$θ$-dependence of the lightest meson resonances in QCD
arXiv:1507.08570 · doi:10.1103/PhysRevD.92.054023
Abstract
We derive the pion mass and the elastic pion-pion scattering amplitude in the QCD theta-vacuum up to next-to-leading order in chiral perturbation theory. Using the modified inverse amplitude method, we study the theta-dependence of the mass and width of the light scalar meson sigma(500) and the vector meson rho(770).
11 pages, 3 figures