Related papers: Vector meson photoproduction processes near thresh…
Precise total cross-sections and invariant-mass distributions have been measured for photoproduction of pion pairs off the proton producing $p\pi^0\pi^0$ and $n\pi^+\pi^0$ final states from the threshold region up to 800 MeV incident photon…
We study the photoproduction of the vector mesons $\Phi$ and $J/\Psi$ off a proton in the kinematical regime of large energies and scattering angles within the framework of perturbative QCD. Our investigations are based on the hard…
Cross sections for the coherent photoproduction of $\rho^{0}$ vector mesons in ultra-peripheral Pb-Pb collisions at $ \sqrt{s_{\mathrm{NN}}}= 5.02$ TeV are reported. The measurements, which rely on the $\pi^+\pi^-$ decay channel, are…
The $\sigma$ meson exchange model for $\rho$ photoproduction at low energies is re-examined and a new model is developed by considering explicit two-pion exchange and the $f_2$ tensor meson exchange. The $f_2$ exchange model, which is…
We analyze threshold photoproduction of heavy mesons off a deuteron and Helium-4, using the QCD factorization method. Assuming large skewness, the production amplitude is dominated by the leading twist-2 gluonic energy-momentum tensor…
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…
The differential cross sections of the forward coherent $\omega$ and $\phi$ mesons photoproduction from nuclei have been calculated using the Glauber model for the nuclear reaction. The measured cross section of the elementary reaction,…
The coherent $\omega$-meson photoproduction from nuclei is proposed as a phenomenological method to evaluate the momentum dependence of $\omega$-meson mass shift and width in nuclear matter. We analyze available data on un-separated…
The $\sigma$-exchange and $f_2$-exchange mechanisms for $\rho$ meson photoproduction are re-examined. Then the commonly employed $\sigma$-exchange amplitude is revised by using the recent information from the analyses on the $\rho \to…
Exclusive diffractive photoproduction of heavy vector mesons (V=phi, J/psi and Upsilon) at HERA is studied in a model employing a dipole Pomeron exchange (P) with an inelastic gamma-P-V vertex. The model is fitted to the data on dsigma/dt,…
We evaluated recent CLAS Collaboration measurements for the $90^\circ$ meson photoproduction off the nucleon using a tagged photon beam spanning the energy interval $s = 3 - 11$ GeV$^2$. The results are compared with the "Quark Counting…
Kaon photo- and electroproduction off a proton near the production threshold are investigated by utilizing an isobar model. The background amplitude of the model is constructed from Feynman diagrams, whereas the resonance term is calculated…
We study photoproduction of rho mesons in a model of hidden local symmetry. The rho meson is introduced as a hidden gauge boson and a phenomenological rho meson-nucleon Lagrangian is constructed respecting chiral symmetry. It is shown that…
The photonuclear production of vector mesons in ultraperipheral heavy ion collisions is investigated within the collinear approach using different parameterizations for the nuclear gluon distribution. The integrated cross section and the…
Results of a combined analysis are presented for the production of $\omega$ and $\phi$ mesons in $\pi N$ reactions in the near-threshold region using throughoutly a conventional ''non-strange'' dynamics based on such processes which are…
We discuss recent preliminary results on the diffractive photoproduction of {\rhoz}, $\phi$, and {\jpsi} mesons at high momentum transfer reported by the ZEUS collaboration at HERA. A special-purpose calorimeter served to tag the quasi-real…
The process of a light neutral vector meson electroproduction is studied in the framework of QCD factorization in which the amplitude factorizes in a convolution of the nonperturbative meson distribution amplitude and the generalized parton…
With the advent of new photon tagging facilities and novel experimental technologies it has become possible to perform photoproduction cross section measurements of pseudoscalar mesons on nuclei with a percent level accuracy. The extraction…
For coherent photoproduction of phi and omega mesons from deuteron at forward angles, the isovector pi-exchange amplitude is strongly suppressed. We show a possibility to study the non-diffractive channels associated with the unnatural…
We revisit near-threshold $J/\psi$ photoproduction on the nucleon within the OPE sum-rule framework combined with vector-meson dominance and dispersion relations, using modern NNLO gluon distributions (ABMP16, MSHT20, CT18, NNPDF4.0). Two…