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arXiv · 2202.08795

Simulating rare kaon decays $K^{+}\to\pi^{+}\ell^{+}\ell^{-}$ using domain wall lattice QCD with physical light quark masses

P. A. Boyle·F. Erben·J. M. Flynn·V. Gülpers·R. C. Hill·R. Hodgson·A. Jüttner·F. Ó hÓgáin·A. Portelli·C. T. Sachrajda
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Abstract

We report the first calculation using physical light-quark masses of the electromagnetic form factor $V(z)$ describing the long-distance contributions to the $K^+\to\pi^+\ell^+\ell^-$ decay amplitude. The calculation is performed on a 2+1 flavor domain wall fermion ensemble with inverse lattice spacing $a^{-1}=1.730(4)$GeV. We implement a Glashow-Iliopoulos-Maiani cancellation by extrapolating to the physical charm-quark mass from three below-charm masses. We obtain $V(z=0.013(2))=-0.87(4.44)$, achieving a bound for the value. The large statistical error arises from stochastically estimated quark loops.

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P. A. Boyle, F. Erben, J. M. Flynn, V. Gülpers, R. C. Hill, R. Hodgson, A. Jüttner, F. Ó hÓgáin, A. Portelli, C. T. Sachrajda. 2022-02-17. Simulating rare kaon decays $K^{+}\to\pi^{+}\ell^{+}\ell^{-}$ using domain wall lattice QCD with physical light quark masses. https://doi.org/10.1103/physrevd.107.l011503

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