James W. Cronin, the only Nobel Prize winner on any Utah campus, will not return to the University of Utah for the next academic year, although he plans to be back the following year.

"I will not be there next year because I have a leave of absence," he told the Deseret News on Tuesday. The newspaper contacted him by telephone at the University of Chicago, where he also teaches.The leave will allow him to teach for a year at a Paris university, where he will hold an international chair. "It's a very wonderful position," he said. "I'll be giving a series of lectures."

Topics will include the history of cosmic ray research as well as the great experiments of the early days of the study of particle physics, he added.

Cronin's appointment to the U.'s physics department was announced in July 1998. During the present academic year he has shuttled between Salt Lake City and Chicago to fulfill his teaching duties.

His appointment to the U. was for five years, on a half-time basis. He has concentrated on cosmic ray research.

Cronin shared the 1980 Nobel Prize with Val L. Fitch for the discovery of a strange aspect of nature. This aspect is the violation of fundamental principles in the decay of subatomic particles.

Brookhaven National Laboratory, where both Cronin and Fitch worked when they carried out their experiments in 1963, described the results as the opposite of what they had expected to find. "Cronin and Fitch had discovered a flaw in physics' central belief that the universe is symmetrical."

In recent years, Cronin turned his attention to cosmic rays, particles that bombard the Earth's atmosphere from outer space. Some rays are high-energy particles, packing a surprising impact as they collide with the molecules of the atmosphere. One cosmic ray detected in Utah was so powerful that scientists were at a loss to understand what could have caused it.

Utah has been a leader in international cosmic ray research, with large observatories dotting Dugway Proving Ground in the western desert. When Cronin's appointment was announced, Prof. Zeev Valentine Vardeny -- at the time, the head of the physics department -- said Cronin agreed to come to Utah because he wanted to be close to the action in astrophysics and high-energy cosmic particle research.