Abstract

We investigate a recently proposed new form of the exact NSVZ β-function, which relates the β-function to the anomalous dimensions of the quantum gauge superfield, of the Faddeev-Popov ghosts, and of the chiral matter superfields. Namely, for the general renormalizable mathcal{N} = 1 supersymmetric gauge theory, regularized by higher covariant derivatives, the sum of all three-loop contributions to the β-function containing the Yukawa couplings is compared with the corresponding two-loop contributions to the anomalous dimensions of the quantum superfields. It is demonstrated that for the considered terms both new and original forms of the NSVZ relation are valid independently of the subtraction scheme if the renormalization group functions are defined in terms of the bare couplings. This result is obtained from the equality relating the loop integrals, which, in turn, follows from the factorization of the integrals for the β-function into integrals of double total derivatives. For the renormalization group functions defined in terms of the renormalized couplings we verify that the NSVZ scheme is obtained with the higher covariant derivative regularization supplemented by the subtraction scheme in which only powers of ln Λ/μ are included into the renormalization constants.

Highlights

  • Where the equation (T A) are the generators of the representation in which the matter superfields lie and f ABC are the structure constants

  • For the renormalization group functions defined in terms of the renormalized couplings we verify that the NSVZ scheme is obtained with the higher covariant derivative regularization supplemented by the subtraction scheme in which only powers of ln Λ/μ are included into the renormalization constants

  • To explain why using the higher derivative regularization naturally leads to the NSVZ β-function, we first note that, according to refs. [33, 34], one should distinguish between renormalization group functions (RGFs) defined in terms of the bare couplings and RGFs defined in terms of the renormalized couplings

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Summary

Dependence of the three-loop β-function on the Yukawa couplings

Unlike eq (1.1), the NSVZ relation in the form (1.3) (for RGFs defined in terms of the bare couplings) admits a simple graphical interpretation which is very similar to the one in the Abelian case. Some explicit calculations made with the higher derivative regularization have demonstrated that the integrals in the left hand side are integrals of total derivatives [39, 51] and even of double total derivatives [40, 43, 53, 54, 56]. We calculate a part of the three-loop β-function containing the Yukawa couplings and compare it with the corresponding parts of the anomalous dimensions of the quantum superfields. We need to calculate the two-point Green functions for the chiral matter superfields and for the quantum gauge superfield V in the two-loop approximation.

NSVZ relation for RGFs defined in terms of the bare couplings
RGFs defined in terms of the bare couplings
Anomalous dimension of the quantum gauge superfield
Anomalous dimension of the chiral matter superfields
RGFs defined in terms of the renormalized couplings
NSVZ scheme and minimal subtractions of logarithms
Conclusion
A Contributions of various supergraphs to the two-point Green functions
B Calculation of the integrals
Anomalous dimension of the matter superfields
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