Related papers: Unitarity constraints on meson electroproduction a…
Due to multiple possible polarizations hard exclusive production of tensor mesons by virtual photons or in heavy meson decays offers interesting possibilities to study the helicity structure of the underlying short-distance process.…
Deeply virtual meson scattering cross sections and asymmetries for the pi^0 and eta exclusive electroproduction in a very wide kinematic range of Q^2, t and x_B have been measured with CLAS (JLab). Initial analysis is already showing…
We discuss two aspects of polarisation in hard exclusive meson production: the leading-twist selection rule for the meson helicity, and the different partial waves of a (pi pi)-pair which may or may not be due to the decay of a rho.
The $\omega$-meson photoproduction, $\gamma+p\to p+\omega$, is studied in the framework of a model, containing $\pi$-meson exchange in t-channel and nucleon-exchange in s- and u-channels. Considering both $\omega NN$-coupling constants in…
A nonperturbative calculation of elastic electroproduction of the J/psi meson is presented and compared to the experimental data. Our model describes well the observed dependences of the cross sections on the photon virtuality Q2 and on the…
This work is a pioneering study of backward-angle omega cross sections through the exclusive 1H(e,e'p)omega reaction using the missing mass reconstruction technique. The extracted cross sections are separated into the transverse (T),…
Exclusive electro-weak processes have peculiar features which make them complementary to usually discussed deeply virtual electroproduction processes such as deep virtual Compton scattering or meson production (and the corresponding crossed…
Latest measurements of $\Delta\eta\Delta\varphi$ correlations of identified particles show differences in particle production between baryons and mesons. The correlation functions for mesons exhibit the expected peak dominated by effects of…
Measurements of the cross section for exclusive virtual-photoproduction of rho^0 mesons from hydrogen are reported. The data were collected by the HERMES experiment using 27.5 GeV positrons incident on a hydrogen gas target in the HERA…
A model for the reaction $\gamma p\to\rho^-\Delta^{++}$ is presented with the $t$-channel $\pi+\rho$ exchanges reggeized to describe the reaction up to high energies. Gauge invariance of $\rho$ exchange is discussed in connection with the…
It is shown that the universality of the initial and final state interactions responsible for the transition between the on-- and off--mass shell states leads to the energy independence of the ratio of exclusive $\rho$ electroproduction…
Results on elastic vector meson production at HERA are presented in the framework of perturbative QCD. The energy dependence of the cross section for J/Psi photoproduction and for rho electroproduction is studied. A full polarisation…
We discuss coherent and incoherent $\phi$ meson photoproduction off the deuteron at low energy and small momentum transfer with the aim to check whether the recent experimental data need for their interpretation the inclusion of exotic…
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…
Deep-inelastic scattering at low x and elastic vector meson production are considered on the basis of the off-shell extension of the s-channel unitarity. We discuss behavior of the structure function F_2(x,Q^2) at low x and the total…
Within the Regge approach, we calculated the exclusive $f_1(1285)$ meson photoproduction cross section at energy of few GeV. The calculation shows that the cross section is sizable, being in the range of 100 nb, and much larger than the the…
We investigate the possibility that the process of $\rho^{0}$-meson photoproduction on proton, $\gamma+p\to p+\rho^{0}$, in the near threshold region $E_{\gamma}< 2$ GeV, can be considered in the framework of model with $\pi$-, $\sigma$-…
We calculate cross sections of a pair $B_c$ meson production on the basis of two-photon mechanism from electron-positron annihilation. We investigate the production cross sections in nonrelativistic approximation and with the account of…
We investigate photoproduction of charged $\rho$ off the nucleon using $\rho(770)+\pi(140)$ Regge pole exchanges by considering the $\rho$-meson electromagnetic multipole moments. The significance of the Ward identity at the…
Photoproduction of $K^*$ vector mesons off nucleon is investigated within the Regge framework where the electromagnetic vertex of $\gamma K^*K^*$ fully takes into account the magnetic dipole and electric quadrupole moments of spin-1 $K^*$…