NSF just announced their Graduate Research Fellowship Program award winners and we are pleased to announce Andy Boyle received a fellowship award. This five-year fellowship includes three years of financial support as well as a cost of education allowance. Andy is being recognized for their outstanding research and potential impact on the field.
Andy Boyle works with Andrew Mann in the Young Worlds Lab studying young (<1 Gyr) stars and exoplanets. His project focuses on using stellar rotation to determine the spatial extent and evolution of young clusters and stellar groups in our region of the Galaxy (< 300 pc). As stars age, their rotation period increases, and the relation can be used to assign ages to stars (a technique known as gyrochronology). By combining spatial and kinematic data from ESA’s Gaia mission with rotation periods measured using light curves from NASA’s TESS mission, Andy aims to find the dissolving parts of stellar associations that would be invisible with kinematics alone. This search will provide insight into stellar structure in the local Galaxy, the evolution of stellar groups, and the dynamical processes that fuel their dispersal, as well as provide an expanded sample of stars to search for young and evolving planets.
The paper “Two-Pole Nature of the Λ(1405) Resonance from Lattice QCD” published by the Baryon Scattering (BaSc) collaboration was recently accepted as editors’ suggestion in the Physical Review Letters. The accompanying paper “Lattice QCD study of πΣ−KN scattering and the Λ(1405) resonance” was also accepted as editors’ suggestion in the Physical Review D.
The role of the fundamental theory of the strong nuclear force, Quantum Chromodynamics (QCD), in the formation of the observed hadron spectrum is an outstanding issue for the standard model of particle physics. The use of QCD to describe the binding of quarks and gluons into hadrons, such as protons and neutrons, is a low-energy phenomenon that requires a nonperturbative calculation that is difficult to apply. The nonperturbative technique we utilize is lattice QCD, where the theory is formulated on a spacetime lattice that allows statistical calculations on computers through Monte Carlo methods. States observed in experiments can be explained using scattering formalism, with theoretical methods necessary to compare calculations on Euclidean spacetime lattices to continuous Minkowski amplitudes. However, the study of nuclear systems using LQCD has been hampered because of a signal-to-noise problem that is heightened when extracting correlation functions. Recent advances in stochastic algorithms have allowed multi-hadron computations and the determination of meson-baryon scattering amplitudes, allowing studies of resonances and excited states in the hadron spectrum.
Lambda Pols Image
The work of the BaSc collaboration is the first lattice QCD study of a coupled-channel scattering system containing meson-baryon scattering amplitudes. This work is concerned with explaining the Lambda (1405) resonance which is a spin-1/2, negative parity state first identified experimentally in 1959. Explaining the nature of the Lambda (1405) has been a challenge to nuclear theorists as its relatively low mass and quantum numbers are difficult to explain in the three-quark model of low-energy QCD, leading to exotic explanations of the particle such as the meson-baryon molecular structure. The lattice study in this work utilizes quarks that are slightly heavier than physical and can identify two poles in the complex scattering amplitude with the resonance near the kaon-nucleon threshold and a virtual bound state as the lower pole below the pion-sigma threshold. These results provide a model-independent determination of the scattering amplitude and support the two-pole picture with qualitative results predicted by chiral symmetry and unitarity. This work also opens the use of lattice QCD toward other baryon resonances that can explain the nature of some of the shortest-lived particles observed in experimental physics.
From 2015 until 2021, the Majorana Demonstrator, tucked nearly a mile underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, searched for an elusive decay that might be the key to solving one of the universe’s biggest puzzles: why matter abounds rather than nothingness. The postulated decay, known as neutrinoless double beta decay, if observed would reveal the quantum nature of neutrinos and prove that neutrinos are their own antiparticles.
The experiment’s final results, while not observing the decay, set a limit on the half-life of the decay of greater than 8 x 1025 years (a timescale more than 1015 times longer than the age of the universe). The experiment has helped pave the way for a next generation experiment known as LEGEND that aims to eventually have a hundred times the sensitivity of the Demonstrator.
UNC Physics and Astronomy faculty Julieta Gruszko, Reyco Henning, and John Wilkerson together with Matthew Busch from Duke, faculty member Matthew Green from NCSU, and UNC and NCSU graduate students and postdoctoral scholars made essential contributions to the Majorana efforts. UNC Postdoctoral fellow Ian Guinn (now at Oak Ridge National Laboratory) served as the paper’s corresponding author. This collaborative research was supported and facilitated by the Triangle Universities Nuclear Laboratory(TUNL), a DOE Center of Excellence that is a consortium of UNC, Duke, NCSU, and NCCU nuclear physics researchers.
The Demonstrator was enabled by support from the U.S. Department of Energy Office of Nuclear Physics and the National Science Foundation.
(Left: the Cover of the Article; Right: The Article has the most downloads under the Nuclear Physics section in 2023)
A technological advance in medical and dental imaging promises to improve diagnostic accuracy while minimizing patient exposure to radiation, according to a research article in the Nature journal Communications Engineering.
In the article, “Volumetric Computed Tomography with Carbon Nanotube X-Ray Source Array for Improved Image Quality and Accuracy,” Shuang Xu, a Materials Science Ph.D. candidate in the Department of Applied Physical Sciences, demonstrated that multisource cone beam computed tomography (ms-CBCT), a type of X-ray imaging, has the potential to offer clinicians detailed 3-D imaging that will improve patient care and treatment.
Xu collaborated on the research with UNC-Chapel Hill Professors Christina Inscoe, Jianping Lu and Otto Zhou of the Department of Physics and Astronomy, Don Tyndall of the Adams School of Dentistry and Yueh Lee of the School of Medicine.
The researchers argue that ms-CBCT would be an improvement over conventional CBCT. Conventional CBCT is a specialized medical imaging technique that provides detailed 3-D volumetric images that offer a 360-degree spherical viewing angle of an object. CBCT imaging is used primarily in the fields of dentistry, maxillofacial surgery, interventional radiology and image-guided radiation therapy, where precise visualization of hard-tissue structures like teeth, jaws and the skull is crucial.
“Despite its advantages, conventional CBCT has limitations due to its large imaging volume,” said Xu. “These limitations include reduced soft tissue contrast, image distortion, use that is restricted primarily to imaging hard tissues and hindered quantitative analysis.”
Ms-CBCT overcomes these challenges by enhancing the accuracy of CT imaging of radiodensity of tissues by 60% and soft-tissue contrast by approximately 50%, allowing radiologists and clinicians to distinguish between different tissues and structures within the body. For example, in a CT scan of the abdomen, the liver might have a different HU value than the spleen, helping to identify and characterize abnormalities.
“This is a critical improvement,” said Otto Zhou, David Godschalk Distinguished Professor in the Department of Physics and Astronomy and a member of the APS adjunct faculty, “because accurate HU values are essential for quantitative analysis, tissue characterization and accurate diagnosis.”
Standing beside their prototype of an ms-CBCT machine are, left to right, Professor Christy Inscoe, Materials Science Ph.D. candidate Negar Mehrabi, and first and second authors of the research article, respectively, Shuang Xu and Yuanming Hu.
In addition to improving image quality and diagnostic accuracy, ms-CBCT reduces the amount of “artifacts,” which can include the presence of metal objects, such as dental fillings or implants, and image distortion due to cone-beam imaging geometry.
“It’s a more comprehensive examination of the imaged area that can be particularly beneficial for capturing larger anatomical structures or regions of interest and improving soft-tissue contrast, making it possible to image more than just hard tissues,” said Xu.
CBCT systems utilize a cone-shaped X-ray beam, as opposed to the fan-shaped beam used in traditional systems. The cone-shaped beam is directed toward the patient or the specific region of interest and a flat-panel detector is positioned opposite the X-ray source. The detector captures the X-rays that pass through the patient, converting them into electrical signals. As the system rotates around the patient, it continuously emits the cone-shaped X-ray beam.
Ms-CBCT involves using multiple X-ray sources configured as an array. Instead of a single, wide cone-angle X-ray tube, this technology employs several X-ray sources that can be strategically positioned around the patient or imaging target. Carbon nanotubes have unique properties that make them suitable for X-ray emission, including their ability to efficiently generate electrons, as well as their small size.
“The ms-CBCT design holds promise for significantly enhancing the capabilities of CBCT scanners,” said Zhou. “These improvements could make CBCT a more versatile tool in medical and dental imaging, potentially competing with multidetector CT images in certain diagnostic applications while retaining its inherent advantages.”
AAS recently announced its 2024 prizes for outstanding achievements in research and education at its 243rd meeting in New Orleans.
The Warner Prize is given to a young scientist for a “significant contribution to observational or theoretical astronomy.” The AAS is an international organization that includes professional astronomers, astronomy educators and amateur astronomers. Its membership of approximately 8,000 also includes physicists, geologists, engineers and others whose interests lie within the broad spectrum of subjects that comprise the astronomical sciences.
Rodriguez was recognized for fundamental advances on the astrophysical origin of gravitational-wave sources. He has discerned how repeat mergers of black holes and stars in dense clusters would lead to the existence of massive black holes, a prediction later verified by gravitational-wave detectors. His work has opened new directions in research into gravitational-wave sources and their connection to the formation of both star clusters and galaxies.
Rodriguez joined the UNC faculty in January 2023 from Carnegie Mellon University. He completed his Ph.D. in 2016 from Northwestern University and received a B.A. in physics from Reed College in 2010.
His research group is interested in both stellar dynamics (the movement of stars and compact objects in star clusters and galaxies) and the astrophysical sources of gravitational waves.
December 19,2023, Chapel Hill, North Carolina – The University of North Carolina at Chapel Hill (UNC-CH) chapter of the Society of Physics Students (SPS) has once again secured the coveted Outstanding Chapter Award from the SPS National Office. This marks the sixth consecutive year that the UNC-CH chapter has been acknowledged for its exceptional contributions as a top-tier student-led physical sciences organization. This designation is bestowed upon less than 15% of all SPS chapters at colleges and universities in the United States and internationally.
The SPS, a professional association for students, operates under the umbrella of the American Institute of Physics (AIP), encompassing various professional physical science societies.
SPS students on the 2023 Science is Awesome Day
Led by faculty advisor, Bowman and Gordon Gray Professor, Dan Reichart, the UNC-CH SPS chapter continues to exemplify excellence in student leadership. The officers for the 2022-2023 academic year are:
President: Ravi Pitelka B.S. Physics, Mathematics B.A., Class of 2023
Vice President: Vimal Palanivelrajan B.S. Physics, Mathematics B.S, Class of 2024
Treasurer: Logan Selph B.S. Astrophysics, Currently Music Minor, Class of 2024
Secretary: Stephen Snare B.S. Physics, Math B.A., Class of 2025
Outreach Coordinator: Abbey Dunnigan B.S. Astrophysics, Class of 2024
Events Coordinator: Em Chittenden B.S. Physics (Astrophysics Option), Class of 2024
Room Managers: Rob Sternquist B.S. Physics, Mathematics B.S., Class of 2024; Landon Overall B.S. Physics, Class of 2023
“One of my favorite things about UNC SPS is how it gives opportunities to do things like go out camping with other physics majors. It’s a really useful resource when you need help on physics problems or with studying, but it’s also a great social space if you just want to hang out,” said Neel Iyer, the current Secretary for the 2024 – 2025 academic year.
SPS chapters undergo rigorous evaluation based on their engagement with the campus community, the professional physics community, the public, and SPS national programs. The Outstanding Chapter Award acknowledges not only high levels of outreach but also innovative approaches aligned with SPS’s mission to “help students transform themselves into contributing members of the professional community.”
For more information about the UNC-CH SPS chapter, please contact President Vimaleshwar Palanivelrajan (vbassic@email.unc.edu) or Secretary, Neel Wilson Iyer (iyern@unc.edu).
James T. Dobbins III, PhD, FAAPM, FSPIE, BSPHYS ’78 (UNC-CH), received a Lifetime Achievement Award in 2023 from the Society of Directors of Academic Medical Physics Programs, Inc (SDAMPP). Dobbins, now retired, spent his entire 37-year career on the faculty and in senior administration at Duke University, where he is Associate Vice Provost Emeritus and Professor Emeritus of Radiology, Biomedical Engineering, and Physics. He is an internationally recognized scholar in the physics of imaging, both theoretical and experimental, whose research has contributed to several FDA-cleared diagnostic imaging techniques now in clinical use in hundreds of hospitals worldwide. He was the Founding Director of the Graduate Program in Medical Physics at Duke, now one of the top three such programs in the US. He was also part of the small team of senior administrators that designed, built, and launched Duke’s joint venture university in China – Duke Kunshan University (DKU) – which offers both graduate and undergraduate degrees to a global community of students; he also served as Secretary of the DKU Board of Trustees. He is past-president of the American Association of Physicists in Medicine (AAPM) and co-founder and past-president of SDAMPP. He won the Sylvia Sorkin Greenfield Award for best publication in the journal Medical Physics and is a Fellow of AAPM and SPIE, the International Society for Optics and Photonics. He and his wife, Catherine N. Dobbins, BA ’77 (former senior management at UNC-TV), live in Durham, NC and enjoy spending time with their son, Scott, daughter-in-law Summer, and grandson Theo in New York City.
The Graduate-to-Undergraduate (G2U) Mentoring program at the University of North Carolina’s Department of Physics & Astronomy (P&A) has recently been awarded a $6,998 grant for unit enhancement by the College of Arts and Sciences’ Diversity, Equity, and Inclusion (DEI) initiative. This success marks a significant step forward for G2U, a program established in 2020 with the mission of providing structured, holistic mentorship to underrepresented minority (URM) undergraduate students in the department.
Mission and Vision
Founded by P&A graduate student Zack Hall with the invaluable support of Dr. Sheila Kannappan and Dr. Jennifer Weinberg-Wolf, G2U aims to create a robust support system for URM students in the department, where they constitute less than 10% of the undergraduate population. G2U is designed around findings and recommendations from an investigation of the persistent underrepresentation of African Americans in U.S. P&A departments, detailed in the American Institute of Physics TEAM-UP report. Accordingly, the program utilizes group-based mentoring and specialized event planning to foster a sense of community. intended to work towards increasing retention and inclusion for URM students in P&A. In March 2022 Science magazine published “The Missing Physicist” package, detailing the woeful lack of African American representation in physics, and G2U was featured among UNC P&A programs as a promising new approach to mitigate this. To date, G2U has over 30 mentees and mentors who have participated in this program.
DEI Grant Success
The success of the graduate student-led application for the DEI grant is a testament to the dedication and impact of the G2U program. The award, endorsed by Dr. Frank Tsui, chair of the department of P&A, recognizes the importance and impact of G2U. Out of nearly 50 submitted proposals, G2U’s stood out to the reviewers, comprised of the Climate Subcommittee of the Dean’s Diversity Advisory Committee. This reflects the department’s support for the College of Arts and Science’s Strategic Plan for DEI, Action Steps for Equity.
Grant Details
The grant will fund the G2U mentoring program from April 15, 2023, to June 30, 2024. This financial support has enabled the program to continue and expand its efforts in providing mentorship training for graduate student mentors and organizing monthly professional development and community-building events for undergraduate mentees. These include semester kick-off events, holiday celebrations, end-of-the-year festivities, and conference funding opportunities.
Context and Acknowledgement
G2U expresses heartfelt appreciation to the Department of Physics & Astronomy for its past funding and ongoing support. Special recognition goes to the faculty who support the development and execution of G2U, which includes Dr. Kannappan, Dr. Weinberg-Wolf, and Dr. Akaa Ayangeakaa, as well as Dr. Julieta Gruszko, who contributed funding through the DEI Scholars Program. The department’s leadership played a pivotal role in providing funds during the program’s inaugural year, highlighting the commitment to fostering a diverse and inclusive academic environment. The department’s diversity committee has also been supportive of G2U’s mission and success. Finally, G2U emphasizes the importance of its graduate student members, both local and virtual, who actively participate as program coordinators and mentors.
Moving Forward
As the G2U Mentoring program moves forward with this grant, it is well aligned with the College of Arts and Sciences’ broader initiatives outlined in the Strategic Plan for Diversity, Equity, and Inclusion. The Action Steps for Equity outlines four DEI priorities, including enhancing climate, understanding pay equity, implementing measures for recruitment and retention, and addressing areas of repair.
For more information about the DEI grant, the College of Arts and Sciences’ initiatives, and the AIP TEAM-UP project please refer to the relevant web pages:
This achievement marks a significant milestone for G2U, reflecting its commitment to fostering an inclusive and supportive environment for underrepresented minority students pursuing their passion for physics and astronomy at UNC. The program looks forward to the positive impact it will continue to make with the support of the DEI grant.
The Horsehead Nebula, residing approximately 1,500 light-years away within the expansive Orion cloud complex, has been sculpted over time by stellar winds and radiation. Standing at about five light-years in height, this interstellar dust cloud, cataloged as Barnard 33, captivates with its distinctive equine profile. Its silhouette becomes visible against the backdrop of the red emission nebula IC 434, thanks to the dust’s obscuring effect.
The image also reveals ongoing star formation within the dark cloud, adding another layer of astronomical significance. Adjacent to the Horsehead Nebula, a contrasting blue reflection nebula identified as NGC 2023 can be seen. This nebula surrounds a young, hot star and occupies the lower left portion of the complete image.
Mark Hanson and Martin Pugh utilized a combination of narrowband and broadband imaging techniques with several telescopes to create this breathtaking color image. The result is a visual masterpiece that not only captures the mesmerizing beauty of the Horsehead Nebula but also highlights the intricate details of the surrounding cosmic landscape.
The recognition on NASA’s APOD platform underscores the contribution of UNC’s Physics and Astronomy department to the exploration and understanding of our vast and fascinating universe.
About PROMPT telescopes:
PROMPT, an acronym for Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes, is being built by the University of North Carolina at Chapel Hill at Cerro Tololo Inter-American Observatory (CTIO) in Chile.
PROMPT’s primary mission revolves around swiftly conducting simultaneous multiwavelength observations of gamma-ray burst afterglows, often capturing them mere tens of seconds after their inception. Beyond this, PROMPT will meticulously measure redshifts through dropout techniques, analyse early-time Spectral Energy Distributions (SFDs), and delve into extinction curves of particularly luminous afterglows with unparalleled precision. The telescope’s versatility extends to facilitating prompt response observations at prominent observatories, including the UNC-led 4.1-m SOAR Telescope. In a notable dual role, PROMPT is poised to serve as an educational platform for both undergraduate and high school students across the State of North Carolina.
Phi Beta Kappa, the nation’s oldest and most honored college honorary society, inducted 259 University of North Carolina at Chapel Hill students as new members. Less than 1% of all college students qualify for acceptance.
Past and present Phi Beta Kappa members from across the country include 17 American presidents, 42 U.S. Supreme Court Justices, more than 150 Nobel Laureates, and numerous artistic, intellectual, and political leaders.
Phi Beta Kappa membership is open to undergraduates in the College of Arts & Sciences and professional degree programs who meet stringent eligibility requirements. A student who has completed 75 hours of course work in the liberal arts and sciences with a GPA of 3.85 or better (on a 4-point scale) is eligible for membership. Also eligible is any student who has completed 105 hours of course work in the liberal arts and sciences with a 3.75 GPA. Grades earned at other universities are not considered.
Phi Beta Kappa has 293 chapters nationwide. UNC’s chapter, Alpha of North Carolina, was founded in 1904 and is the oldest of eight chapters in the state. Each year, Phi Beta Kappa chapters and alumni associations across the country raise and distribute more than $1 million in awards, scholarships and prizes benefiting high schools and college students.
Congratulations to the following physics majors inducted into Phi Beta Kappa:
Ethan Michael Crook
Shourya Mukherjee
Ethan Joshua Meyerhoffer
Sarah Vickers, one of our majors, won the competition for Best Undergraduate Talk at the recent Southeastern Section of the American Physical Society (SESAPS) meeting at Eastern Kentucky University. SESAPS holds meetings to advance and spread knowledge of physics in the Southeastern United States.
Sarah’s talk on Calibration System and Magnetic Shielding for NuDot was selected among 47 participants.
Congratulations to Adrienne Erickcek and Christian Iliadis on being elected as Fellows of the American Physical Society!
Christian’s citation reads: “For pioneering direct measurements of stellar nuclear reactions and fundamental contributions to our understanding of stellar evolution and explosions,”
Adrienne’s citation reads: “For theoretical contributions spanning cosmology, including inflation, cosmic acceleration, and dark matter, with a key focus on understanding primordial density perturbations on small distance scales”
The APS Fellowship Program recognizes 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. Fellowship is a distinct honor signifying recognition by one’s professional peers. Each year, no more than one half of one percent of the APS’s membership is recognized by their peers for election to the status of Fellow of the APS. More information here.
