Contamination of Excited States in Quenched QCD Hadron Propagators

TL;DR

This paper investigates whether quenched QCD hadron propagators accurately reflect ground state masses without excited state contamination, emphasizing the importance of large-time data for reliable mass extraction.

Contribution

It demonstrates that obtaining propagators at large time slices is crucial for accurately determining ground state masses in quenched QCD simulations.

Findings

First excited state masses align with experimental values when large-time propagators are used.

Contamination from excited states can be minimized with sufficiently large time slices.

Reliable ground state masses require asymptotic propagator data at large time slices.

Abstract

Quenched QCD hadron spectrum is calculated with Wilson's quark action at $\beta=5.85$ and 6.0 on a $24^3 \times 54$ lattice. We discuss the problem of whether we have extracted the mass of the ground state at these $\beta$'s without contamination of the excited states. We show that the masses of the first excited states turn out to be consistent with experiment when we are able to obtain the propagators up to the large time slice region where the propagators take the asymptotic forms of the ground states.