1106.2276 (Takumi Doi et al.)

Exploring Three-Nucleon Forces in Lattice QCD    [PDF]

Takumi Doi, Sinya Aoki, Tetsuo Hatsuda, Yoichi Ikeda, Takashi Inoue, Noriyoshi Ishii, Keiko Murano, Hidekatsu Nemura, Kenji Sasaki, for HAL QCD Collaboration

Three-nucleon forces (3NF) are investigated from two-flavor lattice QCD
simulations. We utilize the Nambu-Bethe-Salpeter (NBS) wave function to
determine two-nucleon forces (2NF) and 3NF in the same framework. As a first
exploratory study, we extract 3NF in which three nucleons are aligned linearly
with an equal spacing. This is the simplest geometrical configuration which
reduces the huge computational cost of calculating the NBS wave function.
Quantum numbers of the three-nucleon system are chosen to be (I,
J^P)=(1/2,1/2^+) (the triton channel). Lattice QCD simulations are performed
using N_f=2 dynamical clover fermion configurations at the lattice spacing of a
= 0.156 fm on a 16^3 x 32 lattice with a large quark mass corresponding to
m_\pi= 1.13 GeV. We find repulsive 3NF at short distance in the triton channel.
Several sources of systematic errors are also discussed.

View original: http://arxiv.org/abs/1106.2276