Melvin Schwartz, who shared the 1988 Nobel Prize in physics for creating the first high-energy neutrino beam, has died at his Twins Falls, Idaho, home at 73.

Schwartz died Monday after battling Parkinson's disease for several years.

His experiments, performed with co-Nobelists Leon Lederman and Jack Steinberger, made it possible for the first time to study the so-called weak force, one of the four fundamental forces that control the universe, The New York Times reported.

The research also proved the existence of two distinct types of neutrinos and "opened entirely new opportunities for research into the innermost structure and dynamics of matter," the Nobel citation said.

"We started a sort of cottage industry in identifying basic particles, the quarks and so on," Lederman said when the Nobel was announced. "Now there are hot- and cold-running neutrinos all over the place."

Schwartz taught at Columbia and Stanford universities and served as associate director for high energy and nuclear physics at Brookhaven National Laboratory.

He retired in 2000.

Survivors include his wife of 52 years and three children.

Copyright 2006 by United Press International