相关论文: Polarization observables in vector meson photoprod…
Spin correlations between top-quark and anti-top-quark in pair production are sensitive to physics beyond the standard model. A complete set of observables, that can be used to measure all independent parameters of the production spin…
At moderate and large momentum transfer, high energy vector meson photoproduction and Compton scattering can be consistently explained by mechanisms based on interactions and exchanges of constituent quarks and gluons. This opens an…
The electroweak production processes of vector bosons, $e^+ e^- \rightarrow Z \gamma$, $\gamma e \rightarrow Ze$, and $\gamma e \rightarrow W \nu$ are considered simultaneousely and in the Standard model the covariant polarization density…
We discuss the production of hadrons in polarized lepton nucleon interactions and in the current jet fragmentation region; using the QCD hard scattering formalism we compute the helicity density matrix of the hadron and show how its…
Pion-photoproduction data is examined to check for the nucleon-helicity conservation predicted by asymptotic QCD. The differential cross section shows agreement with constituent-counting rules, and polarization data is not in disagreement…
Polarization observables in inclusive and exclusive electrodisintegration of the deuteron using a polarized beam and an oriented target are systematically surveyed using the standard nonrelativistic framework of nuclear theory but with…
The interaction of orbital electrons with the charge and magnetic moment of the nucleus polarizes it, and the detailed description requires a careful treatment of the nuclear vector polarizability. We present a complete and closed form…
Single and double polarization observables for kaon photoproduction on the deuteron are studied theoretically with modern hyperon-nucleon forces. The kinematical region of the kaon scattered forward with large momentum is thoroughly…
We present an analysis of $13$ observables in Compton scattering on the proton. Cross sections, asymmetries with polarised beam and/or targets, and polarisation-transfer observables are investigated for energies up to the $\Delta(1232)$…
In this paper, we study total and differential observables of electro- and photoproduction of light $\rho$, $\omega$ and $\phi$ mesons as functions of the center-of-mass energy of the $\gamma p$ collision and momentum transfer squared…
We demonstrate that the distinctive features of the forward differential cross section of diffractive leptoproduction of a vector meson can be legitimately calculated in perturbative QCD in terms of the light-cone $q \bar q$ wave function…
The photonuclear production of vector mesons in ultraperipheral heavy ion collisions is investigated within the QCD color dipole picture, with particular emphasis on the saturation model. The integrated cross section and the rapidity…
The differential cross section and the polarization observables for $\Delta $--isobar production in the deuteron electrodisintegration process, $e^-+d\to e^-+\Delta +N$, are calculated in a general formalism based on structure functions.…
The PAX project at GSI Darmstadt plans to polarize an antiproton beam by repeated interaction with a hydrogen target in a storage ring. Many of the beam particles are required to remain within the ring after interaction with the target, so…
In this work we analyse the theoretical uncertainties on the predictions for the photoproduction of light vector mesons in coherent pp, pA and AA collisions at the LHC energies using the color dipole approach. In particular, we present our…
A dark photon is predicted by several well-motivated Standard Model extensions and UV completions. Here the most general effective field theory up to dimension-six operators describing the interactions of a massless dark photon with all…
The photoproduction of $\pi^+\pi^-$ meson pairs off the proton has been studied in the reaction $\gamma p\to p\,\pi^+\pi^-$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target (FROST) in Hall B at the Thomas…
We consider spin asymmetries for prompt photon production in collisions of longitudinally polarized hadrons. This reaction will be a key tool at the BNL-RHIC pp collider for determining the gluon spin density in a polarized proton. We study…
A quark model approach to the photoproduction of vector mesons off nucleons is proposed. Its starting point is an effective Lagrangian of the interaction between the vector meson and the quarks inside the baryon, which generates the…
A successful interpretation of the cross sections for elastic and inelastic vector meson production can be made if one assumes the underlying dynamics to be governed by hard partonic subprocesses. Extending these partonic approaches to…