We present results for the flavor non-singlet u-d parton distribution functions within the nucleon using the quasi-PDF approach. The lattice calculation is performed by employing the twisted mass formulation and two gauge ensembles, having Nf=2 and Nf=2+1+1 dynamical fermions with masses tuned to their physical value. For the Nf=2 physical point ensemble, the unpolarized, helicity and transversity distributions are computed for three values of the nucleon momentum, namely [6, 8, 10]π/L corresponding to [0.83,1.11,1.38] GeV. Upon renormalization, we find that, as the nucleon momentum increases, the lattice results approach the phenomenological distributions resulting from analyses of deep inelastic scattering data, opening a promising path for a direct evaluation of parton distributions from the QCD Lagrangian. For the Nf=2+1+1 physical point ensemble, we present preliminary results for the unpolarized distribution extracted from a nucleon boosted by 8π/L or 0.97 GeV.
@article{arxiv.1811.01589,
title = {Quasi-PDFs from Twisted mass fermions at the physical point},
author = {Constantia Alexandrou and Krzysztof Cichy and Martha Constantinou and Kyriakos Hadjiyiannakou and Karl Jansen and Aurora Scapellato and Fernanda Steffens},
journal= {arXiv preprint arXiv:1811.01589},
year = {2018}
}
Comments
7 pages, 6 figures, The 36th International Symposium on Lattice Field Theory (Lattice 2018)