How are mesons and baryons different?

Mesons and baryons are different in that mesons are composed of a quark and an antiquark, while baryons consist of three quarks.

Mesons and baryons are both types of hadrons, which are particles made up of quarks. Quarks are elementary particles and a fundamental constituent of matter. They come in six types, or 'flavours': up, down, charm, strange, top, and bottom. The difference between mesons and baryons lies in the number and arrangement of these quarks.

Mesons are composed of a quark and an antiquark. They are bosons, meaning they have integer spin, and they obey Bose-Einstein statistics. Mesons are often involved in the mediation of the strong force, which is the force that holds protons and neutrons together in the nucleus of an atom. Examples of mesons include the pion and the kaon.

On the other hand, baryons are composed of three quarks. They are fermions, meaning they have half-integer spin, and they obey Fermi-Dirac statistics. Baryons include the more commonly known particles such as protons and neutrons, which make up the nucleus of atoms. Other examples of baryons include the lambda and the sigma particles.

The properties of mesons and baryons, such as their charge and spin, are determined by the types and arrangement of their constituent quarks. For example, a proton (a baryon) is composed of two up quarks and one down quark, giving it a charge of +1. A pion (a meson) can be composed of an up quark and an anti-down quark, giving it a charge of +1, or a down quark and an anti-up quark, giving it a charge of -1.

In summary, while both mesons and baryons are composed of quarks and are classified as hadrons, they differ in the number and arrangement of these quarks, which in turn determines their properties and behaviours.