Ann Elizabeth Nelson (April 29, 1958 – August 4, 2019) was a

particle physicist Particle physics or high energy physics is the study of Elementary particle, fundamental particles and fundamental interaction, forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standa ...

and professor of physics in the Particle Theory Group at the

University of Washington The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattle a ...

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 The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and ...

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, 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 Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

under the supervision of

Howard Georgi Howard Mason Georgi III (born January 6, 1947) is an American theoretical physicist and the Mallinckrodt Professor of Physics and Harvard College Professor at Harvard University. He is also Director of Undergraduate Studies in Physics. He was Co-M ...

in 1984.

Career

After a post doctoral fellowship at the

Harvard Society of Fellows The Society of Fellows is a group of scholars selected at the beginnings of their careers by Harvard University for their potential to advance academic wisdom, upon whom are bestowed distinctive opportunities to foster their individual and intell ...

from 1984-1987, Nelson became an assistant professor at Stanford University in 1987. In 1990 Nelson moved to

UC San Diego The University of California, San Diego (UC San Diego or colloquially, UCSD) is a public university, public Land-grant university, land-grant research university in San Diego, California. Established in 1960 near the pre-existing Scripps Insti ...

, and then in 1994 moved for the final time her career to the

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 __NOTOC__ Stephen Matthew Barr (born November 28, 1953) is an American physicist who is a professor emeritus of physics at the University of Delaware. A member of its Bartol Research Institute, Barr does research in theoretical particle physics a ...

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 Bose–Einstein may refer to: * Bose–Einstein condensate ** Bose–Einstein condensation (network theory) * Bose–Einstein correlations * Bose–Einstein statistics In quantum statistics, Bose–Einstein statistics (B–E statistics) describe ...

kaon KAON (Karlsruhe ontology) is an ontology infrastructure developed by the University of Karlsruhe and the Research Center for Information Technologies in Karlsruhe. Its first incarnation was developed in 2002 and supported an enhanced version of ...

mesons in dense matter, which predicts strangeness in neutron stars. * The basic mechanism for

electroweak baryogenesis In physical cosmology, baryogenesis (also known as baryosynthesis) is the physical process that is hypothesized to have taken place during the early universe to produce baryonic asymmetry, i.e. the imbalance of matter (baryons) and antimatter (an ...

, 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 Apartheid (, especially South African English: , ; , "aparthood") was a system of institutionalised racial segregation that existed in South Africa and South West Africa (now Namibia) from 1948 to the early 1990s. Apartheid was ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. 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 Iron Cap Mountain is a mountain summit located two miles west-northwest of Dutch Miller Gap, in east King County of Washington state. It is situated in the heart of the Alpine Lakes Wilderness, on land managed by Mount Baker-Snoqualmie National ...

in the

Alpine Lakes Wilderness The Alpine Lakes Wilderness is a large National Wilderness Preservation System, wilderness area spanning the Central Cascades of Washington (state), Washington state in the United States. The wilderness is located in parts of Wenatchee National F ...

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 Spokane ( ) is the largest city and county seat of Spokane County, Washington, United States. It is in eastern Washington, along the Spokane River, adjacent to the Selkirk Mountains, and west of the Rocky Mountain foothills, south of the Ca ...

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