Novel quark-field creation operator construction for hadronic physics in lattice QCD

Michael Peardon,Jozef Dudek,Robert G Edwards,John Bulava,Keisuke Jimmy Juge,Huey-Wen Lin,Justin Foley,Colin Morningstar,Bálint Joó,David G Richards

doi:10.1103/physrevd.80.054506

Abstract

A new quark-field smearing algorithm is defined which enables efficient calculations of a broad range of hadron correlation functions. The technique applies a low-rank operator to define smooth fields that are to be used in hadron creation operators. The resulting space of smooth fields is small enough that all elements of the reduced quark propagator can be computed exactly at reasonable computational cost. Correlations between arbitrary sources, including multihadron operators can be computed a posteriori without requiring new lattice Dirac operator inversions. The method is tested on realistic lattice sizes with light dynamical quarks.

Highlights

One of the goals of lattice calculations is to predict the low-energy hadron spectrum of confined quarks and gluons, starting solely from the QCD lagrangian
Describing the resonances seen in scattering experiments as states in QCD has long presented a challenge to lattice calculations as direct access to the matrix elements related to decay widths is usually missing in Euclidean formulations of field theory
One example is the isoscalar meson sector, where mass determinations require the evaluation of disconnected diagrams as part of the two-point correlation function

Summary

Introduction

One of the goals of lattice calculations is to predict the low-energy hadron spectrum of confined quarks and gluons, starting solely from the QCD lagrangian. This approach to spectroscopy necessitates methods for measuring the two-point correlation functions of field operators with the selected quantum numbers under investigation. One example is the isoscalar meson sector, where mass determinations require the evaluation of disconnected diagrams as part of the two-point correlation function. As well as this ambitious list of requirements, precision data will be crucial for these calculations [4]

Results

Discussion

Conclusion