Related papers: The Nucleon's Virtual Meson Cloud and Deep Inelast…
We investigate deep inelastic lepton scattering from the nucleon within a constituent quark picture, in which the internal structure of constituent quarks is modeled by meson and diquark dressing. In a covariant framework this structure…
Recent deep inelastic scattering and Drell-Yan experiments have revealed a surprisingly large asymmetry between the up and down sea quark distributions in the nucleon. In this article, we review the status of the flavor asymmetry of the…
We demonstrate that to a very good approximation the scale-evolution of the intrinsic heavy quark content of the nucleon is governed by non-singlet evolution equations. This allows us to analyze the intrinsic heavy quark distributions…
Pion-nucleon elastic scattering in the dominant $P_{33}$ channel is examined in the model in which the interaction is of the form $\pi + N\leftrightarrow N, \Delta(1232)$. New expressions are found for the elastic pion-nucleon scattering…
The Quark-quark (QQ) and Quark-nucleon (QN) interactions in this paper are derived from the Extended-soft-core (ESC) interactions. The meson-quark-quark (MQQ) vertices are determined in the framework of the constituent quark model (CQM).…
We present results for the nucleon's leading-twist spin-independent valence parton distribution functions obtained from a theoretical framework based on the Dyson-Schwinger equations (DSEs) of QCD that previously gave an excellent…
The higher-twist formalism is used at $O(\alpha^2_s)$ to compute all possible medium-induced single-scattering emission kernels for an incoming highly energetic and virtual quark traversing the nuclear environment. The effects of the…
We study large-distance contributions to the nucleon parton densities in the transverse coordinate (impact parameter) representation based on generalized parton distributions (GPDs). Chiral dynamics generates a distinct component of the…
We studied the statistical model of nucleons consisting of sea having various quark-gluon Fock states in addition to valence quarks. Using statistical consideration and taking 86% of the total Fock states contributing to the low energy…
Nuclear parton distributions are studied in a parton model with rescaling and recombination mechanisms. Parton x distributions are first calculated at Q^2=1 GeV^2 by the model, and they are evolved to larger Q^2 in order to be compared with…
Viscous modifications to the thermal distributions of quark-antiquarks and gluons have been studied in a quasi-particle description of the quark-gluon-plasma medium created in relativistic heavy ion collision experiments. The model is…
In coordinate space, quark and gluon distributions of the nucleon are defined as correlation functions involving two field operators separated by a light-cone distance $y^+ = 2l$. We study the nuclear modifications of these distributions.…
A gauge invariant method for the investigation of scalar diquark clustering in the nucleon ground state is presented. The method focuses on a comparison of quark distributions in the nucleon with those in the $\Delta$ baryon resonance.…
Understanding the differences between the distribution of quarks bound in protons and neutrons is key for constraining the mechanisms of SU(6) spin-flavor symmetry breaking in Quantum Chromodynamics (QCD). While vast amounts of proton…
Two-quark--two-antiquark systems with four different quark flavors are considered in the framework of two-dimensional QCD, in the light-cone gauge, at leading orders of the $1/N_c^{}$ expansion. Introducing basis functions with…
We present high statistics results for the structure of the nucleon from a mixed-action calculation using 2+1 flavors of asqtad sea and domain wall valence fermions. We perform extrapolations of our data based on different chiral effective…
Analytical expressions for the Transverse Momentum Dependent (TMD, or unintegrated) gluon and sea quark densities in nuclei are derived at leading order of QCD running coupling. The calculations are performed in the framework of the…
The experimental and theoretical status of elastic electron scattering from the nucleon is reviewed. A wealth of new data of unprecedented precision, especially at small values of the momentum transfer, in parallel to new theoretical…
We study the helicity distributions of light flavor quark-antiquark ($q \bar{q}$) pairs in the nucleon sea. The valence quarks are handled by adopting the light-cone SU(6) quark-spectator-diquark model and the sea $q \bar{q}$ pairs are…
The fundamental theory of the strong interaction -- quantum chromodynamics (QCD) -- provides the foundational framework with which to describe and understand the key properties of atomic nuclei. A deep understanding of the explicit role of…