In the similar and more widely used modified minimal subtraction, or MS-bar scheme ( MS ¯ ¯ ), one absorbs the divergent part plus a universal constant that always arises along with the divergence in Feynman diagram calculations into the counterterms. When using dimensional regularization, i.e. d 4 p → → μ μ 4 − − d d d p , it is implemented by rescaling the renormalization scale: μ μ 2 → → μ μ 2 e γ γ E 4 π π , with γ γ E the Euler–Mascheroni constant.