Parton Distributions Functions from Lattice QCD

Fernanda Steffens (HISKP, Bonn)

Abstract:

Hadrons are composite objects, and their most inner structure and dynamics are contained inside their parton distributions functions (PDFs). To calculate PDFs from first principles is, thus, of great interest to hadron physics as well as to particle physics in general, as PDFs are also used as basic inputs in the searches for new physics. Until recently, our knowledge of PDFs came solely from parametrizations of world data, and an ab initio calculation was considered out of reach. This scenario has changed since the introduction of quasi-PDFs in 2013 by Ji, where it was proposed that instead of the usual light-cone PDFs one should compute spatial correlations, the quasi-PDFs. I will present in this colloquium the basic ideas of the quasi-PDFs approach, how lattice QCD can be used to compute them, the relation between them and the light-cone PDFs, and the latest developments in this field, including recent lattice results at the physical point.

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