charm quark; c quark
Technical term in particle physics; one of the six flavors of quarks.
The charm quark was discovered in 1974.
The charm quark is a type of heavy quark.
Variant with interpunct; less common but seen in some texts.
From English 'charm quark'; the term 'charm' was introduced by Sheldon Glashow and James Bjorken in 1964.