Coupling constant (physics)
= Coupling constant
{disambiguate=physics}
{title2=$g$}
A coefficient multiplying an interaction term controls its strength relative to the chosen field normalization. Its <engineering dimension> determines whether it is dimensionless, relevant or irrelevant. A renormalized <coupling constant (physics)> constant is specified at a <renormalization scale>; its change with that scale is described by the <renormalization-group beta function>.