Related papers: Rescattering effects in near-threshold $J/\psi$ ph…
We study the $J/\psi$ photoproduction $\gamma p\to J/\psi p$ near threshold to investigate the role played by the open charm channels and possible signals from the hidden charm $P_c$ pentaquark states. With the diffractive mechanism…
We investigate the dynamical generation of hidden-charm pentaquark resonances in the $\pi N \to J/\psi N$ reaction utilizing an off-shell coupled-channel formalism. Motivated by the absence of pentaquark signals in $J/\psi$ photoproduction,…
The photoproduction of the $J/\psi$ off the proton is believed to deepen our understanding of various physics issues. On the one hand, it is proposed to provide access to the origin of the proton mass, based on the QCD multipole expansion.…
We study the $J/\psi$ photoproduction from nuclei at near-threshold incident photon energies of 5--11 GeV within the nuclear spectral function approach by considering incoherent direct (${\gamma}N \to {J/\psi}N$) and two-step (${\gamma}p…
The study of $J/\psi$ photoproduction at low energies has consequences for the understanding of multiple aspects of nonperturbative QCD, ranging from mechanical properties of the proton, to the binding inside nuclei, and the existence of…
We study phi photoproduction with various hadronic rescattering contributions included, in addition to the Pomeron and pseudoscalar meson-exchange diagrams. We find that the hadronic box diagrams can explain the recent experimental data in…
A reaction model for $\gamma + p \to J/\psi + p$ photoproduction, which exposes the $c \bar c$ content of the photon in making the transition $\gamma\to c\bar c + \mathbb P \to J/\psi$ and couples the intermediate $c \bar c$ system to the…
We show that for the S-state $\pi^0$-production in processes $\gamma+d\to d+\pi^0$ and $e^-+d\to e^-+d+\pi^0$ the rescattering effects due to the transition: $ \gamma+d\to p+p+\pi^-$ (or $n+n+\pi^+)\to d+\pi^0$ are cancelled out due to the…
The near-threshold photoproduction of $J/\psi$ is regarded as one golden process to unveil the nucleon mass structure, pentaquark state involving the charm quarks, and the poorly constrained gluon distribution of the nucleon at large $x$…
We study the observed enhancement of a $p\bar p$ system near the threshold in the process $J/\psi \to \gamma p\bar p$ and $e^+ e^- \to p\bar p$. From early studies the enhancement can be explained by final state interactions, which are in…
We study the near-threshold incoherent $\phi$ photoproduction on the deuteron based on a model of $\gamma N \to \phi N$, consisting of Pomeron, $(\pi, \eta)$ exchanges, and a $J^P = 3/2^-$ resonance, which describes the low energy $\gamma p…
We point out that the new exotic resonances recently reported by LHCb in the $J/\psi p$ channel are excellent candidates for photoproduction off a proton target. This test is crucial to confirming the resonant nature of such states, as…
The diffractive photoproduction of $J/\Psi$ on a nucleon, is mostly due to gluonic exchanges at all $\sqrt{s}$. In holographic QCD (large number of colors and strong $^\prime$t Hooft coupling), these exchanges are captured by gravitons near…
Associative photoproduction of $\omega$-meson and $N^{*}(1440)$ on nucleons, $\gamma+N\to\omega+N^{*}(1440)$, in the near threshold region is investigated in a framework employing effective Lagrangians. Besides $\pi$-exchange in t-channel,…
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)…
By assuming that the $\Lambda _{c}^{\ast }(2940)$ is a $pD^{\ast 0}$ molecular state with spin-parity $J^{P}=\frac{1}{2}^{+}$ and $J^{P}=\frac{1}{2}^{-}$, the photoproduction of charmed $\Lambda _{c}^{\ast }(2940)$ baryon in the $\gamma…
We investigate the reaction mechanism of the $\phi$-meson photoproduction off the proton target, i.e., $\gamma p\to\phi p$, up to $\sqrt{s}=2.8$ GeV. For this purpose, we employ an effective Lagrangian approach in the tree-level Born…
We construct a dynamical coupled-channel approach to photon-induced $J/\psi$ production to search for the trace of the pentaquarks $P_c$. In this approach, the considered open-charm intermediate states are $\Lambda_c \bar{D}^{(*)}$ and…
We update our previous calculation of $J/\psi$ photo-production near threshold \cite{Hatta:2018ina} by incorporating the recent developments in theory and the new experimental data from the GlueX collaboration at Jefferson Lab…
We study the near-threshold $J/\psi$ meson photoproduction from protons and nuclei by considering incoherent direct non-resonant (${\gamma}p \to {J/\psi}p$, ${\gamma}n \to {J/\psi}n$) and two-step resonant (${\gamma}p \to P_{ci}^+ \to…