Bruce Richard Barrett (1939 - 2025)
It is with great sadness to announce that Prof. Bruce Barrett left us this past Saturday, March 15, 2025 after a long struggle with Parkinson’s Disease. He is Physics Emeritus Professor, and former Affiliate Professor of Physics at the University of Washington, Seattle. To me, he is not only a great physicist, but also a mentor that I look up to, a respectful colleague, a kind soul, and most importantly, a dear friend.
Bruce became fascinated with physics during his sophomore year at the University of Kansas, and theoretical nuclear physics eventually became his lifelong passion. He got his PhD at Stanford in 1967. In 1970, he began his 47-year tenure at the UA, where he shared his excitement about physics with countless students inside and outside the classroom. In his research on nuclear structure, Bruce sought to understand the interactions among protons and neutrons inside the atomic nucleus and how they shape the properties of the elements that make us. He is most known for No-Core Shell Model, which has been successful in describing the properties of light nuclei, which is now being extended to heavier mass nuclei.
Bruce’s many awards include two Alexander von Humboldt Fellowships for research in Germany; an Honorary Fulbright (Heidelberg, Germany); a Japan Society for the Promotion of Science Fellowship; and a F.O.M. Fellowship for The Netherlands. Bruce was elected a Fellow of the American Physical Society (APS) for his contributions to the theory of the microscopic structure of nuclei, principally regarding effective nuclear interactions, exact G matrix calculations, and the microscopic structure of the Interacting Boson Model. He also played several important roles in APS.
Bruce was an active member of Phi Beta Kappa, the scholastic honor society. He served as president of the UA's Alpha of Arizona chapter and on the national level as one of the senators, who guide the society. He spearheaded the formation of the Phi Beta Kappa Association of Greater Tucson, which to date has awarded more than $300,000 in scholarships to deserving undergraduate UA students.
Bruce was also a world traveler. With his wife, Joan Barrett, they visited all seven continents and 140 countries together, from Albania to Zimbabwe.
The Physics Department joins everyone that knows Bruce in mourning the passing of a respected figure of our community.
For those who want to donate in Bruce’s memory, please give to the charity of your choice or to The Michael J. Fox Foundation for Parkinson’s Research at give.michaeljfox.org.
From Prof. Bira van Kolck
Physics lost a gentle giant this weekend, and I lost a noble friend.
Bruce's demeanor concealed his passion for physics and his stature in the field. His research was a stream of deep ideas, which culminated in a revolution in nuclear theory. Bruce started with a bang: as a PhD student he predicted the soon-to-be-confirmed ordering of the low-lying resonances of the lightest closed-shell nucleus, the alpha particle. He employed a mean-field model and for most of his career was concerned about the residual, effective interactions among protons and neutrons. An important advance, while he was a postdoc, was the demonstration that the existing effective interactions could not be treated in perturbation theory, rendering them essentially useless. For many years the field struggled to go beyond the simple phenomenology of the nuclear Shell Model, until Bruce pointed the way: just remove the core. The No-Core Shell Model was neither the first nor the last ab initio method employed in nuclear physics. But it is the one that led to a revolution because it had the flexibility to include the nonlocality that arises in the low-energy effective field theory of QCD, which was then being developed. In the new millennium, ab initio methods based on EFTs came to dominate the landscape of nuclear theory and today reach the nucleus of lead. It was Bruce's vision.
Fortunately, what Bruce's demeanor did not hide was kindness and fairness. Like any successful theorist, he had opinions, but he was open about them without ever being insulting. He listened to others' thoughts and feelings regardless of rank, and his steady friendship supported many a younger theorist, including myself as I came to the department. Despite the long fight with the awful, debilitating Parkinson's disease, to the last few days he would still smile.
From Prof. Sumit Mazumdar
Bruce Barrett was a nuclear physicist, very far removed from my own field of condensed matter physics. I still came to know him, - and the other department members of his generation, - reasonably well, mostly because our professional lives were significantly less hectic in the pre-internet days. Many physics and math faculty met over lunch every day at what used to be the second student center and cafeteria on Park Avenue. Bruce was a regular participant. He came across as a serious old-style physicist, who at the same time was a world traveler and a great conversationalist. He had traveled widely as the recipient of multiple international fellowships and was an avid photographer and curious about the world. After each of his trips, be it in Europe or South Africa, he would have a slide show of the photos of the places he had visited in the physics department during lunch hour. These were very popular with the graduate students (and some of us junior faculty too), - it is hard to visualize now those years when one knew little about countries outside North America or Western Europe. Bruce's international scientific connections also brought in several interesting post-doctoral fellows in the department, some of whom would establish themselves as prominent scientists in later years.
At his retirement the department had a half-day workshop in his honor, mostly centered around his important contribution to nuclear physics, that was attended by multiple internationally known scholars from outside the UA. Bruce remained passionate about his research even post-retirement.
He will be missed.