📚 Pion, noun. 🔉 /ˈpʌɪɒn/ 🇬🇧 ❓ Definition: Also called «pi-meson». ❗️ Examples: 1. The proton and the neutron are baryons; the electron, the muon, and the neutrino are leptons; whilst the pions are mesons. 2. Kaons and pions are examples of particles known as mesons, which contain a quark and an antiquark. 3. He worked primarily on the interaction of pions with protons. 4. In turn, these decay into other subatomic particles, like kaons and pions. 5. A neutral pion consists of a down quark and a down antiquark. ━━━━━━━━━━━━━ 🌀 @cambridge_dic