相关论文: Eta photoproduction
We have analyzed the $M_{1+}^{(3/2)}$ and $E_{1+}^{(3/2)}$ multipole amplitudes of pion photoproduction in the framework of fixed-$t$ dispersion relations. Applying the speed plot technique to our results for these multipoles, we have…
A study of the partial-wave content of the $\gamma p\to \eta^\prime p$ reaction in the fourth resonance region is presented, which has been prompted by new measurements of polarization observables for that process. Using the Bonn-Gatchina…
The beam-helicity asymmetry was measured, for the first time, in photoproduction of $\pi^{0}\eta$ pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The results are compared to an earlier measurement on a free…
We analyze the available data on eta photo- and electroproduction, around W~1535 MeV, in the framework of the effective Lagrangian approach, and extract, in a nearly model-independent fashion, the electrostrong amplitude for the gamma+N-->…
Hybrid/exotic meson spectroscopy searches at Jefferson Lab require the accurate theoretical description of the production mechanism in peripheral photoproduction. We develop a model for $\pi\Delta$ photoproduction at high energies ($5 \leq…
We extract a parameter $\xi$, a characteristic product of the strong and electromagnetic amplitudes for the N^*(1535), to be (2.20+-0.15) in unit of 10^(-4)MeV^(-1) from the new data on photoproduction of etas off proton.
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…
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…
Differential cross sections for eta photoproduction off protons have been measured at E_gamma = 1.6 - 2.4 GeV in the backward direction. A bump structure has been observed above 2.0 GeV in the total energy. No such bump is observed in cross…
In this preprint we analyzed the exclusive photoproduction of $\eta_{c}\gamma$ pairs in the collinear factorization framework and evaluated its cross-section in leading order in the strong coupling $\alpha_{s}$. We found that this process…
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…
Quasi-free photoproduction of $\eta$-mesons has been measured off nucleons bound in $^3$He nuclei for incident photon energies from the threshold region up to 1.4 GeV. The experiment was performed at the tagged photon facility of the Mainz…
Total and differential cross sections for $\eta$ and $\eta ^\prime$ photoproduction off the proton have been determined with the CBELSA/TAPS detector for photon energies between 0.85 and 2.55 GeV. The $\eta$ mesons are detected in their two…
We have carried out exclusive measurements for the photoproduction of an $\eta$ meson from a proton target with an egg-shaped calorimeter made of BGO crystals (BGOegg) and forward charged-particle detectors at the SPring-8 LEPS2 beamline.…
Incoherent photoproduction of eta-mesons on the deuteron is considered. The main attention is paid to the region above the S11(1535) resonance where rather narrow resonance like structure in the total cross section extracted for gamma n ->…
The presently available data for the reaction ${\gamma}p{\to}\eta^\prime{p}$ are analyzed in terms of a model in which the dominant production mechanism is the exchange of the vector mesons $\omega$ and $\rho$. To describe the data at…
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…
A combined analysis of photoproduction data on \gamma p to \pi N, eta N was performed including the data on K Lambda and K Sigma. The data are interpreted in an isobar model with s--channel baryon resonances and pi, rho,(omega), K, and K^*…
The beam asymmetry, $\Sigma$, was measured at ELSA in the reaction $\vec \gamma p \to \eta p$ using linearly polarised tagged photon beams, produced by coherent bremsstrahlung off a diamond. The crystal was oriented to provide polarised…
A number of recent multipole analyses from Mainz, RPI, BNL and Virginia Tech (VPI) have focused on the first resonance region. One goal common to these studies was an improved set of Delta(1232) photo-decay amplitudes. There has been…