Valence Quark Ratio in the Proton

Beginning with precise data on the ratio of structure functions in deep inelastic scattering（DIS） from ³ He and ³ H, collected on the domain 0.19 ≤ xB≤ 0.83, where xBis the Bjorken scaling variable, we employ a robust method for extrapolating such data to arrive at a model-independent result for the xB= 1 value of the ratio of neutron and proton structure functions. Combining this with information obtained in analyses of DIS from nuclei, corrected for target-structure depen...     

Revealing pion and kaon structure via generalised parton distributions

Clear windows onto emergent hadron mass(EHM)and modulations thereof by Higgs boson interactions are provided by observable measures of pion and kaon structure,many of which are accessible via generalised parton distributions(GPDs).Beginning with algebraic GPD Ans?tze,constrained entirely by hadron-scaleπand K valence-parton distribution functions(DFs),in whose forms both EHM and Higgs boson influences are manifest,numerous illustrations are provided.They include the properties of electromagnetic form factors,impact parameter space GPDs,gravitational form factors and associated pressure profiles,and the character and consequences of allorders evolution.The analyses predict that mass-squared gravitational form factors are stiffer than electromagnetic form factors;reveal that K pressure profiles are tighter than profiles,with both mesons sustaining near-core pressures at magnitudes similar to that expected at the core of neutron stars;deliver parameter-free predictions for and K valence,glue,and sea GPDs at the resolving scale l=2GeV;and predict that at this scale the fraction of meson mass-squared carried by glue and sea combined matches that lodged with the valence degrees-of-freedom,with a similar statement holding for mass-squared radii.     

All-Orders Evolution of Parton Distributions: Principle,Practice, and Predictions

Parton distribution functions(PDFs) are defining expressions of hadron structure. Exploiting the role of effective charges in quantum chromodynamics, an algebraic scheme is described which, given any hadron’s valence parton PDFs at the hadron scale, delivers predictions for all its PDFs(unpolarized and polarized) at any higher scale. The scheme delivers results that are largely independent of both the value of the hadron scale and the pointwise form of the charge; and, inter alia, enables deriva...     

Empirical Determination of the Pion Mass Distribution

Existing pion+nucleus Drell-Yan and electron+pion scattering data are used to develop ensembles of modelindependent representations of the pion generalized parton distribution(GPD).Therewith,one arrives at a datadriven prediction for the pion mass distribution form factor,θ₂^π.Compared with the pion elastic electromagnetic form factor,θ₂^π is harder:the ratio of the radii derived from these two form factors is r_π^θ₂/r_...