Researchers from the University of Rochester in New York and the University of California–San Diego have published a paper in Physical Review Letters describing a previously unknown class of plasma oscillations. In “Space-Time Structured Plasma Waves,” the researchers “demonstrate that electrostatic wave packets structured with space-time correlations can have properties that are independent of the plasma conditions,” such as “density, temperature, ionization state, or details of the distribution functions.” This finding is technologically relevant, the authors note, because “electrostatic waves play a critical role in nearly every branch of plasma physics from fusion to advanced accelerators, to astro, solar, and ionospheric physics.”

Research with the Department of Energy’s Thomas Jefferson National Accelerator Facility (Jefferson Lab) has revealed new insights into short-range correlations—the brief pairings of nucleons (protons with neutrons, protons with protons, or neutrons with neutrons) in the nuclei of atoms. The study, published in Nature, used precision measurements to determine that short-range correlations differ depending on the density of the nucleus, that is, how many nucleons it contains.