Application of the Maximum Entropy Method to the (2+1)d Four-Fermion Model
Abstract
We investigate spectral functions extracted using the Maximum Entropy Method from correlators measured in lattice simulations of the (2+1)-dimensional four-fermion model. This model is particularly interesting because it has both a chirally broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are only resonances. In the broken phase we study the elementary fermion, pion, sigma and massive pseudoscalar meson; our results confirm the Goldstone nature of the pi and permit an estimate of the meson binding energy. We have, however, seen no signal of sigma -> pi pi decay as the chiral limit is approached. In the symmetric phase we observe a resonance of non-zero width in qualitative agreement with analytic expectations; in addition the ultra-violet behaviour of the spectral functions is consistent with the large non-perturbative anomalous dimension for fermion composite operators expected in this model.
Keywords
Cite
@article{arxiv.hep-lat/0208027,
title = {Application of the Maximum Entropy Method to the (2+1)d Four-Fermion Model},
author = {C. R. Allton and J. E. Clowser and S. J. Hands and J. B. Kogut and C. G. Strouthos},
journal= {arXiv preprint arXiv:hep-lat/0208027},
year = {2009}
}
Comments
25 pages, 13 figures