Towards a unified treatment of $\Delta S=0$ parity violation in low-energy nuclear processes

TL;DR

This paper advances the theoretical understanding of low-energy hadronic parity violation by integrating improved effective Hamiltonians, lattice QCD results, and experimental data to refine parity-violating coupling constants, highlighting ongoing challenges and future directions.

Contribution

It provides a more precise ab initio framework for analyzing parity violation in nuclear processes, bridging effective Hamiltonian methods with lattice QCD and experimental results.

Findings

Improved agreement with experimental measurements of hadronic parity violation.

Identification of remaining tensions between theory and experiment.

Highlighting the potential of future lattice QCD studies to refine understanding.

Abstract

We revisit the unified treatment of low-energy hadronic parity violation espoused by Desplanques, Donoghue, and Holstein to the end of an ab initio treatment of parity violation in low-energy nuclear processes within the Standard Model. We use our improved effective Hamiltonian and precise non-perturbative assessments of the quark charges of the nucleon within lattice QCD to make new assessments of the parity-violating meson-nucleon coupling constants. Comparing with recent, precise measurements of hadronic parity violation in few-body nuclear reactions, we find improved agreement with these experimental results, though some tensions remain. We thus note the broader problem of comparing low-energy constants from nuclear and few-nucleon systems, considering, too, unresolved theoretical issues in connecting an ab initio, effective Hamiltonian approach to chiral effective theories. We note how future experiments and lattice QCD studies could sharpen the emerging picture, promoting the study of hadronic parity violation as a laboratory for testing ``end-to-end'' theoretical descriptions of weak processes in hadrons and nuclei at low energies.