2024/01/15 by Di Carlo, Matteo
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat)
paper · doi:10.48550/arxiv.2401.07666
We provide an overview of the current state of lattice calculations concerning isospin-breaking corrections in weak decays, focusing in particular on leptonic decays of light pseudoscalar mesons. We examine the two currently existing calculations, placing a particular emphasis on the role of electromagnetic finite-volume corrections. Given the large systematic uncertainty associated with such corrections, we propose a novel method to improve the finite-volume scaling of leptonic decay rates and other hadronic observables, like hadron masses and the hadronic vacuum polarization contribution to the muon g-2. We introduce a new prescription for the QED action, referred to as QEDr, which effectively removes finite-volume corrections at O(1/L3) and consequently shifts the systematic uncertainty to a higher order. The specifics of this action, the practical implementation of the infrared improvement, and the ongoing numerical tests are also discussed.