Related papers: Diffractive $\phi$-meson photoproduction on proton…
We comment on the important phenomenological aspects of the recent high-statistics and wide-angle coverage $\phi$ photoproduction data from CLAS at Jefferson Lab. The most prominent feature is a localized structure at a center-of-mass (c.m)…
We measure for the first time the differential photoproduction cross section $d\sigma/dt$ of the $a_2(1320)$ meson at an average photon beam energy of 8.5~GeV, using data with an integrated luminosity of 104~pb$^{-1}$ collected by the GlueX…
We develop a formalism for studying vector meson ($V$) photo-production at the proton ($p$) with polarized photons, $\vec\gamma p \to V p $, through an analysis of the decay distribution in the channel $V\to\pi^0\gamma$. We show that this…
The near-threshold photo- and electroproduction of heavy vector quarkonia off the proton provides direct access to its gluonic structure. In particular, the cross section for $J/\Psi$ photoproduction near threshold is governed by the…
We studied the exclusive reaction e p --> e' p' phi using the phi --> K^+ K^- decay mode. The data were collected using a 4.2 GeV incident electron beam and the CLAS detector at Jefferson Lab. Our experiment covers the range in Q^2 from 0.7…
Coherent photoproduction of $\pi^0$-mesons from threshold ($E_{th} \approx$ 136 MeV) throughout the $\Delta$-resonance region and of $\eta$-mesons close to the production threshold ($E_{th} \approx$ 570 MeV for $\eta$) has been measured for…
We present predictions for the exclusive and dissociative production of vector mesons off protons in an electron-ion collider. The computation is based on the energy-dependent hot spot model that has successfully described the available…
High-statistics total cross sections for the vector meson photoproduction at the threshold: $\gamma p\to\omega p$ (from A2 at MAMI, ELPH, and CBELSA/TAPS), $\gamma p\to \phi p$ (from CLAS and LEPS), and $\gamma p\to J/\psi p$ (from GlueX)…
In this work, the cross sections of $\phi$ photoproduction are systematically investigated with the two gluon exchange model and the pomeron model. The results obtained show that the theoretical values of the two models agree well with the…
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 study the photoproduction of scalar mesons close to the threshold of f_0(980) and a_0(980) using a unitary chiral model. Peaks for both resonances show up in the invariant mass distributions of pairs of pseudoscalar mesons. A discussion…
Hard diffractive photo- and electroproduction of heavy vector mesons ($J/\psi$ and $\Upsilon$) is evaluated within the leading $\alpha_s\ln{Q^2 \over\Lambda_{QCD}^2}$ approximation of QCD. In difference from our earlier work on that…
New data for the differential cross sections, polarization observables $T$, $F$, and $E$ in the reaction of $\eta$ photoproduction on proton from the threshold up to a center-of-mass energy of W=1.9 GeV are presented. The data were obtained…
The exclusive reaction $\gamma p \to p K^+ K^-$ was studied in the photon energy range $3.0 - 3.8 \mbox{ GeV}$ and momentum transfer range $0.6<-t<1.3 \mbox{ GeV}^2$. Data were collected with the CLAS detector at the Thomas Jefferson…
We calculate the cross sections for both electromagnetic and diffractive dissociation of protons for semiexclusive production of $J/\psi$ mesons in proton-proton collisions at the LHC. Several differential distributions in missing mass…
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…
Diffractive photoproduction of D*+/-(2010) mesons was measured with the ZEUS detector at the ep collider HERA, using an integrated luminosity of 78.6 pb^{-1}. The D* mesons were reconstructed in the kinematic range: transverse momentum…
We develop a non-perturbative analysis of the electro-production of heavy vector mesons ($\phi$, $J/\Psi$) from threshold to high energy. We use the holographic construction with bulk confinement enforced through a soft wall. Using Witten…
The differential cross section for the gamma +n --> pi- + p and the gamma + p --> pi+ n processes were measured at Jefferson Lab. The photon energies ranged from 1.1 to 5.5 GeV, corresponding to center-of-mass energies from 1.7 to 3.4 GeV.…
The contributions of direct knockout processes, in addition to the diffractive production and one-pion-exchange processes associated with the phi-rho-pi and phi-gamma-pi couplings, to the polarization observables of the phi photoproduction…