H . Fonvieille

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The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electroand photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical(More)
K. Abe,21 T. Akagi,18,21 B. D. Anderson,7 P. L. Anthony,18 R. G. Arnold,1 T. Averett,5 H. R. Band,23 C. M. Berisso,9 P. Bogorad,15 H. Borel,6 P. E. Bosted,1 V. Breton,3 M. J. Buenerd,18 G. D. Cates,15 T. E. Chupp,10 S. Churchwell,9 K. P. Coulter,10 M. Daoudi,18 P. Decowski,17 R. Erickson,18 J. N. Fellbaum,1 H. Fonvieille,3 R. Gearhart,18 V. Ghazikhanian,8(More)
The neutron longitudinal and transverse asymmetries A n 1 and A n 2 have been extracted from deep inelas-tic scattering of polarized electrons by a polarized 3 He target at incident energies of 19.42, 22.66 and 25.51 GeV. The measurement allows for the determination of the neutron spin structure functions g n 1 (x; Q 2) and g n 2 (x; Q 2) over the range(More)
New precise results of a measurement of the elastic electron-proton scattering cross section performed at the Mainz Microtron MAMI are presented. About 1400 cross sections were measured with negative four-momentum transfers squared up to Q² = 1 (GeV/c)² with statistical errors below 0.2%. The electric and magnetic form factors of the proton were extracted(More)
A massive, but light, Abelian U(1) gauge boson is a well-motivated possible signature of physics beyond the standard model of particle physics. In this Letter, the search for the signal of such a U(1) gauge boson in electron-positron pair production at the spectrometer setup of the A1 Collaboration at the Mainz Microtron is described. Exclusion limits in(More)
A new exclusion limit for the electromagnetic production of a light U(1) gauge boson γ' decaying to e + e- was determined by the A1 Collaboration at the Mainz Microtron. Such light gauge bosons appear in several extensions of the standard model and are also discussed as candidates for the interaction of dark matter with standard model matter. In electron(More)
Virtual Compton Scattering off the proton: γ∗p → γp is a new field of investigation of nucleon structure. Several dedicated experiments have been performed at low c.m. energy and various momentum transfers, yielding specific information on the proton. This talk reviews the concept of nucleon Generalized Polarizabilities and the present experimental status.(More)
We have measured the spin structure functions g(1) and g(2) of 3He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.058 GeV off a polarized 3He target at a 15.5 degrees scattering angle. Excitation energies covered the resonance and the onset of the deep inelastic regions. We have determined for(More)
O. Gayou,1,7 K. A. Aniol,9 T. Averett,1 F. Benmokhtar,2 W. Bertozzi,24 L. Bimbot,26 E. J. Brash,4 J. R. Calarco,25 C. Cavata,27 Z. Chai,24 C.-C. Chang,23 T. Chang,15 J.-P. Chen,5 E. Chudakov,5 R. De Leo,16 S. Dieterich,2 R. Endres,2 M. B. Epstein,9 S. Escoffier,27 K. G. Fissum,22 H. Fonvieille,7 S. Frullani,18 J. Gao,8 F. Garibaldi,18 S. Gilad,24 R.(More)
We present data on the inclusive scattering of polarized electrons from a polarized 3He target at energies from 0.862 to 5.06 GeV, obtained at a scattering angle of 15.5 degrees. Our data include measurements from the quasielastic peak, through the nucleon resonance region, and beyond, and were used to determine the virtual photon cross-section difference(More)