%0 Journal Article
%T Two- and three-body interactions in phi 4 theory from lattice simulations
%A Romero-Lopez, F.
%A Rusetsky, A.
%A Urbach, C.
%J European Physical Journal C
%D 2018
%V 78
%N 10
%I Springer
%@ 1434-6044
%G English
%F Romero-Lopez_etal2018
%O WOS:000448080300003
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3778), last updated on Wed, 07 Nov 2018 12:15:02 +0000
%X We calculate the one-, two- and three-particle energy levels for different lattice volumes in the complex phi(4) 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.
%R 10.1140/epjc/s10052-018-6325-8
%U http://arxiv.org/abs/1806.02367
%U https://doi.org/10.1140/epjc/s10052-018-6325-8
%P 846 - 15pp