arXiv:2605.06560·v1·High Energy Physics — Lattice

$F_{K} / F_{π}$ as a precision test of a new four flavor Domain Wall Fermion action

Renwick J. Hudspith🇺🇸 · Nicolas Garron🇬🇧 · Zack Hall🇺🇸 · Andrew Hanlon🇺🇸 · Henry Monge-Camacho🇺🇸 · Colin Morningstar🇺🇸 · Amy Nicholson🇺🇸 · Dimitra A. Pefkou🇺🇸 · Thomas R. Richardson🇺🇸 · Fernando Romero-López🇨🇭 · Miguel Salg🇨🇭 · Wyatt A. Smith🇺🇸

We present a new set of lattice QCD ensembles with four flavors of smeared Möbius Domain Wall Fermions with good chiral symmetry and small fifth-dimensional extent. A modest amount of computing resources was sufficient to generate 30 publicly-available ensembles spanning five lattice spacings and a broad range of pion masses down to physical. To scrutinize our action we determine $F_{K^{\pm}} / F_{π^{\pm}} = 1.1962 (34)$ , a key quantity for precision CKM unitarity tests, heralding a future of inexpensive high-precision calculations of hadronic observables with chiral fermions.

Comments: 11 pages, 5 figures

FK​/Fπ​ as a precision test of a new four flavor Domain Wall Fermion action

Abstract

$F_{K} / F_{π}$ as a precision test of a new four flavor Domain Wall Fermion action