Speaker
Yong Zhao
(Massachusetts Institute of Technology)
Description
We present a lattice-QCD calculation of the unpolarized isovector parton distribution func- tion (PDF) using ensembles at the physical pion mass with the large proton boost momentum Pz ? {2.2, 3.0} GeV within the framework of large-momentum effective theory (LaMET). In contrast with our previous physical-pion PDF result, we increase the statistics significantly, double the boost momentum, increase the investment in excited-state contamination systematics, and switch to a different operator for the quasi-PDF to avoid mixing with scalar matrix elements. We used four source-sink separations in our analysis to control the systematics associated with excited-state contamination. The one-loop LaMET matching corresponding to the new operator is calculated and applied to our lattice data. We detail the systematics that affect PDF calculations, providing a guide such that future calcula- tions can further improve on the precision of lattice PDF. We find our final parton distribution in reasonable agreement with the PDF provided by the CT14 global analysis.
