Derivation of the exact NSVZ beta-function in N=1 SQED, regularized by higher derivatives, by direct summation of Feynman diagrams

TL;DR

This paper presents a method to derive the exact NSVZ beta-function in N=1 SQED using higher derivative regularization, summing Feynman diagrams directly, and confirms the result with explicit three-loop calculations.

Contribution

It introduces a novel summation method for Feynman diagrams that proves the NSVZ beta-function as a total derivative integral in N=1 SQED.

Findings

Beta-function expressed as a total derivative integral

Exact NSVZ beta-function derived and verified

Method simplifies higher-loop calculations

Abstract

For N=1 supersymmetric quantum electrodynamics, regularized by higher derivatives, a method for summation of all Feynman diagrams defining the beta-function is presented. Using this method we prove that the beta-function is given by an integral of a total derivative, which can be easily calculated. It is shown that surviving terms give the exact NSVZ beta-function. The results are compared with the explicit three-loop calculation.