Related papers: Exclusive meson production at COMPASS
Despite decades of research, we still lack a detailed quantitative understanding of the way quantum chromodynamics (QCD) generates the spectrum of hadrons. Precise experimental studies of the hadron excitation spectrum and the dynamics of…
We discuss the exclusive photoproduction of a photon-meson pair with large $ p_{T} $ as a channel to probe generalised parton distributions (GPDs). Like other $ 2\to3 $ exclusive processes, this channel allows us to better study the $ x…
Exclusive vector meson production and deeply virtual Compton scattering are ideally suited reactions for studying the structure of the proton and the transition from soft to hard processes. The main experimental data obtained at HERA are…
The Common Muon Proton Apparatus for Structure and Spectroscopy (COMPASS) at CERN with its use of beams of naturally polarized muons scattered of a polarized deuteron target, provides an environment of hard scattering between quasi-real…
Hadrons proceeding from quasi-real photo-production are one of the many probes accesible at the Common Muon Proton Apparatus for Structure and Spectroscopy (COMPASS) at CERN. These hadrons provide information on the scattering between…
We report on a measurement of hard exclusive $\pi^0$ muoproduction on the proton by COMPASS using 160 GeV/$c$ polarised $\mu^+$ and $\mu^-$ beams of the CERN SPS impinging on a liquid hydrogen target. From the average of the measured…
We analyze light meson electroproduction in the intermediate energy range where the quark contributions are essential. Our calculations are carried out on the basis of the handbag approach. We study cross sections and spin asymmetries for…
Hard exclusive production in deep inelastic lepton scattering provides access to the unknown Generalized Parton Distributions (GPDs) of the nucleon. At HERMES, different observables for hard exclusive pi^+ production have been measured with…
This talk summarized the proof of hard-scattering factorization for hard exclusive electroproduction processes: deeply virtual Compton scattering and exclusive meson production.
The hard exclusive electroproduction processes provide new information about hadronic structure accumulated in nonforward parton distributions. The NFPD's are universal hybrid functions having the properties of parton densities, hadronic…
This Ph.D.~thesis is divided into two distinct parts. The first part focuses on hard exclusive scattering processes in Quantum Chromodynamics (QCD) at high energies, while the second part delves into spin phenomena at the Large Hadron…
In the 1970s, an unexpected transverse $\Lambda$ polarization in unpolarized proton-Beryllium collisions was discovered, which initiated extensive studies on spin phenomena in high-energy physics. Over the past five decades, similar…
We show within proton hot spot picture that the exclusive vector meson production in electron-proton deeply inelastic scattering is sensitive to the individual width of the constituent quarks of the proton. For comparison, we calculate the…
Production of electroweak bosons, heavy quarks and jets in proton-proton collisions probe different aspects of QCD and are sensitive to the details of proton structure, expressed by parton distribution functions (PDFs). Precise measurements…
In this talk various spin effects in hard exclusive electroproduction of mesons are briefly reviewed. The data are discussed in the light of recent theoretical calculations within the frame work of the handbag approach.
We examine the potential of the COMPASS experiment at CERN to study color transparency via exclusive vector meson production in hard muon-nucleus scattering. It is demonstrated that COMPASS has high sensitivity to test this important…
COMPASS at CERN is preparing for a new series of measurements on the nucleon structure comprising deep virtual Compton scattering and hard exclusive meson production using muon beams, as well as Drell-Yan reactions using a polarised proton…
Exclusive meson leptoproduction from nucleons in the deeply virtual exchanged boson limit can be described by generalized parton distributions (GPDs). Including spin dependence in the description requires 8 independent quark-parton and…
We report on an attempt to describe hard exclusive photoproduction of $J/\Psi$ mesons, i.e. the reaction $\gamma p \to J/\Psi p$, by means of a modified version of the hard-scattering approach, in which the proton is treated as a…
We consider the reaction $\gamma p \to M p$, with M being either a $\Phi$ or a $J/\Psi$ meson, within perturbative QCD treating the proton as a quark-diquark system. The phenomenological couplings of gauge bosons to (spatially extended)…