First results on 12L C production at DAFNE

Λ-hypernuclei are produced and studied, with the FINUDA spectrometer, for the first time at an e+e− collider: DAFNE, the Frascati φ-factory. The slow negative kaons from φ(1020) decay are stopped in thin (0.2 g/cm2) nuclear targets, and Λ-hypernuclei formation is detected by measuring the momentum of the outgoing π−. A preliminary analysis on 12ΛC shows an energy resolution of 1.29 MeV FWHM on the hypernuclear levels, the best obtained so far with magnetic spectrometers at hadron facilities. Capture rates for the ground state and the excited ones are reported, and compared with previous experiments.