  We show that transverse-momentum-dependent parton distribution functions
(TMDPDFs), important non-perturbative quantities for describing the properties
of hadrons in high-energy scattering processes such as Drell-Yan and
semi-inclusive deep-inelastic scattering with observed small transverse
momentum, can be obtained from Euclidean QCD calculations in the framework of
large-momentum effective theory (LaMET). We present a LaMET factorization of
the Euclidean quasi-TMDPDFs in terms of the physical TMDPDFs and off-light-cone
soft function at leading order in $1/P^z$ expansion, with the perturbative
matching coefficient satisfying a renormalization group equation. We also
discuss the implementation in lattice QCD with finite-length gauge links as
well as the rapidity-regularization-independent factorization for Drell-Yan
cross section.
