Ab initio calculation of the spectrum and structure of $^{16}$O

Evgeny Epelbaum, Hermann Krebs, Timo A. Lähde, Dean Lee, Ulf-G. Meißner, Gautam Rupak

Published 2013-12-30, updated 2014-02-24Version 2

We present ab initio lattice calculations of the low-energy even-parity states of $^{16}$O using chiral nuclear effective field theory. We find good agreement with the empirical energy spectrum, and with the electromagnetic properties and transition rates. For the ground state, we find that the nucleons are arranged in a tetrahedral configuration of alpha clusters. For the first excited spin-0 state, we find that the predominant structure is a square configuration of alpha clusters, with rotational excitations that include the first spin-2 state.