Assertion: photon's mass | /r/HasProperty | free parameter
Facets:
value: unfortunately
type: MANNER
value: in standard model
type: OTHER
value: in its couplings to other particles
type: OTHER
Source sentences:
text: Unfortunately, the mass of the Higgs boson is a free parameter in standard model and its couplings to other particles are very weak, which makes the experiments searching it very difficult.