· Nuclear & Particle Physics
Hideki Yukawa and the Meson: How a Force’s Range Predicted a New Particle
In 1934 Hideki Yukawa asked why the force that holds the nucleus together reaches only about the width of a proton. His answer: a force carried by a particle with mass has a range set by that mass, λ = ħ/(mc). Working backwards from the range, he predicted a new particle about 200 times heavier than the electron. Here is the physics, the numbers, and the twisty hunt that found it.