Chiral dynamics with strange quarks: Mysteries and opportunities

Abstract

Recent developments and open issues in chiral dynamics with strange quarks are reviewed. Topics include: Order parameters of chiral symmetry breaking, the flavor dependence of these order parameters, speculations about the phase structure of QCD with varying number of flavors, OZI violation and its natural emergence in case of a small strange quark condensate, heavy kaon chiral perturbation theory, an update on pion-pion, pion-kaon and pion-nucleon sigma terms, the dynamics and nature of scalar mesons, the role of the scalar pion and kaon form factors, attempts to describe some strange baryons employing coupled channel dynamics tied to unitarity and chiral perturbation theory, and the role of final state interactions in Goldstone boson pair production in proton-proton collisions.