Prompt neutrinos: present issues and future prospects

Prompt neutrinos were first discovered at CERN in 1977. The 1977 arrangement layout is shown. Present issues are currently interpreted in terms of the production and subsequent semileptonic decays of charmed particles. Some problems--discrepancy between cross section data at CERN beam dump, and at the 300 GeV emulsion experiments; the consistency with unity of prompt flux measurements; agreement of energy spectrum of prompt electronneutrino events with DD central model; and the value of prompt flux rates, which are too low--are all treated. Experiments set up at the Fermilab determined cross sections and event rates for prompt neutrinos. Future experiments, after the construction of the prompt neutrino beam at Fermilab, are awaited