This process cannot generally occur in one- or two-dimensional systems according to the Mermin-Wagner theorem. When a gauge is associated with the invariance that underlies this process, its associated gauge particles are said to "eat" the particles 
This process cannot generally occur in one- or two-dimensional systems according to the Mermin-Wagner theorem. When a gauge is associated with the invariance that underlies this process, its associated gauge particles are said to "eat" the particles that appear in models in which this process occurs, those being Goldstone bosons. Perhaps the most discussed instance of this phenomenon occurs for the electroweak theory and is the process that transforms photons into W- and Z-bosons, the Higgs mechanism. For ten points, name this phenomenon in theoretical physics in which a system that is initially unchanged under some mathematical operation suddenly transitions to not being so that is exemplified by the acquisition of mass.
This process cannot generally occur in one- or two-dimensional systems according to the Mermin-Wagner theorem.
spontaneous {symmetry breaking} (accept close equivalents)