We present a first lattice QCD calculation of the transverse-momentum-dependent wave functions (TMDWFs) of the pion using large-momentum effective theory. Numerical simulations are based on one ensemble with 2+1+1 flavors of highly improved staggered quarks action with lattice spacing a=0.121~fm from the MILC Collaboration, and one with 2 +1 flavor clover fermions and tree-level Symanzik gauge action generated by the CLS Collaboration with a=0.098~fm. As a key ingredient, the soft function is first obtained by incorporating the one-loop perturbative contributions and a proper normalization. Based on this and the equal-time quasi-TMDWFs simulated on the lattice, we extract the light-cone TMDWFs. The results are comparable between the two lattice ensembles and a comparison with phenomenological parametrization is made. Our studies provide a first attempt of abinitio calculation of TMDWFs which will eventually lead to crucial theory inputs for making predictions for exclusive processes under QCD factorization.
@article{arxiv.2302.09961,
title = {Transverse-Momentum-Dependent Wave Functions of Pion from Lattice QCD},
author = {Min-Huan Chu and Jin-Chen He and Jun Hua and Jian Liang and Xiangdong Ji and Andreas Schafer and Hai-Tao Shu and Yushan Su and Ji-Hao Wang and Wei Wang and Yi-Bo Yang and Jun Zeng and Jian-Hui Zhang and Qi-An Zhang},
journal= {arXiv preprint arXiv:2302.09961},
year = {2023}
}