrman shift. It is shown that the description of the Coulomb displacement energies requires a consistency among three parameters: the ${}^{16}$Ne decay energy $E_T$, the ${}^{15}$F ground state energy $E_r$, and the configuration mixing parameters for the ${}^{16}$Ne/${}^{16}$C $0^{+}$ and $2^{+}$ states. Basing on this analysis we infer the ${}^{15}$F $1/2^{+}$ ground state energy to be $E_r=1.39-1.42$ MeV.

Comments: 10 pages 8 figures