| 释义 |
pi-meson
\ˈ ̷ ̷| ̷ ̷ˌ ̷ ̷\ noun
Etymology: pi (I) + meson
: a short-lived meson that is primarily responsible for the nuclear force and that exists in three charge states of which the positive and negative have mass 273.2 times the electron mass and the neutral has mass 264.2 times the electron mass |