title: Isolating the Λ(1405) in lattice QCD.
abstract: The odd-parity ground state of the Λ baryon lies surprisingly low in mass. At 1405 MeV, it lies lower than the odd-parity ground-state nucleon, even though it has a valence strange quark. Using the PACS-CS (2+1)-flavor full-QCD ensembles, we employ a variational analysis using source and sink smearing to isolate this elusive state. For the first time we reproduce the correct level ordering with respect to nearby scattering thresholds. With a partially quenched strange quark to produce the appropriate kaon mass, we find a low-lying, odd-parity mass trend consistent with the experimental value.
authors.affiliation: Special Research Centre for the Subatomic Structure of Matter, School of Chemistry & Physics, University of Adelaide, South Australia 5005, Australia.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Menadue
authors.forename: Waseem
authors.initials: W
authors.lastname: Kamleh
authors.forename: Derek B
authors.initials: DB
authors.lastname: Leinweber
authors.forename: M Selim
authors.initials: MS
authors.lastname: Mahbub