For 10 points, name this value denoted g, which gives the strength of an interaction in a quantum field theory.
In non-Abelian theories, the Lagrangian contains a term equal to minus one divided by the square of this value times the trace of the field tensor. In one instance, this dimensionless quantity can be converted into one with a value of 220 MeV in a process called "dimensional transmutation." For a generic scattering process, the matrix element equals the product of each vertex's value of this quantity times the propagator. A field theory is referred to as "scale invariant" when this quantity is independent of the energy scale. Taking the derivative of this value with respect to the logarithm of the energy scale gives the beta function, which describes the "running" of this value. If this value decreases as distance decreases and energy increases, the result is called asymptotic freedom. For 10 points, name this value denoted g, which gives the strength of an interaction in a quantum field theory.
In non-Abelian theories, the Lagrangian contains a term equal to minus one divided by the square of this value times the trace of the field tensor.
coupling constant