# QED self energies from lattice QCD without power-law finite-volume errors

## TL;DR

This paper introduces a lattice QCD method to compute electromagnetic corrections to hadron masses with only exponentially suppressed finite-volume errors, improving accuracy over traditional power-law approaches.

## Contribution

The authors develop a novel technique using the infinite-volume photon propagator to reduce finite-volume errors from power-law to exponential suppression in lattice QCD calculations.

## Key findings

- Electromagnetic corrections to hadron masses can be computed with exponential finite-volume suppression.
- The method enables more precise calculations of QED effects in lattice QCD.
- Potential extensions include QED corrections to leptonic and rare decays.

## Abstract

Using the infinite-volume photon propagator, we developed a method which allows us to calculate electromagnetic corrections to stable hadron masses with only exponentially suppressed finite-volume effects. The key idea is that the infinite volume hadronic current-current correlation function with large time separation between the two currents can be reconstructed by its value at modest time separation, which can be evaluated in finite volume with only exponentially suppressed errors. This approach can be extended to other possible applications such as QED corrections to (semi-)leptonic decays and some rare decays.