Probing Exotic Cross-Shell Interactions at N=28 with Single-Neutron Transfer on ^{47}K

Area of Science:

• Nuclear Physics
• Atomic and Molecular Physics

Background:

• The ^{48}K nucleus is crucial for understanding nuclear structure near the N=28 island of inversion.
• Previous studies lacked detailed spectroscopic information for ^{48}K.

Purpose of the Study:

• To perform the first measurement of the ^{47}K(d,pγ)^{48}K transfer reaction.
• To extend the known level scheme of ^{48}K and deduce spectroscopic factors.
• To investigate proton-neutron interactions in 1s and fp orbitals.

Main Methods:

• Utilized inverse kinematics with a reaccelerated ^{47}K beam.
• Performed a deuteron-induced proton transfer reaction (d,pγ).
• Analyzed gamma-ray coincidences to identify excited states.

Main Results:

• Identified nine new bound excited states in ^{48}K, significantly extending its level scheme.
• Deduced spectroscopic factors for these states.
• Observed discrepancies between experimental data and SDPF-U/SDPF-MU shell-model calculations.

Conclusions:

• The ^{47}K(d,p) reaction provides unique insights into proton-neutron interactions.
• Current shell-model interactions may not accurately describe proton configuration mixing in ^{48}K.
• Challenges our understanding of light nuclei near the N=28 region.