Professor Christine Nattrass is among the College of Arts and Sciences faculty working in extreme environments. She talks about her nuclear physics research and the importance of moving the boundaries of what’s possible in this CAS feature.
Rebecca Godri isn’t afraid of the hard work needed to test the Standard Model of Physics. As the department’s newest student selected for the prestigious Department of Energy (DOE) Office of Science Graduate Student Research (SCGSR) program, she’s won financial support to pursue this effort at Oak Ridge National Laboratory (ORNL).
Looking for new physics
As part of UT’s fundamental neutron physics group, Godri investigates the weak force, one of the four fundamental interactions in nature. She’s working on the Nab experiment at ORNL; a project designed to discover the nuances of neutron beta decay, a weak process.
A free (unbound) neutron is unstable: it will decay into a proton, electron, and antineutrino. Professor Nadia Fomin, one of Godri’s advisors, explained that “As experimentalists, we can ‘observe’ the neutron spin, momenta of the charged particles, and the angles between them. While the antineutrinos are detectable, the efficiency is very low, and we can get all the necessary information from basic principles of energy and momentum conservation.”
The Nab experiment will make precise determinations of “little a” and “little b,” decay correlation parameters of neutron beta decay. These determinations provide a stringent test for physics beyond the Standard Model.
Flipping the Spin
As small as protons, electrons, and antineutrinos are, the Nab experiment requires mighty tools to study them. Godri is working at the Fundamental Neutron Physics Beamline (FnPB) at the ORNL Spallation Neutron Source, a state-of-the-art facility that directs a powerful neutron stream down beamlines for instruments purpose-built for specific kinds of measurements. As their name implies, neutrons have no positive or negative charge. They do, however, have spin, a magnetic property that points them in certain direction. When neutrons decay, their speed, energy, and direction can give scientists critical information. The FnPB is unique in that can support different experiments with different full-scale apparatus, such as Nab.
Godri’s work, which she recently presented at an American Physical Society meeting, is getting neutrons to reveal more clues about the weak interaction in physics. To do that she’s measuring the residual polarization of the neutron beam at the FNPB and characterizing the Nab experiment’s spin flipper—a device that lets scientists control the neutron’s spin. She works with both Fomin at UT and Chenyang Jiang, a research scientist in ORNL’s Neutron Technologies Division.
While some may find all the preparation tedious, Godri said she enjoys both the groundwork and the payoff.
“The hands-on work is exciting,” she said. “My favorite part is being able to get data from the measurements we’ve spent months preparing for!”
An Easy Decision
Godri earned a bachelor’s degree in physics from the University of Tennessee at Chattanooga in 2021 and started her graduate studies in Knoxville that fall. She finished a master’s in physics last year and is working toward a PhD.
UT’s nuclear physics research opportunities made it an obvious choice for her graduate studies.
“Nadia’s research at ORNL aligned with my research interests post-undergrad, so UT was an easy decision,” she said. Godri’s SCGSR award is the 14th for UT Physics since 2016 and the fifth this year. She’s part of the latest cohort, comprising 62 PhD students from 24 states
Imagination, quite literally, made Lindsey Hessler a Vol before she even started high school. Now a UT senior, she has won an assistantship from Jefferson Lab to support her research in nuclear physics.
It’s the Small Things in Life
Hessler said her interest in physics came about because she is “incredibly fascinated by the intricacies of the universe and understanding how the small things in life work.”
During COVID she spent hours on YouTube watching videos about stars, galaxies, energy—anything explaining the building blocks of our world and universe.
For nearly a year she’s been working with Professor Nadia Fomin and Assistant Professor Dien Nguyen as part of the nuclear physics research group. She was one of the department’s 2024 Summer Research Fellows and learned in August she had won a Jefferson Science Associates Minority/Female Undergraduate Research Assistantship.
The program supports minority or female undergraduates working on projects that are part of the Jefferson Lab research program or are directly related its scientific or engineering aspects. Situated in Virginia, this United States Department of Energy facility is a leader in accelerator science, dedicated to probing the particles and forces that comprise and govern the matter that makes up our world. With this award, Hessler will contribute to the lab’s scientific mission.
“This assistantship will cover a variety of projects,” she explained. “I will be working to collect data with a Helium-3 Polarization apparatus as well as developing a projection of runtime for upcoming experiments at CEBAF (the Continuous Electron Beam Accelerator Facility).”
Her physics studies are driven by a creative and curious worldview that began when she was still in middle school and ultimately brought her to Knoxville.
Solving Problems in the Lab and Industry
Hessler is from Germantown, Wisconsin, but early on her college die was cast in Tennessee orange.
“I chose UT because as a kid I was involved in a competition/club called Destination Imagination (DI),” she said. “The Global Finals were held at UT after the college semester ended, so I spent a week in the dorms at age 12 and fell in love with the campus, ambience, and culture in Knoxville. Ever since then I was determined to be a Volunteer.”
She explained that she began her UT studies as a management major but quickly discovered she had a knack for science.
“At this point I had a decent amount of business classes completed (so) I decided to add physics as a second major,” Hessler said. “I have loved learning two very different studies and have found that both educational paths teach me how to work through problems (and life) in very different but beneficial ways.”
Despite the demands of a double major in business administration (management) and physics, she’s on track academically and said that “ideally (she) will be graduating next December holding a diploma from the Haslam College of Business and UT’s College of Arts and Sciences.”
Her plans include going on to graduate school with a focus on nuclear physics, using the full advantage of her combined majors to design her career.
“I would love to work in the energy and/or defense industry and apply my physics degree as well as my BS in management to project management and operations,” she said.
From her first days as an imaginative kid visiting campus, Hessler has followed her passion and is headed for a promising next destination as a nuclear scientist.
(UT/Jlab/ORNL Invited Meeting) | August 12-13, 2024 | Knoxville, Tennessee
Invited Speakers and Topics:
Organized by N. Fomin
Ian Cox is proof that you don’t always have to travel far to go a long way. He grew up in Knoxville, graduated from Hardin Valley Academy, and came to UT on a physics scholarship. Now he’s finishing a PhD in nuclear physics with Professor Robert Grzywacz and is first author on a Physical Review Letters publication detailing a new approach to understanding exotic nuclei.
Researchers from 13 universities and five national laboratories collaborated on this investigation at the Facility for Rare Isotope Beams (FRIB), a premiere research hub at Michigan State University. The nucleus is the heart of every atom, and since 2022 FRIB has produced hundreds of rare isotopes so that scientists can unearth how the most exotic nuclei hold together or decay. FRIB explores this unknown territory by creating extremely imbalanced and short-lived assemblies of protons and neutrons, helping physicists gain a deeper understanding of these quantum mechanical systems. The more complete that picture, the greater the likelihood scientists can predict how nuclei form, what their properties are, and how those properties can be of use. In this case, the starring isotope was chlorine-45. With 17 protons and 28 neutrons, it has a touch of what physicists categorize as magic.
Protons and neutrons in a nucleus are known collectively as nucleons and they’re arranged in shells. When they appear in certain numbers (2, 8, 20, 28, 50, 82, and 126), scientists call them “magic” because they fill complete shells and make the nucleus more stable (although that may be a lifetime of only a few milliseconds). Magic numbers are like sentinels in what’s known as the valley of stability. A proton or neutron count with a magic number (as in chlorine-45) resides at the border, where on one side you have nucleons bound strongly enough to hold the nucleus together and on the other their imbalance causes it to fall apart. This isn’t always straightforward, however. Magic numbers change for nuclei rich with neutrons, and scientists want to know how that alters the shell structure.
In this experiment the scientific team found that the beta decay of chlorine-45 converts one of its 28 neutrons to one of the 18 protons in argon-45. This lies outside the magic threshold of a 20-proton shell, creating a particularly unstable, unbound system. Grzywacz said “the experiment provided a unique method to study how the protons behave in a very neutron-rich nucleus. Understanding the persistence of nuclear shell gaps is crucial to describe the properties and formation of atomic nuclei.”
A combined arrangement of innovative tools, talent, and effort made this work successful.
“This was an important experiment because we tried a lot of new things,” Grzywacz said.
His team was particularly pleased to use the full capabilities of the FRIB Decay Station Initiator (FDSi) for the first time. Grzywacz is the spokesperson for the FDSi, a years-long collaboration that designed, built, and implemented a modular combination of beta, neutron, and gamma-ray detectors to measure the decay of the most exotic nuclei produced at FRIB.
The FDSi played a crucial role in determining the complete decay pattern of chlorine-45. Cox identified the isotopes in this experiment as interesting candidates to show what the decay station could do. A key element was the two-focal plane detection system, which allows for simultaneous measurements and ultimately a combined and consistent data analysis that wouldn’t be possible with a single multi-detector system.
This is what Grzywacz called a scientific “symphony,” where “the instruments combined produce a different result than if played separately and individually.”
That metaphor extends to the scientists involved in the experiment.
Cox and Zhengyu Xu (a UT postdoctoral research associate) helped install FDSi at FRIB from the ground up. They’ve supported every FDSi experiment since, and led the analysis on the work published in PRL. Wei Jia Ong of Lawrence Livermore National Laboratory (LLNL) directed the measurement. Her interest was to measure decay of another isotope, calcium-54; this experiment was a prelude to the 2024 measurement.
Navigating multiple instruments and working with a large team were part of the learning experience for Cox.
“Working at FRIB on FDSi, I have learned a great deal about the complex nature of radioactive ion beam facilities and specifically the challenges which come with combining multiple different detector systems for a single experiment,” he said. “The varying types of detectors require a large collaboration of researchers, each with their own expertise to handle the individual detector systems, while also having to work together to ensure a successful experiment.”
Cox explained that frustrations could arise while everyone was trying to optimize their system in a limited amount of time. However, he found that having a sizable collaboration was helpful because in the end, working together, smaller groups could focus on individual detectors. Sharing the responsibility meant the science moved forward more seamlessly. This is the fourth publication based on FDSi findings and the third published in PRL.
Cox stayed in Tennessee for his education and ended up travelling far and wide. In addition to FRIB, he’s worked at the Radioactive Isotope Beam Factory at RIKEN in Japan and presented his research at conferences all over the world. He arrived on campus with a William Bugg Physics Scholarship and a spot in the Chancellor’s Honors Program. Over his undergraduate and graduate studies, he won the department’s Robert Talley Award for Outstanding Undergraduate Research, secured a Graduate Advancement and Training Education Fellowship from the UT-Oak Ridge Innovation Institute (UT-ORII), and won the department’s Paul Stelson Fellowship for Professional Promise in recognition of his outstanding research contributions as well as his departmental citizenship.
He plans to finish his PhD this summer and work in either the private sector or at a national laboratory. Whatever comes next, his time at UT has prepared him well, especially with the nuclear research group collaborating at laboratories in different states and countries.
“I have really enjoyed both travelling all over the world, for participating in experiments and presenting results, and the ability to meet many different researchers from all corners of the globe,” Cox said. “I believe this will greatly help me in my career, as I have been able to form many connections and establish myself as a young scientist.”
Mother Nature keeps moving the goalposts for Anthony Mezzacappa and he wouldn’t have it any other way. His years of dedication to computational and theoretical astrophysics research, even as the landscape shifts, have earned him election as a Fellow of the American Association for the Advancement of Science (AAAS).
The AAAS Council bestows this honor on members whose “efforts on behalf of the advancement of science, or its applications, are scientifically or socially distinguished.”
Mezzacappa is the Newton W. and Wilma C. Thomas Chair in Theoretical and Computational Astrophysics and a College of Arts and Sciences Excellence Professor. He develops sophisticated models of supernovae through roles in UT’s Physics Department (since 1994) and at Oak Ridge National Laboratory (since 1996). It’s the foundation for his AAAS Fellowship, where he was cited “for distinguished contributions to the field of computational and theoretical astrophysics, particularly for developing theoretical frameworks and computational methods to model core collapse supernovae.”
“The AAAS Fellowship is about the advancement of science writ large,” Mezzacappa said. “This Fellowship really is special in that sense. I’ve spent a lot of time doing things for the field and for computational science. It’s really nice to receive a recognition of that.”
From Upstart to Leadership
Early in his career Mezzacappa was the principal investigator for the first large-scale, multi-investigator, multi-institutional computational astrophysics effort in the country to focus on core collapse supernovae. That was the beginning of a long list of professional accomplishments in astrophysics.
“When you first start out, there are more senior people who are leaders in the field and you’re a young upstart,” he said. “I was glad to get the vote of confidence by senior people to lead that effort.”
He said he knew after directing a program of that size there was no going back to smaller initiatives where he’d be the lone PI on a single project. He also noticed that over time, he and his contemporaries evolved from upstarts just beginning in the field to leaders who were guiding it.
“That changes the whole responsibility,” Mezzacappa said. “It changes how you think about yourself and your field. One of your jobs is to usher the science forward, which implicitly means with integrity and scientific accuracy.”
For him, it also means cultivating a network of fellow scientists to dive into the mysteries of astrophysics.
“Over time, you wind up contributing where you can, where your strengths are,” he said. “One of the things I know how to do is build and manage projects and programs. I created the largest core collapse supernova theory group in the world here between (ORNL) and the university.”
That gift for organizing expertise and assets has certainly benefited the research and teaching environment at UT.
“Professor Mezzacappa is the definition of a fearless scientist who chases after the solutions to some of the most challenging and interesting problems underlying how the universe functions,” said Adrian Del Maestro, professor of physics and head of the department. “The recognition by the AAAS for his dedication to discovery in computational astrophysics is well deserved, and the department (and especially his students and postdocs) are extremely lucky to have Professor Mezzacappa at the University of Tennessee.”
Moving the Goalposts
When a gigantic star can no longer support its own weight, gravity will eventually cause it to collapse on itself in some of the Universe’s most spectacular fireworks. When Mezzacappa and his colleagues were first developing models for core-collapse supernovae, they began with spherical symmetry, though they knew the physics would eventually lead them to more complex models.
“We always knew that we had a long way to go,” he said.
As they accumulate a deeper knowledge base and their tools (supercomputers) get bigger and faster, Mezzacappa said astrophysicists can now create beautiful three-dimensional supernovae models. As amazing as they are, however, those models still don’t answer all their questions.
“The thing that’s really changed is that Mother Nature is moving the goalposts,” he said.
“When you start out you think it’s a fixed target, because you have limited knowledge,” he went on to explain. “As you learn more and move forward, you realize the problem is even harder than you imagined to begin with. As the models have gotten more sophisticated, we’ve discovered the physics of supernovae is richer, and some of that richness is very challenging to model.”
To Mezzacappa, that’s part of the what makes fundamental science so meaningful.
“As humans, we always want to find the answers,” he explained. “As I’ve grown, one of the things that’s changed is that I kind of enjoy the mystery more now. I think knowing everything would be quite boring.”
Back to the Beginning, and the Future
Mezzacappa was in high school when he first learned about Einstein’s theories and decided what he wanted to study for the rest of his life.
“Relativity is what pulled me into physics from the get-go,” he said.
Decades later, his work keeps him close to the spark that ignited his imagination. He explained that core-collapse supernovae are one of the primary sources of gravitational waves and the only known source from which they’ve yet to be detected.
“We are in a position now, because we are a leading group and we have some of the leading models, to make predictions for what the gravitational waves for the supernovae look like,” he said. “I feel like I’m really contributing—not just to astrophysics but to relativity, which is special for me.”
The Most Important Impact
The AAAS Fellowship is one of many honors Mezzacappa has earned over a distinguished career. In the past year he’s been named a College of Arts and Science Excellence Professor, won the College’s Senior Award for Excellence in Research & Creative Achievement, and been recognized with the university’s Alexander Prize. He was elected a Fellow of the American Physical Society in 2004 and a UT-Battelle Corporate Fellow in 2005 in recognition of his supernova research and his broader role in the development of computational science in the United States.
“They all mean a lot,” Mezzacappa said of his honors, but “your most important impact is the impact you have for others, not for yourself.”
Professor Mezzacappa becomes the fourth member of the current physics faculty elected to AAAS Fellowship, joining Professors Elbio Dagotto, Adriana Moreo, and Hanno Weitering.
Abhyuday Sharda Wins JLab Fellowship
Abhyuday Sharda likes an open question. For him, that’s where the real beauty of science lies. His search for answers will be supported this academic year with a new graduate fellowship from the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, commonly known as JLab.
Sharda is a graduate student who’s been working with Professor Nadia Fomin since 2022.
“What I am working on in JLab is studying the structure of the atomic nucleus,” he explained. “The nucleus is more than 99 percent of the visible universe by mass but it is not completely understood. My research is an attempt to understand how protons and neutrons (and their underlying quark distributions) change when inside the nucleus as compared to a free proton or a neutron. We do this by scattering energetic electrons off of nuclei. The way they scatter allows us to infer information about the nucleus.”
With his experimental component complete, Sharda said he’s now analyzing data, the results of which he said are anticipated by the hadronic physics community in general. The JLab graduate fellowship (one of nine granted this year) will support this work, which Fomin pointed out has been rated as high-priority and high-impact by JLab’s Program Advisory Committee.
Going Beyond the Familiar
Sharda’s hometown is Delhi, India, and he traveled across the globe to UT to earn a master’s degree in physics. He said he had such a positive grad school experience he decided to stay on for a PhD. Nuclear physics in particular speaks to his wide-open view of science, and the world in general.
“What I find interesting about it is that the atomic nucleus can be called the building block of the matter in the universe, yet we don’t completely understand it,” he said. “Any open question in physics often leads to beautiful and unexpected discoveries.”
This willingness to embrace the unknown underlies Sharda’s personal philosophy about what science can achieve, summed up nicely by one of his favorite quotes (from Physicist Lisa Randall):
“In the history of physics, every time we’ve looked beyond the scales and energies we were familiar with, we’ve found things that we wouldn’t have thought were there. You look inside the atom and eventually you discover quarks. Who would have thought that? It’s hubris to think that the way we see things is everything there is.”
Star-Stuff, Indeed
We are made of star-stuff, Carl Sagan said in the Cosmos TV series.
William Raphael (Raph) Hix knew that quote. As a high school kid in Maryland he’d taken advanced physics and chemistry. He’d watched Cosmos and heard Sagan talk about stars and elements. But something changed when he encountered this concept in one of his college astronomy textbooks. It took on a gravitas that has captivated him ever since, leading him to climb inside stars (theoretically) to see how the stuff that makes us—carbon, iron, etc.—came to be.
For his “contributions to understanding explosive thermonuclear burning and nucleosynthesis, particularly in contexts like supernovae,” Hix, a UT-Oak Ridge National Laboratory joint faculty professor, has been elected a Fellow of the American Physical Society. This honor is bestowed on only one half of one percent of the Society’s membership each year. Hix is one of 153 Fellows in the 2023 cohort and the second UT physicist elected in the past two years.
Adrian Del Maestro, UT Physics Professor and Department Head, had high praise for the department’s newest APS Fellow.
“Dr. Hix is exemplary of the unique and visionary researchers that bridge the University of Tennessee and Oak Ridge National Lab as joint faculty,” he said. “He is a driving force behind our astrophysics program and is a sought-after mentor and teacher, involving both graduate and undergraduate students in his cutting-edge research on stellar evolution.”
Late Bloomers
Hix is interested in how the chemical elements are made, or nucleosynthesis. The Big Bang gave us hydrogen, helium, and lithium. Since then, nuclear reactions accompanying the life and death of stars have created most of the other elements. As it turns out, stars are late bloomers.
“Most of the elements get made at the end of a star’s life,” he said.
Stars run on the fusion of hydrogen into helium for most of their lives. Hix explained that as a star begins to run out of fuel, temperatures go up and conditions become more extreme. That’s when the heavier elements, like carbon and iron, are made. Once the fuel is exhausted, an ordinary star (like our Sun) violently expels its outer layers, including elements made late in its life, and becomes a white dwarf. For more massive stars, like Betelgeuse, Rigel and Antares, the exhaustion of fuel leads to a supernova—sending those recently made elements into the cosmos—while the stellar core collapses, leaving a neutron star or a black hole.
With colleagues at ORNL and UT, Hix develops sophisticated models to understand how all this works. He leads ORNL’s Theoretical and Computational Physics group, utilizing some of the national lab’s powerful tools, like Summit and Frontier.
“We use the biggest supercomputer we can to model as much physics as possible within the intricate workings inside a star that we (then) blow up,” he said.
The results become part of a chain of handing off data—ultimately going to scientists who use telescopes to see if the model holds up to observation. Hix explained this is how they prove their models are accurate.
“It’s a way to climb inside a star and see the parts that are ordinarily hidden from view,” he said.
When Everything Was Cool and New
Hix finished undergraduate studies at the University of Maryland at College Park, where he re-discovered Sagan’s quote and graduated with bachelor’s degrees in physics and astronomy as well as math. He earned AM and PhD degrees in astronomy at Harvard University. Following a postdoctoral appointment at the University of Texas, he came to UT in Knoxville. He began as a postdoc, became a research professor, and then in 2004 moved (without moving) to ORNL. In 2010, he rejoined the UT faculty with a joint faculty appointment.
In his case, he explained, being joint faculty means that he’s an ORNL astrophysicist and the university subcontracts half of his time to teach courses (like Honors Introductory Astronomy) and supervise students. Hix said he really enjoys working with undergraduates. He loves seeing how excited they are when they come to the national lab and have an office for the summer. He likes being reminded, he said, “of that time in my career when everything was cool and new and interesting.”
About APS Fellows
The APS Fellowship Program was created to recognize members who may have made advances in physics through original research and publication, or made significant innovative contributions in the application of physics to science and technology. They may also have made significant contributions to the teaching of physics or service and participation in the activities of the Society.
Raph Hix is the 10th APS Fellow on UT’s current faculty.
What determines the shape of a nucleus? UT’s physicists played a key role in recently-reported findings that shed new light on that mystery. Their dedicated work to develop and deploy a sophisticated yet nimble detection system was central to an Oak Ridge National Laboratory-led study of how nuclear shapes evolve. The unexpected results could point to a deeper understanding of how nuclei stay together and how elements form.
Shape Shifters
Nuclei typically appear as spherical or deformed (football-like). Some can shift their shape depending on their energy level— deformed at higher energy (excited state) and spherical at low energy (ground state). The reverse (deformed at low energy; spherical at high energy) has been harder to pin down, especially in regions of the nuclear landscape where little experimental data is available.
In this work, scientists found that a sodium-32 nucleus has an exceptionally long-lived excited state, also known as an isomer. This nucleus sits at the heart of the “island of inversion,” where previous experiments have documented spherical-to-deformed shape reversal. Isomers can help probe nuclear structure, and the one observed in sodium-32 is a rare microsecond isomer in this particular area of the nuclide chart. It can provide a window into the underlying conditions where the spherical-to-deformed transition begins.
The analysis is based on data collected from the very first experiment at the Facility for Rare Isotope Beams (FRIB)—specifically the FRIB Decay Station Initiator (FDSi). This is Professor Robert Grzywacz’s home office, so to speak, as he and his group have invested years in this sensitive, modular detector system, starting with the plans on paper and now actually “catching” the fragments of a rare isotopes created by FRIB’s powerful linear accelerator and measuring their decay.
“We poured an enormous amount of work into this experiment,” he said. “It had to succeed.”
Getting an Early Start
While the observation of the sodium-32 isomer is new, the premise is not. As a graduate student Grzywacz was a lead author on papers outlining a novel method suited to scanning large swaths of the nuclear chart in search of new isomers. His work eventually led him to Tennessee, where in 1998 he became a postdoctoral fellow at UT and in 2003 joined the faculty.
Since then he’s built a talented nuclear physics team of fellow faculty, students, and staff. These latest findings are outlined in Physical Review Letters and UT Physics co-authors include Grzywacz as well as Miguel Madurga (assistant professor); Zhengyu Xu and Kevin Siegl (postdoctoral research associates), Noritaka Kitamura (postdoctoral research associate, now assistant professor at University of Tokyo); Joseph Heideman, Shree Neupane, and Maninder Singh (PhD alumni); Ian Cox and James Christie (graduate students); Harrison Huegen and Amanda Nowicki (undergraduates); and Jason Chan (Electronics Shop Supervisor).
Learn more about the results at Oak Ridge National Laboratory’s website.
With thanks to Dawn Levy of Oak Ridge National Laboratory.
Graduate Student Jesse Harris wins presentation prize at the 2022 NSBP conference
Graduate Student Jesse Harris knows how to explain the search for new physics. That talent was much appreciated at the National Society of Black Physicists (NSBP) conference last month, where he won the award for Best Oral Presentation in the field of Nuclear and Particle Physics.
Harris, who works with Professor Stefan Spanier in UT’s Compact Muon Solenoid (CMS) group, presented his work searching for certain rare Higgs decays, a strategy to probe physics beyond the standard model, or, as Spanier describes it, “physics beyond the textbooks.”
They’re looking for glimmers of small, rare differences in how the Higgs boson shows up in experiment versus what present theory predicts. Harris uses machine learning to improve sensitivity in the search and his preliminary findings have shown improvement by a factor of two.
A native of Big Stone Gap, Virginia, Harris earned a bachelor’s degree at the University of Virginia’s College at Wise before joining UT’s graduate program in physics. His work in both research and teaching labs has been recognized before. In 2020 he won a research stipend from the UT Office of Research and Engagement and in 2021 he was selected for the department’s Outstanding Graduate Teaching Assistant Award. The NSBP award was sponsored by the Facility for Rare Isotope Beams (FRIB) and the National Science Foundation.
Harris was one of eight UT physics students attending the NSBP conference, along with Associate Professor Lucas Platter. Graduate students were Idris Abijo, Victor Ale, Olesson Cesalien, Harris, and Olugbenga Olunloyo. The undergraduate cohort comprised Carson Broughton, Cordney Nash, and Cora Thomas. (Nash, another of Spanier’s students, presented his on-campus research on silicon pixel detectors for the High-Luminosity Large Hadron Collider.)
The NSBP conference is the largest academic meeting of minority physicists in the United States. The meeting provides mentorship opportunities, access to recruiters, and networking opportunities while informing the broader physics community on best practices. UT Physics has sent delegations of students every year since 2016, typically led by Associate Professor Christine Nattrass. UT was a gold sponsor of the 2022 meeting, held November 6- 9, 2022, in Charlottesville, Virginia, and will co-host the 2023 conference with Oak Ridge National Laboratory. This year’s gathering provided a welcome return to the in-person experience after two years of virtual meetings.
“The pandemic has just been brutal on all of our students but in particular on students who also come from marginalized groups,” Nattrass said. “I think our students needed this.”
