N. Swan | Searcharxiv

arXiv2026

Short-range correlated pair formation and nuclear shell structure

Short-range correlated (SRC) nucleon pairs - caused by brief, high-momentum interactions between two nucleons - are dominated by neutron-proton pairs with large relative and smaller center-of-mass momenta. However, the underlying dynamics that determines which nucleons form such pairs remains uncertain. Previous measurements showed that proton pairing probabilities increased strongly with nuclear asymmetry N/Z, but could not rule out an increase with nuclear mass A. We measured high-missing-momentum protons knocked out in electron scattering from selected nuclei with a range of shell configurations, A, and N/Z, including 9Be, 10B, 11B, 12C, 40Ca, 48Ca, 54Fe and 197Au. Unexpectedly, we found that while the pairing probability increased with A, the slope of the increase was much greater from Be to C and from 40Ca to Fe, than from Be to Au. This shows the importance of long-range nuclear shell structure on the probability of short-range nucleon pairing.

nucl-ex↗

arXiv2018

Saturation and alternate pathways in four-wave mixing in rubidium

We have examined the frequency spectrum of the blue light generated via four-wave mixing in a rubidium vapor cell inside a ring cavity. At high atomic density and input laser power, two distinct frequency components separated by $116 \pm 4$ MHz are observed, indicating alternate four-wave mixing channels through the $6p_{3/2}$ hyperfine states. The dependence of the generated light on excitation intensity and atomic density are explored, and indicate the primary process has saturated. This saturation results when the excitation rate through the 6p state becomes equal to the rate through the 5p state, giving no further gain with atomic density while a quadratic intensity dependence remains.

physics.atom-ph↗