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arXiv · 1708.05301

Improved Parton Distribution Functions at Physical Pion Mass

Huey-Wen Lin·Jiunn-Wei Chen·Tomomi Ishikawa·Jian-Hui Zhang
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Abstract

We present the first lattice results on isovector unpolarized and longitudinally polarized parton distribution functions (PDFs) at physical pion mass. The PDFs are obtained using the large-momentum effective field theory (LaMET) framework where the full Bjorken-$x$ dependence of finite-momentum PDFs, called "quasi-PDFs", can be calculated on the lattice. The quasi-PDF nucleon matrix elements are renormalized nonperturbatively in RI/MOM-scheme. However, the recent renormalized quasi-PDFs suffer from unphysical oscillations that alter the shape of the true distribution as a function of Bjorken-$x$. In this paper, we propose two possible solutions to overcome this problem, and demonstrate the efficacy of the methods on the 2+1+1-flavor lattice data at physical pion mass with lattice spacing 0.09~fm and volume $(5.76\mbox{ fm})^3$.

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Huey-Wen Lin, Jiunn-Wei Chen, Tomomi Ishikawa, Jian-Hui Zhang. 2017-08-17. Improved Parton Distribution Functions at Physical Pion Mass. https://doi.org/10.1103/physrevd.98.054504

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