Invariant-mass spectroscopy of ^37,38Sc, ³⁵Ca, and ³⁴K near the proton drip-line

At the National Superconducting Cyclotron Laboratory, a secondary beam of ³⁷Ca impinged on a ⁹Be target resulting in a set of reactions that populate isotopes beyond the proton drip-line including ^37,38Sc, ³⁵Ca, and ³⁴K. Invariant-mass spectroscopy has revealed the ground-state masses and binding energies of ³⁸Sc and ³⁴K. ³⁷Sc also has a promising decay-energy spectrum that could reveal its ground-state mass. Excited states of all four isotopes are presented, serving as important tests of nuclear shell model calculations. These nuclei straddle the Z=20 shell closure, as well as the N=16 subshell closure which has been observed to exist in this region of nuclei.