Related papers: Spin effects in high energy diffractive reactions
We calculate the spin density matrix of a heavy quark-antiquark pair ($b\bar{b}$, $c\bar{c}$ or $s\bar{s}$) diffractively produced in Deep Inelastic Scattering and Ultraperipheral Collisions. We show that the Pomeron exchange leaves…
We present predictions for the diffractive production of heavy quarks in deep-inelastic scattering and hadron-hadron collisions and for double diffractive dijet production in hadron-hadron collisions. With the assumption of hard scattering…
Spin observables may reveal much deeper properties of non perturbative hadronic physics than unpolarized quantities. We discuss the polarization of hadrons produced in $e^+e^-$ annihilation at LEP. We show how final state $q \bar q$…
Model-independent identities and inequalities relating the various spin observables of a reaction are reviewed in a unified formalism, together with their implications for dynamical models, their physical interpretation, and the quantum…
We review what is currently known about the transverse spin structure of hadrons, in particular from observables that can be analyzed within a collinear framework. These effects have been around for 40 years and represent a critical test of…
We study $pp$ scattering at high energies and moderately large momentum transfer using a QCD--based model in which the proton is viewed as being composed of a quark and a diquark. This model leads to spin asymmetries which are neither small…
Electromagnetic dipole interactions of light quarks induce distinct spin correlations in quark pairs produced at lepton colliders, favoring entangled spin-triplet state aligned along the $\hat{z}$ axis or spin-singlet state. These…
We review topical results on diffractive processes from the experiments H1 and ZEUS at the HERA electron-proton collider. Emphasis is placed on the phenomenological and experimental consequences of the discoveries at HERA for the proposed…
We calculate the single-spin and double-spin asymmetry differential cross sections for the polarized hadron scattering $PP \to l^+ l^- + jet$ up to $O(\alpha_s)$ by the helicity amplitude method. Numerical results of the differential cross…
We give a theoretical perspective on the vorticity and spin polarization in heavy-ion collisions. We discuss the recent progress in spin hydrodynamics and spin kinetic theory. We also discuss other effects caused by vorticity including the…
It is shown that the proton "spin crisis'' or "spin puzzle" can be understood by the relativistic effect of quark transversal motions due to the Melosh-Wigner rotation. The quark helicity $\Delta q$ measured in polarized deep inelastic…
The spin structure of the proton is investigated in the framework of an extended quark potential model which in addition to the conventional $3q$--structure also takes into account $(3q)(q\bar q)$--admixtures in the proton wave function.…
Using heavy quark effective theory a factorized form for inclusive production rate of a heavy meson can be obtained, in which the nonperturbative effect related to the heavy meson can be characterized by matrix elements defined in the heavy…
We discuss a few examples of structure functions for polarized, semi-inclusive scattering processes to show the richness of structure. Then we indicate how polarization and particle production can be used to study the quark and gluon…
HERMES is a second generation experiment to study the spin structure of the nucleon, in which measurements of the spin dependent properties of semi-inclusive deep-inelastic lepton scattering are emphasized. Data have been accumulated for…
In inclusive deep-inelastic lepton-hadron scattering multi-photon exchange between the leptonic and the hadronic part of the process causes single spin asymmetries. The asymmetries exist for a polarized target as well as a polarized…
Spin correlations are carefully investigated in elastic $e^{+}e^{-}$ scattering in QED, for initially \textit{polarized} as well as \textit{unpolarized} particles, with emphasis placed on energy or speed of the underlying particles involved…
In this article we review the present understanding of azimuthal and single spin asymmetries for inclusive and semi-inclusive particle production in unpolarized and polarized hadronic collisions at high energy and moderately large…
The process of two pion production in the electron-polarized proton scattering is investigated. In the Weizs\"acker-Williams approximation the differential spectral distributions and the spin-momentum correlations are considered. The spin…
Spin and polarization effects and correlations between them in the processes of pair production by a photon and synchrotron radiation in a magnetic field are considered. Expressions for the probabilities of the processes with arbitrary…