2025/11/03 by Alex Gnech, Xilin Zhang, Gnech, Alex +13
Physics and Astronomy · #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2511.01844
We introduce highly accurate and efficient emulators for proton-deuteron scattering below the deuteron breakup threshold. We explore two different reduced-basis method strategies: one based on the Kohn variational principle and another on Galerkin projections of the underlying system of linear equations. We use the adaptive greedy algorithm previously developed for two-body scattering for optimal selection of high-fidelity training points in the input parameter space. We demonstrate that these emulators reproduce ab initio hyperspherical harmonics calculations of R-matrix elements with remarkable precision, achieving relative errors as low as 10-7 with a small number of training points, even in regions of strong nonlinear parameter dependence. They also dramatically accelerate the exploration of the scattering predictions in the parameter space, a capability highly desired for calibrating (chiral) three-nucleon forces against scattering measurements. Our formalism can be further generalized to handle nucleon-deuteron scattering above the breakup threshold. These emulator developments will provide valuable tools to accelerate uncertainty quantification and rigorous parameter inference in the study of nuclear forces.