Page "Gauge boson" Paragraph 6

According to the Standard Model, the W and Z bosons gain mass via the Higgs mechanism.

In the Higgs mechanism, the four gauge bosons ( of SU ( 2 )× U ( 1 ) symmetry ) of the unified electroweak interaction couple to a Higgs field.

This field undergoes spontaneous symmetry breaking due to the shape of its interaction potential.

As a result, the universe is permeated by a nonzero Higgs vacuum expectation value ( VEV ).

This VEV couples to three of the electroweak gauge bosons ( the Ws and Z ), giving them mass ; the remaining gauge boson remains massless ( the photon ).

This theory also predicts the existence of a scalar Higgs boson, which may have been observed in experiments that were reported on 4 July, 2012.