| Answer | Crossword Clue |
|---|---|
| PSIS | Particles of the meson family |
| TAUS | Particles of the lepton family |
| multipion | comprising many pions, pi-meson particles |
| leptonic | any of a family of particles (as electrons, muons, and neutrinos) that have spin quantum number 1/2 and that experience no strong forces |
