Low-mode deflation for twisted-mass and RHMC reweighting in lattice QCD

Author:

Simon Kuberski

Keyword:

High Energy Physics - Lattice, High Energy Physics - Lattice (hep-lat)

journal:

MITP-23-021

date:

2023-06-03 16:00:00

Abstract

We propose improved estimators to compute the reweighting factors which are needed for lattice QCD calculations that rely on twisted-mass reweighting for the light quark contribution and the Rational Hybrid Monte Carlo (RHMC) algorithm for non-degenerate quark masses. This is the case for a number of modern large-scale simulations based on O(a) improved Wilson fermions. We find a significant reduction of uncertainties for the reweighting factors at similar computational cost compared to the conventional estimation. This leads to a significant increase in precision for phenomenologically relevant observables with high correlation to the low eigenmodes of the Wilson-Dirac operator in the presence of exceptionally small eigenvalues.

PDF: Low-mode deflation for twisted-mass and RHMC reweighting in lattice QCD.pdf