High-precision continuum limit study of the HVP short-distance window
Sebastian Spiegel, Christoph Lehner
Abstract
The separation of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment into Euclidean windows allows for a tailored approach to address the different dominant challenges at short, intermediate, and long distances. We present a novel approach to compute the short-distance window without the need for using perturbative QCD. We combine a quenched continuum extrapolation using 18 lattice spacings ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mn>1.6</a:mn> <a:mtext> </a:mtext> <a:mtext> </a:mtext> <a:mi>GeV</a:mi> <a:mo>≲</a:mo> <a:msup> <a:mi>a</a:mi> <a:mrow> <a:mo>−</a:mo> <a:mn>1</a:mn> </a:mrow> </a:msup> <a:mo>≲</a:mo> <a:mn>6.1</a:mn> <a:mtext> </a:mtext> <a:mtext> </a:mtext> <a:mi>GeV</a:mi> </a:math> ) with a separate continuum extrapolation of the sea quark effects. This method allows for the computationally expensive sea quark effects to be estimated using only a smaller number of ensembles at coarser lattice spacings, while largely confining the logarithmic dependency of the continuum extrapolation to the quenched component.