Massive Photons: An Infrared Regularization Scheme for Lattice QCD+QED.
- Author(s): Endres, Michael G
- Shindler, Andrea
- Tiburzi, Brian C
- Walker-Loud, André
- et al.
Published Web Locationhttps://doi.org/10.1103/physrevlett.117.072002
Standard methods for including electromagnetic interactions in lattice quantum chromodynamics calculations result in power-law finite-volume corrections to physical quantities. Removing these by extrapolation requires costly computations at multiple volumes. We introduce a photon mass to alternatively regulate the infrared, and rely on effective field theory to remove its unphysical effects. Electromagnetic modifications to the hadron spectrum are reliably estimated with a precision and cost comparable to conventional approaches that utilize multiple larger volumes. A significant overall cost advantage emerges when accounting for ensemble generation. The proposed method may benefit lattice calculations involving multiple charged hadrons, as well as quantum many-body computations with long-range Coulomb interactions.