In a groundbreaking discovery, researchers at the Institute of Modern Physics (IMP) in China have confirmed a new proton magic number in silicon-22 (Si-22). Published in *Physical Review Letters* on July 2, 2025, this finding sheds new light on the stability of atomic nuclei and the forces that hold them together.
Magic numbers, such as 2, 8, 20, 28, 50, 82, and 126, are specific quantities of protons or neutrons that make atomic nuclei exceptionally stable. The IMP team used advanced mass spectrometry techniques at the Heavy Ion Research Facility in Lanzhou to study the neutron-deficient isotope silicon-22, which has 14 protons and 8 neutrons.
Their experiments confirmed that silicon-22 is bound against particle emission, indicating its doubly magic character. This discovery not only deepens our understanding of exotic nuclear structures but also provides crucial insights into nucleon interactions and the existence of extremely exotic nuclei. This research, supported by the National Key R&D Program of China, marks a significant advancement in nuclear physics, potentially impacting our understanding of element formation in the universe.