f_{0}(1370) Controversy from Dispersive Meson-Meson Scattering Data Analyses

We establish the existence of the long-debated f_{0}(1370) resonance in the dispersive analyses of meson-meson scattering data. For this, we present a novel approach using forward dispersion relations, valid for generic inelastic resonances. We find its pole at (1245±40)-i(300_{-70}^{+30})  MeV in ππ scattering. We also provide the couplings as well as further checks extrapolating partial-wave dispersion relations or with other continuation methods. A pole at (1380_{-60}^{+70})-i(220_{-70}^{+80})  MeV also appears in the ππ→KK[over ¯] data analysis with partial-wave dispersion relations. Despite settling its existence, our model-independent dispersive and analytic methods still show a lingering tension between pole parameters from the ππ and KK[over ¯] channels that should be attributed to data.