2021/06/30 by J. A. Melendez, C. Drischler, A. J. Garcia +2 · 1 citation
Physics and Astronomy · #nucl-th #cond-mat.mtrl-sci #hep-lat #hep-ph #nucl-ex
paper · pdf · doi:10.1016/j.physletb.2021.136608
9 pages, 6 figures; minor updates, close to published version
arxiv created 2021/09/07 · arxiv updated 2021/09/08
We combine Newton's variational method with ideas from eigenvector continuation to construct a fast & accurate emulator for two-body scattering observables. The emulator will facilitate the application of rigorous statistical methods for interactions that depend smoothly on a set of free parameters. Our approach begins with a trial K or T matrix constructed from a small number of exact solutions to the Lippmann--Schwinger equation. Subsequent emulation only requires operations on small matrices. We provide several applications to short-range potentials with and without the Coulomb interaction and partial-wave coupling. It is shown that the emulator can accurately extrapolate far from the support of the training data. When used to emulate the neutron-proton cross section with a modern chiral interaction as a function of 26 free parameters, it reproduces the exact calculation with negligible error and provides an over 300x improvement in CPU time.