Jack Steinberger obituary

Nobel prizewinning scientist whose work played a significant role in the development of modern particle physics theory

Jack Steinberger, who has died aged 99, was one of the three winners of the Nobel prize for physics in 1988 for their work with neutrinos and the discovery of the muon-neutrino. This research did much to advance understanding of fundamental particles.

The reality of the ghostly neutrino was not confirmed experimentally until 1956, but back in 1948, working at the University of Chicago, Steinberger had first given indirect hints of its presence in his measurement of decays of the muon - a heavy sibling of the electron. He showed that when a muon converts into an electron, two very light, possibly massless, electrically neutral particles are also produced. These, it was later shown, are neutrinos.