Leon Lederman was born in New-York in 1922. He studied chemistry at first, later physics, receiving his doctor degree at Columbia university in 1951. He became a brilliant researcher, responsible for many important discoveries in his field.

Leon Lederman received the 1988 Nobel prize in physics, together with Jack Steinberger and Melvin Schwartz, “For the neutrino beam method and the demonstration of the doublet structure of the leptons through the discovery of the muon neutrino.”

The standard model of particle physics divides the elementary particles into two families: quarks and leptons. Until the end of the 1950’s only three leptons were known: electron, muon and neutrino. The neutrinos can be produced from either electrons or muons, and can turn back to be either of them.

In 1960, scientists assumed the existence of two kinds of neutrinos: one that one that is associated with electrons and the other, which is associated with muons. However, they had much difficulty in establishing an empirical evidence to support their assumption.

In 1961 Lederman and his colleagues executed the neutrino experiment that was appreciated by the Nobel committee. They used a muon originated neutrino beam, produced by high energy collisions in the Brookhaven accelerator. All the neutrinos reverted to being muons, not a single on turned into an electron; this proved that the neutrino observed in this experiment is a different kind of particle – a muon-neutrino.

The differentiation between electron-neutrino and muon-neutrino is of much theoretical importance. The electron and the electron neutrino are considered a “doublet”, two leptons that belong to the same generation. The muon and the moun-neutrino form another “doublet”, belonging to a different generation altogether.