Scientists have developed a groundbreaking method to peer into the heart of an atom's nucleus, offering a new perspective on nuclear physics. A team led by MIT researchers has achieved this feat using a simple molecule, radium monofluoride, to observe electrons and their interactions with the nucleus. This innovative approach, conducted at CERN in Switzerland, bypasses the need for extensive colliders, making it a practical and accessible way to study nuclear structure and the fundamental question of why matter prevails over antimatter in the universe.
The study's lead researcher, Ronald Fernando Garcia Ruiz, and his team focused on the hyperfine structure of radium monofluoride, which reveals tiny energy changes from nucleus-electron interactions. These shifts act as a signature from the nucleus itself when electrons briefly pass through it. Radium monofluoride's unusual sensitivity to the size of the nucleus hints at the potential for electrons in this molecule to unveil details usually hidden from view.
The team's experiment involved pairing radium with fluoride, cooling and trapping the molecules, and then laser probing their electron energies. They observed a small but clear offset from theoretical predictions, indicating that electrons spend a sliver of time inside the nucleus. This discovery has significant implications for understanding nuclear magnetization distribution and the behavior of heavy systems like radium.
Radium 225, with its octupole deformed nucleus, showcases a rare symmetry that amplifies certain symmetry-breaking effects. These effects are crucial in understanding time reversal and charge parity violations, which may explain the dominance of matter over antimatter in our universe. The team's choice of radium as the molecule's core was strategic, as its asymmetric charge and mass contribute to these symmetry-breaking phenomena.
The study's approach diverges from traditional nuclear scattering methods, which use electron beams and detectors in large facilities. Instead, the molecule-based technique reads nuclear information from light emitted or absorbed by trapped molecules, offering precision over brute force. Despite the challenges of working with scarce and radioactive radium, the team successfully extracted a clear signal, indicating electrons briefly sampling the nuclear interior.
Looking ahead, the researchers aim to map the distribution of magnetism across the radium nucleus, which could enhance our understanding of symmetry violations and electric dipole moments. These findings may challenge parts of the Standard Model or help narrow down the search for new physics. The study's publication in Science highlights the potential of this method to revolutionize our understanding of atomic nuclei and their interactions.
