Assertion: proton's quark | /r/CapableOf | change its flavour
Facets:
value: by emission of a w boson
type: MANNER
Source sentences:
text: Nucleons are composed of up quarks and down quarks, and the weak force allows a quark to change its flavour by emission of a W boson leading to creation of an electron/antineutrino or positron/neutrino pair.