Unlike fermions, of which matter is made, bosons are not conserved in number, and can appear out of nothing and disappear into nothing. Any number of identical bosons can be put into the same state, or into the same region of space, whereas only one of a set of identical fermions can be put into a given state, or into a small volume of space. Forces are "made out of" bosons! |
A Feynman diagram, depicting the interaction of two positively charged particles interacting by exchange of a “virtual” photon. Remember that photons are both chargeless and massless. |
Every fundamental particle in nature has a corresponding antiparticle, which has the same mass, but can differ in other properties, for instance charge. The electron has an antiparticle, the positron, which has a positive charge. The proton has an antiparticle, the anti-proton, which has a negative charge. And so on. It is not unusual for a particle to be its own antiparticle, the obvious example being the photon (γ).