A little question:
is x-boson included in su(5)? (or in some generalization of it) :uhh:
The su(5) Lie algebra has 24 dimensions -- so 24 gauge bosons. In the su(5) GUT, 4 of these get identified with the electroweak, W and Z, bosons and 8 get identified with the gluons, G. This leaves 12 gauge bosons -- the X -- which are given large masses to explain why we haven't seen them.
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