Douglas Higinbotham Named 2026 APS Fellow

Douglas W. Higinbotham, interim division director of CEBAF Experimental Physics at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, has been named a 2026 Fellow of the American Physical Society. The APS Division of Nuclear Physics recognized his studies of nucleon-nucleon short-range correlations in nuclei, work on the proton radius puzzle, and mentorship and leadership at Jefferson Lab. Higinbotham has served as spokesman for 17 CEBAF experiments and mentored more than 60 students, from high school through Ph.D. No more than one-half of 1% of APS membership, excluding student members, is recognized by peers for election as fellows each year.

Nuclear Correlation Research

Higinbotham first arrived at Jefferson Lab in 1993 as a summer intern, returned in December 1999 as a postdoc from the Massachusetts Institute of Technology, and joined the lab as a staff scientist in 2001. His early work used the BigBite magnet to study the behavior of protons and neutrons in atomic nuclei.

A 2004 Jefferson Lab experiment found that pairs were about 20 times more likely to be a proton with a neutron than two protons. A later re-analysis proposed the universal modification function as a model for the EMC Effect, with roughly 20 percent of the nucleons in a nucleus’s correlated pairs at any one time having an outsized effect on measurements.

Douglas W. Higinbotham, interim division director of CEBAF Experimental Physics at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, said:

“It is a complete paradigm shift. For years, people thought these pairs couldn’t be isolated. Once we did, it opened a whole new window into how protons and neutrons behave in the nucleus, and it seems to be pointing us to the solution of an old puzzle.”

Proton Radius Measurements

The proton radius puzzle emerged after a 2010 measurement using muonic hydrogen found a proton about 4% smaller. In 2016, Higinbotham and high school summer student Vincent Lin found that carefully analyzed electron-scattering data could be consistent with the smaller radius.

Jefferson Lab’s PRad experiment measured electrons that barely glance off protons and found the smaller radius. The results, published in scientific journals in 2016 and 2019, led to a revision of the Rydberg constant in 2019.

Douglas W. Higinbotham, interim division director of CEBAF Experimental Physics at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, said:

“Collectively, the proton radius work has changed the Rydberg constant, a number we thought we knew. It sets the scale of the energy levels in atoms and is known to better than two parts in a trillion, yet it had to be revised in 2019.”

Mentoring Physics Students

Higinbotham’s former students include Fatiha Benmokhtar, now a professor at Duquesne University, whose students have interned with him since 2019. All three are authors on papers from that work. Dien Nguyen, formerly a University of Virginia graduate student and later a Nathan Isgur Postdoctoral Fellow in Nuclear Experiment, is now an assistant professor at the University of Tennessee.

The CaFe results, with Nguyen as first author, were published this year in Nature. Higinbotham is a two-time U.S. Department of Energy Office of Science Outstanding Mentor and an APS Career Mentoring Fellow.

Douglas W. Higinbotham, interim division director of CEBAF Experimental Physics at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, said:

“At this point in my career, my goal is to enable the next generation. So, seeing them succeed, and the continuing amazing results from CEBAF, is my holy grail. I think I have it, and I’m using it.”

Research And Leadership

In 2024, Higinbotham joined the Oppenheimer Science and Energy Leadership Program, visiting all 17 national labs. From August 2025-August 2026, he chaired the Electron-Ion Collider User Group and served as director of Jefferson Lab’s EIC research group and physics division director of experiment operations. Since June, he has served as interim division director of CEBAF Experimental Physics.