QUANTUM-CHROMODYNAMICS PERTURBATION EXPANSIONS IN A COUPLING-CONSTANT RENORMALIZED BY MOMENTUM-SPACE SUBTRACTION

We relate two popular methods of renormalization; minimal subtraction and momentum-space subtraction. It is shown that ΛmomΛmin=5.73, where Λ is the mass used to parametrize the quantum-chromodynamic running coupling constant. Perturbation expansions are compared in the two methods. Our results support the conjecture that momentum-space subtraction leads to better convergence and that, therefore, Λmom is the parameter which should be measured by experiments. © 1979 The American Physical Society.