Lynne H. Orr and Kevin McFarland, professors of physics at the University of Rochester, have been elected fellows of the American Physical Society (APS), the world's largest and most prestigious association of physicists. Less than one-half of one percent of the society's 40,000 members become fellows each year.

Orr, a theoretical physicist, was elected "for her contributions to the phenomenology of the top quark and studies of gluon radiation in top quark production and decay."

"Lynne has a gift for illuminating some of the most difficult insights to such phenomena as the origin of mass," says Arie Bodek, chair of the Department of Physics and Astronomy. "This selection as a fellow is a fitting honor in recognition of her pioneering research."

Orr's research is concentrated on the fundamental particles of nature and how they interact with one another. She is especially interested in phenomenology, the study of how these interactions are evident in experiments, in case at extremely high energies, such as those achieved in a particle accelerator. Some of her current work is dedicated to understanding the origin of electroweak breaking—a phenomenon that may give scientists clues to the origin of mass. In particular, Orr works at the interface between theory and experiment, using experiments to test and explore theory in detail, and to answer the questions about which physicists have few clues.

Orr received her doctorate in physics in 1991 from the University of Chicago. After a postdoctoral position at the University of California at Davis, she joined the University as an assistant professor of physics in 1993. She has been the recipient of an SSC Postdoctral Fellowship, a University of California President's Postdoctoral Fellowship, a U.S. Department of Energy Outstanding Junior Investigator Award, and a National Science Foundation Faculty Early Career Development Award. She was promoted to associate professor in 1999 and to professor in 2004.

McFarland was elected a fellow for his "precision studies of the weak interactions of high energy neutrinos." His citation is for work completed shortly after he arrived at Rochester to join with Bodek's group on the NuTeV experiment at Fermi National Accelerator Laboratory.

"Kevin exemplifies the academic scientist," says Bodek. "He has not only been a leader in the quest to understand the neutrino, but he is an exceptional educator; conducting, among other things, a summer class to give local science teachers hands-on experience in particle physics."

McFarland is currently collaborating on another Fermilab experiment, CDF, where he studies proton-antiproton collisions to find evidence for unexpected interactions of the top quark that could provide clues about the origin of its surprisingly large mass. He is also leading a multi-institutional new project at Fermilab called the MINERvA Neutrino Experiment. The experiment, which involves the construction of an underground detector the size of a school bus, will help physicists understand the mysterious nature of the neutrino. MINERvA is one of a series of planned experiments that will contribute to the ultimate goal of determining the parameters of "neutrino mixing." Neutrinos spontaneously change their "flavors" as they travel, and these different flavors may behave differently than expected in matter and anti-matter forms. If such a difference is observed, MINERvA and companion experiments may be able to explain why today's universe is full of matter and not anti-matter, even though the two were equally present at the universe's birth.

McFarland did his graduate work in physics at the University of Chicago and received his masters degree in 1991 and his doctorate in 1994. He held a Lederman Fellowship at Fermilab from 1994 to 1998, and joined the University as an assistant professor of physics in 1998. He was promoted to associate professor in 2002 and professor in 2005. McFarland was named an Alfred P. Sloan Research Fellow in 1998, a Department of Energy Outstanding Junior Investigator in 1999, a Cottrell Scholar in 2001 and received a National Science Foundation CAREER award in 2002.

The APS Fellowship Program was created to recognize members who have made advances in knowledge through original research and publication, or made significant and innovative contributions in the application of physics to science and technology, and significant contributions to the teaching of physics or service and participation in the activities of the society.