Two- and three-body interactions in $\varphi^4$ theory from lattice simulations
Abstract
We calculate the one-, two- and three-particle energy levels for different lattice volumes in the complex theory on the lattice. We argue that the exponentially suppressed finite-volume corrections for the two- and three-particle energy shifts can be reduced significantly by using the single particle mass, which includes the finite-size effects. We show numerically that, for a set of bare parameters, corresponding to the weak repulsive interaction, one can reliably extract the two- and three-particle energy shifts. From those, we extract the scattering length, the effective range and the effective three-body coupling. We show that the parameters, extracted from the two- and three-particle energy shifts, are consistent. Moreover, the effective three-body coupling is significantly different from zero.
Keywords
Cite
@article{arxiv.1806.02367,
title = {Two- and three-body interactions in $\varphi^4$ theory from lattice simulations},
author = {Fernando Romero-López and Akaki Rusetsky and Carsten Urbach},
journal= {arXiv preprint arXiv:1806.02367},
year = {2018}
}
Comments
Update to match published version