Neutron-Antineutron Production at ADONE

In 1990, after several years dedicated to single beam operation for synchrotron radiation and nuclear physics, two beam operation with electrons and positrons was resumed to perform the last subnuclear physics experiment, FENICE, whose data taking lasted until the final shutdown of ADONE in 1993. The FENICE experiment’s goal is to overcome a gap in our knowledge about the internal structure of the neutron, by measuring its electromagnetic form factor through the reaction electron + positron -> neutron + antineutron.

The results of such a measurement, never done before, together with the existing data on the reaction electron + positron -> proton + antiproton yield one of the essential experimental backgrounds for the most modern theories based on the quark structure of the proton and the neutron.