Related papers: Meson-production experiments at COSY-Juelich
A first observation is presented for the electroweak production of a W boson, a photon, and two jets in proton-proton collisions. The W boson decays are selected by requiring one identified electron or muon and an imbalance in transverse…
Photoproduction of \eta mesons off light nuclei (d, 3He, 7Li) has been measured at the tagged photon beam of the Mainz MAMI accelerator with the combined Crystal Ball/TAPS detection system. Special attention was given to the threshold…
The analysing power measurements for the p(pol)p -> pp eta reaction studied in this dissertation are used in the determination of the reaction mechanism of the eta meson production in nucleon-nucleon collisions. Measurements have been…
We report the first measurement of the differential cross section for the process gamma gamma --> eta eta in the kinematic range above the eta eta threshold, 1.096 GeV < W < 3.8 GeV over nearly the entire solid angle range, |cos theta*| <=…
A new precise determination of the {\eta} meson mass is presented. It is based on a measurement of the threshold for the {\gamma}p -> p{\eta} reaction using the tagger focal-plane microscope detector at the MAMI-B facility in Mainz. The…
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 different nuclei has been measured using the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn. Recent results on the in-medium properties of the $\eta^{'}$-meson,…
New measurements of the $\eta$ and $K^0$ masses have been performed using decays to 3$\pi^0$ with the NA48 detector at the CERN SPS. Using symmetric decays to reduce systematic effects, the results $M(\eta) = 547.843\pm0.051$ MeV/c$^2$ and…
For the first time, the pair production of the heavy charged gauge bosons, known as $W'$ bosons is considered, when both decay to $\tau$ leptons. The reported detailed efficiency of object/event selection by the CMS experiment is used to…
A measurement of the pp --> p p eta reaction at the excess energy of Q = 15.5 +- 0.4 MeV has been carried out at the internal beam facility COSY-11 with an integrated luminosity of 811 nb^-1 The number of ~24000 identified events permits a…
The low emittance and small momentum spread of the proton and deuteron beams of the Cooler Synchrotron COSY combined with the high mass resolution of the COSY-11 detection system permit to study the creation of mesons in the nucleon-nucleon…
Recent BABAR results on two-photon processes are presented. A high statistics study of the two-photon production of the charmonium states eta_c and eta_c(2S) is performed. The mass and width of eta_c and eta_c(2S) are measured; the ratio of…
Measurements of production of the neutral and charged strange hadrons in ep collisions with the ZEUS detector are presented. The data on differential cross sections, baryon-to-meson ratios, baryon-antibaryon asymmetry and Bose-Einstein…
Recent results from the CMS experiment on the production of multiple vector bosons in proton-proton collisions at the CERN LHC are presented. Measurements of WZ and ZZ production with fully leptonic decays, Z$(\nu\nu)\gamma$, and WV (V $=$…
Measurements of electroweak gauge-boson pair-production in sqrt(s) = 7 and 8 TeV pp collisions at the LHC probe self-couplings and interference effects to an accuracy of O(10%) or better. ATLAS measurements of ZZ and WZ production at both…
Several electroweak precision measurements are performed by the ATLAS and CMS collaborations at the LHC. The main ones are carried out using Drell-Yan production of single W and Z boson. They regard the measurement of the production cross…
Coherent photoproduction of $\pi^0$-mesons from threshold ($E_{th} \approx$ 136 MeV) throughout the $\Delta$-resonance region and of $\eta$-mesons close to the production threshold ($E_{th} \approx$ 570 MeV for $\eta$) has been measured for…
The aim of this work was to determine the total width of the eta-prime meson. The investigated meson was produced via the pp->ppeta-prime reaction in the collisions of beam protons from COSY synchrotron with protons from a hydrogen cluster…
We report evidence for the $B$ meson decays, $B^\pm\to J/\psi \eta K^\pm$ and $B^0\to J/\psi \eta K^0_S$, using {90} million $B\bar B$ events collected at the $\ensuremath{\Upsilon{(4S)}}$ resonance with the \babar detector at the PEP-II…
We report the observation of the $B$ meson decay $B^\pm\to J/\psi \eta K^\pm$ and evidence for the decay $B^0\to J/\psi \eta K^0_S$, using {90} million $BBbar$ events collected at the $\ensuremath{\Upsilon{(4S)}}\xspace$ resonance with the…