Project Description

The team will perform a high statistics calculation of the isospin-2 parity violating amplitude in the two-nucleon system. The lack of knowledge of this amplitude currently limits the physics the team can extract from the field’s most precise measurements, on the p~ + p asymmetry. These calculations will provide important theoretical support for current and future experimental efforts such as the NPDGamma Experiment at ORNL.

An understanding of Hadronic Parity Violation (HPV) directly from the Standard Model of physics remains an outstanding theoretical challenge. The underlying weak interactions between the quarks are well understood. However, these interactions are masked by the non-perturbative nature of QCD, which describes the interactions between quarks and gluons that are bound into the observed hadrons. The least constrained of all the Standard Model currents is the hadronic neutral weak interaction, which is best studied in low-energy nuclear environments. The typical strength of this hadronic weak interaction is 7 orders of magnitude smaller than the typical QCD interactions, making it extremely challenging to measure experimentally. An improved theoretical understanding of these phenomena will be necessary to interpret the experimental results in terms of the underlying interactions. Lattice QCD is the only theoretical tool available to quantitatively determine these HPV quantities directly in terms of the Standard Model parameters.

This research is supported by the DOE Office of Science SciDAC 3 Initiative and the Early Career Award program.

Allocation History

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