Parton distribution functions (PDFs) at large $x$ are difficult to be extracted from experimental data, but are extremely important in understanding hadron structures as well as searching for new physics beyond the Standard Model. We study the large $x$ PDFs under the framework of large momentum $P^z$ expansion of lattice quasi-PDFs. In the threshold limit, the matching kernel of quasi-PDF can...
Generalized parton distibutions (GPDs) are a key construct for understanding the spatial distribution of quarks and gluons inside nucleons. These distributions are accessed through deeply virtual exclusive processes, the cross sections of which are parameterized using a class of observables known as Compton Form Factors (CFFs). We present a spectator model-based parameterization of twist 2...
From polarised Deep Inelastic scattering (DIS) asymmetries, and cross-section data, it is possible to extract the polarized structure functions $g_1$ and $g_2$. In the parton model picture of proton, the structure function $g_1^p$ is expressed in terms of $g_1^p = \Delta \Sigma + \Delta G$, the net quark and gluon helicity contributions to the proton spin. This spin structure function can also...
Generalized parton distributions (GPDs) provide information about the internal structure of the proton, but GPDs do not enter cross sections directly; instead, they enter through, e.g., the Compton form factors (CFFs), which are the observables of deeply virtual Compton scattering (DVCS). Additionally, one of the most physically interesting quantities in hadron structure is the angular...
AI/ML informed Symbolic Regression is the next stage of scientific modeling. We utilize a highly customizable symbolic regression package "PySR" to model the x and t dependence of the flavor isovector combination $H^{u-d}(x,t,ζ,Q^2)$ at ζ=0 and $Q^2$= 4 GeV$^2$. These PySR models were trained on GPD pseudodata provided by both Lattice QCD and phenomenological sources GGL, GK, and VGG. Symbolic...
We present an analysis of Machine Learning techniques applied to the determination of ratios of nucleon 3-point and 2-point correlation functions in Euclidean time. These quantities are typically computed in the regime of Lattice QCD and are of interest in determining various measures of hadronic structure, such as parton distribution functions (PDFs) and generalised parton distributions...
We calculate Euclidean hadronic matrix elements of two spatially separated local quark currents in position space, in order to determine the $x$ dependence of parton distribution functions (PDFs). This approach is often referred to by the term lattice cross section (LCS). We extend previous works on that topic by considering valence quark PDFs of the proton and adapt the formalism to our...
