Answer: pion

AnswerCrossword Clue
PIONAtomic particle
piona meson that is a combination of up and down quarks and antiquarks, that may be positive, negative, or neutral, and that has a mass about 270 times that of the electron
PIONSpinless particle
PIONTwo-quark particle
PIONMeson that helps hold the nucleus together
PIONSubatomic bit
PIONSubatomic particle that is a nuclear binder
PIONSemistable subatomic particle
PIONNuclear binder
PIONFirst meson discovered
PIONShort-lived particle
PIONUnstable nuclear particle
PIONNuclear particle
PIONCertain subatomic particle
PIONLightest meson
PIONSubatomic partical
PIONZero-spin particle
PIONMeson with zero spin
PIONSubatomic particle
PIONCyclotron output