f0(1370)

Abstract

A summary is given of the main sets of data requiring the existence of f0(1370). Crystal Barrel data on pbar-p -> eta eta pizero contain a visible f0(1370) peak and require at least a 19 standard deviation contribution. This alone is sufficient to demonstrate its existence. More extensive data on pbar-p -> 3pizero at rest contain delicate interferences which determine the mass and width independently in 1S_0 and 3P_1 annihilation and agree within 5 MeV for both mass and width. The peak in 2pi is at 1282 +- 5 MeV, but the rapid increase in 4pi phase space with mass displaces the 4pi peak to 1360 MeV. BES II data for J/Psi -> phi-pi-\pi contain a visible f0(1370) -> 2pi signal >8 sigma. In all cases, a resonant phase variation is required.