The meson belongs to the group of bosons , it is a force carrier particle. Built up of a quark and an anti quark, mesons have a very low life expectancy and are usually only detected in high energy experiments. The ones built up of a quark and its own anti quark livefor an especially short time since particles and antiparticles annihilate each other.
The most important meson is the pion . The positive pion, consisting of an up quark and an anti down quark, turns neutrons into protons inside a nucleus. Its negative antiparticle turns neutrons into protons. Through this process, the nucleons stay together inside the nucleus . This makes the pion the force carrier particle of the nuclear force .
About Meson in German. (Meson)