Related papers: Multimeson production in pp interactions as a back…
We study near-threshold $\eta$ meson production in $pp$ collisions within an effective Lagrangian approach combined with the isobar model, by allowing for the various intermediate nucleon resonances due to the $\pi$, $\eta$, and…
The ratio of the total exclusive production cross sections for $\eta\prime$ and $\eta$ mesons has been measured in the $pp$ reaction at $p_{beam}=3.67$ GeV/c. The observed $\eta\prime/\eta$ ratio is $(0.83\pm{0.11}^{+0.23}_{-0.18})\times…
The eta-mesic nuclei in which the {\eta} meson is bound with nucleus via strong interaction was postulated already in 1986, however till now no experiment confirmed empirically its existence. The discovery of this new kind of an exotic…
We perform a theoretical study of the $D_s^{+}\to \pi^{+}\pi^{+}\pi^{-}\eta$ decay. We look first at the basic $D_s^{+}$ decay at the quark level from external and internal emission. Then hadronize a pair or two pairs of $q\bar{q}$ states…
We perform an updated coupled-channel analysis of eta-meson production including all recent photoproduction data on the proton. The dip observed in the differential cross sections at c.m. energies W=1.68 GeV is explained by destructive…
Using the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn the \eta' photoproduction off nuclei (C, Ca, Nb and Pb) was studied via the hadronic decay channel \eta' -> \pi^0\pi^0\eta . Recent results on the…
We review the present understanding of etaprime and eta meson physics and these mesons as a probe of gluon dynamics in low-energy QCD. Recent highlights include the production mechanism of eta and etaprime mesons in proton-nucleon…
The cross section for the reaction $dd\rightarrow \,^4\!H\!e\,\eta$ close to threshold is estimated in a two-step model, similar to that which successfully describes near-threshold $pd\rightarrow \,^3\!H\!e\,\eta$ production. A $\pi$-meson,…
The proton-proton and proton-eta' invariant mass distributions have been determined for the pp -> ppeta' reaction at an excess energy of Q = 16.4 MeV. The measurement was carried out using the COSY-11 detector setup and the proton beam of…
The production of $\eta$ mesons in $NN$ collisions in the near threshold region is analyzed with special emphasis on the role of final state interaction which is calculated using three-body scattering theory. The three-body aspects are…
In June 2008 we performed a search for the 4He-eta bound state by measuring the excitation function of the dd to 3He p pi- reaction near the eta production threshold using the WASA-at-COSY detector. During the experimental run the momentum…
The ALICE detector at the LHC studies $\pi^0$ and $\eta$ meson production by two complementary methods, using electromagnetic calorimeters and the central tracking system for converted photons. Production spectra of $\pi^0$ and $\eta$…
Photoproduction of eta mesons from nucleons can provide valuable information about the excitation spectrum of the nucleons. The angular dependence of photoproduction in the photon-induced reaction is investigated in the multi-source thermal…
The existence of eta-mesic nuclei in which the eta meson is bound in a nucleus by means of the strong interaction was postulated already in 1986, albeit not yet confirmed it by experiment. The discovery of this new kind of an exotic nuclear…
Coherent photoproduction of $\eta$-mesons off $^3$He, i.e. the reaction $\gamma ^3{He}\rightarrow \eta ^3{He}$, has been investigated in the near-threshold region. The experiment was performed at the Glasgow tagged photon facility of the…
The photoproduction of eta-mesons from 2H and 4He has been studied for energies close to the production thresholds. The experiments were carried out with the tagged photon beam of the Mainz MAMI accelerator. The eta-mesons were detected via…
New high-precision total and differential cross sections for $\eta$ and $\eta'$ photoproduction on the proton obtained by the A2 Collaboration at the Mainz Microtron are presented. The data for $\eta$ photoproduction demonstrate a cusp at…
Data on the total cross sections for the pp -> pp eta, pn -> pn eta, and pn -> d eta reactions and the pp -> pp eta differential cross section near threshold are analysed in a one-meson-exchange model. After including initial and…
Very recent data for the reaction gamma{d} --> eta{np} are analyzed within a model that includes contributions from the impulse approximation and next order corrections due to the np and eta{N} interactions in the final state. Comparison…
A deailed knowledge of pp collision is required both as input to comprehensive theoretical models of strong interactions and as baseline to decipher the AA collisions at relativistic and ultrarelativistic energies, which has been of great…