We derive the pion mass and the elastic pion-pion scattering amplitude in the QCD -vacuum up to next-to-leading order in chiral perturbation theory. Using the modified inverse amplitude method, we study the -dependence of the mass and width of the light scalar meson and the vector meson .
DOI:https://doi.org/10.1103/PhysRevD.92.054023
© 2015 American Physical Society
Feynman diagrams for the scattering amplitude up to . Here the filled circles and square denote the vertices from the LO and NLO Lagrangian, respectively. The and channel two-point loops are not shown.
Reuse & PermissionsThe -dependence of the masses (left panel) and widths (right panel) of the (blue, full) and the (red, dashed).
Reuse & PermissionsOne-loop diagrams for producing a neutral pion from the vacuum. Here and the black dot denote CP violating and conserving vertices from the LO Lagrangian, respectively.
Reuse & Permissions
