Limits on the abundance of millicharged particles bound to matter

Millicharged particles (mCPs) are hypothesized particles possessing an electric charge that is a fraction of the charge of the electron. We report a search for mCPs with charges greater than or similar to 10(-4)e that improves sensitivity to their abundance in matter by roughly two orders of magnitude relative to previous searches. This search is sensitive to such particles over a wide range of masses and charges for which they can form stable bound states with matter, corresponding to a gap in parameter space that is beyond the reach of previous searches from accelerators, colliders, cosmic-ray experiments, and cosmological constraints.

Automated summary

mCPs, hypothesized particles with a fraction of the charge of the electron, are the subject of a sensitive search in this study that aims to improve detection of their abundance in matter. The research covers a wide range of masses and charges where mCPs could form stable bound states with matter, filling a gap in parameter space previously unexplored by traditional methods.