相关论文: Nucleonic resonance effects in the $\phi$ meson ph…

We investigate the importance of crossing symmetry in effective field models and the effects of phenomenological nucleon resonance widths on the paradigmatic case of pion photoproduction. We use reaction models containing four star…

The differential cross section, $d\sigma/dt$, for $\rho^0$ meson photoproduction on the proton above the resonance region ($2.6<W<2.9$ GeV) was measured up to a momentum transfer $-t = 5$ GeV$^2$ using the CLAS detector at the Thomas…

A chiral quark-model approach is adopted to study the $\gamma p\rightarrow \eta'p$ and $\gamma n\rightarrow \eta' n$. Good descriptions of the recent observations from CLAS and CBELSA/TAPS are obtained. Both of the processes are governed by…

The photoproduction of $J/\psi$ meson off the nucleon is investigated within a dynamical model approach based on a Hamiltonian which describes the reaction mechanisms of the Pomeron exchange, meson exchange, and direct $J/\psi$ radiation…

We study the near-threshold $\eta '$ production mechanism in nucleon-nucleon and $\pi N$ collisions under the assumption that sub-threshold resonance $N^{*}(1535)$ is predominant. In an effective Lagrangian approach which gives a reasonable…

Fluctuations play an important role in diffractive production of vector mesons. It was in particular recently suggested, based on the Impact-Parameter dependent Saturation model (IPSat), that geometrical fluctuations triggered by the motion…

We explore the photoproduction mechanisms for charged and neutral pion pairs off a heavy nucleus at threshold. We calculate the production of charged pairs in the Coulomb field of the nucleus in the Born approximation using explicit…

We evaluate the contribution to the nucleon-nucleon interaction due to correlated $\pi\rho$ exchange in the $\pi$, $\omega$, and $A_1$/$H_1$ channels by means of dispersion-theoretic methods based on a realistic meson exchange model for the…

The production of $\phi$ mesons in the reaction $e^{+}p \rightarrow e^{+} \phi p$ ($\phi \rightarrow K^{+}K^{-}$) at a median $Q^{2}$ of $10^{-4} \ \rm{GeV^2}$ has been studied with the ZEUS detector at HERA. The differential $\phi$…

The most recent high-precision data on spin observables $\Sigma$, $T$, $P'$, $E$, $F$ and $H$ reported by the CLAS Collaboration together with the previous data on differential cross sections and spin-density-matrix elements reported by the…

We show that the differential cross section d_sigma/d_t of gamma p --> \phi p reaction at the threshold is finite and its value is crucial to the mechanism of the phi meson photoproduction and for the models of phi-N interaction.

We discuss ${\gamma}{\gamma}\to {\pi}{\pi}$ reactions, starting from the two-pion threshold up to about $\sqrt{s_{{\gamma}{\gamma}}}$ = 6 GeV. We include the dipion continuum due to pion exchange (for ${\pi}^+{\pi}^-$) and ${\rho}^\pm$…

The Reggeized pion is expected to provide the main contribution to the forward cross section in light meson photoproduction reactions with charge exchange at high energies. We discuss the Reggeization of pion exchange in charged pion…

We present a unitary and gauge-invariant model with coupled channels, which provides a consistent description of pion photoproduction off nucleons in the E$_{0+}$ channel and eta-meson photoproduction off protons and deuterons. An effective…

We study the photoproduction of $K^*(892)$ vector meson from both the charged and neutral reactions, $\gamma p \to K^{*+} \Lambda$ and $\gamma n \to K^{*0} \Lambda$. The production mechanisms that we consider include $t$-channel $K^*$, $K$,…

We present a detailed study of vector meson photoproduction in ultraperipheral heavy ion collisions (UPCs). Using the dipole model, we develop a framework for the joint impact parameter and transverse momentum dependent cross sections. We…

The role of the low lying nucleon resonances beyond the $\Delta(1232)$ in the reaction $pp\to pp\pi^0$ near threshold is shown to be numerically significant by a calculation, which takes into account the pion re-scattering contribution…

We show that nuclear sigma, omega, and pi mesons can contribute coherently to enhance the electroproduction cross section on nuclei for longitudinal virtual photons at low Q^2 while depleting the cross section for transverse photons. We are…

The study of radiative phi decays into scalar mesons, with subsequent decay into pi pi gamma, constitutes an important topic at the electron-positron collider DAPHNE. The interference of the respective amplitude with the one for pi+ pi-…

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…