PT Journal
AU Romero-Lopez, F
   Rusetsky, A
   Urbach, C
TI Two- and three-body interactions in phi 4 theory from lattice simulations
SO European Physical Journal C
JI Eur. Phys. J. C
PY 2018
BP 846 - 15pp
VL 78
IS 10
DI 10.1140/epjc/s10052-018-6325-8
LA English
AB 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.
ER