相关论文: Mesons in Nuclei: eta and omega mesons

We reanalyze data from ELSA on $\omega$ production in nuclei, from where claims of a large shift of the mass were made earlier, which are tied to a certain election of the background in nuclei, very different in shape to the one on the…

The exclusive electroproduction of omega mesons, ep -> e omega p, has been studied in the kinematic range 3<Q^2<20 GeV^2, 40<W<120 GeV and |t|<0.6 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 37.7 pb^{-1}. The…

A microscopic four-body description of near-threshold coherent photoproduction of the $\eta$ meson on the (3N)-nuclei is given. The photoproduction cross-section is calculated using the Finite Rank Approximation (FRA) of the nuclear…

We study inclusive omega photoproduction in nuclei and propose a measurement of the nuclear transparency ratio as a means to learn about the in-medium properties of the omega meson. To this end we are using the semi-classical…

Coherent photoproduction of eta mesons from the deuteron has been measured from threshold up to incident photon energies of 750 MeV using the photon spectrometer TAPS at the tagged photon facility at the Mainz microtron MAMI. For the first…

The feasibility to study the in-medium properties of the omega meson in photon induced reactions on nuclei is investigated by means of a semiclassical transport model. The calculations are dedicated to an experiment presently being analyzed…

The isobar models eta-MAID and eta'-MAID have been used to analyze new data on quasi-free eta photoproduction on the deuteron from Bonn and recent eta' data on the proton from Jlab. In eta photoproduction on the neutron a bump around W=1700…

A brief review of searches for eta-mesic nuclei is presented with emphasis on photoreactions and results of a new experiment done at the LPI electron synchrotron are reported. Decay products of eta-mesic nuclei presumably formed by photons…

We present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the $\vec \gamma \vec p\to\eta p$ reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the…

The excitation function and momentum distribution of {\eta}' mesons have been measured in photoproduction off 93^Nb in the energy range of 1.2-2.9 GeV. The experiment has been performed with the combined Crystal Barrel and MiniTAPS detector…

Recent data on eta-meson photoproduction off a proton target in the energy range 2 < sqrt{s} < 3 GeV are analyzed with regard to their overall consistency. Results from the ELSA and CLAS measurements are compared with predictions of a Regge…

We have measured excitation function for dp -> ppp_pi- reaction near the eta production threshold. We observe an enhancement of the counting rate above the threshold which can originate from the production of the eta meson in the reaction…

The photoproduction of omega mesons off protons has been studied at the Bonn ELSA accelerator from threshold to E_gamma = 1700 MeV. Linearly polarized beams were produced via coherent bremsstrahlung. Large photon asymmtries in excess of 50%…

We discuss the possibility to study the in-medium changes of the properties of the omega meson in reactions on ordinary nuclei with elementary electromagnetic probes. We present a tree-level calculation of the elementary gamma p -> omega p…

Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to…

Multimeson production in pp interactions comprises important background for eta, omega and eta' mesons production experiments and for the studies of their decays planned with WASA detector at COSY. The available information about the…

Photoproduction off protons of the $p\pi^0\eta$ three-body final state was studied with the Crystal Barrel/TAPS detector at the electron stretcher accelerator ELSA at Bonn for incident energies from the $\pi^0\eta$ production threshold up…

The excitation function for the $pd\rightarrow$ $d p \pi^{0}$ reaction has been measured by WASA-at-COSY experiment with the aim of searching for $^{3}\hspace{-0.03cm}\mbox{He}$-$\eta$ mesic nuclei. The measurement in the vicinity of $\eta$…

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…

We propose a simple meson-exchange model of the photoproduction of $\rho$- and $\omega$-mesons off protons near threshold ($E_\gamma$ less than 2 GeV). This model provides a good description of the available data and implies a large…