[en] Time-like electromagnetic form factors can be obtained from unpolarized measurements of the differential cross section in proton antiproton annihilation in a pair of leptons, as p-bar + p ↔ e⁺ + e^-, with the PANDA detector at FAIR. We study the sensitivity of such measurements and focus on observables such as the angular asymmetry and the ratio of electric to magnetic form factors. We also collect useful formulas and references for future simulations and studies. (authors)

[en] Measurement of the parity violating asymmetry of polarized electron scattering on hydrogen at 855 MeV with a non-magnetic calorimetric counter is in progress. The different developments at the IPN-Orsay are here emphasized. (authors)

[en] A source of polarized electrons based on a helium flowing afterglow has been developed at Orsay. This source, SELPO-M, has been placed on a 100 kV platform and set up in such a way as to allow its connection to the MAMI accelerator. Its performances in terms of current, polarization and optical properties are given. Its figure of merit (IP²≅75 μA) appears highly competitive as compared to strained GaAs sources. (author)

[en] Highly polarized hydrogen molecules in the solid phase are of primary interest as 'polarized targets' for Nuclear Physics experiments and polarized fuel for Inertial Confinement Fusion (ICF). Within the French-Italian GRAAL collaboration, we are constructing a new Polarized HD Target Factory, implanted at IPN Orsay. It consists of a powerful Dilution Refrigerator (12 μW at 10 mK) equipped with a 16.5 T superconducting magnet and several ancillary cryostats for condensation, storage, transfer and transport of polarized HD samples. The primary objective is to produce polarized HD targets (HYDILE project) for the photoproduction experiments with the GRAAL polarized high energy real photon beams, obtained from backscattering of laser light against the electron stored in the ESRF ring at Grenoble. Production of targets for other sites is forseen. The system will be described and the results already obtained for the static polarization of a HD sample will be given. The possibility to investigate dynamic polarization methods for HD and apply them to DT in order to produce polarized DT fuel for fusion will be discussed

[en] The static polarization of HD samples has been achieved using 'brute force', for HD samples purified by double distillation. Proton polarization in excess of 60% and deuteron vector polarization higher than 14% have been reached. It has been demonstrated that the ageing technique allows to get relaxation times at 1.5 K and 1 T larger than a week. It is advocated that the conventional dynamic polarization of HD should be feasible for the proton and the deuteron contained in the HD molecule. This would simplify considerably the machinery presently necessary to perform nuclear physics experiments with HD targets polarized by the static method

[en] The dimuon arm of the LHC detector ALICE, will be equipped with pad and cathode strip chambers. An R and D program has been launched at IPN to optimize the characteristics of these chambers, both the front-end and the read-out electronics. The present report gives the description of the tests carried out at CERN-SPS. The test beam data has been analyzed and a comparison between the experimental results and the simulation calculations has been presented. (authors)

[en] The tensor polarization of deuterons, ρ₂₀, emitted at zero degree in the ¹H(³He, d-↔)X reaction, was measured at the Saturne National Laboratory in Saclay, using the SPES4 magnetic channel and the HYPOM polarimeter. The momentum of the detected deuterons was kept fixed at 3.77 GeV/c, while the momentum of the ³He beam was varied from 5.66 to 4.60 GeV/c; this provided a range of internal momenta of a deuteron in ³He, k, from 0 to 0.43 GeV/c

[en] The question of the determination of the proton charge radius R${}_p$ from electron scattering data led to an unprecedented experimental effort for measurements of the electric form factor of the proton at low and very low momentum transfer in electron and muon elastic scattering. On the basis of basic properties of densities and fitting bias considerations, a procedure is developed in order to evaluate the impact of forthcoming data on R${}_p$. Particularly, it is shown that a 0.1% precision on these future cross section data is necessary to establish indisputably the R${}_p$-value as determined from lepton scattering. An experimental method to meet this stringent constraint is further discussed in the case of the ProRad (Proton Radius) experiment at the PRAE (Platform for Research and Applications with Electrons) facility in Orsay.

[en] The charge radius of the proton can be determined using two different kinds of experiments: the spectroscopy technique, measuring the hyperfine structure of hydrogen atoms, and the scattering technique, deducing the radius from elastic lepton scattering off a proton target. These two methods lead to quite different results, a discrepancy known as the “proton radius puzzle”. To shed light on this problem, we have proposed a novel method for the determination of spatial moments from densities expressed in the momentum space. This method provides a direct access not only to the second order moment, directly related to the proton radius, but to all moments of any real order larger than-3. The method is applied to the global analysis of proton electric form factor experimental data from Rosenbluth separation and low-Q² experiments, paying specific attention to the evaluation of the systematic errors. Within this analysis, the integer order moments of the proton charge density are evaluated, the moment of second order leading to a new determination of the proton charge radius. (author)

[en] Since 1996 the GRAAL experiment is running at the ESRF, using a linearly polarized photon beam produced by backscattering a laser beam on the electron beam in the storage ring. A liquid hydrogen target and a large acceptance detector are used. All sizeable photoproduction reactions are measured and analyzed. We present the results of η meson, one and two pions, and ω photoproduction, which are partly published or still preliminary. Predictions or fits of these data by theoretical models are given