Chiral Symmetry Breaking : Meson and Nucleon Masses

[摘要] From consideration of the role in current algebra of theequal-time commutator involving an axial vector charge anddivergence of the axial vector current, estimates of meson andnucleon scalar density matrix elements are given. The scalardensities, behaving as (3,3*) + (3*,3) under the SU(3) x SU(3)algebra of vector and axial vector charges, participate in theSU(3) x SU(3) non-invariant part of an (abstracted) energy density.The meson scalar density matrix elements are estimated in connectionwith a Kπ, KK scattering length determination and arelation for the relevant symmetry breaking parameter η whichmultiplies the octet algebraic scalar piece of the hadronic energydensity. An application is given in which a Kπ amplitude expansion,containing the information of a kaon scalar density term, is usedin determining the low energy limits of a K_L4 form factor. Theestimates for the nucleon scalar density terms are somewhat inconclusiveand emphasis is placed on discussion of various dispersiveapproaches involved.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics