Volker D. Burkert

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Time resolution of Burle 85001 micro-channel plate photo-multipliers in comparison with Hamamatsu R2083. Abstract The CLAS detector will require improvements in its particle identification system to take advantage of the higher energies provided by the Jefferson Laboratory accelerator upgrade to 12 GeV. To this end, we have studied the timing(More)
In an exclusive measurement of the reaction gammad-->K(+)K(-)pn, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1 is seen in the K(+)n invariant mass spectrum. The peak is at 1.542+/-0.005 GeV/c(2) with a measured width of 0.021 GeV/c(2) FWHM, which is largely determined by experimental mass resolution. The statistical(More)
Beam-helicity asymmetries for the two-pion-photoproduction reaction gammap-->ppi(+)pi(-) have been studied for the first time in the resonance region for center-of-mass energies between 1.35 and 2.30 GeV. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer using circularly polarized tagged photons incident on an(More)
We extract the Bjorken integral Gamma1(p-n) in the range 0.17 < Q2 < 1.10 GeV2 from inclusive scattering of polarized electrons by polarized protons, deuterons, and 3He, for the region in which the integral is dominated by nucleon resonances. These data bridge the domains of the hadronic and partonic descriptions of the nucleon. In combination with earlier(More)
The reaction gamma p-->pi(+)K(-)K(+)n was studied at Jefferson Laboratory using a tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state with strangeness S=+1 and mass M=1555+/-10 MeV/c(2) was observed in the nK(+) invariant mass spectrum. The peak's width is consistent with the CLAS resolution (FWHM=26 MeV/c(2)), and its statistical(More)
We propose to measure the Beam Spin Asymmetry (BSA) in Deeply Virtual Compton Scattering (DVCS) off 4 He. The measurements will use a 6 GeV polarized electron beam, a 4 He pressurized gas target, the CLAS and the BoNuS RTPC detectors. The major goal of this proposal is to perform the first fully quantitative investigation of the DVCS reaction off a nuclear(More)
The longitudinal target-spin asymmetry AUL for the exclusive electroproduction of high-energy photons was measured for the first time in ep-->e;'pgamma. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from(More)
Weinstein) is actively involved in this proposal, as well as two other proposal using CLAS12. Other members of our group are pursuing a proposal for Hall A, but their contributions are not included here. Among CLAS12 baseline equipment, the group intends to take responsibility for the design, prototyping, construction and testing of the Region 1 Drift(More)
We investigate the transition from the nucleon-meson to the quark-gluon description of the strong interaction using the photon energy dependence of the d(gamma,p)n differential cross section for photon energies above 0.5 GeV and center-of-mass proton angles between 30 degrees and 150 degrees. A possible signature for this transition is the onset of(More)
We propose to search for new forms of hadronic matter utilizing a photon beam at CLAS in Hall B. Motivated by recent experimental results for glu-onic hybrid meson candidates and from recent theoretical Lattice QCD and Flux-tube model calculations, photoproduction should provide an ideal hunting ground for gluonic matter. Jefferson Lab offers an excellent(More)