A fundamental particle that obeys Bose-Einstein statistical rules, but not the Pauli exclusion principle; the spin value of a boson is always an integer. Examples of bosons are alpha particles, photons, and those nuclei which have an even mass number.
a particle with integer spin (e.g. photons). The wave function describing a collection of bosons is symmetric with respect to the exchange of identical particles. Bosons are not constrained by the Pauli exclusion principle and can condense into a single energy state at very low temperatures. This is called Bose-Einstein condensation.
a particle, or pattern of string vibration, with a whole number amount of spin; typically a messenger particle.