Calculation and Interpretation of Hadron Correlation Functions in Lattice QCD

Abstract

Several new developments in the calculation and interpretation of hadron density-density correlation functions are presented. The asymptotic behavior of correlation functions is determined from a tree diagram path integral. A method is developed to use this behavior to correct for leading image contributions on a finite periodic spatial lattice and to correct for the finite temporal extent of the lattice. Equal time correlation functions are shown to determine a sum of the ground state rms radius plus a polarization correction, and it is shown how to extract the hadron polarizability from unequal time correlation functions. Image-corrected correlation functions calculated in quenched lattice QCD are presented and used to determine the size of the pion and nucleon.