Lattice studies of hadron physics with disconnected quark loops

TL;DR

This paper discusses lattice QCD studies of hadron physics focusing on disconnected quark loops, which are computationally challenging but crucial for understanding flavor singlet hadrons and scalar form factors.

Contribution

It introduces a method using all-to-all propagators to efficiently compute disconnected diagrams in lattice QCD simulations.

Findings

Successful calculation of flavor-singlet meson spectrum

Determination of nucleon strange quark content

Reduction in computational cost for disconnected diagrams

Abstract

Disconnected diagrams give crucial contributions to the physics of flavor singlet hadrons and to scalar form factors of non-singlet hadrons. Naive lattice calculation of the disconnected diagrams, however, requires a huge number of fermion matrix inversions and hence a prohibitively large computational cost. In this article, we present recent studies of the flavor-singelt meson spectrum and nucleon strange quark content using the all-to-all propagator to calculate the relevant disconnected diagrams.