Any of a family of subatomic particles that participate in strong interactions,are composed of a quark and an antiquark,and have masses generally intermediate between leptons and baryons.

• 介子，任一种具有较强相互作用力的亚原子粒子群，由一夸克与一反夸克构成，并具有通常介于轻子和重子间的质量。