How should one formulate, extract, and interpret `non-observables' for nuclei?

TL;DR

This paper discusses a systematic framework for defining, extracting, and interpreting nuclear structure 'non-observables' like spectroscopic factors, inspired by parton distribution functions, to improve consistency between experiment and theory.

Contribution

It proposes a new systematic approach for formulating and interpreting nuclear non-observables, addressing ambiguities and uncertainties in their extraction and theoretical calculation.

Findings

Framework allows consistent extraction of non-observables from experimental data.

Provides a method to interpret the significance of short-range correlations.

Illustrates the approach with parton distribution functions as an example.

Abstract

Nuclear observables such as binding energies and cross sections can be directly measured. Other physically useful quantities, such as spectroscopic factors, are related to measured quantities by a convolution whose decomposition is not unique. Can a framework for these nuclear structure `non-observables' be formulated systematically so that they can be extracted from experiment with known uncertainties and calculated with consistent theory? Parton distribution functions in hadrons serve as an illustrative example of how this can be done. A systematic framework is also needed to address questions of interpretation, such as whether short-range correlations are important for nuclear structure.