Windows on the Universe: Probing the Equation of State of Neutron Stars in the Laboratory

Understanding the origin of the elements remains one of the most fundamental questions in modern science. Closely connected to this inquiry is the need to characterize the properties of dense nuclear matter—particularly as it relates to the interiors of neutron stars. This research program aims to address these challenges directly through an integrated approach that combines experimental investigations with advanced theoretical modeling. The components of the project are closely linked in both scope and methodology. The Principal Investigator will mentor both undergraduate and graduate students, providing hands-on training in a broad array of experimental and analytical techniques. This experience will equip students with the skills necessary to pursue impactful careers in STEM disciplines. The primary goals of the proposed work are to: perform a dedicated experiment at FRIB, advance the precision of constraints on the density and momentum dependence of the symmetry energy, and continue related investigations using complementary experiments at both FRIB and RIKEN to improve our understanding of the neutron star equation of state. A central focus of the experimental effort is to investigate the density and momentum dependence of the symmetry energy at supranuclear densities—conditions that are directly relevant to the structure and dynamics of neutron stars. The resulting data will help resolve discrepancies among theoretical predictions and contribute to a more accurate description of the nuclear equation of state (EoS), which plays a critical role in determining neutron star properties such as mass, radius, and tidal deformability. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.