Related papers: Polarisation in deeply virtual meson production
It is pointed out that the meson cloud model predicts a substantial polarization of the sea quarks of the nucleon due to interference of $\pi$ and $\rho$ exchanges. This polarization is strongly flavour dependent. The model gives an…
The tensor polarisation of omega mesons produced in the pd-->3He+omega reaction has been studied at two energies near threshold. The 3He nuclei were detected in coincidence with the pi0pi+pi- or pi0gamma decay products of the omega. In…
An analysis of all possible polarization observables for the case of vector meson photoproduction from a nucleon target is presented. The question of which observables are needed to determine completely the basic photoproduction amplitudes…
The three-loop vacuum polarization function $\Pi(q^2)$ induced by a massive quark is calculated. A comprehensive description of the method is presented. From the imaginary part the ${\cal O}(\alpha_s^2)$ result for the production of heavy…
Exclusive $\pi^0$ electroproduction from nucleons at large $Q^2$ can be described by Generalized Parton Distributions (GPDs), particularly the chiral odd subset related to transversity. These GPDs can be accessed experimentally from various…
We present a computation of diboson production in the $W^\pm Z$ channel at the Large Hadron Collider (LHC), incorporating leptonic decays of the gauge bosons and considering intermediate gauge bosons with definite polarization states. The…
We present a status report on a study of vector meson leptoproduction for the HERA energy range on the basis of the generalized handbag approach. In contrast to the leading twist approach transverse degrees of freedom as well as Sudakov…
Polarization transfer (PT) observables in the single pion production induced by the charged current interaction of the neutrino with the nucleon are examined. The polarization components of the final nucleon and the charged lepton are…
Surprisingly large polarization in hyperon production by unpolarized proton beam has been known since long time. Huge inclusive hyperon polarization data are available in literature, few data are disponible on spin observables and none on…
We investigate the production of spin-3/2 hyperon pairs, $\Omega^- \bar{\Omega}^+$, in electron-positron annihilation within the helicity amplitude formalism. A refined selection of helicity basis matrices is proposed to relate polarization…
Within the context of flux tube models, heavy quark fragmentation takes place through the breaking of flux tubes with the production of a (di)quark-anti(di)quark pair. It is found that the (di)quark produced are more likely to be found in…
Polarized antiprotons can be produced in a storage ring by spin--dependent interaction in a purely electron--polarized hydrogen gas target. The polarizing process is based on spin transfer from the polarized electrons of the target atoms to…
Longstanding puzzles in spin physics can be confronted at the high energies of the LHC. Will large s-quark and c-quark polarization be observed through heavy hyperon production? Top quarks are expected to have significant polarization -…
Exclusive pi0 electroproduction from nucleons at large photon virtuality can be described in terms of Generalized Parton Distributions, particularly the chiral odd subset. Chiral odd GPDs are related to transversity and can be accessed…
The exclusive photoproduction of a pair of light mesons is studied within the framework of collinear factorisation. The amplitude factorises into a process-dependent perturbatively calculable hard part, a generalised parton distribution…
The new formalism for description of (un)polarized semi-inclusive DIS at moderate energies is developed. Hadron production is modeled as a product of distribution functions and hadronization functions (HFs) weighted by the hard scattering…
Understanding the polarization property of $J/\psi$ is critical to constrain its production mechanism. In addition, the polarization of $J/\psi$ can reveal the impact of strong electromagnetic and vorticity fields in relativistic heavy ion…
Deeply virtual electroproduction of pion in exclusive reaction $p(e,e'\pi^+)n$ is studied using a two-component model which includes soft hadronic and hard partonic reaction mechanisms. The results are compared with the experimental data…
We considered the electro- and photoproduction of \rho and other vector mesons with moderately large transverse momentum in the scattering of unpolarized electrons on unpolarized nucleons and nuclei. For these processes we have analyzed how…
A new transversely polarised frozen spin target has been developed at MAMI which will be used in conjunction with the photon tagger and the Crystal Ball detector. The new target permits a major new programme of accurate measurement of…