The Columbia Encyclopedia, Sixth Edition. 2001-07.
W and Z particles
elementary particles that mediate, or carry, the fundamental force associated with weak interactions. The discovery of the W and Z particles at CERN near Geneva, Switzerland, in the early 1980s was an important confirmation of electroweak theory, which unifies the electromagnetic and weak forces. The W and Z particles are quite massive for elementary particles; they are roughly 100 times as massive as the proton.
