W boson

In particle physics, the W and Z bosons are vector bosons that are together known as the weak bosons or more generally as the intermediate vector bosons. These elementary particles mediate the weak interaction; the respective symbols are W , W , and Z . The W  bosons have either a positive or negative electric charge of 1 elementary charge and are each other's antiparticles. The Z  boson is electrically neutral and is its own antiparticle. The three particles each have a spin of 1. The W  bosons have a magnetic moment, but the Z has none. All three of these particles are very short-lived, with a half-life of about 3×10 s. Their experimental discovery was pivotal in establishing what is now called the Standard Model of particle physics.

The W bosons are named after the weak force. The physicist Steven Weinberg named the additional particle the "Z particle", and later gave the explanation that it was the last additional particle needed by the model. The W bosons had already been named, and the Z bosons were named for having zero electric charge.