Analysis of the pion-pion scattering data and rho-like mesons

摘要

Considering analyticity, unitarity and an influence of coupled channels, experimental data on the isovector P-wave of pi pi scattering was analyzed to study rho-like mesons below 1900 MeV. The analysis indicates that in the energy range 1200-1900 MeV, there are possibly four p-like mesons: rho(1250), rho(1450), rho(1600), and rho(1900). The obtained P-wave pi pi-scattering length (a(1)(1) = 33.9 +/- 2.02 vertical bar 10(-3)m(pi+)(-3) vertical bar) matches most to that calculated in the local Nambu-Jona-Lasinio model.