English

Transversity GPDs of the proton from lattice QCD

High Energy Physics - Lattice 2022-02-16 v2 High Energy Physics - Experiment High Energy Physics - Phenomenology High Energy Physics - Theory Nuclear Theory

Abstract

We present the first calculation of the xx-dependence of the isovector transversity generalized parton distributions (GPDs) for the proton within lattice QCD. We compute the matrix elements with non-local operators containing a Wilson line. The calculation implements the Breit symmetric frame. The proton momenta are chosen as 0.83,1.25,1.670.83,\,1.25,\,1.67 GeV, and the values of the momentum transfer squared are 0.69,1.020.69,\,1.02 GeV2^2. These combinations include cases with zero and nonzero skewness. The calculation is performed using one ensemble of two degenerate-mass light, a strange and a charm quark of maximally twisted mass fermions with a clover term. The lattice results are renormalized non-perturbatively and finally matched to the light-cone GPDs using one-loop perturbation theory within the framework of large momentum effective theory. The final GPDs are given in the MS\overline{\rm MS} scheme at a scale of 2 GeV. In addition to the individual GPDs, we form the combination of the transversity GPDs that is related to the transverse spin structure of the proton. Finally, we extract the lowest two moments of GPDs and draw a number of important qualitative conclusions.

Keywords

Cite

@article{arxiv.2108.10789,
  title  = {Transversity GPDs of the proton from lattice QCD},
  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:2108.10789},
  year   = {2022}
}

Comments

24 pages, 11 figures, version accepted in Phys. Rev. D