Theoretical physicist Evgeny Epelbaum joined Jefferson Lab late in 2003 as the inaugural Nathan Isgur Distinguished Postdoctoral Fellow.

The Department of Energy's Jefferson Lab and the Southeastern Universities Research Association (SURA) established the Nathan Isgur Distinguished Postdoctoral Fellowship as a memorial to the late Nathan Isgur, who served as head of Jefferson Lab's Theory Group and as Chief Scientist until his death in July 2001. The fellowship is intended to further the career of a young person displaying extraordinary scientific ability, allowing the recipient to pursue independent research in theoretical or experimental physics at Jefferson Lab for a period of three years with a possible two-year extension.

Applications were invited in March 2002, and review of applications began that September. John Domingo, Associate Director Emeritus of Jefferson Lab's Physics Division, says there were dozens of applications from all over the world. The JLab selection committee narrowed the field to 16 candidates. After informal interviews with the applicants, the committee short-listed two experimentalists and two theoreticians. Each of these four candidates gave public lectures at the Lab in November and December 2002. Videotapes of the presentations and copies of transparencies were sent to the external committee. The external and internal committee members then held a teleconference to make their selection. "The decision was unanimous," says Domingo.

He was born in St. Petersburg, Russia — at that time, Leningrad — and grew up in Gatchina, a small town near St. Petersburg. Gatchina is familiar to many physicists through the Petersburg Nuclear Physics Institute (PNPI) situated there. When he was 19 his family immigrated to Germany, where he lived for about 10 years before coming to the United States.

"I became interested in science relatively early, during my first school years. I think my interest in science was mainly due to my parents, especially my father. He spent a lot of time with my older brother and me, reading books and telling us about physics, mathematics, literature and history. He often encouraged us to think about interesting problems and puzzles in mathematics and physics," Epelbaum notes. "I really enjoyed the time we spent together."

At school, his favorite discipline was chemistry, rather than physics and mathematics. "A friend and I liked to make small chemical experiments and had even a lot of different chemicals at home," Epelbaum reminisces.

"My interest in natural sciences was further influenced by participation in various school and student Olympiads. In Russia, students start competing in Olympiads early, but it really begins to get serious in the last three years of school," he adds.

Epelbaum began studying physics at St. Petersburg State Polytechnic University. After his family moved to Germany, he continued to study at Ruhr-Universität Bochum (RUB) and obtained his Master's of Science in 1997, earning his diploma under the supervision of Walter Glöckle, leader of the theoretical nuclear physics research group at the RUB.

For postgraduate study he moved to Forschungszentrum Jülich (FZ Jülich or Research Center Juelich), and worked under the supervision of Ulf-G. Meißner, director of the Institute for Nuclear Physics Theory (IKP) at FZ Jülich, and Walter Glöckle. "It was - and still is - a great pleasure to collaborate with these excellent physicists," Epelbaum notes.

He received his Ph.D. from RUB in 2000. In his thesis, "The Nucleon-Nucleon Interaction from a Chiral Effective Field Theory," he concentrated on the description of nuclear forces within the framework of chiral effective field theory, among other subjects, and performed applications to the two-nucleon system. After completing his Ph.D. he moved back to RUB and again joined Glöckle's group, where he worked with collaborators from Germany, Poland and Japan on extensions of his previous research of systems with three and four nucleons. He also considered higher-order corrections to the nuclear force and its quark mass dependence. The latter might be important for upcoming quantum chromodynamics (QCD) lattice gauge theory calculations.

During 2002, he spent three months at the Institut de Physique Nucléaire, Université de Paris-Sud in Orsay, France, by invitation from Jan Stern. There he delivered lectures on various topics related to his research.

"I am very happy about my selection for the position of Nathan Isgur Distinguished Postdoctoral Fellow. It is a big honor for me to receive this Fellowship associated with Nathan Isgur's name," Epelbaum comments. "Unfortunately, I did not have the pleasure of knowing Nathan Isgur personally. However, as a Ph.D. student I attended the Baryons '98 Conference in Bonn, Germany, where he delivered an introductory and overview lecture."

Epelbaum arrived at Jefferson Lab, located in Newport News, Va., on October 1, 2003, and plans to stay for three years.

"During the interview process [for the Fellowship] in November 2002, I gave a presentation designed to reach a broad audience including experimental physicists and researchers from different fields of physics," Epelbaum says, reflecting back on the Fellowship selection process. "Basically, I wanted to give an introduction to the subject of my research — application of effective field theory to various problems in nuclear physics — and try to convey to the audience that this is an interesting and important topic. In my talk I included various subjects I worked on during and after finishing my Ph.D. thesis. I still work on some of these projects, such as application of the chiral nuclear forces to three-nucleon scattering. I was pleased to answer several questions from the audience after my talk. I considered it a good indication that at least some people enjoyed my lecture and learned something new."

That was Epelbaum's first visit to Jefferson Lab. "I was — and continue to be — very impressed by the Lab," he says. "Its importance for the whole nuclear physics community cannot be underestimated. I enjoy the high level of scientific activity provided by the Lab. One has the unique opportunity to talk to many highly qualified staff and guest scientists, and to attend seminars and workshops."

Epelbaum has several ideas and topics he intends to work on during his stay at Jefferson Lab. Among other projects, he will address the nature of the three-nucleon force from the point of view of chiral perturbation theory. He would also like to concentrate on electron scattering on light nuclei, which might be of interest for experimental research performed at Jefferson Lab.

In addition, he considers his stay at Jefferson Lab as an excellent opportunity to learn new things and to begin new collaborations.