With a new molecule-based method, physicists peer inside an atom’s nucleus

Amazing stuff! However, can this approach be transferred to atoms of other elements?

"Physicists at MIT have developed a new way to probe inside an atom’s nucleus, using the atom’s own electrons as “messengers” within a molecule.

In a study appearing today in the journal Science, the physicists precisely measured the energy of electrons whizzing around a radium atom that had been paired with a fluoride atom to make a molecule of radium monofluoride. They used the environments within molecules as a sort of microscopic particle collider, which contained the radium atom’s electrons and encouraged them to briefly penetrate the atom’s nucleus. ... 

The team’s new molecule-based method offers a table-top alternative to directly probe the inside of an atom’s nucleus.

Amazing stuff!

Within molecules of radium monofluoride, the team measured the energies of a radium atom’s electrons as they pinged around inside the molecule. They discerned a slight energy shift and determined that electrons must have briefly penetrated the radium atom’s nucleus and interacted with its contents. As the electrons winged back out, they retained this energy shift, providing a nuclear “message” that could be analyzed to sense the internal structure of the atom’s nucleus.

The team’s method offers a new way to measure the nuclear “magnetic distribution.” In a nucleus, each proton and neutron acts like a small magnet, and they align differently depending on how the nucleus’ protons and neutrons are spread out. The team plans to apply their method to precisely map this property of the radium nucleus for the first time. What they find could help to answer one of the biggest mysteries in cosmology: Why do we see much more matter than antimatter in the universe? ..."

From the editor's summary and the abstract:

"Editor’s summary

Precision molecular spectroscopy is increasingly being used to probe symmetry violations relevant to fundamental physics studies. Of particular interest are molecules containing heavy radioactive nuclei, such as the pear-shaped radium isotope 225Ra. Wilkins et al. performed laser spectroscopy measurements of the hyperfine structure of the radium monofluoride molecule, which is especially challenging given the molecule’s short lifetime. In combination with calculations, the researchers were able to test models of magnetization distribution inside the radium nucleus. Their findings may lead to improved tests of fundamental symmetries. ...

Abstract

Precise experimental control and interrogation of molecules and calculations of their structure are enriching the investigation of nuclear and particle physics phenomena. Molecules containing heavy, octupole-deformed nuclei, such as radium, are of particular interest.

Here, we report precision laser spectroscopy measurements and theoretical calculations of the structure of the radioactive radium monofluoride molecule 225Ra19F.

Our results reveal fine details of the short-range electron-nucleus interaction, indicating the high sensitivity of this molecule to the distribution of magnetization, within the radium nucleus.

These results provide a stringent test of the description of the electronic wave function inside the nuclear volume, highlighting the suitability of these molecules for investigating subatomic phenomena."

With a new molecule-based method, physicists peer inside an atom’s nucleus | MIT News | Massachusetts Institute of Technology "An alternative to massive particle colliders, the approach could reveal insights into the universe’s starting ingredients."

Observation of the distribution of nuclear magnetization in a molecule (no public access)

Observation of the distribution of nuclear magnetization in a molecule (open access)