Strong-coupling constant at three loops in momentum subtraction scheme Original Research Article

In this paper we compute the three-loop corrections to the β function in a momentum subtraction (MOM) scheme with a massive quark. The calculation is performed in the background field formalism applying asymptotic expansions for small and large momenta. Special emphasis is devoted to the relation between the coupling constant in the MOM and image schemes as well as their ability to describe the phenomenon of decoupling.