Related papers: Polarisation in deeply virtual meson production
The factorisation of the hard amplitude for exclusive meson production in deep inelastic scattering is considered in the framework of a simple model. It is demonstrated explicitly how gauge invariance ensures the cancellation of…
Anisotropy in heavy-ion collisions leads to polarization of both direct and virtual photons, the latter detected via internal conversion to dileptons pairs. Thus measurement of photon polarization probes the anisotropy at all stages of…
The main goals of `spin physics' are recalled, and some theoretical and phenomenological aspects of longitudinally polarized deep inelastic scattering and other hard processes are reviewed. The spin dependent parton densities of protons and…
We discuss results on the diffractive production of the vector mesons rho, phi and omega reported by the H1 and ZEUS collaborations at HERA. Unique to such studies is the experimental accessibility to the polarization of the vector mesons…
We discuss the production of polarized hadrons in polarized lepton nucleon interactions and show that the helicity density matrix of the hadron, when measurable, can give information on the spin structure of the nucleon and the spin…
In this talk various spin effects in hard exclusive electroproduction of mesons are briefly reviewed and the data discussed in the light of recent theoretical calculations within the frame work of the handbag approach. For electroproduction…
Little information is known about the polarization of gluons inside a longitudinally polarized proton. I report on the sensitivity of photoproduction experiments to it. Both jet and heavy quark production are considered.
The production of hadrons in polarized lepton-nucleon deep inelastic scattering is discussed. The helicity density matrix of the hadron is computed within the QCD hard scattering formalism and its elements are shown to yield information on…
The production of a highly-polarized positron beam via nonlinear Breit-Wheeler processes during the interaction of an ultraintense circularly polarized laser pulse with a longitudinally spin-polarized ultrarelativistic electron beam is…
It is shown that the polarization in inclusive hyperon production and the left-right asymmetries in meson and hyperon production are closely related to one other. They can be understood in terms of a picture in which the orbital motion of…
Exclusive vector meson production from real and virtual photons is, for the most part, described well by soft pomeron exchange. However, there are some unsolved normalisation problems, and just a hint that an additional contribution from…
We analyze in detail the size of next-to-leading order corrections to hard exclusive meson production within the collinear factorization approach. Corrections to the cross section are found to be huge at small xB and substantial in typical…
Frequency dependence of pulsar linear polarization is investigated by simulations of emission and propagation processes. Linearly polarized waves are generated through curvature radiation by relativistic particles streaming along curved…
We study the polarisation of gauge bosons produced at the LHC. Polarisation effects for W bosons manifest themselves in the angular distributions of the lepton and in the distributions of lepton transverse momentum and missing transverse…
Exclusive $\rho^0$-meson electroproduction is studied by the HERMES experiment, using the 27.6 GeV longitudinally polarized electron/positron beam of HERA and a transversely polarized hydrogen target, in the kinematic region 1.0…
The role of transversity or helicity-flip generalized parton distributions (GPDs) in leptoproduction of vector mesons is investigated within the framework of the handbag approach. The transversity GPDs in combination with twist-3 meson wave…
We point out that hard exclusive production of tensor mesons $f_2(1270)$ with helicity $\lambda=\pm 2$ is dominated by the gluon component in the meson wave function and can be used to determine gluon admixture in tensor mesons in a…
Pion production at threshold from nucleon-deuteron collisions is considered, with reference to the outgoing channel where the three-nucleon system is bound. The available experimental data are compared with calculations using accurate…
We analyze polarization phenomena for pseudoscalar and vector mesons production in nucleon-nucleon collisions. We identify three energy regions corresponding to different physics and different approaches in the analysis of polarization…
Based on the formalism presented in [1], we make a systematic study of spin polarizations of hadrons with different spins including vector mesons, spin-1/2 and spin-3/2 hyperons and spin correlations of hadron-hadron such as…