Parton physics from a heavy-quark operator product expansion: Formalism and strategy

Chi-Jen Lin^1*, William Detmold², Anthony Grebe², Issaku Kanamori³, Robert Perry¹, Yong Zhao⁴

¹Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
²Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
³RCCS, RIKEN, Kobe, Japan
⁴Department of Physics, Argonne National Lab, Lemont, IL, USA

* Presenter:Chi-Jen Lin, email:dlin@nycu.edu.tw

Parton distribution functions (PDFs) and light-cone distribution amplitudes (LCDAs) are crucial non-perturbative quantities of for understanding  high-energy inelastic and elastic scattering of hadrons, respectively.   As a result, first-principle calculations for these objects are important.  Being the only reliable non-perturbative method for performing computations in quantum field theory, lattice field theory is the most suitable tool for such calculations.  In this talk, I discuss the challenges in applying lattice QCD to parton physics, and introduce a strategy for this task [Phys. Rev. D 73 (2006), 014501and Phys. Rev. D 104 (2021) 7, 074511].  The key feature of this strategy is the introduction of a fictitious, valence heavy quark, which leads to several advantages, such as a partial suppression of higher-twist effects, in lattice calculation.   A numerical implementation of this approach for the pion light-cone distribution amplitude is presented at Robert Perry's talk at this conference.

Keywords: quantum chromodynamics, lattice field theory, hadron structure