Melvin Schwartz, Nobel Prize winner in physics, dead at 73

Melvin Schwartz, a Nobel Prize winner and member of the Stanford physics faculty from 1966 to 1984 who also founded a Silicon Valley company, died Aug. 28 at a Twin Falls, Idaho, nursing home after struggling with Parkinson's disease and hepatitis C. He was 73.

In 1988, Schwartz shared the Nobel Prize with Leon Lederman and Jack Steinberger "for the neutrino beam method and the demonstration of the doublet structure of the leptons through the discovery of the muon neutrino."

"Mel Schwartz proposed and subsequently carried out (with Jack Steinberger, Leon Lederman and four younger colleagues) the first accelerator neutrino experiment, which demonstrated the existence of neutrino flavors," Professor Stanley Wojcicki, chair of Stanford's Physics Department, wrote in an e-mail interview. "This experiment was the forerunner of a rich experimental program all over the world utilizing accelerator neutrino beams, which discovered neutral currents and contributed significantly to the establishment of the Standard Model of particle physics. Mel deserves to be known as the father of accelerator neutrino physics."

Sidney Drell, a professor emeritus at the Stanford Linear Accelerator Center (SLAC), recounted how physicists discovered the fundamental patterns of subatomic particles that advanced the field. "We had studied the electron and we learned that for the weak forces, which are important in radioactivity, they were associated with a neutrino," he said. "When we discovered the muon in the 1940s, in every way it was just like an electron—only about 200 times heavier!" Scientists set out to understand what the muon did in weak interactions. The muon was also associated with a neutrino. But was it the same neutrino with which the electron was associated, or was it a different one?

"The neutrino was an extremely elusive particle, but [Schwartz] found a way to make a beam of them at Brookhaven [National Laboratory]," Drell said. "He, Lederman and Steinberger, the three managed to show that the muon's neutrino, though very similar in many ways to the electron's neutrino, was a different particle. Subsequently, these two families of so-called 'lepton doublets'—the electron and its neutrino, and the muon and its own neutrino—acquired a third cousin when SLAC physicist Martin Perl went on to discover the tau lepton at SLAC, for which he received the 1995 Nobel Prize in physics."

Born Nov. 2, 1932, in New York City, Schwartz attended the Bronx High School of Science and went on to earn bachelor's and doctoral degrees in physics from Columbia University in 1953 and 1958, respectively. After working in Brookhaven National Laboratory as a research scientist from 1956 to 1958, he joined the Columbia faculty as an assistant professor in 1958 and went on to become an associate professor in 1960 and a professor in 1963.

In 1966, as a new linear accelerator was being completed, Schwartz joined the Stanford faculty and undertook two major research efforts: investigating the charge asymmetry in the decay of the long-lived neutral kaon and producing and detecting relativistic hydrogen-like atoms made up of a pion and a muon.

Schwartz left Stanford in 1983 to work full-time for a Mountain View, Calif., company he had founded called Digital Pathways, dedicated to the secure management of data communications. He remained a consulting professor at Stanford until 1991, when he returned to Columbia as a physics professor and to Brookhaven National Laboratory as associate director for high energy and nuclear physics. He supervised experiments in which gold atoms were accelerated to near the speed of light and stripped of all electrons.

Schwartz became Columbia's I.I. Rabi Professor of Physics in 1994. In 1995, Columbia presented him with its highest honor, the Alexander Hamilton Medal.

In 1997 he moved to Ketchum, Idaho. Survivors include his wife, Marilyn Schwartz, of Ketchum; brother, Bernard Schwartz, of Walnut Creek, Calif.; son, David Schwartz, of New York City; daughters Diane Bodell of Bolingbrook, Ill., and Betty Marcon of San Francisco; and six grandchildren.

Memorial services are pending for New York and San Francisco. Contributions in Schwartz's memory may be made to the Parkinson's Disease Foundation, 1359 Broadway, Suite 1509, New York, NY 10018.