Related papers: Quark and Gluon Angular Momentum in the Nucleon
We propose a new model of the nucleon in which quark-diquark configurations immersed in a pion cloud are treated in a manner consistent with Poincar\'e invariance. With suitably chosen parameters, the computations employing this model…
We study the connection between the quark orbital angular momentum and the pretzelosity transverse-momentum dependent parton distribution function. We discuss the origin of this relation in quark models, identifying as key ingredient for…
We study the correlation between the quark spin and orbital angular momentum inside the pion meson. Similar to the case inside the nucleon, the longitudinal spin-orbit correlation $C_z^{q/\pi}$ in pion meson can be expressed in terms of the…
Parallel to the construction of gauge invariant spin and orbital angular momentum for QED in paper (I) of this series, we present here an analogous but non-trivial solution for QCD. Explicitly gauge invariant spin and orbital angular…
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.…
We show how generalized quark distributions in the nucleon describe the density of polarized quarks in the impact parameter plane, both for longitudinal and transverse polarization of the quark and the nucleon. This density representation…
Diffractive production of J/Psi particles by virtual photons on a proton target is studied with a view towards understanding two important corrections to the leading order result. First, the effect of Fermi motion of the heavy quarks is…
We study the semi-classical interpretation of the $x^3$ and $x^4$ moments of twist-3 parton distribution functions (PDFs). While no semi-classical interpretation for the higher moments of $g_T(x)$ and $e(x)$ was find, the $x^3$ moment of…
Due to the presence of a large orbital angular momentum of the parton system produced at the early stage of non-central heavy-ion collisions, quarks and anti-quarks are shown to be polarized in the direction opposite to the reaction plane…
We investigate the transverse momentum dependent (TMD) quark and gluon distribution functions in the modified chiral quark model ($\chi QM$). Calculations of the TMD quark and gluon densities, using the modified $\chi QM$ are done for the…
We investigate the gravitational form factors (GFFs) and the longitudinal momentum densities ($p^+$ densities) for proton in a light-front quark-diquark model. The light-front wave functions are constructed from the soft-wall AdS/QCD…
We present a complete study of the leading-twist quark Wigner distributions in the nucleon, discussing both the $\mathsf T$-even and $\mathsf T$-odd sector, along with all the possible configurations of the quark and nucleon polarizations.…
The gluon distribution of a nucleon propagating through a nucleus can change depending on how far the penetration depth is. It is a nonperturbative process that we describe by an evolution equation. The kernel of the integral equation is to…
We solve for the $\rho$-meson's wave functions from a light-front QCD Hamiltonian determined for its constituent quark-antiquark and quark-antiquark-gluon Fock components, with a three-dimensional confinement using basis light-front…
Using an intrinsic parton model we estimate the rough shape and size of the intrinsic gluon component of the nucleon, corresponding to an energy scale $Q$ of the order $\lqcd$. It is nearly as hard in shape as the valence quark, while its…
The electromagnetic nucleon form factors provide constraints on generalized quark distributions. Key results of the study presented here are a strong dependence of the average impact parameter of quarks on their longitudinal momentum…
The Generalized Parton Distributions (GPDs) are the appropriate framework for a universal description of the partonic structure of the nucleon. They characterize the dynamics of quarks and gluons inside the nucleon and consequently contain…
The implications of one gluon exchange generated configuration mixing in the Chiral Quark Model ($\chi$QM$_{gcm}$) with SU(3) and axial U(1) symmetry breakings are discussed in the context of proton flavor and spin structure as well as the…
The onset of equilibration in nuclear collisions can lead to related trends in the centrality dependence of the average transverse momentum, pt fluctuations and net charge fluctuations. We extend the transport description of S. Gavin (Phys.…
It is shown that, based only on two empirically known facts besides two reasonable theoretical postulates, we are inevitably led to a conclusion that the quark orbital angular momentum carries nearly half of the total nucleon spin. We also…