 In 1987 he accepted a professorship at Columbia University, where he has remained as a professor ever since.He has been a scientific leader in the field of heavy ion physics since early in his career, and he has performed extensive service for the broader nuclear physics community in the U.S. William A. Zajc was named a Fellow of the American Physical Society in 1997 and a Fellow of the AAAS in 2012.Since the 1980s, his research has focused on experiments performed at Brookhaven National Laboratory (BNL) on Long Island, New York, first at the Alternating Gradient Synchrotron (AGS) and now at the Relativistic Heavy Ion Collider (RHIC).