Related papers: Forces within hadrons on the light front
We clarify the meaning of spatial densities of hadrons. A physical density is given by the expectation value of a local operator for a physical state, and depends on both internal structure and the hadron's wave packet. In some particular…
Densities associated with the energy-momentum tensor are calculated for spin-one targets. These calculations are done in a light front formalism, which accounts for relativistic effects due to boosts and allows for arbitrary spatial…
We clarify the physical origin and meaning of the two-dimensional relativistic densities of the light front formalism. The densities are shown to originate entirely from the use of light front time instead of instant form time, which…
We review some of the recent developments regarding mass, angular momentum and pressure forces inside hadrons. These properties are all encoded in the energy-momentum tensor of the system, which is described at the non-perturbative level in…
The use of light front coordinates allows a fully relativistic description of a hadron's spatial densities to be obtained. These densities must be two-dimensional and transverse to a chosen spatial direction. We explore their relationship…
Light front formalism for composite systems is presented. Derivation of equations for bound state and scattering problems are given. Methods of constructing of elastic form factors and scattering amplitudes of composite particles are…
The interpretation of the energy-momentum tensor form factor $D(t)$ of hadrons in terms of pressure and shear force distributions is discussed, concerns raised in the literature are reviewed, and ways to reconcile the concerns with the…
The light front densities of momentum, angular momentum, and intrinsic pressure are calculated for the photon, both in the free case and at leading order in quantum electrodynamics. In the latter case, we moreover decompose the form factors…
The quantum mechanical definition of probability, the uncertainty principle and Poincare invariance provide strong basic restrictions on the ability to define spatial densities associated with form factors describing the properties of…
The physics related to the form factors of the energy momentum tensor spans a wide spectrum of problems, and includes gravitational physics, hard exclusive reactions, hadronic decays of heavy quarkonia, and the physics of exotic hadrons…
We show that the matrix element of a local operator between hadronic states gives rise to an unambiguous definition of the associated spatial density. As an explicit example, we consider the charge density of a spinless particle in the rest…
The hadron physics community has been actively debating the interpretation of so-called mechanical properties of hadrons. Non-relativistic quantum-mechanical systems like the hydrogen atom have been appealed to in these debates as…
The three-dimensional spatial structure of hadrons is encoded in their form factors. Via appropriate Fourier transform, the latter describe how charge, energy, linear and angular momentum, but also pressure are distributed inside these…
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 gravitational form factors of a hadron are defined through the matrix elements of the energy-momentum tensor current, which can be decomposed into the quark and gluonic parts, between the hadronic states. These form factors provide…
A classical model of a stable particle of finite size is studied. The model parameters can be chosen such that the described particle has the mass and radius of a proton. Using the energy-momentum tensor (EMT), we show how the presence of…
Light-Front quantization is one of the most promising and physical tools towards studying deep inelastic scattering on the basis of quark gluon degrees of freedom. The simplified vacuum structure (nontrivial vacuum effects can only appear…
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…
This is the first of a sequence of papers that address the non-perturbative origin of the central, and spin-dependent forces between quarks. Its main thrust is a focus on meson spectroscopy in the center of mass frame. We suggest a "dense…
The gravitational form factors which are obtained from the matrix elements of the energy-momentum tensor provide us information about internal distributions of mass, energy, pressure and shear. The Druck term is the least understood among…