Facility for Rare Isotope Beams

More than 50 years after the discovery of neutrons stars, their interior composition and structure remains unknown. Because the extreme densities and matter asymmetry in neutron star interiors are out of reach for Earth laboratories, the equation of state of bulk nuclear matter is unknown, with important implication for astrophysics and nuclear physics. Thankfully, measurements of neutron stars masses and radii are direct probes of the interior of these compact objects. In the past two decades, X-ray observatories have provided some measurements of neutron star radii and therefore some constraints on the dense matter equation of state. But recently, the results from the NICER Observatory have provided the most promising, robust and precise constraints. I will review some of the key results from the NICER mission (including the most recent measurements) and give an overview of other existing measurements of masses and radii, as well as present their impact on our knowledge of dense nuclear matter. Finally, I will detail future prospects to constrain the equation of state of dense nuclear matter with upcoming X-ray observatories.

Committee: Witold Nazarewicz (Chairperson), Metin Aktulga, Paul Gueye, Filomena Nunes, Johannes Pollanen. Thesis is available @ https://pa.msu.edu/graduate-program/current-graduate-students/draft-dissertations-for-review.aspx - Select student name

Committee: Witold Nazarewicz (Chairperson), Heiko Hergert, Ryan LaRose, Hendrik Schatz, Yang Yang Thesis is available @ https://pa.msu.edu/graduate-program/current-graduate-students/draft-dissertations-for-review.aspx - Select student name

In recent times, it has become commonplace to mention the unification of structure and reaction nuclear theory as one of the hot topics in low-energy nuclear physics. This interest is, of course, not new, but some present circumstances might have made it more acute. First, the experimental access to very weakly bound or unbound nuclei has blurred the limits between structure and reaction theory. Second, the fast development of computational tools and resources has rendered scattering problems tractable with bound states techniques. We will also address some ideas in the path to another important unification: the theory of direct and compound nucleus reactions. This line of research is important in order to address important processes, such as capture reactions, involving nuclei away from the stability valley, where an unusually low level density calls for the description of a transition between the statistical and direct reaction regimes.

The RMS radii of the neutron distribution in both 208Pb and 48Ca have been precisely measured by the PREX and CREX experiments via the parity violating asymmetry in longitudinally polarized elastic electron-nucleus scattering. The advantage of these parity violating electron scattering measurements lies in the use of an electroweak probe to measure these quantities, significantly reducing uncertainties from theoretical interpretations. The PREX measurement of the large 208Pb nucleus, for which nuclear density functional theory can be applied, provides meaningful constraints on the density dependence of the symmetry energy of neutron-rich nuclear matter; an important parameter for the nuclear equation of state. The complimentary CREX measurement of the modestly sized, neutron rich 48Ca nucleus, for which edge effects are significant, provides an important benchmark for nuclear theory to help bridge ab-initio theoretical approaches and the nuclear density functional theory. While the electroweak nature of the interaction lends itself to a clean interpretation of the results it also presents significant experimental hurdles, including the need to employ innovative precision beam control techniques. This talk will give an overview experimental results from the PREX and CREX collaborations, will touch upon the tension observed between these results and select theoretical calculations and measurements, and will describe the techniques employed to meet the stringent systematic uncertainty goals arising from beam asymmetries during the PREX-II and CREX experiments. The upcoming MOLLER experiment which will utilize these beam control techniques to search for new BSM (Beyond the Standard Model) physics through ultra-precise measurement of the weak charge of the electron will also be discussed.

Committee: Steven Lidia (Thesis Advisor), Scott Pratt (Committee Chair), Sergey Baryshev Joshua Coleman, Artemis Spyrou. Thesis is available @ https://pa.msu.edu/graduate-program/current-graduate-students/draft-dissertations-for-review.aspx - Select student name

Trio in A major for two violin and viola by Mykola Lysenko I. Andante. Allegro animato II. Romance III. Scherzo IV. Finale Bios: Mengyuan Song is a violist from China. She is currently a first year DMA student at Michigan State University, studying violia performance with Professor Mike Chen. She previously completed the master degree from The University of Northern Colorado and completed Graduate Professional Diploma from The Hartt School. Min-Han Tsai is a violinist from Taiwan. He is currently a first year DMA student at Michigan State University, studying violin performance with Professor I-Fu Wang. He previously completed the master degree and a performance Certificate from Bowling Green State University, and he was the concertmaster of the BGSU Philharmonia and performed in the Graduate String Quartet. Min-Han is currently an active performer in Michigan. Lyudmila Gofurova is a violinist from Tashkent, Uzbekistan. She is currently pursuing a Master's degree in Violin Performance at Michigan State University under the guidance of Professor Yvonne Lam. She earned her Bachelor's degree in Tashkent. As a member of the Uzbekistan Youth Symphony Orchestra and the National Symphony Orchestra of Uzbekistan, she has performed in over 10 countries. Lyudmila is an active performer, chamber musician, and dedicated educator in Michigan.

A James Madison College event at FRIB.

TBD

Learning is one way how biological systems change. Evolution can also be thought of as learning but on longer time scales. This presentation will describe emerging evidence showing that biological systems organize them according to hyperbolic surfaces and that these surfaces expand according to similar principles in both learning and evolution. Across different scales of biological organization, biological networks often exhibit hierarchical tree-like organization. For networks with such structure, hyperbolic geometry provides a natural metric because of its exponentially expanding resolution. I will describe how the use of hyperbolic geometry can be helpful for visualizing and analyzing information acquisition and learning process from across biology, from viruses, to plants and animals, including the brain. We find that local noise causes data to exhibit Euclidean geometry on small scales, but that at broader scales hyperbolic geometry becomes visible and pronounced. The hyperbolic maps are typically larger for datasets of more diverse and differentiated cells, e.g. with a range of ages. We find that adding a constraint on large distances according to hyperbolic geometry improves the performance of t-SNE algorithm to a large degree causing it to outperform other leading methods, such as UMAP and standard t-SNE. For neural responses, I will describe data showing that neural responses in the hippocampus have a low-dimensional hyperbolic geometry and that their hyperbolic size is optimized for the number of available neurons. It was also possible to analyze how neural representations change with experience. In particular, neural representations continued to be described by a low-dimensional hyperbolic geometry but the radius increased logarithmically with time. This time dependence matches the maximal rate of information acquisition by a maximum entropy discrete Poisson process, further implying that neural representations continue to perform optimally as they change with experience. Tatyana Sharpee received her PhD in condensed matter physics from Michigan State University studying under the supervision of Mark Dykman. After her PhD, she started to work in computational neuroscience at UCSF where she developed statistical methods for analyzing neural responses to natural stimuli, which exhibit strong correlations and non-Gaussian effects. These methods made it possible to reveal new adaptation processes in the brain by comparing neural responses to white noise and natural stimuli. Her independent research program has started at the Salk Institute for Biological Studies where she is currently a Professor in the Computational Neurobiology and Integrative Biology Laboratories. Dr. Sharpee is a fellow of the American Physical Society.

The Nuclear Science Summer School (NS3) is a summer school that introduces undergraduate student participants to the fields of nuclear science and nuclear astrophysics. NS3 is hosted by FRIB on the campus of Michigan State University (MSU). The school will offer lectures and activities covering selected nuclear science and astrophysics topics.

PAN introduces participants to the fundamentals of the extremely small domain of atomic nuclei and its connection to the extremely large domain of astrophysics and cosmology.

The PAN @ Michigan State Experience

• Learn about research in one of the top rare-isotope laboratories in the world.
• Get introduced to the fascinating fields of astrophysics, precision measurement, and nuclear science.
• Perform your own nuclear physics experiments.
• Meet researchers who are exploring a wide array of questions.
• Discover the surprising array of career opportunities in science.
• Experience the atmosphere of college life.
• Participants in the 2024 program get free room and board on campus (if required).