New Developments in Light-Front Nuclear Structure

Abstract

Nuclear physics is the study of many-body systems of protons and neutrons and their constituent interactions. Historically, our understanding of nuclear structure developed from low-energy scattering experiments, for which independent-particle models proved widely successful. Early A(e,e'p) measurements at NIKHEF and Saclay, however, revealed that this picture is incomplete, updating our theoretical description of the nucleus toward a correlated many-body framework. In particular, these experiments---along with later high-momentum-transfer work at Jefferson Lab---highlighted the importance of nucleon-nucleon short-range correlations (SRCs), two-nucleon configurations with high relative momentum and low center-of-mass momentum. SRC phenomenology uses such configurations to explain the plateaus observed in ratios of inclusive electron-nucleus to deuterium cross sections. With current and forthcoming high-energy electron-nucleus experiments at Jefferson Lab and the Electron-Ion Collider, nuclear structure must once again be updated---this time into a relativistic formulation suitable for such kinematics, which has not previously been carried out. This dissertation develops nuclear structure in that direction, motivated by these future experiments. Building on existing tools from conventional nuclear physics, we reformulate them in a relativistic, light-front-quantized framework. Our light-front nuclear structure calculations, adapted from density functional theory, reproduce nuclear binding energies and shell structure well, and incorporate the physics of nucleon-nucleon SRCs through similarityrenormalization group techniques. Our results indicate that a purely nucleonic description of scattering is insufficient to capture inclusive electron-nucleus data and does not fully reproduce the plateaus seen at high Bjorken-$x_B$, pointing to the importance of inelastic final-state interactions that current SRC phenomenology does not account for.