https://doi.org/10.1140/epja/i2012-12058-9
Regular Article - Theoretical Physics
Exact calculation of three-body contact interaction to second order
Physik Department T39, Technische Universität München, D-85747, Garching, Germany
* e-mail: nkaiser@ph.tum.de
Received:
31
January
2012
Accepted:
28
March
2012
Published online:
2
May
2012
For a system of fermions with a three-body contact interaction the second-order contributions to the energy per particle 
are calculated exactly. The three-particle scattering amplitude in the medium is derived in closed analytical form from the corresponding two-loop rescattering diagram. We compare the (genuine) second-order three-body contribution to 
with the second-order term due to the density-dependent effective two-body interaction, and find that the latter term dominates. The results of the present study are of interest for nuclear many-body calculations where chiral three-nucleon forces are treated beyond leading order via a density-dependent effective two-body interaction.
© SIF, Springer-Verlag Berlin Heidelberg, 2012
