Towards measuring the eta' mass with N_f=2+1 staggered fermions

TL;DR

This paper investigates the eta' meson mass using 2+1 flavor staggered fermions, focusing on the challenges of measuring flavor-singlet states and testing the validity of the fourth-root trick in lattice QCD.

Contribution

It provides preliminary lattice QCD results for flavor-singlet pseudoscalar mesons and discusses strategies to improve measurement accuracy.

Findings

Initial measurements of eta' mass on 2+1 flavor lattices.

Discussion of signal-to-error improvement strategies.

Insights into the validity of the fourth-root trick.

Abstract

Because the propagators of flavor-singlet states incorporate disconnected diagrams, they are uniquely sensitive to any differences in the actions governing sea and valence fermions on the lattice. As such, they present an important test of the validity of the ``fourth-root trick'' in the staggered fermion formulation. The pseudoscalar's relationship to topological charge also makes it of theoretical interest. We present preliminary results from our measurements of flavor-singlet pseudoscalar mesons on 2+1 flavor Asqtad lattices, and discuss some strategies for improving the signal-to-error ratio of disconnected singlet correlators.