N. Liyanage, B. D. Anderson, K. A. Aniol, L. Auerbach, F. T. Baker, J. Berthot, W. Bertozzi, P. -Y. Bertin, L. Bimbot, W. U. Boeglin, E. J. Brash, V. Breton, H. Breuer, E. Burtin, J. R. Calarco, L. Cardman, G. D. Cates, C. Cavata, C. C. Chang, J. -P. Chen, E. Cisbani, D. S. Dale, R. De Leo, A. Deur, B. Diederich, P. Djawotho, J. Domingo, B. Doyle, J. -E. Ducret, M. B. Epstein, L. A. Ewell, J. M. Finn, K. G. Fissum, H. Fonvieille, B. Frois, S. Frullani, J. Gao, F. Garibaldi, A. Gasparian, S. Gilad, R. Gilman, A. Glamazdin, C. Glashausser, J. Gomez, V. Gorbenko, T. Gorringe, F. W. Hersman, R. Holmes, M. Holtrop, N. d’Hose, C. Howell, G. M. Huber, C. E. Hyde-Wright, M. Iodice, C. W. de Jager, S. Jaminion, M. K. Jones, K. Joo, C. Jutier, W. Kahl, S. Kato, J. J. Kelly, S. Kerhoas, M. Khandaker, M. Khayat, K. Kino, W. Korsch, L. Kramer, K. S. Kumar, G. Kumbartzki, G. Laveissière, A. Leone, J. J. LeRose, L. Levchuk, M. Liang, R. A. Lindgren, G. J. Lolos, R. W. Lourie, R. Madey, K. Maeda, S. Malov, D. M. Manley, D. J. Margaziotis P. Markowitz, J. Martino, J. S. McCarthy, K. McCormick, J. McIntyre, R. L. J. van der Meer, Z. -E. Meziani, R. Michaels, J. Mougey, S. Nanda, D. Neyret, E. A. J. M. Offermann, Z. Papandreou, C. F. Perdrisat, R. Perrino, G. G. Petratos, S. Platchkov, R. Pomatsalyuk, D. L. Prout, V. A. Punjabi, T. Pussieux, G. Quéméner, R. D. Ransome, O. Ravel, Y. Roblin, R. Roche, D. Rowntree, G.A. Rutledge, P. M. Rutt, A. Saha, T. Saito, A. J. Sarty, A. Serdarevic-Offermann, T. P. Smith, A. Soldi, P. Sorokin, P. Souder, R. Suleiman, J. A. Templon, T. Terasawa, L. Todor, H. Tsubota, H. Ueno, P. E. Ulmer, G.M. Urciuoli, P. Vernin, S. van Verst, B. Vlahovic, H. Voskanyan, J. W. Watson, L. B. Weinstein, K. Wijesooriya, R. Wilson, B. Wojtsekhowski, D. G. Zainea, V. Zeps, J. Zhao, Z. -L. Zhou

During the last decade the detailed analysis of several observables and especially of electron scattering data has shown conclusively the presence of short-range nucleon correlations. As a result the degree to which the shape and amplitude of a correlated wave function can be approximated by an independent particle wave function has emerged as a question of fundamental importance. A presentation will be given below of an experiment that will be performed at the Bates Linear Accelerator Center attempting to study this question. The elastic cross-section ratios from 208,207,206Pb,205Ti(e,e) will be measured with high accuracy up to momentum transfers of 3.4 fm^-1 in order to study the influence of correlations on the shape of the 3s1/2 proton wave function. The purpose, motivation and main aspects of the new research will be explained and the experimental considerations together with the running scenario for the experiment will be presented.

We have made the first measurements of the virtual Compton scattering process via the e p -> e p gamma exclusive reaction at Q**2 = 1 GeV**2 in the nucleon resonance region. The cross section is obtained at center of mass (CM) backward angle, theta_gamma_gamma*, in a range of total (gamma* p) CM energy W from the proton mass up to W = 1.91 GeV. The data show resonant structures in the first and second resonance regions, and are well reproduced at higher W by the Bethe-Heitler+Born cross section, including t-channel pi0-exchange. At high W, our data, together with existing real photon data, show a striking Q**2 independence. Our measurement of the ratio of H(e,e'p)gamma to H(e,e'p)pi0 cross sections is presented and compared to model predictions.

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from protons. Significant contributions to this asymmetry could arise from the contributions of strange form factors in the nucleon. The measured asymmetry is A = −15.05 ± 0.98(stat) ± 0.56(syst) ppm at the kinematic point 〈θlab〉 = 12.3 and 〈Q2〉 = 0.477 (GeV/c)2. Based on these data as well as data on electromagnetic form factors, we extract the linear combination of strange form factors GE + 0.392G s M = 0.014 ± 0.020 ± 0.010 where the first error arises from this experiment and the second arises from the electromagnetic form factor data. This paper provides a full description of the special experimental techniques employed for precisely measuring the small asymmetry, including the first use of a strained GaAs crystal and a laser-Compton polarimeter in a fixed target parity-violation experiment. PACS numbers: 13.60.Fz; 11.30.Er; 13.40.Gp; 14.20.Dh Electronic address: finn@physics.wm.edu Now at: Duke University, Durham, North Carolina 27708 USA Now at: University of Chicago, IL, 60637, USA Electronic address: souder@phy.syr.edu

This paper briefly reviews the next generations of nuclear reactors and the perspectives of development of nuclear energy. Advanced reactors will progressively replace the existing ones during the next two decades. Future systems of the fourth generation are planned to be built beyond 2030. These systems have been studied in the framework of the "Generation IV" International Forum. The goals of these systems is to have a considerable increase in safety, be economically competitive and produce a significantly reduced volume of nuclear wastes. The closed fuel cycle is preferred.

G. Laveissière, L. Todor, N. Degrande, S. Jaminion, C. Jutier, 2 R. Di Salvo, L. Van Hoorebeke, L.C. Alexa, B.D. Anderson, K.A. Aniol, K. Arundell, G. Audit, L. Auerbach, F.T. Baker, M. Baylac, J. Berthot, P.Y. Bertin, W. Bertozzi, L. Bimbot, W.U. Boeglin, E.J. Brash, V. Breton, H. Breuer, E. Burtin, J.R. Calarco, L.S. Cardman, C. Cavata, C.-C. Chang, J.-P. Chen, E. Chudakov, E. Cisbani, D.S. Dale, C.W. de Jager, R. De Leo, A. Deur, 16 N. d’Hose, G.E. Dodge, J.J. Domingo, L. Elouadrhiri, M.B. Epstein, L.A. Ewell, J.M. Finn, K.G. Fissum, H. Fonvieille, G. Fournier, B. Frois, S. Frullani, C. Furget, H. Gao, 21 J. Gao, F. Garibaldi, A. Gasparian, 18 S. Gilad, R. Gilman, 16 A. Glamazdin, C. Glashausser, J. Gomez, V. Gorbenko, P. Grenier, P.A.M. Guichon, J.O. Hansen, R. Holmes, M. Holtrop, C. Howell, G.M. Huber, C.E. Hyde-Wright, S. Incerti, M. Iodice, J. Jardillier, M.K. Jones, 16 W. Kahl, S. Kato, A.T. Katramatou, J.J. Kelly, S. Kerhoas, A. Ketikyan, M. Khayat, K. Kino, S. Kox, L.H. Kramer, K.S. Kumar, G. Kumbartzki, M. Kuss, A. Leone, J.J. LeRose, M. Liang, R.A. Lindgren, N. Liyanage, 31 G.J. Lolos, R.W. Lourie, R. Madey, K. Maeda, S. Malov, D.M. Manley, C. Marchand, D. Marchand, D.J. Margaziotis, P. Markowitz, J. Marroncle, J. Martino, K. McCormick, 23 J. McIntyre, S. Mehrabyan, F. Merchez, Z.E. Meziani, R. Michaels, G.W. Miller, J.Y. Mougey, S.K. Nanda, D. Neyret, E.A.J.M. Offermann, Z. Papandreou, B. Pasquini, C.F. Perdrisat, R. Perrino, G.G. Petratos, S. Platchkov, R. Pomatsalyuk, D.L. Prout, V.A. Punjabi, T. Pussieux, G. Quémenér, R.D. Ransome, O. Ravel, J.S. Real, F. Renard, Y. Roblin, 16 D. Rowntree, G. Rutledge, P.M. Rutt, A. Saha, T. Saito, A.J. Sarty, A. Serdarevic, 16 T. Smith, G. Smirnov, K. Soldi, P. Sorokin, P.A. Souder, R. Suleiman, 11 J.A. Templon, T. Terasawa, R. Tieulent, E. Tomasi-Gustaffson, H. Tsubota, H. Ueno, P.E. Ulmer, G.M. Urciuoli, M. Vanderhaeghen, 7, 16 R. Van De Vyver, R.L.J. Van der Meer, 16 P. Vernin, B. Vlahovic, H. Voskanyan, E. Voutier, J.W. Watson, L.B. Weinstein, K. Wijesooriya, R. Wilson, B.B. Wojtsekhowski, D.G. Zainea, W-M. Zhang, J. Zhao, and Z.-L. Zhou

We present a measurement of the longitudinal spin cross section asymmetry for deep inelasticmuon-nucleon interactions with two high transverse momentum hadrons in the final state. Twomethods of event classification are used to increase the contribution of the Photon Gluon Fusionprocess to above 30%. The most effective one, based on a neural network approach, provides theasymmetries A

We present a measurement of the longitudinal spin cross section asymmetry for deep inelastic muon-nucleon interactions with two high transverse momentum hadrons in the final state. Two methods of event classification are used to increase the contribution of the Photon Gluon Fusion process to above 30%. The most effective one, based on a neural network approach, provides the asymmetries A_p(lN->lhhX)=0.030+/-0.057+/-0.010 and A_d(lN->lhhX)=0.070+/-0.076+/-0.010. From these values we derive an averaged gluon polarization delta(G)/G=-0.20+/-0.28+/-0.10 at an average fraction of nucleon momentum carried by gluons eta=0.07.

K.G. Fissum, 2, ∗ M. Liang, B.D. Anderson, K.A. Aniol, L. Auerbach, F.T. Baker, J. Berthot, W. Bertozzi, P.-Y. Bertin, L. Bimbot, W.U. Boeglin, E.J. Brash, V. Breton, H. Breuer, E. Burtin, J.R. Calarco, L.S. Cardman, G.D. Cates, 16 C. Cavata, C.C. Chang, J.-P. Chen, E. Cisbani, D.S. Dale, C.W. de Jager, R. De Leo, A. Deur, 16, 3 B. Diederich, P. Djawotho, J. Domingo, J.-E. Ducret, M.B. Epstein, L.A. Ewell, J.M. Finn, H. Fonvieille, B. Frois, S. Frullani, J. Gao, 23 F. Garibaldi, A. Gasparian, 24 S. Gilad, R. Gilman, 25 A. Glamazdin, C. Glashausser, J. Gomez, V. Gorbenko, T. Gorringe, F.W. Hersman, R. Holmes, M. Holtrop, N. d’Hose, C. Howell, G.M. Huber, C.E. Hyde-Wright, M. Iodice, 29 S. Jaminion, M.K. Jones, 3 K. Joo, † C. Jutier, 20 W. Kahl, S. Kato, J.J. Kelly, S. Kerhoas, M. Khandaker, M. Khayat, K. Kino, W. Korsch, L. Kramer, K.S. Kumar, 33 G. Kumbartzki, G. Laveissière, A. Leone, J.J. LeRose, L. Levchuk, R.A. Lindgren, N. Liyanage, 3, 16 G.J. Lolos, R.W. Lourie, 36 R. Madey, 3, 24 K. Maeda, S. Malov, D.M. Manley, D.J. Margaziotis, P. Markowitz, J. Martino, J.S. McCarthy, K. McCormick, 4, 25 J. McIntyre, R.L.J. van der Meer, 3 Z.-E. Meziani, R. Michaels, J. Mougey, S. Nanda, D. Neyret, E.A.J.M. Offermann, 36 Z. Papandreou, C.F. Perdrisat, R. Perrino, G.G. Petratos, S. Platchkov, R. Pomatsalyuk, D.L. Prout, V.A. Punjabi, T. Pussieux, G. Quéméner, 8, 37 R.D. Ransome, O. Ravel, Y. Roblin, 3 R. Roche, 20 D. Rowntree, G.A. Rutledge, ‡ P.M. Rutt, A. Saha, T. Saito, A.J. Sarty, 39 A. Serdarevic-Offermann, 3 T.P. Smith, A. Soldi, P. Sorokin, P. Souder, R. Suleiman, 1 J.A. Templon, § T. Terasawa, L. Todor, ¶ H. Tsubota, H. Ueno, P.E. Ulmer, G.M. Urciuoli, P. Vernin, S. van Verst, B. Vlahovic, 3 H. Voskanyan, J.W. Watson, L.B. Weinstein, K. Wijesooriya, 42, 28 B. Wojtsekhowski, D.G. Zainea, V. Zeps, J. Zhao, and Z.-L. Zhou

The physics program in Hall A at Jefferson Lab commenced in the summer of 1997 with a detailed investigation of the ^(16)O(e,e′p) reaction in quasielastic, constant (q,ω) kinematics at Q^2≈0.8(GeV/c)^2, q≈1GeV/c, and ω≈445MeV. Use of a self-calibrating, self-normalizing, thin-film waterfall target enabled a systematically rigorous measurement. Five-fold differential cross-section data for the removal of protons from the 1p-shell have been obtained for 0<p_miss<350MeV/c. Six-fold differential cross-section data for 0<E_miss<120MeV were obtained for 0<p_miss<340MeV/c. These results have been used to extract the ALT asymmetry and the R_L, R_T, R_LT, and R_(L+TT) effective response functions over a large range of E_miss and p_miss. Detailed comparisons of the 1p-shell data with Relativistic Distorted-Wave Impulse Approximation (RDWIA), Relativistic Optical-Model Eikonal Approximation (ROMEA), and Relativistic Multiple-Scattering Glauber Approximation (RMSGA) calculations indicate that two-body currents stemming from meson-exchange currents (MEC) and isobar currents (IC) are not needed to explain the data at this Q^2. Further, dynamical relativistic effects are strongly indicated by the observed structure in ALT at p_miss≈300MeV/c. For 25<E_miss<50MeV and p_miss≈50MeV/c, proton knockout from the 1s1/2-state dominates, and ROMEA calculations do an excellent job of explaining the data. However, as p_miss increases, the single-particle behavior of the reaction is increasingly hidden by more complicated processes, and for 280<p_miss<340MeV/c, ROMEA calculations together with two-body currents stemming from MEC and IC account for the shape and transverse nature of the data, but only about half the magnitude of the measured cross section. For 50<E_miss<120MeV and 145<p_miss<340MeV/c, (e,e′pN) calculations which include the contributions of central and tensor correlations (two-nucleon correlations) together with MEC and IC (two-nucleon currents) account for only about half of the measured cross section. The kinematic consistency of the 1p-shell normalization factors extracted from these data with respect to all available O16(e,e′p) data is also examined in detail. Finally, the Q^2-dependence of the normalization factors is discussed.

The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro- and 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 drift chambers in the focal plane to provide a momentum resolution of better than 2×10−4. A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 1038cm−2s−1. The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium.

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.

Exclusive electroproduction of pi0 mesons on protons in the backward hemisphere has been studied at Q**2 = 1.0 GeV**2 by detecting protons in the forward direction in coincidence with scattered electrons from the 4 GeV electron beam in Jefferson Lab's Hall A. The data span the range of the total (gamma* p) center-of-mass energy W from the pion production threshold to W = 2.0 GeV. The differential cross sections sigma_T+epsilon*sigma_L, sigma_TL, and sigma_TT were separated from the azimuthal distribution and are presented together with the MAID and SAID parametrizations.

The physics program in Hall A at Jefferson Lab commenced in the summer of 1997 with a detailed investigation of the $^{16}\mathrm{O}(e,{e}^{\ensuremath{'}}p)$ reaction in quasielastic, constant $(q,\ensuremath{\omega})$ kinematics at ${Q}^{2}\ensuremath{\approx}0.8\phantom{\rule{0.3em}{0ex}}{(\mathrm{GeV}∕c)}^{2}$, $q\ensuremath{\approx}1\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}∕c$, and $\ensuremath{\omega}\ensuremath{\approx}445\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$. Use of a self-calibrating, self-normalizing, thin-film waterfall target enabled a systematically rigorous measurement. Five-fold differential cross-section data for the removal of protons from the $1p$-shell have been obtained for $0<{p}_{\mathrm{miss}}<350\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕c$. Six-fold differential cross-section data for $0<{E}_{\mathrm{miss}}<120\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ were obtained for $0<{p}_{\mathrm{miss}}<340\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕c$. These results have been used to extract the ${A}_{LT}$ asymmetry and the ${R}_{L}$, ${R}_{T}$, ${R}_{LT}$, and ${R}_{L+TT}$ effective response functions over a large range of ${E}_{\mathrm{miss}}$ and ${p}_{\mathrm{miss}}$. Detailed comparisons of the $1p$-shell data with Relativistic Distorted-Wave Impulse Approximation (RDWIA), Relativistic Optical-Model Eikonal Approximation (ROMEA), and Relativistic Multiple-Scattering Glauber Approximation (RMSGA) calculations indicate that two-body currents stemming from meson-exchange currents (MEC) and isobar currents (IC) are not needed to explain the data at this ${Q}^{2}$. Further, dynamical relativistic effects are strongly indicated by the observed structure in ${A}_{LT}$ at ${p}_{\mathrm{miss}}\ensuremath{\approx}300\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕c$. For $25<{E}_{\mathrm{miss}}<50\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ and ${p}_{\mathrm{miss}}\ensuremath{\approx}50\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕c$, proton knockout from the $1{s}_{1∕2}$-state dominates, and ROMEA calculations do an excellent job of explaining the data. However, as ${p}_{\mathrm{miss}}$ increases, the single-particle behavior of the reaction is increasingly hidden by more complicated processes, and for $280<{p}_{\mathrm{miss}}<340\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕c$, ROMEA calculations together with two-body currents stemming from MEC and IC account for the shape and transverse nature of the data, but only about half the magnitude of the measured cross section. For $50<{E}_{\mathrm{miss}}<120\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ and $145<{p}_{\mathrm{miss}}<340\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕c$, $(e,{e}^{\ensuremath{'}}pN)$ calculations which include the contributions of central and tensor correlations (two-nucleon correlations) together with MEC and IC (two-nucleon currents) account for only about half of the measured cross section. The kinematic consistency of the $1p$-shell normalization factors extracted from these data with respect to all available $^{16}\mathrm{O}(e,{e}^{\ensuremath{'}}p)$ data is also examined in detail. Finally, the ${Q}^{2}$-dependence of the normalization factors is discussed.

Virtual Compton Scattering is studied at the Thomas Jefferson National Accelerator Facility at low Center-of-Mass energies, below pion threshold. Following the Low Energy Theorem for the $ ep \to ep \gamma$ process, we obtain values for the two structure functions Pll-Ptt/epsilon and Plt at four-momentum transfer squared Q2=0.92 and 1.76 GeV2.

A Compton polarimeter has been installed in Hall A at Jefferson Laboratory. This Letter reports on the first electron beam polarization measurements performed during the HAPPEX experiment at an electron energy of 3.3 GeV and an average current of 40 muA. The heart of this device is a Fabry-Perot cavity which increased the luminosity for Compton scattering in the interaction region so much that a 1.4% statistical accuracy could be obtained within one hour, with a 3.3% total error. (C) 2002 Elsevier Science B.V. All rights reserved.