MEM study of true flattening of free energy and the $\theta$ term

Abstract

We study the sign problem in lattice field theory with a $\theta$ term, which reveals as flattening phenomenon of the free energy density $f(\theta )$. We report the result of the MEM analysis, where such mock data are used that `true' flattening of $f(\theta )$ occurs. This is regarded as a simple model for studying whether the MEM could correctly detect non trivial phase structure in $\theta$ space. We discuss how the MEM distinguishes fictitious and true flattening.

Poster presented at Lattice2004(topology), Fermilab, June 21-26, 2004; 3 pages, 3 figures