Related papers: Novel features in exclusive vector--meson producti…
Results on elastic electroproduction of rho mesons are presented for a photon virtuality in the range 1 < Q^2 < 60 GeV^2 and for a hadronic centre of mass energy in the range 30 < W < 140 GeV. The shape of the (pi pi) mass distribution is…
Energy dependence of $\gamma^*p$ total cross section is considered. It is known from the HERA data that the cross section grows with energy, and the rate of growth is an increasing function of the virtuality $Q^2$ of the photon $\gamma^*$.…
It is demonstrated that universal mass dependence for meson and baryon inclusive cross-sections advocated recently in $e^+e^-$ annihilation and in hadronic reactions is consistent also with heavy ion collisions data and can therefore be…
We consider the fidelity of the vector meson dominance (VMD) assumption as an instrument for relating the electromagnetic vector-meson production reaction $e + p \to e^\prime + V + p$ to the purely hadronic process $V + p \to V+p$. Analyses…
We present the color dipole phenomenology of diffractive photo- and electroproduction $\gamma^{*} N\to V(V') N$ of vector mesons ($V(1S) = \phi^0, \omega^0, \rho^0, J/\Psi, \Upsilon$) and their radial excitations ($V'(2S) = \phi', \omega',…
The effects of final-state interaction of hadrons, produced in $e^{+}e^{-}$ annihilation near the threshold, are discussed. If there is a loosely bound state or a virtual state in a system of produced hadrons, then the energy dependence of…
Inelastic and diffractive production of J/psi mesons at HERA is reviewed. The data on inelastic photoproduction are described well within errors by the Colour Singlet Model in next-to-leading order. A search for colour octet processes…
We provide a framework to analyze the electroproduction process ep -> ep rho with a polarized target, writing the angular distribution of the rho decay products in terms of spin density matrix elements that parameterize the hadronic…
Through an analysis of diffractive vector meson production, we show that the proton appears quite dense to a small size probe at present HERA energies. This means that saturation effects are already important.
Multi-electron and multi-muon production have been measured at high transverse momentum in electron-proton collisions at HERA.Good overall agreement is found with the Standard Model predictions, dominated by photon-photon interactions.…
The cross section for the elastic photoproduction of \r0 mesons ($\gamma p \to \rho^0 p$) has been measured with the H1 detector at HERA for two average photon-proton centre-of-mass energies of 55 and 187 GeV. TheFcenterline lower energy…
Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e^+ + p --> e^+ + n + jet + jet + X_r have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4…
We present a short review of anomalous properties in diffractive photo- and electroproduction of radially excited V'(2S) vector mesons. Using the color dipole gBFKL phenomenology we analyze anomalous Q^{2} and energy dependence of the…
Recent results on the properties of the hadronic final state at the HERA collider are presented. Strangeness production and correlations have been studied in the laboratory system for deep inelastic scattering (DIS). Inclusive $K^0_S$,…
Differential photoproduction cross sections are measured for events containing D* mesons. The data were taken with the H1 detector at the ep collider HERA and correspond to an integrated luminosity of 51.1 pb-1. The kinematic region covers…
We use gauge/gravity duality to study vector meson (J/{\Psi}, {\rho}_0, {\Omega}, {\Phi}) production in electron-proton scattering, in the limit of high center of mass energy at fixed momentum transfer, corresponding to the limit of low…
In high energy p+p(bar) interactions the mean multiplicity and transverse mass spectra of neutral mesons from eta to Upsilon (m = 0.5 - 10 GeV/c^2) and the transverse mass spectra of pions (m_T > 1 GeV/c^2) reveal a remarkable behaviour:…
The photoproduction of $\omega$ and $\eta^\prime$ mesons off carbon and niobium nuclei has been measured as a function of the meson momentum for incident photon energies of 1.2-2.9 GeV at the electron accelerator ELSA. The mesons have been…
Protons and antiprotons at collider energies are a source of high energy Weizsaecker--Williams photons. This opens up a possibility to study at the LHC exclusive photoproduction of heavy vector mesons at energies much larger than possible…
The ratio of the total exclusive production cross sections for $\eta\prime$ and $\eta$ mesons has been measured in the $pp$ reaction at $p_{beam}=3.67$ GeV/c. The observed $\eta\prime/\eta$ ratio is $(0.83\pm{0.11}^{+0.23}_{-0.18})\times…