TY  - JOUR
AU  - Romero-Lopez, F.
AU  - Rusetsky, A.
AU  - Urbach, C.
PY  - 2018
DA  - 2018//
TI  - Two- and three-body interactions in phi 4 theory from lattice simulations
T2  - Eur. Phys. J. C
JO  - European Physical Journal C
SP  - 846 - 15pp
VL  - 78
IS  - 10
PB  - Springer
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.
SN  - 1434-6044
UR  - http://arxiv.org/abs/1806.02367
UR  - https://doi.org/10.1140/epjc/s10052-018-6325-8
DO  - 10.1140/epjc/s10052-018-6325-8
LA  - English
N1  - WOS:000448080300003
ID  - Romero-Lopez_etal2018
ER  -