Lattice QCD and baryon-baryon interactions: HAL QCD method

Understand

In this article, we review the HAL QCD method to investigate baryon-baryon interactions such as nuclear forces in lattice QCD.

• We first explain our strategy in detail to investigate baryon-baryon interactions by defining potentials in field theories such as QCD.
• We introduce the Nambu-Bethe-Salpeter (NBS) wave functions in QCD for two baryons below the inelastic threshold.
• We then define the potential from NBS wave functions in terms of the derivative expansion, which is shown to reproduce the scattering phase shifts correctly below the inelastic threshold.