Searching for low-lying multi-particle thresholds in lattice spectroscopy

Understand

We explore the Euclidean-time tails of odd-parity nucleon correlation functions in a search for the S-wave pion-nucleon scattering-state threshold contribution.

• The analysis is performed using 2+1 flavor 32^3 x 64 PACS-CS gauge configurations available via the ILDG.
• Correlation matrices composed with various levels of fermion source/sink smearing are used to project low-lying states.
• The consideration of 25,600 fermion propagators reveals the presence of more than one state in what would normally be regarded as an eigenstate-projected correlation function.