1. plural of mesotron; subatomic particles of intermediate mass between electrons and protons, now called muons
Usage: physics; archaic

Examples

• Scientists in the 1930s discovered mesotrons in cosmic ray experiments.
• The mesotrons were found to have properties between those of electrons and protons.
• Early particle physicists studied mesotrons before understanding their true nature.
• Mesotrons were later renamed muons as our understanding of particle physics evolved.
• The detection of mesotrons helped advance theories about subatomic particles.