What are Pions?

A pion is a subatomic particle that is a type of meson, which is a class of particles made up of one quark and one antiquark. Pions are the lightest mesons and are important in understanding the strong nuclear force, which holds quarks together inside protons and neutrons. They were discovered in 1947 by physicists Cecil Powell and his colleagues.

Pions have a mass of about 139 MeV (million electron volts) and a lifetime of about 260 femtoseconds (10^-15 seconds). They are charged particles, with a positive charge of +1e and a negative charge of -1e. Pions interact with other particles through the strong nuclear force, which is mediated by particles called gluons.

Pions play an important role in many areas of particle physics, including the study of quark matter and the search for new physics beyond the Standard Model. They are also used in medical applications, such as cancer treatment, and in industrial applications, such as the production of radioisotopes for medical imaging.