GENERAL KNOWLEDGE

Detailed explanation-1: -Outside the nucleus, mesons appear in nature only as short-lived products of very high-energy collisions between particles made of quarks, such as cosmic rays (high-energy protons and neutrons) and baryonic matter.

Detailed explanation-2: -meson, any member of a family of subatomic particles composed of a quark and an antiquark. Mesons are sensitive to the strong force, the fundamental interaction that binds the components of the nucleus by governing the behaviour of their constituent quarks.

Detailed explanation-3: -Mesons are intermediate mass particles which are made up of a quark-antiquark pair. Three quark combinations are called baryons. Mesons are bosons, while the baryons are fermions. There was a recent claim of observation of particles with five quarks (pentaquark), but further experimentation has not borne it out.