(1921–    ), German-born American physicist and Nobel laureate who contributed to the discovery of a new type of neutrino.

Born in Bad Kissingen, Germany, Steinberger came to the U.S. at the age of 13 (with 300 other children from Germany for whom the American Jewish charities found a home in the U.S.); he went to high school in Chicago and was educated at the University of Chicago. During his service (1942–45) with the U.S. Army in World War II, he worked at the radiation laboratory of the Massachusetts Institute of Technology, in Cambridge, Mass., then did graduate study at the University of Chicago, receiving his Ph.D. in 1948. Encouraged by the Italian-American physicist Enrico Fermi to specialize in particle physics (see Elementary Particles; Physics), he first worked on a cosmic ray experiment, particularly on stopping cosmic ray muons and then, at the University of California at Berkeley, on experiments involving photoproduction of pions. In 1950 he moved to Columbia University, working also at its NEVIS Laboratory, in Irvington-on-the-Hudson, N.Y. In 1968 he became director of experimental research at the European Organization for Nuclear Research, known as CERN, in Geneva, Switzerland, retiring in 1986.

In the early 60s, Steinberger joined his Columbia colleagues, American physicists Leon Lederman and Melvin Schwartz, in experiments with a neutrino beam that revealed that a new type of neutrino existed. The experiment was carried out with the alternating gradient synchrotron at the Brookhaven National Laboratory, in Upton, Long Island, N.Y. The muon type of neutrino that was detected formed a pair with the muon (the muon, like the electron- and the tau-type of neutrino, is an elementary particle classified as a lepton). At the time of the experiment only the electron- neutrino type was known; a third type, the tau neutrino, was discovered in the 1970s. Their discovery revealed the “family” structure of these particles and led to a new method of classifying families of subatomic particles.

Steinberger shared the 1988 Nobel Prize in physics with Lederman and Schwartz “for the neutrino beam method and the demonstration of the doublet structure of the leptons through the discovery of the muon neutrino.”

See also Atom and Atomic Theory; Particle Accelerators; Particle Detectors.