KLOE first results on hadronic physics

The KLOE detector (1) at DAΦNE, the Frascati φ-factory, has started taking data in April 1999 and a total integrated luminosity of 2.4 pb has been collected by the end of ’99, corresponding to ∼8 millions φ decays. With these data a preliminary measurement of φ radiative decays φ → ηγ, φ → πγ, φ → ηγ, φ → ππγ, φ → ππγ, φ → ηπγ and of the hadronic decay φ → πππ has been performed. The energy spectrum of the radiated photon in case of the ππγ, ππγ, ηπγ final states allows us to extract the information on the contribution of the direct decays φ → f0γ, φ → a0γ. The measurement of BR( φ → f0γ), BR(φ → a0γ) can help in understanding the nature of f0(980) and a0(980) which is still under debate. The value of BR(φ → η γ) can be related to the gluonic content of the η(958) while the ratio R=BR(φ → ηγ)/BR(φ → ηγ) can help in establishing the value of the η − η mixing angle θp. Furthermore a high statistics analysis of the Dalitz plot in the φ → πππ decay allows us to extract a possible contribution of the direct decay with respect to the dominant ρπ mode and to obtain a new measurement of the parameters of the ρ line shape, including the ρ − ρ mass difference. Contributed paper N.503 to the XXX International Conference on High Energy Physics, Osaka 27 jul 2 aug 2000.