Ann Elizabeth Nelson (April 29, 1958 – August 4, 2019) was a particle physicist and professor of physics in the Particle Theory Group at the University of Washington from 1994 until her death. Nelson received a

Guggenheim Fellowship Guggenheim Fellowships are grants that have been awarded annually since by the John Simon Guggenheim Memorial Foundation to those "who have demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the ar ...

in 2004, and she was elected to the American Academy of Arts and Sciences in 2011 and the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

in 2012. She was a recipient of the 2018

J. J. Sakurai Prize for Theoretical Particle Physics The J. J. Sakurai Prize for Theoretical Particle Physics, is presented by the American Physical Society at its annual April Meeting, and honors outstanding achievement in particle physics#Theory, particle physics theory. The prize consists of a m ...

, presented annually by the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of k ...

and considered one of the most prestigious prizes in physics.

Education

Born in Baton Rouge, Louisiana, Nelson earned her Bachelor of Science degree at

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

in 1980, and her Ph.D. degree at Harvard University under the supervision of Howard Georgi in 1984.

Career

After a post doctoral fellowship at the Harvard Society of Fellows from 1984-1987, Nelson became an assistant professor at Stanford University in 1987. In 1990 Nelson moved to UC San Diego, and then in 1994 moved for the final time her career to the University of Washington.

Research

Nelson and her collaborators are known for a number of theories, including: * The Nelson–Barr mechanism, a proposed solution to the

strong CP problem The strong CP problem is a puzzling question in particle physics: Why does quantum chromodynamics (QCD) seem to preserve CP-symmetry? In particle physics, CP stands for the combination of charge conjugation symmetry (C) and parity symmetry (P) ...

. The theory was developed independently by Nelson and Stephen Barr in 1984. Nelson was a doctoral student at Harvard at the time. *The theory of spontaneous violation of CP (charge conjugation and parity symmetry), which may explain the origin of the asymmetry observed between matter and anti-matter. * The theory of Bose–Einstein condensation of kaon mesons in dense matter, which predicts strangeness in neutron stars. * The basic mechanism for electroweak baryogenesis, which may explain the origin of matter in the universe. * The theory of gauge-mediated

supersymmetry breaking In particle physics, supersymmetry breaking is the process to obtain a seemingly non-supersymmetric physics from a supersymmetric theory which is a necessary step to reconcile supersymmetry with actual experiments. It is an example of spontaneous s ...

, which accounts for how supersymmetry at short distances might be compatible with the absence of observed flavor-symmetry violation at long distances. * The

little Higgs In particle physics, little Higgs models are based on the idea that the Higgs boson is a pseudo-Goldstone boson arising from some global symmetry breaking at a TeV energy scale. The goal of little Higgs models is to use the spontaneous breaking of ...

theory, which may explain why the Higgs boson must be relatively light. * The theory of "accelerons", which relates neutrino masses to the cosmological dark energy responsible for the relatively recent acceleration of the expansion of the universe.

Personal life

Nelson was married to

David B. Kaplan David B. Kaplan (born 1958) is an American physicist. He is a professor of physics at the University of Washington, where he was director of the Institute for Nuclear Theory during the period 2006-2016 and is now a senior fellow. Research Kapl ...

, also a professor of physics at the University of Washington. She had been an active member of The Mountaineers club in Seattle since 1994. She had two children. Nelson was an activist for equal rights throughout her life. In 1980, when graduating from Stanford University, she and her husband wore colored ribbons to protest Stanford's investments in Apartheid South Africa. In 2017, she led physics lectures in

Palestine __NOTOC__ Palestine may refer to: * State of Palestine, a state in Western Asia * Palestine (region), a geographic region in Western Asia * Palestinian territories, territories occupied by Israel since 1967, namely the West Bank (including East ...

to support social justice and promote diversity in science fields around the world. She advocated for greater representation of women in physics research.

Death

On August 4, 2019, while hiking Iron Cap Mountain in the Alpine Lakes Wilderness with her husband and two friends, Nelson lost her footing and died after falling into a rocky gully. Her husband and fellow hikers were rescued on August 4 by a Spokane helicopter crew. Her body was recovered on August 6.

References

* {{DEFAULTSORT:Nelson, Ann Elizabeth 1958 births 2019 deaths 20th-century American physicists 20th-century American women scientists 21st-century American physicists 21st-century American women scientists Accidental deaths from falls Accidental deaths in Washington (state) American women physicists Fellows of the American Academy of Arts and Sciences Harvard University alumni Members of the United States National Academy of Sciences Particle physicists People from Baton Rouge, Louisiana Scientists from Louisiana J. J. Sakurai Prize for Theoretical Particle Physics recipients