Electron-Nuclei Interactions Offer New Dark Matter Constraints

A recent study suggests that dark matter particles may mediate interactions between electrons and atomic nuclei. This research provides new constraints on hypothetical particles not included in the Standard Model of particle physics. It also addresses a previously unexplored area of forces between electrons and nuclei.

Researchers from Johannes Gutenberg University Mainz, Helmholtz Institute Mainz, and the PRISMA++ Cluster of Excellence conducted the study. They used precision measurements on barium monofluoride (BaF) molecules. This allowed them to constrain interactions mediated by Z' bosons for the first time. Z' bosons are hypothetical mediators of the weak interaction and potential dark matter particles.

Visible matter accounts for about four percent of the universe. Dark matter comprises approximately 23 percent. Its presence is confirmed by astrophysical observations. However, the particles that make up dark matter remain unknown. Many theories and experiments are currently investigating this question.

The team utilized the MOGON 2 supercomputer at Johannes Gutenberg University Mainz. They reinterpreted existing precision measurement results from BaF molecules. This interdisciplinary approach combined knowledge of weak interaction, hypothetical bosons, and atomic, molecular, and nuclear physics. The study found similar bounds by analyzing experiments with cesium 133 atoms. However, diatomic molecules like BaF offer more precise results. They are not affected by uncertainties related to nuclear physics.

Future experiments with heavy diatomic species like BaF could increase sensitivity by one hundred-fold. This would allow deeper exploration into unknown territories. The findings were published in *Physical Review Letters*.