Gauged linear sigma model and pion-pion scattering

Understand

A simple gauged linear sigma model with several parameters to take the symmetry breaking and the mass differences between the vector meson and the axial vector meson into account is considered here as a possibly useful template for the role of a light scalar in QCD as well as for (at a different scale) an effective Higgs sector for some recently proposed walking technicolor models.

• An analytic procedure is first developed for relating the Lagrangian parameters to four well established (in the QCD application) experimental inputs.
• One simple equation distinguishes three different cases:1.
• QCD with axial vector particle heavier than vector particle, 2.