### Sarah Wesolowski

Ohio State University
###
Bayesian truncation errors in chiral effective field theory

Properly constructed effective field theories hold the promise of model independence and order-by-order
convergence of observable calculations. We have entered an era in low-energy nuclear physics where
many-body methods are precise enough that we are sensitive to uncertainties in nuclear interactions. The
predictable order-by-order improvement of EFT calculations means that systematic uncertainties from the
interaction itself can in principle be estimated. Using Bayesian methods, we have developed a procedure to
estimate truncation errors in EFT predictions as part of a larger program to fully
quantify EFT uncertainties. The statistical model yields posterior probability distribution
functions (pdfs) for these errors based on expectations of naturalness encoded in Bayesian priors and the
observed order-by-order convergence pattern of the EFT. As a general example, we apply this method to the
semi-local potentials of Epelbaum, Krebs, and Meißner (EKM) for a set of regulator parameters, energies, and NN observables.
The Bayesian approach allows for statistical validations of the assumptions and enables the calculation of posterior pdfs
for the EFT breakdown scale. The statistical model is validated when convergence behavior is not distorted by regulator artifacts.

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