Researchers at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility discovered new quantum selection rules for proton-neutron pairing in atomic nuclei. Their experiments revealed that shell structure, rather than just neutron excess, plays a crucial role in determining how protons and neutrons pair up, enhancing our understanding of nuclear behavior.

• 01The study revealed new quantum selection rules that govern proton-neutron pairing, which were previously unknown.
• 02Experiments compared magic and doubly magic nuclei, specifically Calcium-40, Calcium-48, and Iron-54, to analyze short-range correlations (SRCs).
• 03Adding six protons to a nucleus resulted in a 50% increase in SRCs, contrary to expectations based on simple proton counting.
• 04The experiment was conducted over just four days, utilizing advanced methodologies developed at Jefferson Lab over two decades.
• 05The research is set to continue with further analysis of lighter nuclei and related experiments.

The findings enhance the understanding of nuclear physics, which can have implications for various fields, including energy production and medical applications.