Halo EFT for ${}^{31}$Ne in a spherical formalism

Abstract

We calculate the electromagnetic properties of the deformed one-neutron halo candidate ${}^{31}$Ne using Halo Effective Field Theory (Halo EFT). In this framework, ${}^{31}$Ne is bound via a resonant $P$-wave interaction between the ${}^{30}$Ne core and the valence neutron. We set up a spherical formalism for ${}^{31}$Ne in order to calculate the electromagnetic form factors and the E1-breakup strength distribution into the ${}^{30}$Ne-neutron continuum at leading order in Halo EFT. The associated uncertainties are estimated according to our power counting. In particular, we assume that the deformation of the ${}^{30}$Ne core enters at next-to-leading order. It can be accounted for by including the $J^P=2^{+}$ excited state of ${}^{30}$Ne as an explicit field in the effective Lagrangian.

Comments: 25 pages, 10 figures