Kaon Thresholds and Two-Flavor Chiral Expansions for Hyperons

Understand

Two-flavor chiral expansions provide a useful perturbative framework to study hadron properties.

• Such expansions should exhibit marked improvement over the conventional three-flavor chiral expansion.
• Although one can theoretically formulate two-flavor theories for the various hyperon multiplets, the nearness of kaon thresholds can seriously undermine the effectiveness of the perturbative expansion in practice.
• We investigate the importance of virtual kaon thresholds on hyperon properties, specifically their masses and isovector axial charges.