Study of the Isomeric State in ${}^{16}$N Using the ${}^{16}$N${}^{g,m}$($d$,${}^3$He) Reaction

Abstract

The isomeric state of ${}^{16}$N was studied using the ${}^{16}$N${}^{g,m}$($d$,${}^3$He)~proton-removal reactions at \mbox{11.8~MeV/$u$} in inverse kinematics. The ${}^{16}$N beam, of which 24% was in the isomeric state, was produced using the ATLAS in-fight facility and delivered to the HELIOS spectrometer, which was used to analyze the ${}^3$He ions from the ($d$,${}^3$He) reactions. The simultaneous measurement of reactions on both the ground and isomeric states, reduced the systematic uncertainties from the experiment and in the analysis. A direct and reliable comparison of the relative spectroscopic factors was made based on a Distorted-Wave Born Approximation approach. The experimental results suggest that the isomeric state of ${}^{16}$N is an excited neutron-halo state. The results can be understood through calculations using a Woods-Saxon potential model, which captures the effects of weak-binding.

8 pages, 7 figurs