Simulating the Schroedinger functional with two pseudo-fermions: algorithmic study and the running mass

TL;DR

This paper investigates an improved algorithm for simulating two massless Wilson quarks with Schroedinger functional boundary conditions, achieving significant computational efficiency gains for studying the running quark mass.

Contribution

It introduces an optimized Hybrid Monte Carlo algorithm with two pseudo-fermions, reducing CPU costs and enhancing simulation efficiency for the ALPHA project.

Findings

CPU cost reduced by a factor of two with two pseudo-fermions

Successful simulation of massless Wilson quarks with improved efficiency

Updated physics results on the running of the renormalized quark mass

Abstract

We present an algorithmic study for the simulation of two massless flavors of O(a) improved Wilson quarks with Schroedinger functional boundary conditions. The algorithm used is Hybrid Monte Carlo with two pseudo-fermion fields as proposed by M. Hasenbusch. A gain in CPU cost of a factor two is reached when compared to one pseudo-fermion field due to the larger possible step-size. This study is integrated in the ALPHA project for the computation of the running of the renormalized quark mass. We include an update on these physics results.