Parton Distribution Functions at a Crossroad

Dear Colleagues,

Parton distribution functions (DFs) are a renowned source of hadron structure information. Moreover, experiments, interpretable in terms of hadron DFs, have been a high priority for more than fifty years. For much of this time, DFs were inferred from global fits to data and viewed as benchmarks. Such fitting remains crucial, providing input for the conduct of numerous experiments worldwide. However, the past decade has witnessed the dawn of a new era in theory, with continuum and lattice studies of quantum chromodynamics beginning to yield robust DF predictions. These developments expose conflicts with fitting results, and such disagreements encourage one of the following conclusions: global fit outcomes are misconstrued; not all considered data are a true expression of intrinsic hadron qualities; or QCD, as currently understood, is not the theory of strong interactions. This volume will provide a modern perspective on DFs—experiment, phenomenology, and theory. It will canvass an array of experiments and new ways to make advancements in phenomenology and theory, so that the emerging controversies can be swiftly resolved and a coherent description of hadron structure can be developed.

Dr. Zhu-Fang Cui
Prof. Dr. Craig Roberts
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Particles is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• confinement of gluons and quarks
• dynamical chiral symmetry breaking
• emergence of mass
• Higgs mechanism of mass generation
• pion structure
• proton structure
• parton distributions
• quantum chromodynamics
• Schwinger function methods (continuum and lattice)
• strong interactions in the standard model of particle physics