A new anomalous contribution to the central charge of the N=2 monopole

TL;DR

This paper computes one-loop quantum corrections to the mass and central charge of N=2 monopoles, revealing an anomaly that ensures BPS saturation and aligns with Seiberg-Witten theory.

Contribution

It introduces a supersymmetry-preserving dimensional regularization method to uncover nontrivial quantum corrections to monopole central charges in N=2 super-Yang-Mills.

Findings

Identifies a new anomaly in the central charge of N=2 monopoles.

Shows quantum corrections preserve BPS saturation at one loop.

Restores consistency with Seiberg-Witten low-energy effective action.

Abstract

We calculate the one-loop corrections to the mass and central charge of the BPS monopole in N=2 super-Yang-Mills theory in 3+1 dimensions using a supersymmetry-preserving version of dimensional regularization adapted to solitons. In the renormalization scheme where previous studies have indicated vanishing quantum corrections, we find nontrivial corrections that we identify as the 3+1 dimensional analogue of the anomaly in the conformal central charge of the N=1 supersymmetric kink in 1+1 dimensions. As in the latter case, the associated contribution to the ordinary central charge has exactly the required magnitude to preserve BPS saturation at the one-loop level. It also restores consistency of calculations involving sums over zero-point energies with the low-energy effective action of Seiberg and Witten.