50 years ago, on 11 November 1974, the independent discovery was announced of an extremely narrow resonance at 3.1 GeV, respectively at the Brookhaven National Laboratory and at the Stanford Linear Accelerator Centre. The resonance was dubbed J in Brookhaven and ψ at SLAC, and it is since known as J/ψ. Soon after the news, the three experiments at the ADONE electron-positron collider of the Frascati Laboratory, pushing the machine beyond its nominal energy limit of 3.0 GeV, in the night between 13 and 14 November were able to observe the J/ψ. In the historical Physical Review Letters issued on 2 December 1974 the ADONE report appeared together with those announcing the momentous finding.

In the morning of this one-day Meeting, the J/ψ discovery, together with the ADONE contribution and its deep impact on Particle Physics, will be recalled by protagonists. The afternoon will include an outlook to the future of Particle Physics and Accelerator Technology.

The meeting will be accompanied by an exhibition of a large number of newspapers, magazines and TV footage that reported the news of the discovery at the time.