Related papers: Gluon contribution to the angular momentum distrib…
We investigate the different decompositions of the angular momentum in QCD for a relativistic spin $1/2$ composite state, namely a quark dressed with a gluon. We use light-front Hamiltonian perturbation theory, and in the light-front gauge,…
We present a recent calculation of the quark and gluon contributions to the angular momentum of a composite spin -$1/2$ state in QCD. The state we consider is a quark dressed with a gluon, and we use the two-component framework in…
We calculate the contribution to the gravitational form factors (GFFs) from the gluon part of the energy-momentum tensor in QCD. We take a simple spin $1/2$ composite state, namely a quark dressed with a gluon. We use the light-front…
We present the first complete parametrization for the matrix elements of the generic light-front gauge-invariant energy-momentum tensor, derive the expressions giving separately the spin and orbital angular momentum of quarks and gluons as…
We consider a light-front dressed quark state, per se, instead of a proton state, we consider a simple composite spin-1/2 state of a quark dressed with a gluon. This perturbative model incorporates gluonic degrees of freedom, which enable…
We obtain the energy-momentum tensor (EMT) in the 't Hooft model of two-dimensional quantum chromodynamics. The EMT is decomposed into contributions from quark and gluon fields, with all of the (plus component of) the light front momentum…
We calculate the gravitational form factors (GFFs) and pressure, shear and energy distributions for a quark state dressed with a gluon at one loop in QCD. We use the light-front Hamiltonian approach. In the light-front gauge, we use a…
We define the form factors of the quark and gluon symmetric energy-momentum tensor (EMT). The static EMT is related to the spatial distributions of energy, spin, pressure and shear forces. They are obtained in the form of a multipole…
The lowest two Mellin moments of hadronic Generalized Parton Distributions are explored within a model that allows investigation of the inter-related quark and gluon contributions. For light quarks their dynamical connection is strong due…
We study the quark angular momentum distribution in the nucleon within a light-front covariant quark model. Special emphasis is put into the orbital angular momentum: a quantity which is very sensitive to the relativistic treatment of the…
We present a calculation of Wigner distributions for gluons in light-front dressed quark model. We calculate the kinetic and canonical gluon orbital angular momentum and spin-orbit correlation of the gluons in this model.
Orbital Angular Momentum (OAM) twist-two parton distributions are studied. At the low energy, hadronic, scale we calculate them for the relativistic MIT bag model and for non-relativistic potential quark models. We reach the scale of the…
Everything gravitates and they do so through the energy-momentum tensor (EMT). However, there is no consensus on how to define the EMT of a hadron, e.g. the proton, the fundamental building blocks of the visible world. In this work, we show…
The parton structure of the nucleon and pion is investigated in an exploratory model that allows one to assess whether the dressing of quarks can, by itself, produce realistic gluon contributions to light-cone momentum fractions,…
We investigate the angular momentum decomposition with a quantum electrodynamics example to clarify the proton spin decomposition debates. We adopt the light-front formalism where the parton model is well defined. We prove that the sum of…
The mass components of charmoniumlike states are investigated through the decomposition of QCD energy-momentum tensor (EMT) on lattice. The quark mass contribution $\langle H_m\rangle$ and the momentum fraction $\langle x\rangle$ of valence…
We critically reexamine the formalism for treating the leading-twist contributions from the two-gluon Fock components occurring in hard processes that involve eta and eta' mesons and establish a consistent set of conventions for the…
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 the instanton picture of the QCD vacuum we compute the nucleon $\bar c^Q(t)$ form factor of the quark part of the energy momentum tensor (EMT). This form factor describes the non-conservation of the quark part of EMT and contributes…
We introduce gauge-invariant quark and gluon angular momentum distributions after making a generalization of the angular momentum density operators. From the quark angular momentum distribution, we define the gauge-invariant and…