相关论文: Measurement of polarization observables in omega-p…
The CBELSA/TAPS experiment with a longitudinally or transversely polarized target and an energy tagged, linearly or circularly polarized photon beam allows the measurement of a large set of polarization observables. Due to its good energy…
Polarisation observables are measured with the Crystal Barrel/TAPS experiment at ELSA for photoproduction reactions with various final states, using a circularly or linearly polarised photon beam and a longitudinally or transversely…
One of the remaining problems within the standard model is to gain a good understanding of the low energy regime of QCD, where perturbative methods fail. One key towards a better understanding is baryon spectroscopy. Unfortunately, in the…
This paper reports on a measurement of the double-polarization observable G in $\pi^0$ photoproduction off the proton using the CBELSA/TAPS experiment at the ELSA accelerator in Bonn. The observable G is determined from reactions of…
The first measurements of the beam-target-helicity-asymmetries $E$ and $G$ in the photoproduction of $\omega$-mesons off protons at the CBELSA/TAPS experiment are reported. $E$ ($G$) was measured using circularly (linearly) polarised…
The excitation spectrum of the nucleon consists of several overlapping resonances. To identify these resonances and their contributions to the measured cross sections, a partial wave analysis is used. A set of at least eight, well chosen,…
First measurements of double-polarization observables in $\omega$ photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson…
To unambiguously identify baryon resonances the measurement of polarization observables is of great importance. With the CBELSA/TAPS experiment, located at the ELSA accelerator facility in Bonn, polarization observables have been…
We propose to extend the investigations of the eta meson production in nucleon-nucleon collisions by studying single and double polarization observables. Over the last years, the eta meson has been studied at several different experiments…
A measurement of the double-polarization observable $E$ for the reaction $\gamma p\to \pi^0 p$ is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C$_4$H$_9$OH)…
Measurements of target asymmetries and double-polarization observables for the reaction $\gamma p\to p\pi^0\pi^0$ are reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility (Bonn University) using the Bonn…
The photoproduction of $\pi^+\pi^-$ meson pairs off the proton has been studied in the reaction $\gamma p\to p\,\pi^+\pi^-$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target (FROST) in Hall B at the Thomas…
The process of electron-positron pair production by linearly polarized photons is used as a polarimeter to perform mobile measurement of linear photon polarization. In the limit of high photon energies, omega, the distributions of the…
The differential cross sections and unpolarized spin-density matrix elements for the reaction $\gamma p\to p\omega$ were measured using the CBELSA/TAPS experiment for initial photon energies ranging from the reaction threshold to 2.5 GeV.…
The polarization observable I^s, a feature exclusive to the acoplanar kinematics of multi-meson final states produced via linearly polarized photons, has been measured for the first time. Results for the reaction g p -> p pi0 eta are…
$\gamma (p,K^0)\Sigma^+$ cross section was measured at the CBELSA/TAPS experiment at the ELSA electron stretcher facility. A cusp-like structure was apparent near the $K^*$ production threshold, where the cross section reduced by a factor…
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%…
A new transversely polarised frozen spin target has been developed at MAMI which will be used in conjunction with the photon tagger and the Crystal Ball detector. The new target permits a major new programme of accurate measurement of…
Photoproduction of $\eta$ mesons from neutrons} \abstract{Results from measurements of the photoproduction of $\eta$ mesons from quasifree protons and neutrons are summarized. The experiments were performed with the CBELSA/TAPS detector at…
One of the remaining challenges within the standard model is to gain a good understanding of QCD in the non-perturbative regime. One key step toward this aim is baryon spectroscopy, investigating the spectrum and the properties of baryon…