Novel Calculation of Nucleon Generalized Form Factors in Lattice QCD at the Physical Point

PI Martha Constantinou, Temple University
Co-PI Constantia Alexandrou, University of Cyprus and The Cyprus Institute
Constantinou INCITE Graphic

Caption: Demonstration of the successful reconstruction of the pion and kaon PDF from their Mellin moments calculated in lattice QCD (Phys.Rev.D 104 (2021) 5, 054504). The methodology will be used for the proton using the INCITE award. Credit: Martha Constantinou, Temple University, and Constantia Alexandrou, University of Cyprus and The Cyprus Institute.

Project Summary

This project aims to research Mellin moments of the proton generalized parton distributions. Numerical simulations will be performed with quark masses as encountered in nature.

Project Description

This project aims to evaluate key quantities so as to probe nucleon structure with unprecedented accuracy using lattice quantum chromodynamics. The work will enable a continuum extrapolation directly from the physical pion mass, thereby advancing the state-of-the-art. In particular, the continuum limit will be obtainable without the need to combine data with heavier-than-physical point simulations—thus avoiding a chiral extrapolation that introduces a systematic error difficult to quantify for for the baryon sector. 

The researchers will employ their well-developed methodology to construct quark correlation functions yielding a broad set of quantities, primarily focusing on the generalized form factors up to three covariant derivatives and extracting up to the fourth Mellin moments. In addition to generalized form factors, nucleon form factors will be obtained without extra computational cost. 

The project is fully aligned with a central milestone of nuclear physics—that is, to address important questions of how properties of the nucleon emerge directly from the dynamics of its constituents, recently reaffirmed by The National Academies of Sciences, Engineering, and Medicine.