Relating Chiral Perturbation Theory and QCD Simulations with Overlap Hypercube Fermions

TL;DR

This paper reports on lattice QCD simulations using chirally symmetric overlap hypercube fermions at very low pion masses, connecting results with Random Matrix Theory and Chiral Perturbation Theory to extract key physical parameters.

Contribution

It introduces the use of overlap hypercube fermions in lattice QCD simulations at low pion masses and relates the results to theoretical frameworks for parameter extraction.

Findings

Successful simulation at very low pion masses.

Extraction of pion decay constant and scalar condensate.

Validation of overlap hypercube fermions for chiral symmetry.

Abstract

We present simulation results for lattice QCD with light pions. For the quark fields we apply chirally symmetric lattice Dirac operators, in particular the overlap hypercube operator, along with the standard overlap operator for comparison. This allows us to simulate at very low pion masses. The results are related to Random Matrix Theory and to Chiral Perturbation Theory in order to extract information about the pion decay constant, the scalar condensate and the topological susceptibility.