相关论文: Nucleonic resonance effects in the $\phi$ meson ph…
A formalism based on a chiral quark model ($\chi$QM) approach complemented with a one-gluon exchange model, to take into account the breakdown of the $SU(6)\otimes O(3)$ symmetry, is presented. The configuration mixing of wave functions for…
The subject of this doctoral study is the pseudoscalar meson photoproduction from nuclei. Two types of processes are investigated in this regard: coherent and quasifree processes. In the case of the coherent process, we study it for the…
In this work, the production of baryon resonances in the $\gamma p \to \phi \pi p$ reaction near threshold is investigated within an effective Lagrangian approach. incorporates intermediate resonances, including $\Delta(1232)$, $N(1440)$,…
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…
We analyze the process $\vec \gamma +p\to \rho^0 \pi^{+}n$ at low momentum transfer focusing on a possibility of production of an exotic $J^{PC}=1^{-+}$ meson state. In particular we discuss polarization observables and conclude that linear…
In this work the roles of the nucleon resonances in the $\Lambda$(1520) photoproduction off proton target are investigated within the effective Lagrangian method. Besides the Born terms,including contact term, $s$-, $u$- and $K$ exchanged…
The near threshold $\phi$ meson production in proton-proton and $\pi^- p$ collisions is studied with the assumption that the production mechanism is due to the sub-$N\phi$-threshold $N^*(1535)$ resonance. The $\pi^0$, $\eta$ and…
In this paper, we develop a general framework to study the meson-photoproductions of nucleons in the chiral quark model. The S and U channel resonance contributions are expressed in terms of the Chew-Goldberger-Low-Nambu (CGLN) amplitudes.…
We study the vector meson density matrix and the associated polarization asymmetries in $\phi$ photoproduction near threshold. In order to study the OZI violating processes, we consider the direct $\phi NN$ coupling as well as the knockout…
Exclusive diffractive meson production represents a golden channel for investigating gluonic saturation inside nucleons and nuclei. In this letter, we settle a systematic framework to deal with beyond leading power corrections at small-$x$,…
We calculate the quasifree photoproduction of pions and eta mesons on nuclei from 12C to 208Pb. Assuming that for the quasifree process the cross sections for pi/eta - photoproduction on a nucleon in medium are -- besides a lowering due to…
The details of the analysis of the near-threshold bump structure in the forward differential cross section of the \phi-meson photoproduction to determine whether it is a signature of a resonance are presented. The analysis is carried out in…
Within the meson exchange model we study $\omega$ meson photoproduction at energies above the s channel resonance region. Different model prescriptions for the $\omega{NN}$ vertex function are investigated imposing gauge invariance as well…
The LEPS/SPring-8 experiment made a comprehensive measurement of the spin-density matrix elements for $\gamma p \to \phi p$, $\gamma d \to \phi p n$ and $\gamma d \to \phi d$ at forward production angles. A linearly polarized photon beam at…
In the present talk, we report a recent investigation on photoproduction of the $\gamma N \to f_0(500)N$ within a framework of the effective Lagrangian. We include the nucleon resonances with pin $1/2$ in the $s$ channel. The coupling…
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,…
Differential cross sections and photon beam asymmetries for $\pi^0$ photoproduction have been measured at $E_\gamma$ = 1.5--2.4 GeV and at the $\pi^0$ scattering angles, --1 $<$ cos$\Theta_{c.m.} <$ --0.6. The energy-dependent slope of…
We study the $\gamma p \to p f_0$ [$f_0(980)$ and $f_0(1500)$] reaction close to threshold within an effective Lagrangian approach. The production process is described by $s$-channel nucleon pole or $t$-channel $\rho$ and $\omega$ exchange.…
We investigate near-threshold $J/\psi$ photoproduction off the nucleon, focusing on hadronic rescattering effects induced by open-charm meson-baryon intermediate states. Beyond the conventional Pomeron-exchange mechanism, the $\bar…
The most recent data on beam asymmetries, $\Sigma$, and beam-target asymmetries, $E$, from the CLAS Collaboration, together with the previous data on differential cross sections and beam asymmetries from the CLAS and LEPS Collaborations,…