arXiv subjects

Sven Heihoff

Publications and source records attributed to Sven Heihoff.

3 recordsLinked to original sources

arXiv2026

Spectroscopic basis for short-range three-nucleon forces

We introduce a spectroscopic basis for the subleading contact three-nucleon forces, which allows one to classify these interactions according to the total angular momentum and parity quantum numbers in a transparent way. Using this new basis, we explore the sensitivity of nucleon-deuteron observables to the three-nucleon short-range interactions. The low dimensionality of the variable-parameter space in the spectroscopic basis allows us to build a simple nucleon-deuteron scattering emulator using radial basis function interpolation. We perform exploratory fits of the subleading contact three-nucleon interactions and demonstrate that 9 of 13 low-energy constants can be reliably determined from elastic nucleon-deuteron scattering data.

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arXiv2026

Exact emulation of few-body systems at low cost

Effective field theories have established themselves as key pillars of modern nuclear physics. They enable a quantitative understanding of the strong nuclear force, provided low-energy constants that parametrize short-distance physics can be determined from experimental data. This, however, often becomes prohibitively expensive due to a significant computational cost of solving the A-body problem. The computational challenge is particularly severe for three-body forces, which are at the frontier of nuclear and atomic physics and play an important role in the equation of state of neutron stars. Here we prove that for a parametric low-rank update of a Hamiltonian, the A-body problem at a fixed energy exactly reduces to a low-dimensional matrix equation regardless of the size of the Hilbert space. As a proof-of-principle, we present exact and computationally cheap snapshot-based emulators for few-body scattering and bound states. Unlike alternatives, our emulators can be used far away from the snapshot region without loss of precision and yield accurate results for parameter values not accessible using conventional solution techniques. Our approach is not restricted by the interaction type, number of particles, and methods for generating snapshots and can be applied to mitigate the computational burden of the A-body problem to a broad class of problems in nuclear, atomic, and molecular physics.

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arXiv2025

Can the strong interactions between hadrons be determined using femtoscopy?

In the last decades, femtoscopic measurements from heavy-ion collisions have become a popular tool to investigate the strong interactions between hadrons. The key observables measured in such experiments are the two-hadron momentum correlations, which depend on the production mechanism of hadron pairs and the final-state interactions. Given the complexity of ultra-relativistic collision experiments, the source term describing the production mechanism can only be modeled phenomenologically based on numerous assumptions. The commonly employed approach for analyzing femtoscopic data relies on the Koonin-Pratt formula, which relates the measured correlation functions with the relative wave function of an outgoing hadron pair and a source term that is assumed to be universal. Here, we critically examine this universality assumption and show that for strongly interacting particles such as nucleons, the interpretation of femtoscopic measurements suffers from a potentially large intrinsic uncertainty. We also comment on the ongoing efforts to explore three-body interactions using this experimental technique.

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