Bayesian Analysis of $\chi$EFT at Leading Order in a Modified Weinberg Power Counting Approach

Understand

We present a Bayesian analysis of renormalization-group invariant nucleon-nucleon interactions at leading order in chiral effective field theory ($\chi$EFT) with momentum cutoffs in the range 400--4000 MeV.

• We use history matching to identify relevant regions in the parameter space of low-energy constants (LECs) and subsequently infer the posterior probability density of their values using Markov chain Monte Carlo.
• All posteriors are conditioned on experimental data for neutron-proton scattering observables and we estimate the $\chi$EFT truncation error in an uncorrelated limit.
• We do not detect any significant cutoff dependence in the posterior predictive distributions for two-nucleon observables.