Lederman-Schwartz-Steinberger two-neutrino beam experiment
ID: lederman-schwartz-steinberger-two-neutrino-beam-experiment
In 1962, Leon Max Lederman, Melvin Schwartz, Jack Steinberger and collaborators distinguished muon neutrinos from electron neutrinos using a neutrino beam.[ref]
1988 Nobel Prize by Brookhaven National Laboratory. Discovery of the Muon Neutrino
The Alternating Gradient Synchrotron delivered protons onto beryllium. Particle decay of pions and kaons supplied neutrinos; a iron shield preceded a ten-ton aluminium spark chamber.[ref]
Production and detection are separate. In modern neutrino flavour notation,Shielding suppresses the daughter muon; a newly produced muon inside the spark chamber's aluminium marks an interaction.[ref]
1988 Nobel Prize by Brookhaven National Laboratory. Decay and aluminium readout
Beam-timed coincidence circuits and veto counters rejected entering tracks. Machine-off runs measured cosmic ray contamination; shield-thickness changes tested neutrons. Placing lead near the target shortened the meson decay path and reduced events. Cosmotron Electron calibration established particle shower recognition.[ref]
Observation of High-Energy Neutrino Reactions and the Existence of Two Kinds of Neutrinos by G. Danby and others. pp. 38–42, Table II, Figs. 8–9
The paper compared single-muon candidates, including estimated cosmic ray events, with six shower candidates unlike calibrated Electron showers. Kaon decays could supply genuine electron neutrinos. The deficit favored distinct neutrino flavours under lepton universality.[ref]
The inference concerns production and detection channels. It does not measure neutrino mass or establish permanently fixed neutrino flavour. Later neutrino oscillation experiments address changes during propagation.[ref]
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