Speaker
Description
The strong force governing Nucleon-Nucleon (NN) scattering can be modelled using chiral effective field theory -- a systematic low-energy expansion that preserves the symmetries of quantum chromodynamics. In this framework, NN scattering observables are predicted order-by-order. The series is truncated to facilitate computations, and the omission of higher-order terms leads to a theoretical truncation error.
This work investigates how these truncation errors are correlated across scattering energies and angles, but also across different observable types by utilising the fact that all neutron-proton (np) scattering observables depend on only five complex amplitudes.
A Gaussian process-based Bayesian uncertainty quantification model was used to predict truncation errors of the scattering amplitudes, effectively incorporating all symmetries of the scattering event, except the unitarity of the scattering operator. The resulting uncertainties were then propagated to various observables, revealing strong correlations. We showed that these correlations reduced the number of independent np scattering data points.
The error model could enhance the physical robustness of effective field theory parameter inference and the reliability of theoretical predictions for nuclear observables.
