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1. $$K^{+}\Lambda $$ photoproduction at forward angles and low momentum transfer

Author

P. Pedroni, P. Levi Sandri, A. V. Sarantsev, Patrick Bauer, M. Romaniuk, R. Messi, A. M. Lapik, Giuseppe Mandaglio, B.-E. Reitz, D. Elsner, R. Di Salvo, O. Freyermuth, A. Fantini, J. Hannappel, V. Tarakanov, Frank Frommberger, F. Ghio, N. G. Kozlenko, G. Scheluchin, V. G. Nedorezov, P. L. Cole, T. Zimmermann, D. Novinskiy, S. Goertz, D. Hammann, J. Bieling, K. Kohl, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, A. Polonskiy, V. Lisin, S. Alef, V. V. Sumachev, V. A. Nikonov, A. Bella, R. Beck, T. C. Jude, V. Vegna, D. Moricciani, A. Stuglev, Francesco Messi, and A. Braghieri

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Settore FIS/04, Momentum transfer, Hyperon, Lambda, 01 natural sciences, Charged particle, Momentum, Nuclear physics, Cross section (physics), Recoil, 0103 physical sciences, Nuclear Experiment, 010306 general physics
Abstract

$\gamma p \rightarrow K^+ \Lambda$ differential cross sections and recoil polarisation data from threshold for extremely forward angles are presented. The measurements were performed at the BGOOD experiment at ELSA, utilising the high angular and momentum resolution forward spectrometer for charged particle identification. The data discriminates between conflicting results in the world data set and enable extraction of the cross section as the minimum momentum transfer to the recoiling hyperon is approached., Comment: 12 pages (including a 2 page appendix), 14 figures

Published
2021

2. Strangeness Photoproduction at the BGO-OD Experiment

Author

D. Moricciani, K. Kohl, V. G. Nedorezov, D. Novinskiy, P. Levi Sandri, N. G. Kozlenko, A. Polonski, Giuseppe Mandaglio, A. Fantini, P. Cole, R. Messi, V. Lisin, R. Di Salvo, G. Scheluchin, V. Tarakanov, Christian Tillmanns, A. M. Lapik, D. Elsner, O. Freyermuth, D. Hammann, J. Hannappel, Reinhard Beck, V. V. Sumachev, S. Alef, H. Schmieden, A. B. Gridnev, B.-E. Reitz, F. Ghio, T. C. Jude, Patrick Bauer, M. Romaniuk, and P. Pedroni

Subjects
Physics, Settore FIS/01, Nuclear and High Energy Physics, Calorimeter (particle physics), Spectrometer, Nuclear Theory, Momentum transfer, Bremsstrahlung, Elementary particle, Strangeness, Tracking (particle physics), Nuclear physics, Nuclear Experiment, Nucleon
Abstract

The BGO-OD experiment at the ELSA accelerator facility uses an energy tagged bremstrahlung photon beam to investigate the excitation structure of the nucleon. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating low momentum transfer processes due to the acceptance and high momentum resolution at forward angles. In particular, this enables the investigation of strangeness photoproduction where t-channel exchange mechanisms play an important role. This also allows access to a kinematic region where extended, molecular structure may manifest in reaction mechanisms. The extensive strangeness photoproduction programme includes the photoproduction of neutral and charged kaons using both hydrogen and deuterium targets.

Published
2019

3. Strangeness photoproduction at the BGO-OD experiment

Author

V. Metag, V. Tarakanov, R. Joosten, O. Freyermuth, S. Friedrich, D. Burdeynyi, K. Kohl, Francesco Messi, A. Polonski, D. Novinskiy, Hans-Georg Zaunick, G. Gervino, J. Hannappel, J. Bieling, R. Messi, A. Fantini, Wolfgang Hillert, D. Hammann, K.-T. Brinkmann, D. Moricciani, P. L. Cole, R. Jahn, P. Pedroni, B. Krusche, Giuseppe Mandaglio, V. Lisin, D. Elsner, G. Scheluchin, A. Stugelev, A. M. Lapik, Frank Klein, R. Di Salvo, A. Bella, A. Braghieri, Reinhard Beck, Frank Frommberger, T. Zimmermann, A. N. Mushkarenkov, V. V. Sumachev, P. Levi Sandri, I. V. Lopatin, T. C. Jude, Patrick Bauer, E. Gutz, V. G. Nedorezov, D. Walther, S. Boese, V. Vegna, M. Romaniuk, S. Alef, B.-E. Reitz, F. Ghio, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, and Mariana Nanova

Subjects
Settore FIS/01, Physics, Calorimeter (particle physics), Meson, Nuclear Theory, Momentum transfer, Hadron, Constituent quark, Strangeness, strangeness photoproduction, Baryon, Nuclear physics, Nuclear Experiment, Nucleon
Abstract

The BGO-OD experiment at the ELSA accelerator facility uses an energy tagged bremstrahlung photon beam to investigate the excitation spectrum of the nucleon. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating the photoproduction of hadrons of non-zero strangeness. The high momentum resolution at forward angles covers a kinematic region where t-channel exchange mechanisms play a dominant role. Access to this low momentum transfer region also allows the investigation of degrees of freedom not derived from constituent quark models, for example, the role of (vector) meson - baryon interactions and dynamically generated states in photoproduction reactions. Data taking for the first part of an extensive physics programme is complete and preliminary results and ongoing analysis are presented. (Less)

Published
2018

4. Search for light vector boson production ine+e−→μ+μ−γinteractions with the KLOE experiment

Author

R. Messi, T. Johansson, S. Giovannella, Aleksander Gajos, Antonio Budano, S. Miscetti, K. Kacprzak, F. Bossi, R. Di Salvo, E. Dané, G. Felici, Vincenzo Patera, Andrzej Kupsc, S. Loffredo, Wojciech Wiślicki, Paweł Moskal, M. Martemianov, F. Happacher, Jarosław Zdebik, G. Giardina, Daria Kamińska, D. Domenici, P. De Simone, Gianfranco Morello, A. Passeri, A. Di Cicco, Marco Schioppa, Magnus Wolke, P. Gauzzi, F. Loddo, G. Venanzoni, A. De Santis, M. Mascolo, C. Bloise, Michał Silarski, A. Ranieri, F. Nguyen, Barbara Sciascia, M. Martini, A. Di Domenico, G. De Robertis, P. Santangelo, A. Palladino, Eryk Czerwiński, L. Caldeira Balkeståhl, I. Sarra, O. Erriquez, S. Fiore, Bo Höistad, G. Fanizzi, E. Graziani, G. Bencivenni, D. Babusci, V. De Leo, D. Moricciani, F. Ceradini, E. De Lucia, I. Balwierz-Pytko, Giuseppe Mandaglio, I. Prado Longhi, P. Franzini, J. Lee-Franzini, Lena Heijkenskjöld, Wojciech Krzemien, P. Branchini, P. Ciambrone, Francesca Curciarello, L. Tortora, and A. Fantini

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle decay, Particle physics, Antiparticle, Electron–positron annihilation, Antimatter, High Energy Physics::Experiment, Elementary particle, Vector boson, Boson, Lepton
Abstract

We have searched for a light vector boson U, the possible carrier of a "dark force", with the KLOE detector at the DA Phi NE e(+)e(-) collider, motivated by astrophysical evidence for the presence of dark matter in the Universe. Using e(+)e(-) collisions collected with an integrated luminosity of 239.3 pb(-1), we look for a dimuon mass peak in the reaction e(+)e(-) -> mu(+)mu(-)gamma, corresponding to the decay U -> mu(+)mu(-). We find no evidence for a U vector boson signal. We set a 90% CL upper limit for the mixing parameter squared between the photon and the U boson of 1.6 x 10(-5) to 8.6 x 10(-7) for the mass region 520 < m(U) < 980 MeV.

Published
2014

5. Precision measurements of the e+e−→π+π−(γ) cross section with the KLOE detector

Author

G. Mandaglio, D. Babusci, D. Badoni, I. Balwierz-Pytko, G. Bencivenni, C. Bini, C. Bloise, F. Bossi, P. Branchini, A. Budano, L. Caldeira Balkeståhl, G. Capon, F. Ceradini, P. Ciambrone, E. Czerwiński, E. Danè, E. De Lucia, G. De Robertis, A. De Santis, A. Di Domenico, C. Di Donato, R. Di Salvo, D. Domenici, O. Erriquez, G. Fanizzi, A. Fantini, G. Felici, S. Fiore, P. Franzini, P. Gauzzi, G. Giardina, S. Giovannella, F. Gonnella, E. Graziani, F. Happacher, L. Heijkenskjöld, B. Höistad, L. Iafolla, M. Jacewicz, T. Johansson, A. Kupsc, J. Lee-Franzini, B. Leverington, F. Loddo, S. Loffredo, M. Martemianov, M. Martini, M. Mascolo, R. Messi, S. Miscetti, G. Morello, D. Moricciani, P. Moskal, F. Nguyen, A. Passeri, V. Patera, I. Prado Longhi, A. Ranieri, C.F. Redmer, P. Santangelo, I. Sarra, M. Schioppa, B. Sciascia, M. Silarski, C. Taccini, L. Tortora, G. Venanzoni, W. Wiślicki, M. Wolke, and J. Zdebik

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Muon, Luminosity (scattering theory), Photon, Anomalous magnetic dipole moment, Hadron, Form factor (quantum field theory), Atomic and Molecular Physics, and Optics, Nuclear physics, Pion, High Energy Physics::Experiment, Anomaly (physics)
Abstract

The muon anomalous magnetic moment is one of the most precisely measured quantities in particle physics and a persistent discrepancy of about 3 σ between standard model (SM) prediction and the experimental measurement has been observed. The leading order contribution aμhlo is actually the main source of uncertainty in the theoretical evaluation of the muon anomaly. It is obtained by a dispersion integral using the precision measurement of hadronic cross section. The KLOE experiment at the DAΦNE ϕ−factory in Frascati was the first to exploit Initial State Radiation (ISR) processes to obtain the e+e−→π+π−(γ) cross section below 1 GeV, that accounts for most (70%) of the leading order contribution to the muon anomaly. In year 2005 and 2008 the KLOE-collaboration has published two measurements of the π+π− cross section with the photon in the initial state emitted at small angle, and an independent measurement with the photon emitted at large angle was finalized in year 2011. These measurements were normalized using luminosity from Bhabha. In the last years, a new analysis of KLOE data has been performed for obtaining the pion form factor directly from the bin-by-bin π+π−γ to μ+μ−γ ratio. We present the results of this new measurement, showing the comparison with our previous measurements, and its impact on the hadronic contribution to the muon anomaly.

Published
2014

6. A new limit on the CP violating decay KS→3π0 with the KLOE experiment

Author

Paweł Moskal, M. Martemianov, C. F. Redmer, P. Franzini, J. Lee-Franzini, G. Fanizzi, G. Venanzoni, D. Moricciani, G. Capon, V. De Leo, E. De Lucia, I. Balwierz-Pytko, F. Nguyen, I. Prado Longhi, Cecilia Taccini, Magnus Wolke, B. Leverington, Lena Heijkenskjöld, C. Di Donato, K. Kacprzak, P. Gauzzi, F. Loddo, Giuseppe Mandaglio, S. Loffredo, L. Tortora, L. Iafolla, S. Fiore, A. De Santis, P. Ciambrone, Michał Silarski, Bo Höistad, O. Erriquez, Marek Jacewicz, A. Ranieri, P. Santangelo, Francesca Curciarello, Antonio Budano, G. Giardina, E. Graziani, A. Passeri, Vincenzo Patera, Andrzej Kupsc, Marco Schioppa, A. Di Domenico, Cesare Bini, A. Fantini, Jarosław Zdebik, Barbara Sciascia, M. Martini, S. Giovannella, Eryk Czerwiński, G. Bencivenni, S. Miscetti, D. Domenici, W. Wiślicki, F. Gonnella, D. Babusci, Gianfranco Morello, L. Caldeira Balkeståhl, I. Sarra, F. Bossi, E. Dané, R. Messi, T. Johansson, C. Bloise, M. Mascolo, R. Di Salvo, F. Happacher, P. Branchini, G. De Robertis, G. Felici, Davide Badoni, and F. Ceradini

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, 010308 nuclear & particles physics, 01 natural sciences, Standard Model, Calorimeter, Nuclear physics, 0103 physical sciences, CP violation, Direct search, Limit (mathematics), 010306 general physics
Abstract

We have carried out a new direct search for the CP violating decay K-S -> 3 pi(0) with 1.7 fb(-1) of e(+)e(-) collisions collected by the KLOE detector at the Phi-factory DA Phi NE. We have searched for this decay in a sample of about 5.9 x 10(8) KSKL events tagging the K-S by means of the K-L interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake K-S tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of K-S -> 2 pi(0) events in the same sample, we set the upper limit on BR(K-S -> 3 pi(0))

Published
2013

7. Polarised Photon Beams for the BGO-OD Experiment at ELSA

Author

P. Levi Sandri, S. Friedrich, B.-E. Reitz, V. Ganenko, D. Elsner, Francesco Messi, R. Jahn, T. C. Jude, F. Ghio, K.-T. Brinkmann, V. G. Nedorezov, D. P. Watts, M. Becker, D. Moricciani, A. Bella, D. Walther, P. Pedroni, V. Vegna, R. Joosten, A. M. Lapik, H. Schmieden, D. E. Bayadilov, P. Bielefeldt, A. B. Gridnev, Mariana Nanova, S. Boese, T. Zimmermann, A. Stugelev, V. De Leo, E. Gutz, V. Metag, Wolfgang Hillert, S. Alef, P. Hartmann, B. Krusche, Giuseppe Mandaglio, G. Gervino, T. Rostomyan, M. Romaniuk, A. Braghieri, G. Scheluchin, G. Giardina, J. Hannappel, I. V. Lopatin, H. Dutz, A. Fantini, V. Tarakanov, P. L. Cole, N. V. Rudnev, Reinhard Beck, O. Freyermuth, Hans-Georg Zaunick, V. V. Sumachev, A. Ignatov, C. Schaerf, D. Hammann, Francesca Curciarello, K. Koop, R. Messi, Frank Frommberger, A. N. Mushkarenkov, D. Novinskiy, S. Goertz, Frank Klein, and R. Di Salvo

Subjects
Physics, Nuclear physics, Elastic scattering, law, Bremsstrahlung, Polarimeter, Particle accelerator, Electron, Nuclear Experiment, Polarization (waves), Nucleon, Electromagnetic radiation, law.invention
Abstract

The new BGO-OD experiment at the electron accelerator ELSA, of the University of Bonn, is designed to study the reaction dynamics of nucleon excitations in meson photoproduction. It consists of a central BGO calorimeter with a magnetic spectrometer in forward direction. The physics programme includes the measurement of polarisation observables using linearly and circularly polarised photon beams. Linear polarisation is obtained by coherent bremsstrahlung off a diamond crystal, and circular polarisation is obtained via bremsstrahlung from longitudinally polarised electrons. The degree of linear polarisation is determined from the bremsstrahlung spectrum itself. To determine the polarisation of the circularly polarised photon beam, the polarisation of the electron beam is measured by a Moller polarimeter. As a preliminary consistency check, the (linear) polarisation observable, Σ, was compared to world data for π^0 and η photoproduction. To determine the degree of circular polarisation, a Moller polarimeter was setup and first measurements of the electron beam polarisation performed.

Published
2016

8. Commissioning and initial experimental program of the BGO-OD experiment at ELSA

Author

D. Elsner, K. Koop, V. G. Nedorezov, D. Geffers, Wolfgang Hillert, R. Jahn, H. Dutz, H. Schmieden, D. Moricciani, D. E. Bayadilov, R. Messi, T. C. Jude, G. Scheluchin, Friedrich Klein, T. Rostomyan, A. B. Gridnev, A. Ignatov, Mariana Nanova, M. Becker, S. Böse, V. Tarakanov, G. Gervino, P. Levi Sandri, D. Walther, J. Knaust, D. P. Watts, E. Gutz, P. Bielefeldt, Reinhard Beck, S. Friedrich, A. Braghieri, A. M. Lapik, N. Rudnev, Francesco Messi, B.-E. Reitz, A. Stugelev, V. Ganenko, S. Görtz, Hans-Georg Zaunick, Patrick Bauer, F. Ghio, V. V. Sumachev, C. Schaerf, I. V. Lopatin, D. Hammann, Volker Metag, K.-T. Brinkmann, S. Alef, T. Zimmermann, V. Vegna, P. Cole, R. Joosten, P. Pedroni, K. Kohl, A. Fantini, B. Krusche, Giuseppe Mandaglio, M. Romaniuk, O. Freyermuth, A. Bella, J. Hannappel, D. Novinskiy, A. Mushkarenkov, R. Di Salvo, and Frank Frommberger

Subjects
Photon, Meson, QC1-999, Hadron, Nuclear Theory, Elementary particle, Astrophysics, radiation detection, 01 natural sciences, Particle detector, Nuclear physics, Hadron Physics, 0103 physical sciences, Nuclear Physics, Hadron Physics, radiation detection, 010306 general physics, Nuclear Experiment, Nuclear Physics, Physics, 010308 nuclear & particles physics, Settore FIS/04, Detector, High Energy Physics::Phenomenology, Hyperon, Baryon, High Energy Physics::Experiment
Abstract

BGO-OD is a new meson photoproduction experiment at the ELSA facility of Bonn University. It aims at the investigation of non strange and strange baryon excitations, and is especially designed to be able to detect weekly bound meson-baryon type structures. The setup for the BGO-OD experiment is presented, the characteristics of the photon beam and the detector performances are shown and the initial experimental program is discussed.

Published
2016

9. Measurement of the ϕ→π0e+e− transition form factor with the KLOE detector

Author

M. Berlowski, G. D'Agostini, E. Dané, A. D'Uffizi, Paolo Santangelo, G. Giardina, G. Felici, Wojciech Krzemien, Eryk Czerwiński, A. Passeri, L. Caldeira Balkeståhl, I. Sarra, F. Sirghi, P. Branchini, S. Loffredo, A. Fantini, A. Anastasi, Lena Heijkenskjöld, D. Moricciani, Antonio Budano, Filippo Ceradini, A. Di Cicco, L. Tortora, F. Happacher, Aleksander Gajos, W. Ikegami Andersson, S. Giovannella, Vincenzo Patera, R. Messi, T. Johansson, Daria Kamińska, Andrzej Kupsc, M. Papenbrock, V. De Leo, F. Bossi, E. De Lucia, Paolo Ciambrone, D. Domenici, R. Di Salvo, G. Venanzoni, Giuseppe Mandaglio, F. Curciarello, Wojciech Wiślicki, B. Cao, S. Fiore, E. Perez del Rio, E. Graziani, G. Bencivenni, Magnus Wolke, P. Gauzzi, Piotr Salabura, S. Miscetti, A. De Santis, P. De Simone, M. Mascolo, A. Di Domenico, Michał Silarski, Paweł Moskal, Gianfranco Morello, D. Babusci, Marco Schioppa, C. Bloise, A. Ranieri, M. Martini, Anastasi, A., Ceradini, Filippo, DI CICCO, Alessandro, Loffredo, Salvatore, and Fiore, S.

Subjects
Nuclear and High Energy Physics, Electron–positron annihilation, e+e− collisions, Transition form factor, 01 natural sciences, Conversion decay, E+e- collisions, High Energy Physics - Experiment, law.invention, Nuclear physics, Subatomär fysik, e(+)e(-) collisions, law, 0103 physical sciences, Subatomic Physics, 010306 general physics, Collider, E+e- collision, Settore FIS/01, Physics, 010308 nuclear & particles physics, Branching fraction, Detector, Form factor (quantum field theory), Pseudoscalar, High Energy Physics - Phenomenology, Transition form factors, electron positron collider, KLOE experiment, High Energy Physics::Experiment
Abstract

A measurement of the vector to pseudoscalar conversion decay $\phi \to \pi^0 e^+e^-$ with the KLOE experiment is presented. A sample of $\sim 9500$ signal events was selected from a data set of 1.7 fb$^{-1}$ of $e^+e^-$ collisions at $\sqrt{s} \sim m_{\phi}$ collected at the DA$\Phi$NE $e^+e^-$ collider. These events were used to obtain the first measurement of the transition form factor $| F_{\phi \pi^0}(q^2) |$ and a new measurement of the branching ratio of the decay: $\rm{BR}\,(\phi \to \pi^0 e^+e^-) = (\,1.35 \pm 0.05^{\,\,+0.05}_{\,\,-0.10}\,) \times 10 ^{-5}$. The result improves significantly on previous measurements and is in agreement with theoretical predictions., Comment: 13 pages, 4 figures; matches published version

Published
2016

10. Strangeness Photoproduction at the BGO-OD Experiment

Author

V. G. Nedorezov, Frank Frommberger, V. Metag, A. Ignatov, Hans-Georg Zaunick, V. Tarakanov, T. Zimmermann, N. V. Rudnev, D. Hammann, D. Moricciani, P. Bielefeldt, Wolfgang Hillert, P. Pedroni, A. N. Mushkarenkov, D. P. Watts, V. Vegna, O. Freyermuth, D. Novinskiy, D. Elsner, Francesca Curciarello, S. Goertz, V. De Leo, B. Krusche, Giuseppe Mandaglio, R. Messi, M. Romaniuk, H. Dutz, A. Braghieri, B.-E. Reitz, P. Levi Sandri, A. Bella, V. Ganenko, Reinhard Beck, P. Hartmann, Frank Klein, R. Di Salvo, T. Rostomyan, G. Scheluchin, E. Gutz, A. Fantini, D. Walther, S. Friedrich, F. Ghio, Francesco Messi, V. V. Sumachev, S. Boese, P. L. Cole, R. Joosten, S. Alef, G. Giardina, R. Jahn, K. Koop, J. Hannappel, T. C. Jude, M. Becker, I. V. Lopatin, A. Stugelev, K.-T. Brinkmann, A. M. Lapik, G. Gervino, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, and Mariana Nanova

Subjects
Meson, Nuclear Theory, FOS: Physical sciences, Electron, Strangeness, Tracking (particle physics), nucl-ex, 01 natural sciences, Nuclear physics, photoproduction, dynamically generated resonance, strangeness, BGO-OD, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Settore FIS/01, Calorimeter (particle physics), Spectrometer, 010308 nuclear & particles physics, photoproduction, dynamically generated resonance, strangeness, BGO-OD, High Energy Physics::Experiment, Nucleon, Beam (structure)
Abstract

BGO-OD is a newly commissioned experiment to investigate the internal structure of the nucleon, using an energy tagged bremsstrahlung photon beam at the ELSA electron facility. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating meson photoproduction. The extensive physics programme for open strangeness photoproduction is introduced, and preliminary analysis presented., 6 pages, 4 figures. Proceedings for the 10th International Workshop on the Physics of Excited Nucleons (NSTAR2015)

Published
2016

11. Limit on the production of a new vector boson in e+e-→Uγ, U→π+π- with the KLOE experiment

Author

A. D'Uffizi, Aleksander Gajos, Eryk Czerwiński, L. Caldeira Balkeståhl, I. Sarra, A. De Santis, G. D'Agostini, E. Dané, B. Cao, A. Di Cicco, Wojciech Krzemien, V. De Leo, Filippo Ceradini, S. Loffredo, G. Venanzoni, M. Papenbrock, F. Bossi, D. Moricciani, F. Sirghi, D. Babusci, P. Branchini, G. Felici, F. Curciarello, C. Bloise, Paolo Ciambrone, M. Berlowski, R. Di Salvo, S. Fiore, A. Ranieri, E. Graziani, A. Fantini, S. Giovannella, S. Miscetti, L. Tortora, G. Giardina, Lena Heijkenskjöld, Paweł Moskal, Antonio Budano, M. Martini, A. Di Domenico, Michał Silarski, A. Passeri, Daria Kamińska, P. De Simone, D. Domenici, Wojciech Wiślicki, Gianfranco Morello, M. Mascolo, Magnus Wolke, P. Gauzzi, E. Perez del Rio, Marco Schioppa, F. Happacher, W. Ikegami Andersson, Vincenzo Patera, Andrzej Kupsc, E. De Lucia, Giuseppe Mandaglio, Paolo Santangelo, R. Messi, T. Johansson, A. Palladino, G. Bencivenni, A. Anastasi, Fiore, S., Anastasi, A., Ceradini, Filippo, DI CICCO, Alessandro, and Loffredo, Salvatore

Subjects
Particle physics, Nuclear and High Energy Physics, Dark forces, Photon, Electron–positron annihilation, Dark matter, U boson, Radiation, 01 natural sciences, Dark photon, Vector boson, Nuclear physics, Subatomär fysik, 0103 physical sciences, Subatomic Physics, 010306 general physics, Physics, Gauge boson, 010308 nuclear & particles physics, Branching fraction, Settore FIS/01 - Fisica Sperimentale, Dark force
Abstract

The recent interest in a light gauge boson in the framework of an extra U(1) symmetry motivates searches in the mass range below 1 GeV. We present a search for such a particle, the dark photon, in e + e − → U γ , U → π + π − based on 28 million e + e − → π + π − γ events collected at DAΦNE by the KLOE experiment. The π + π − production by initial-state radiation compensates for a loss of sensitivity of previous KLOE U → e + e − , μ + μ − searches due to the small branching ratios in the ρ – ω resonance region. We found no evidence for a signal and set a limit at 90% CL on the mixing strength between the photon and the dark photon, e 2 , in the U mass range between 527 and 987 MeV . Above 700 MeV this new limit is more stringent than previous ones.

Published
2016

12. Precision measurement of the η → π +π −π 0Dalitz plot distribution with the KLOE detector

Author

M. Papenbrock, F. Bossi, E. Perez del Rio, P. De Simone, A. Fantini, S. Loffredo, A. Di Cicco, Gianfranco Morello, C. Bloise, Lena Heijkenskjöld, R. Messi, S. Miscetti, T. Johansson, Paolo Santangelo, Filippo Ceradini, Marco Schioppa, A. Di Domenico, Antonio Budano, G. Venanzoni, A. De Santis, A. D'Uffizi, Aleksander Gajos, V. De Leo, Paweł Moskal, B. Cao, F. Curciarello, Michał Silarski, Eryk Czerwiński, D. Moricciani, Daria Kamińska, G. Bencivenni, L. Caldeira Balkeståhl, I. Sarra, E. De Lucia, Paolo Ciambrone, D. Domenici, M. Berlowski, W. Wislicki, Giuseppe Mandaglio, S. Fiore, A. Ranieri, M. Mascolo, E. Graziani, G. Giardina, M. Martini, L. Tortora, D. Babusci, F. Happacher, W. Ikegami Andersson, R. Di Salvo, S. Giovannella, A. Anastasi, Wojciech Krzemien, F. Sirghi, P. Branchini, G. Felici, G. D'Agostini, E. Dané, A. Passeri, Vincenzo Patera, Andrzej Kupsc, Magnus Wolke, P. Gauzzi, Fiore, S, Anastasi, A., Ceradini, Filippo, DI CICCO, Alessandro, and Loffredo, Salvatore

Subjects
e+-e- Experiment, Nuclear and High Energy Physics, Particle physics, Electron–positron annihilation, Dalitz plot, Electron positron collider, e plus -e- Experiments, QCD, 01 natural sciences, e plus -e- Experiments, QCD, Subatomär fysik, Nuclear physics, Subatomic Physics, 0103 physical sciences, Eta meson, 010306 general physics, Polynomial expansion, Settore FIS/01, Physics, Quantum chromodynamics, e+-e- Experiments, 010308 nuclear & particles physics, Detector, Charge (physics), 16. Peace & justice, Distribution (mathematics), Eta meson, Electron positron collider, KLOE experiment, KLOE experiment, Dimensionless quantity
Abstract

Using 1.6 fb−1 of e + e − → ϕ → ηγ data collected with the KLOE detector at DAΦNE, the Dalitz plot distribution for the η → π + π − π 0 decay is studied with the world’s largest sample of ∼ 4.7 · 106 events. The Dalitz plot density is parametrized as a polynomial expansion up to cubic terms in the normalized dimensionless variables X and Y . The experiment is sensitive to all charge conjugation conserving terms of the expansion, including a gX 2 Y term. The statistical uncertainty of all parameters is improved by a factor two with respect to earlier measurements.

Published
2016

13. Measurement of η photoproduction on the proton from threshold to 1500 MeV

Author

M. L. Sperduto, C. Schaerf, C. Gaulard, V. Vegna, T. Russew, A. N. Mushkarenkov, Marco Capogni, Giuseppe Mandaglio, P. Levi Sandri, G.V. Russo, V. Bellini, F. Ghio, A. Fantini, L. Nicoletti, A. Giusa, M. Guidal, M. C. Sutera, J. P. Didelez, F. Mammoliti, L. Casano, V. G. Nedorezov, R. Kunne, J. P. Bocquet, E. Hourany, D. Franco, A. D'Angelo, M. Castoldi, D. Rebreyend, G. Giardina, D. Moricciani, P. Calvat, Annick Lleres, C. Perrin, A. M. Lapik, G. Gervino, A. Turinge, N. V. Rudnev, R. Di Salvo, F. Renard, O. Bartalini, C. Randieri, B. Girolami, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Laboratori Nazionali di Frascati (LNF), Istituto Nazionale di Fisica Nucleare (INFN), and GRAAL

Subjects
Scattering cross-section, Nuclear and High Energy Physics, Photon, Proton, media_common.quotation_subject, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Resonance (particle physics), Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, photon energies, Nuclear physics, sigma(0), 13.60.Le, 13.88.+e, 25.20.Lj, graal, 0103 physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, mesons, media_common, Physics, model, 010308 nuclear & particles physics, Eta meson, differential cross-section, baryon resonances, lambda, photoexcitation, asymmetry, Photoexcitation, Meson production, Polarization in interactions and scattering, Photoproduction reactions, High Energy Physics::Experiment, Beam (structure)
Abstract

Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found., 18 pages, 14 figures, 4 tables Submitted to EPJA

Published
2007

14. Meson photoproduction on the nucleon with polarized photons

Author

T. Russew, O. Bartalini, C. Randieri, V. G. Nedorezov, V. Vegna, Marco Capogni, J. P. Bocquet, D. Moricciani, G. Gervino, R. Di Salvo, M. L. Sperduto, Annick Lleres, M. C. Sutera, V. Bellini, V. Kouznetsov, A. M. Lapik, J. P. Didelez, G.V. Russo, A. D'Angelo, M. Guidal, B. Girolami, E. Hourani, A. N. Mushkarenkov, D. Rebreyend, P. Levi Sandri, P. Calvat, L. Casano, Giuseppe Mandaglio, R. Kunne, L. Nicoletti, F. Ghio, A. Giusa, A. Fantini, F. Mammoliti, M. Castoldi, G. Giardina, C. Schaerf, F. Renard, A. Turinge, N. V. Rudnev, D. Franco, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], PROTON, K+, Lambda baryon, 01 natural sciences, 7. Clean energy, DECAYS, Settore FIS/04 - Fisica Nucleare e Subnucleare, Sigma baryon, Nuclear physics, Photoproduction reactions, Pion, Polarization, 0103 physical sciences, SIGMA(0), Nuclear Experiment, 010306 general physics, Physics, 13.60.Le, 13.88.+e, 25.20.Lj, 010308 nuclear & particles physics, scattering, Hyperon, ELECTROPRODUCTION, Meson production, ETA, LAMBDA, Baryon, BARYON RESONANCES, ISOBAR MODEL, High Energy Physics::Experiment, Nucleon
Abstract

International audience; Meson photoproduction with polarized photons has proved to be a powerful tool to identify contributions of baryon resonances that are not evident in the differential cross-sections. It provides information that are complementary to those extracted using pion-nucleon scattering data. Extensive results have been produced in the past on beam asymmetries by the Graal collaboration for η and $\pi ^0$ on the proton. New results are now available for the same reactions on the quasi-free neutron and for the K+ photoproduction on the proton. Contributions from hitherto undetected baryon resonances may be important to understand the results.

Published
2007

15. MESON PHOTOPRODUCTION ON THE NEUTRON AT GRAAL

Author

N. V. Rudnev, M. Guidal, L. Casano, A. M. Lapik, C. Randieri, B. Girolami, V. G. Nedorezov, E. Hourany, R. Kunne, V. Kuznetsov, D. Moricciani, A. D'Angelo, V. Bellini, Annick Lleres, D. Rebreyend, M. C. Sutera, A. Fantini, G.V. Russo, C. Schaerf, A. Turinge, R. Di Salvo, A. N. Mushkarenkov, M. Castoldi, F. Ghio, A. Giusa, P. Levi Sandri, M. L. Sperduto, D. Franco, J. P. Bocquet, and J. P. Didelez

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, Meson, Hydrogen, ETA-PHOTOPRODUCTION, BGO CALORIMETER, PROTON, RESONANCE, MODEL, BEAM, chemistry.chemical_element, Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Deuterium, chemistry, Neutron
Abstract

Using a Deuterium target, the GRAAL experiment has collected meson photoproduction data. The data have been analysed in the quasi free regime. The results of the quasi free process on the proton reproduce quite well the results previously obtained with a Hydrogen target. The preliminary results on the quasi free neutron for π0 and η photoproduction are presented and discussed.

Published
2007

16. Polarization observable measurements for γp → K+Λ and γp → K+Σfor energies up to 1.5 GeV

Author

T. Russew, G.V. Russo, J. P. Bocquet, D. Rebreyend, Annalisa D'Angelo, M. C. Sutera, P. Calvat, O. Bartalini, M. Guidal, J. P. Didelez, M. Castoldi, C. Randieri, G. Gervino, Annick Lleres, A. N. Mushkarenkov, L. Casano, P. Levi Sandri, A. Fantini, Marco Capogni, B. Girolami, R. Di Salvo, M. L. Sperduto, V. Bellini, L. Nicoletti, A. M. Lapik, V. G. Nedorezov, R. Kunne, F. Ghio, A. Giusa, V. Kouznetsov, C. Perrin, C. Gaulard, E. Hourany, D. Moricciani, A. Turinge, C. Schaerf, F. Renard, and N. V. Rudnev

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, media_common.quotation_subject, Partial wave analysis, Hadron, Hyperon, Lambda baryon, 01 natural sciences, 7. Clean energy, Asymmetry, Sigma baryon, Nuclear physics, Recoil, 0103 physical sciences, 010306 general physics, media_common
Abstract

Beam asymmetries and hyperon recoil polarizations for the reactions γp → K +Λ and γp → K +Σ0 have been measured from the threshold production to 1500MeV with the GRAAL facility located at the ESRF in Grenoble. These results complement the database for the beam asymmetry, covering for the first time the production threshold region. Recent theoretical analyses are presented for which the beam asymmetry data bring interesting new information and allow to better determine some resonance parameters. Most importantly, these results strengthen the need of a new D13 state around 1900MeV.

Published
2007

17. Disintegration of C-12 nuclei by 700-1500 MeV photons

Author

Giuseppe Mandaglio, A. N. Mushkarenkov, Marina Manganaro, V. G. Nedorezov, P. Levi Sandri, V. De Leo, Igor Pshenichnov, V. Bellini, Francesca Curciarello, G. Gervino, J. P. Didelez, A. D'Angelo, A. A. Turinge, G.V. Russo, A. Fantini, M. L. Sperduto, V. Vegna, A. M. Lapik, M. C. Sutera, F. Mammoliti, I. Zonta, M. Castoldi, Marco Capogni, D. Franco, O. Bartalini, G. Giardina, C. Randieri, R. Di Salvo, D. Moricciani, L. Casano, B. Girolami, C. Schaerf, N. V. Rudnev, F. Ghio, A. Giusa, University of Zurich, Pshenichnov, I, Institut de Physique Nucléaire d'Orsay (IPNO), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear reaction, Fragmentation of light nuclei, Photonuclear reactions, Tagged photons, Nuclear and High Energy Physics, Photon, 530 Physics, Hadron, Nuclear Theory, 10192 Physics Institute, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Total photoabsorption cross section, 0103 physical sciences, Neutron, Multiplicity (chemistry), 3106 Nuclear and High Energy Physics, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Carbon-12, Baryon, Atomic physics, Nucleon
Abstract

Disintegration of C-12 nuclei by tagged photons of 700-1500 MeV energy at the GRAAL facility has been studied by means of the LAGRAN gamma E detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of C-12 into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on C-12 in the same energy range is also reported. (C) 2015 Elsevier B.V. All rights reserved.

Published
2015

18. Measurement of theΣbeam asymmetry for theωphotoproduction off the proton and the neutron at the GRAAL experiment

Author

J. P. Didelez, N. V. Rudnev, A. Fantini, G.V. Russo, Marina Manganaro, V. Vegna, P. Levi Sandri, C. Schaerf, F. Mammoliti, Francesca Curciarello, V. De Leo, R. Di Salvo, V. G. Nedorezov, Giuseppe Mandaglio, M. C. Sutera, F. Ghio, O. Bartalini, A. Turinge, C. Randieri, D. Franco, A. Giusa, Annick Lleres, A. N. Mushkarenkov, A. D'Angelo, D. Rebreyend, Marco Capogni, A. M. Lapik, G. Gervino, M. L. Sperduto, D. Moricciani, L. Casano, J.P. Boquet, B. Girolami, V. Bellini, I. Zonta, M. Castoldi, and G. Giardina

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, 010308 nuclear & particles physics, media_common.quotation_subject, Nuclear Theory, Photon energy, 01 natural sciences, 7. Clean energy, Asymmetry, Pseudoscalar meson, Nuclear physics, Deuterium, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, Nucleon, Beam (structure), media_common
Abstract

We report on new measurements of the beam asymmetry for. photoproduction on protons and neutrons in hydrogen and deuterium targets from the GRAAL Collaboration. The beam asymmetry values are extracted from the reaction threshold (E-gamma = 1.1 GeV in the free nucleon kinematics) up to 1.5 GeV of incoming photon energy. For the first time both the radiative and the three-pion decay channels are simultaneously investigated on the free proton. Results from the two decay channels are in agreement, leading to the world's most precise measurements of the beam asymmetry for omega photoproduction off free protons. First experimental results on the deuteron allow the extraction of the Sigma beam asymmetry on quasifree nucleons. The beam asymmetry angular distributions obtained for the free and the quasifree kinematics show the same behavior, similar to the findings in pseudoscalar meson photoproduction reactions. First results of the beam asymmetry on the quasifree neutrons are presented, showing different strengths and angular distributions from the results on the proton target.

Published
2015

19. Search for dark Higgsstrahlung in e+ e- -> mu+ mu- and missing energy events with the KLOE experiment

Author

M. Berlowski, M. Silarski, S. Miscetti, W. Krzemien, M. Mascolo, S. Fiore, A. Fantini, R. Di Salvo, L. Tortora, E. Perez del Rio, G. Morello, P. De Simone, F. Sirghi, P. Branchini, Andrzej Kupsc, A. D'Uffizi, Aleksander Gajos, Magnus Wolke, P. Gauzzi, A. Palladino, Eryk Czerwiński, I. Sarra, G. Felici, P. Ciambrone, S. Loffredo, R. Messi, G. D'Agostini, L. Caldeira Balkeståhl, A. Passeri, D. Babusci, W. Ikegami Andersson, D. Moricciani, A. Anastasi, A. Di Cicco, F. Curciarello, T. Johansson, D. Domenici, G. Giardina, W. Wiślicki, G. Bencivenni, F. Bossi, A. De Santis, S. Giovannella, G. Venanzoni, P. Santangelo, M. Schioppa, V. De Leo, Lena Heijkenskjöld, Paweł Moskal, E. Dane, E. Graziani, Daria Kamińska, M. Martini, A. Di Domenico, F. Nguyen, A. Budano, B. Cao, C. Bloise, F. Ceradini, V. Patera, A. Ranieri, E. De Lucia, F. Happacher, Giuseppe Mandaglio, Nguyen, F., Anastasi, A, Ceradini, Filippo, DI CICCO, Alessandro, and Loffredo, Salvatore

Subjects
Particle physics, Dark forces, Nuclear and High Energy Physics, Photon, Dark matter, Dark photon, electron positron collider, KLOE experiment, Dark matter, U boson, 7. Clean energy, Dark photon, High Energy Physics - Experiment, Nuclear physics, dark matter, dark forces, upper limit, Higgsstrahlung, WIMP, Upper limit, electron positron collider, Settore FIS/01, Physics, Muon, Missing energy, High Energy Physics::Phenomenology, State (functional analysis), lcsh:QC1-999, Dark force, Higgs boson, Physics::Accelerator Physics, High Energy Physics::Experiment, KLOE experiment, lcsh:Physics
Abstract

We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with a dark photon U and a dark Higgs boson h', with the KLOE detector at DAFNE. We investigated the case of h' lighter than U, with U decaying into a muon pair and h' producing a missing energy signature. We found no evidence of the process and set upper limits to its parameters in the range 2m_mu, Comment: 16 pages, 7 figures, submitted to Physics Letters B

Published
2015

20. Monte Carlo simulation of virtual Compton scattering below pion threshold

Author

Ch. Hyde-Wright, Marc Vanderhaeghen, J.M. Friedrich, D. Marchand, P.Y. Bertin, N. Degrande, Harald Merkel, David Lhuillier, R. Van de Vyver, R. Di Salvo, J. Roche, P. Janssens, M. O. Distler, G. Tamas, J. Van de Wiele, I. K. Bensafa, H. Fonvieille, Luca Doria, S. Kerhoas, N. d'Hose, Th. Walcher, L. Van Hoorebeke, S. Jaminion, G. Laveissière, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), VCS, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, Nuclear and High Energy Physics, Photon, 010308 nuclear & particles physics, Monte Carlo method, Compton scattering, Solid angle, Probability and statistics, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, Pion, Physics - Data Analysis, Statistics and Probability, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Nuclear Experiment, 010306 general physics, Instrumentation, [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an]
Abstract

This paper describes the Monte Carlo simulation developed specifically for the VCS experiments below pion threshold that have been performed at MAMI and JLab. This simulation generates events according to the (Bethe-Heitler + Born) cross section behaviour and takes into account all relevant resolution-deteriorating effects. It determines the `effective' solid angle for the various experimental settings which are used for the precise determination of photon electroproduction absolute cross section., Comment: 24 pages, 6 figures, to be published in Nuclear Instruments and Methods in Physics Research, A One author added

Published
2006

21. Measurement of πphotoproduction on the proton from 550 to 1500 MeV at GRAAL

Author

B. Girolami, D. Moricciani, T. Russew, Annick Lleres, F. Ghio, V. Bellini, M. C. Sutera, A. Giusa, A. Fantini, L. Casano, G. Gervino, Annalisa D'Angelo, O. Bartalini, J. P. Bocquet, Marco Capogni, C. Perrin, M. Castoldi, A. M. Lapik, R. Di Salvo, D. Rebreyend, C. Gaulard, G.V. Russo, P. Calvat, A. Turinge, M. L. Sperduto, C. Schaerf, F. Renard, N. V. Rudnev, V. G. Nedorezov, V. Kouznetsov, A. N. Mushkarenkov, P. Levi Sandri, L. Nicoletti, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
Nuclear and High Energy Physics, Particle physics, Proton, media_common.quotation_subject, Partial wave analysis, Nuclear Theory, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Asymmetry, Resonance (particle physics), Nuclear physics, Photoproduction reactions, Pion, 0103 physical sciences, Nuclear fusion, Nuclear Experiment, 010306 general physics, media_common, Physics, 13.60.Le, 13.88.+e, 25.20.Lj, 010308 nuclear & particles physics, meson production, Physics::Accelerator Physics, High Energy Physics::Experiment, Beam (structure)
Abstract

Neutral pion photoproduction has been measured from 550 to 1500 MeV with the GRAAL facility, located at the ESRF in Grenoble. Differential cross-section and beam asymmetry have been measured over a wide angular range. These high-precision data improve significantly the database for the beam asymmetry in the second and third resonance regions covering for the first time the energy domain 1100-1500 MeV. New partial-wave analyses including these data are presented for which the beam asymmetry brings crucial constraints.

Published
2005

22. Analysis of the η' photoproduction off the proton and preliminary beam asymmetry results at the GRAAL experiment

Author

V. G. Nedorezov, A. Fantini, M. L. Sperduto, V. Bellini, G. Gervino, F. Mammoliti, V. De Leo, P. Levi Sandri, A. M. Lapik, Francesca Curciarello, B. Girolami, Giuseppe Mandaglio, A. Turinge, I. Zonta, D. Rebreyend, A. N. Mushkarenkov, M. C. Sutera, G. Giardina, D. Moricciani, J. P. Didelez, A. D'Angelo, C. Schaerf, F. Ghio, N. V. Rudnev, D. Franco, R. Di Salvo, Marina Manganaro, V. Vegna, Annick Lleres, J. P. Bocquet, Marco Capogni, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
Physics, Range (particle radiation), Particle physics, Proton, Meson, media_common.quotation_subject, QC1-999, Sigma, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Cross section (physics), High Energy Physics::Experiment, Nuclear Experiment, Beam energy, Beam (structure), ComputingMilieux_MISCELLANEOUS, media_common
Abstract

Differential and total cross section measurements on eta' photoproduction were published by the CLAS Collaboration (M. Dugger et al., Phys. Rev. Lett. 96, 062001 (2006) and M. Williams et al., Phys.Rev.C80, 045213 (2009)) for center-of-mass energies from near the threshold up to 2.84 GeV, and by the CB-ELSA-TAPS Collaboration (V. Crede et al., Phys. Rev. C80, 055202 (2009)) up to 2.36 GeV and also making a precise threshold scan of the differential cross section in the 1446 -1527.4 MeV gamma beam energy range. However, the wide information about reaction cross sections are not sufficient to understand the role of resonances involved in the process. Different theoretical works stressed the importance to have also polarization observables in order to solve the ambiguity in the choice of the parameters used in their models. We present the analysis of the eta' photoproduction off the proton, identifying the meson via the gamma gamma, pi(0)pi(0)eta, and pi(+)pi(-)eta decay modes by using the GRAAL apparatus; and we show the preliminary GRAAL results on the beam asymmetry Sigma from the threshold (1.446 GeV) up to 1.5 GeV.

Published
2013

23. New Measurement ofΣBeam Asymmetry forηMeson Photoproduction on the Proton

Author

V. G. Nedorezov, R. Di Salvo, C. Schaerf, R. Frascaria, D. Moricciani, L. Casano, E. Guinault, J. Ajaka, J. P. Bocquet, J. P. Didelez, E. Hourany, V. Kouznetsov, T. Russew, J. Van de Wiele, M. Taiuti, Alessandro Zucchiatti, P. Levi Sandri, P. Rossi, L. Ciciani, A. D'Angelo, D. Rebreyend, L. Nicoletti, B. Girolami, A. M. Lapik, M. Castoldi, G. Berrier, M. Anghinolfi, M. Morlet, M. L. Sperduto, F. Roudot, M. Sanzone, F. Renard, I. Kilvington, M. Breuer, V. Bellini, C. Perrin, G. Gervino, A. Turinge, A. Sudov, M. A. Duval, P. Corvisiero, L. H. Rosier, P. Girard, M. Ripani, C. Djalali, P. Hoffmann-Rothe, P. Calvat, F. Ghio, and Marco Capogni

Subjects
Physics, Particle physics, Photon, Proton, Meson, media_common.quotation_subject, Eta meson, General Physics and Astronomy, Sigma, Observable, Asymmetry, Nuclear physics, High Energy Physics::Experiment, Nuclear Experiment, Beam (structure), media_common
Abstract

We present new Sigma beam asymmetry data for eta meson photoproduction on the proton, using a novel tagged, laser backscattered, linearly polarized photon beam up to 1.1 GeV. The data show large, positive asymmetries, at all incident photon energies. In addition to the S-11(1535) and D-13(1520) resonances necessary to reproduce the cross sections, P-13(1720) and D-15(1675) "four stars" resonances contribute to the Sigma observable, but cannot reproduce the strong forward asymmetries measured at energies higher than 900 MeV.

Published
1998

24. Recent results of the BGO-OD experiment at ELSA facility

Author

V. G. Nedorezov, D. Walther, J. Hannappel, G. Gervino, S. Boese, D. I. Glazier, H. Dutz, P. Levi Sandri, D. P. Watts, A. Bella, G. Giardina, D. Elsner, S. Goertz, P. Vlasov, M. Romaniuk, A. M. Lapik, R. Jahn, P. Pedroni, J. Bieling, D. Burdeynyi, Wolfgang Hillert, Francesco Messi, V. Vegna, K.-T. Brinkmann, O. Jahn, Francesca Curciarello, Friedrich Klein, R. Di Salvo, Veronica De Leo, D. Moricciani, Frank Frommberger, T. Zimmermann, Hans-Georg Zaunick, C. Schaerf, D. Hammann, A. Braghieri, R. Messi, T. C. Jude, M. Becker, V. Tarakanov, I. V. Lopatin, B. Bantes, D. Noviskiy, T. Rostomyan, B. Krusche, Giuseppe Mandaglio, R. Joosten, A. Fantini, K. Koop, A. Ignatov, Reinhard Beck, V. V. Sumachev, T. Frese, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, V. Ganenko, F. Ghio, and B. Girolami

Subjects
Nuclear physics, Physics, History, Particle physics, Meson, Physics::Instrumentation and Detectors, Advisory committee, Settore FIS/04, Monte Carlo method, Nuclear Experiment, Computer Science Applications, Education
Abstract

The results obtained at the BGO-OD experiment with the BGO calorimeter, equipped with the new electronic readout based on sampling ADCs, during the tests performed with the beam time of March and June 2012 are presented. The proper functioning of the apparatus has allowed the reconstruction of the pseudo-scalar mesons π0 and η invariant masses. The simulation of the η' photoproduction reaction prepared for a proposal to the joint ELSA-MAMI Physics Advisory Committee is also presented.

Published
2013

25. KLOE results in flavour physics and prospects for KLOE-2

Author

E. Czerwiński, D. Babusci, D. Badoni, I. Balwierz, G. Bencivenni, C. Bini, C. Bloise, V. Bocci, F. Bossi, P. Branchini, A. Budano, L. Caldeira Balkeståhl, G. Capon, F. Ceradini, P. Ciambrone, E. Dané, E. De Lucia, G. De Robertis, A. De Santis, A. Di Domenico, C. Di Donato, R. Di Salvo, D. Domenici, O. Erriquez, G. Fanizzi, A. Fantini, G. Felici, S. Fiore, P. Franzini, P. Gauzzi, G. Giardina, S. Giovannella, F. Gonnella, E. Graziani, F. Happacher, B. Höistad, L. Iafolla, E. Iarocci, M. Jacewicz, T. Johansson, A. Kupść, J. Lee-Franzini, B. Leverington, F. Loddo, G. Mandaglio, M. Martemianov, M. Martini, M. Mascolo, R. Messi, S. Miscetti, G. Morello, D. Moricciani, P. Moskal, F. Nguyen, A. Passeri, V. Patera, I. Prado Longhi, A. Ranieri, C.F. Redmer, P. Santangelo, I. Sarra, M. Schioppa, B. Sciascia, M. Silarski, C. Taccini, L. Tortora, G. Venanzoni, R. Versaci, W. Wiślicki, M. Wolke, and J. Zdebik

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, KLOE-2, Detector, Flavour, Atomic and Molecular Physics, and Optics, flavour, Nuclear physics, Interferometry, CP, Quantum state, KLOE, Quantum interference, Homogeneous space, Physics::Accelerator Physics, High Energy Physics::Experiment, CPT, Quantum
Abstract

The ϕ-factory DAΦNE offers a possibility to select pure kaon beams, charged and neutral ones. In particular, neutral kaons from ϕ → K S K L are produced in pairs and the detection of a K S ( K L ) tags the presence of a K L ( K S ) . This allows to perform precise measurements of kaon properties by means of KLOE detector. Another advantage of a ϕ-factory consists in fact that the neutral kaon pairs are produced in a pure quantum state ( J P C = 1 − − ) , which allows to investigate CP and CPT symmetries via quantum interference effects, as well as the basic principles of quantum mechanics. A review of the most recent results of the KLOE experiment at DAΦNE using pure kaon beams or via quantum interferometry is presented together with prospects for kaon physics at KLOE–2.

Published
2013

26. Virtual Compton scattering and the generalized polarizabilities of the proton atQ2=0.92and 1.76 GeV2

Author

L. B. Auerbach, C. Cavata, D. J. Margaziotis, K. Kino, A. J. Sarty, Seigo Kato, J. A. Templon, B. Frois, Ronald Ransome, D. Rowntree, R. W. Lourie, Christophe Furget, P. Grenier, M. K. Jones, D. S. Dale, G. W. Miller, H. Voskanyan, C. Jutier, S. Frullani, Z. L. Zhou, C. R. Howell, W. Kahl, M. Khayat, A. T. Katramatou, M. Kuss, J. W. Watson, K. Wijesooriya, W. M. Zhang, J. Jardillier, G.I. Smirnov, David L. Prout, G. Laveissière, A. Deur, G. E. Dodge, J. R. Calarco, G. Fournier, N. Degrande, R. A. Lindgren, J. J. LeRose, R. I. Pomatsalyuk, E. J. Brash, W. U. Boeglin, V. Gorbenko, R. Suleiman, F. T. Baker, S. Platchkov, G. M. Huber, F. Garibaldi, Ronald Gilman, K. McCormick, G. Rutledge, T. Saito, Richard Madey, G. G. Petratos, Z. E. Meziani, K. Arundell, Marc Vanderhaeghen, J. Martino, James J. Kelly, S. Kox, J. Marroncle, L. Cardman, C. E. Hyde, Raphael Noel Tieulent, Z. Papandreou, Pierre A.M. Guichon, F. Merchez, Bogdan Wojtsekhowski, D. Marchand, E. Tomasi-Gustaffson, M. Liang, P. M. Rutt, F. Renard, Shalev Gilad, S. Mehrabyan, G. Quéméner, V. A. Punjabi, D. M. Manley, C. W. de Jager, R. L.J. van der Meer, K. A. Aniol, Nilanga Liyanage, A. Gasparian, B. D. Anderson, G. J. Lolos, M. B. Epstein, Richard Wilson, Branislav Vlahovic, L. C. Alexa, A. Ketikyan, P. E. Ulmer, A. V. Glamazdin, E. A.J.M. Offermann, Jing Zhao, P. Y. Bertin, L. Van Hoorebeke, T. Pussieux, Mauro Iodice, Larry Weinstein, Laird Kramer, T. Terasawa, Vincent Breton, J. Gao, C. F. Perdrisat, C. Marchand, D. Neyret, William Bertozzi, R. Michaels, R. Holmes, H. Fonvieille, D. G. Zainea, Charles Glashausser, C. C. Chang, K. S. Kumar, J. Domingo, Pavel Sorokin, Haiyan Gao, Pete Markowitz, L. Bimbot, R. Di Salvo, J. M. Finn, J. S. Real, Justin I. McIntyre, S. Jaminion, G. Kumbartzki, E. Chudakov, Barbara Pasquini, Latifa Elouadrhiri, N. d'Hose, Roberto Perrino, R. De Leo, M. Baylac, J. O. Hansen, J. P. Chen, R. Van de Vyver, G. M. Urciuoli, J. Berthot, H. Breuer, Kevin Fissum, L. A. Ewell, G. Audit, Kazushige Maeda, J. Mougey, O. Ravel, S. Malov, E. Burtin, M. Holtrop, J. Gomez, Thomas E. Smith, Paul Souder, H. Ueno, S. K. Nanda, Hiroaki Tsubota, S. Kerhoas, L. Todor, A. Leone, A. Saha, E. Voutier, K. Soldi, A. Serdarevic, Sebastien Incerti, Y. Roblin, P. Vernin, and E. Cisbani

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, Chiral perturbation theory, Proton, 010308 nuclear & particles physics, Structure function, Compton scattering, 01 natural sciences, Nuclear physics, Amplitude, Dispersion relation, 0103 physical sciences, Beta (velocity), 010306 general physics
Abstract

Virtual Compton Scattering (VCS) on the proton has been studied at Jefferson Lab using the exclusive photon electroproduction reaction (e p --> e p gamma). This paper gives a detailed account of the analysis which has led to the determination of the structure functions P{sub LL}-P{sub TT}/epsilon and P{sub LT}, and the electric and magnetic generalized polarizabilities (GPs) alpha{sub E}(Q{sup 2}) and beta{sub M}(Q{sup 2}) at values of the four-momentum transfer squared Q{sup 2} = 0.92 and 1.76 GeV{sup 2}. These data, together with the results of VCS experiments at lower momenta, help building a coherent picture of the electric and magnetic GPs of the proton over the full measured Q{sup 2}-range, and point to their non-trivial behavior.

Published
2012

27. Results from polarized experiments at LEGS and GRAAL

Author

C. S. Whisnant, F. Ghio, A. D'Angelo, D. Rebreyend, D. Franco, S. Kucuker, M. Lowry, A. M. Lapik, Giuseppe Mandaglio, A. Giusa, A. Turinge, N. V. Rudnev, C. E. Thorn, S. Hoblit, B. Preedom, M. Khandaker, M. L. Sperduto, J.-P. Bocqueti, C. Gibson, Marina Manganaro, S. Kizilgul, A. Caracappa, Marco Capogni, A. Sandorfi, M. Lucas, K. Ardashev, G. Gervino, J. Mahon, M. C. Sutera, A. Lehmann, M. Pap, L. Miceli, A. Fantini, C. Schaerf, X. Wei, F. Mammoliti, D. Moricciani, L. Casano, M. Blecher, K. Hicks, H. Seyfarth, A. Honig, B. Norum, V. Vegna, T. Kageya, H. Stroher, C. Bade, Annick Lleres, G.V. Russo, V. G. Nedorezov, V. Bellini, H. Glükler, M. Castoldi, G. Giardina, K. Wang, P. Levi Sandri, B. Girolami, O. C. Kistner, R. Di Salvo, O. Bartalini, C. Randieri, A. N. Mushkarenkov, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), GRAAL, and LEGS

Subjects
Particle physics, POSITIVE PION-PHOTOPRODUCTION, media_common.quotation_subject, Nuclear Theory, Photoreactions, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], PROTON, 7. Clean energy, 01 natural sciences, Asymmetry, NUCLEONIC RESONANCE EXCITATIONS, SIGMA-BEAM ASYMMETRY, DECAYS, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Pion, 0103 physical sciences, N-PI, GAMMA-P, PRECISE MEASUREMENT, Nuclear Experiment, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Circular polarization, media_common, Physics, polarized photon beams, polarized targets, BARYON RESONANCES, MESON PHOTOPRODUCTION, 010308 nuclear & particles physics, Gamma ray, Polarization (waves), Compton backscattering, 3. Good health, Deuterium, SIGMA-BEAM ASYMMETRY, NUCLEONIC RESONANCE EXCITATIONS, POSITIVE PION-PHOTOPRODUCTION, BARYON RESONANCES, MESON PHOTOPRODUCTION, PRECISE MEASUREMENT, GAMMA-P, N-PI, PROTON, DECAYS, High Energy Physics::Experiment, Beam (structure)
Abstract

Compton backscattering gamma ray beams are characterized by a high degree of linear and circular polarization with low unpolarized backgrounds and have proven to provide very precise measurements of polarization observables. Latest results from LEGS and GRAAL experiments on proton and deuteron targets are presented. The Σ beam asymmetry for ω photoproduction has been measured by the GRAAL collaboration for both the ω→π0γ and the ω→π+π−π0 decay channels on the proton target; single and double polarization asymmetries have been provided also for the K photoproduction channel. E and G double polarization asymmetries for single pion photoproduction on the proton and deuteron have been measured at LEGS using a frozen spin HD target.

Published
2012

28. Beam asymmetryΣmeasurements ofπ−photoproduction on neutrons

Author

C. Schaerf, D. Rebreyend, Giuseppe Mandaglio, C. Randieri, W. J. Briscoe, A. N. Mushkarenkov, G.V. Russo, M. L. Sperduto, I. I. Strakovsky, N. V. Rudnev, D. Moricciani, B. Girolami, L. Casano, G. Gervino, V. Vegna, F. Mammoliti, J. P. Bocquet, V. G. Nedorezov, R. Di Salvo, A. M. Lapik, Marina Manganaro, Annick Lleres, A. D'Angelo, M. C. Sutera, P. Levi Sandri, D. Franco, A. Giusa, A. Turinge, A. Ignatov, F. Ghio, V. Bellini, A. Fantini, and G. Giardina

Subjects
Physics, Nuclear and High Energy Physics, Meson, 010308 nuclear & particles physics, media_common.quotation_subject, Nuclear Theory, Hadron, 01 natural sciences, Asymmetry, Nuclear physics, Pion, Deuterium, 0103 physical sciences, High Energy Physics::Experiment, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Beam (structure), media_common
Abstract

The -beam asymmetry {Sigma} in the photoproduction of negative pions on quasi-free neutrons in a deuterium target was measured at the Grenoble Anneau Accelerateur Laser in the energy interval 700-1500 MeV and over a wide angular range, using polarized and tagged photons. Results are compared with recent partial-wave analyses.

Published
2010

29. PHOTOPRODUCTION OF π0π+ ON THE PROTON AND DEUTERON AT Eγ = 0.7 - 1.5 GeV

Author

V. Bellini, N. V. Rudnev, A. Mushkarenkov, R. Di Salvo, A. Ignatov, L. Casano, D. Rebreyend, C. Randieri, G. Giardina, C. Schaerf, M. L. Sperduto, D. Franco, D. Moricciani, A. Turinge, V. G. Nedorezov, P. Levi Sandri, A. Fantini, M. C. Sutera, F. Mammoliti, V. Vegna, Giuseppe Mandaglio, J. P. Bocquet, B. Girolami, Marina Manganaro, G. Gervino, A. M. Lapik, Annick Lleres, A. D’Angelo, G.V. Russo, F. Ghio, A. Giusa, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
Physics, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Hadron, General Physics and Astronomy, Elementary particle, Photon energy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Baryon, Massless particle, DOUBLE-PION-PHOTOPRODUCTION, RESONANCE REGION, CROSS-SECTION, NUCLEON, PHOTOABSORPTION, GRAAL, 0103 physical sciences, Invariant mass, 010306 general physics, Nucleon, ComputingMilieux_MISCELLANEOUS
Abstract

The preliminary results obtained by the GRAAL collaboration for the π0π+ photoproduction on the free and quasi-free proton (deuteron) at Eγ = 0.7-1.5 GeV are presented. The total cross section of the γp → π0π+n reaction and invariant mass spectra for the π+π0, π+n and π0n systems are presented in the photon energy range from 0.7 to 1.5 GeV. These results are in good agreement with the 2π-MAID calculations.

Published
2010

30. Measurements ofH→D→(γ→,π)and Implications for the Convergence of the Gerasimov-Drell-Hern Integral

Author

S. Hoblit, A. M. Sandorfi, K. Ardashev, C. Bade, O. Bartalini, M. Blecher, A. Caracappa, A. D’Angelo, A. d’Angelo, R. Di Salvo, A. Fantini, C. Gibson, H. Glückler, K. Hicks, A. Honig, T. Kageya, M. Khandaker, O. C. Kistner, S. Kizilgul, S. Kucuker, A. Lehmann, M. Lowry, M. Lucas, J. Mahon, L. Miceli, D. Moricciani, B. Norum, M. Pap, B. Preedom, H. Seyfarth, C. Schaerf, H. Ströher, C. E. Thorn, C. S. Whisnant, K. Wang, and X. Wei

Subjects
Physics, Nuclear physics, Baryon, Meson, Hadron, General Physics and Astronomy, Elementary particle, Production (computer science), Sum rule in quantum mechanics, Nucleon, Delta baryon
Abstract

We report new measurements of inclusive $\ensuremath{\pi}$ production from frozen-spin HD for polarized photon beams covering the $\ensuremath{\Delta}(1232)$ resonance. These provide data simultaneously on both H and D with nearly complete angular distributions of the spin-difference cross sections entering the Gerasimov-Drell-Hearn (GDH) sum rule. Recent results from Mainz and Bonn exceed the GDH prediction for the proton by $22\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$, suggesting as yet unmeasured high-energy components. Our ${\ensuremath{\pi}}^{0}$ data reveal a different angular dependence than assumed in Mainz analyses and integrate to a value that is $18\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$ lower, suggesting a more rapid convergence. Our results for deuterium are somewhat lower than published data, considerably more precise, and generally lower than available calculations.

Published
2009

31. Vertex identification of events in photonuclear reactions by cylindrical multiwire proportional chambers

Author

R. Di Salvo, C. Randieri, M. L. Sperduto, D. Franco, C. M. Sutera, A. D'Angelo, V. Vegna, D. Rebreyend, A. M. Lapik, Giuseppe Mandaglio, J. P. Bocquet, A. N. Mushkarenkov, Marina Manganaro, D. Moricciani, F. Ghio, Annick Lleres, A. Giusa, L. Casano, V. G. Nedorezov, A. Fantini, F. Mammoliti, P. Levi Sandri, G.V. Russo, G. Gervino, B. Girolami, N. V. Rudnev, C. Schaerf, F. Renard, A. Turinge, A. Ignatov, V. Bellini, G. Giardina, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Meson, reaction vertex, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, photonuclear reaction, 0103 physical sciences, General Materials Science, Neutron, Fermi momentum, 010306 general physics, Nuclear Experiment, Physics, Radiation, 010308 nuclear & particles physics, Beam polarization, Condensed Matter Physics, C-MWPC, deuterium target, +n- plus p reaction channel, Charged particle, Vertex (geometry), Graal, Deuterium, Beam direction, Cross point, Atomic physics
Abstract

International audience; In the framework of investigation of meson photo-production on proton and neutron in a deuterium target at the GRAAL experiment, we present a method to identify the vertex of interaction when in reaction products there are at least two charged particles, by the information provided by the cylindrical multiwire proportional chambers. By this device, we are able to obtain the direction of charged particles that leave the target after a photo-production reaction. For each charged particle, the device provides the coordinates of two points in the laboratory reference system, and the z-axis represents the beam direction. We calculate the trajectory of each charged particle and its cross point, representing the vertex of the reaction.

Published
2009

32. Measurement of $\Sigma$ beam asymmetry in $\pi^{0}$ photoproduction off the neutron in the second and third resonances region

Author

D. Rebreyend, M. L. Sperduto, A. Fantini, D. Moricciani, D. Franco, L. Casano, A. Fix, F. Mammoliti, V. G. Nedorezov, G. Gervino, G. Giardina, B. Girolami, A. D'Angelo, Marina Manganaro, V. Bellini, Giuseppe Mandaglio, J. P. Bocquet, M. Guidal, A. M. Lapik, V. Vegna, M. C. Sutera, S.S. Kamalov, G.V. Russo, Annick Lleres, A. N. Mushkarenkov, P. Levi Sandri, N. V. Rudnev, E. Hourany, L. Tiator, O. Bartalini, C. Schaerf, C. Randieri, J. P. Didelez, A. Turinge, R. Di Salvo, R. Kunne, F. Ghio, A. Giusa, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear reaction, Nuclear and High Energy Physics, Proton, Meson, GRAAL, media_common.quotation_subject, Hadron, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], PROTON, 01 natural sciences, 7. Clean energy, Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Pion, ETA-PHOTOPRODUCTION, BARYONIC RESONANCE, 0103 physical sciences, BGO CALORIMETER, Neutron, 010306 general physics, NUCLEON, Nuclear Experiment, media_common, Physics, PHOTON, MODEL, 010308 nuclear & particles physics, NEUTRON, NUCLEAR RECATION INDUCED BY PHOTON BEAM, Physics::Accelerator Physics, High Energy Physics::Experiment, Atomic physics, Nucleon, pi0 beam asymmetry off neutron
Abstract

The $ \Sigma$ beam asymmetry in the photoproduction of neutral pions from quasi-free nucleons in a deuteron target was measured for the first time between 0.60 and 1.50GeV, with the GRAAL polarized and tagged photon beam. The asymmetry values from the quasi-free proton were found equal to the ones extracted from a pure proton target. The asymmetries from quasi-free proton and quasi-free neutron were found equal up to 0.82GeV and substantially different at higher energies. The results are compared with recent partial-wave analyses.

Published
2009

33. Virtual Compton Scattering and Neutral Pion Electroproduction in the Resonance Region up to the Deep Inelastic Region at Backward Angles

Author

Seigo Kato, H. Ueno, K. Wijesooriya, R. Di Salvo, L. C. Alexa, G. W. Miller, H. Voskanyan, C. Jutier, J. Jardillier, E. Voutier, J. A. Templon, G. Rutledge, B. Frois, D. G. Zainea, C. C. Chang, E. Chudakov, David L. Prout, G. Laveissière, T. Terasawa, Vincent Breton, Mauro Iodice, Bogdan Wojtsekhowski, K. S. Kumar, Latifa Elouadrhiri, J. O. Hansen, A. Gasparian, K. Arundell, Pavel Sorokin, Sebastien Incerti, Larry Weinstein, P. Grenier, R. W. Lourie, W. Kahl, J. Berthot, G. Audit, L. B. Auerbach, T. Pussieux, G. Fournier, William Bertozzi, A. Deur, P. Vernin, Pierre A.M. Guichon, Ronald Ransome, Kazushige Maeda, K. Kino, N. Degrande, Pete Markowitz, D. Rowntree, Z. Papandreou, R. L.J. van der Meer, A. T. Katramatou, T. Saito, Richard Madey, Paul Souder, P. M. Rutt, S. K. Nanda, Roberto Perrino, R. De Leo, D. S. Dale, S. Mehrabyan, S. Kerhoas, J. M. Finn, W. U. Boeglin, D. J. Margaziotis, R. I. Pomatsalyuk, A. Ketikyan, L. Todor, A. Leone, M. Baylac, S. Jaminion, Nilanga Liyanage, S. Malov, E. Burtin, M. Holtrop, Thomas E. Smith, Richard Wilson, G. E. Dodge, R. Holmes, J. Marroncle, D. Marchand, E. Tomasi-Gustaffson, S. Platchkov, J. S. Real, J. Martino, Raphael Noel Tieulent, G.I. Smirnov, J. P. Chen, R. Van de Vyver, G. M. Urciuoli, Branislav Vlahovic, R. A. Lindgren, J. J. LeRose, C. R. Howell, Justin I. McIntyre, J. R. Calarco, L. Tiator, L. Bimbot, Arijit Saha, K. Soldi, O. Ravel, Hiroaki Tsubota, A. Serdarevic, C. E. Hyde, Y. Roblin, J. Y. Mougey, G. M. Huber, F. Garibaldi, E. Cisbani, J. Gomez, V. Gorbenko, J. W. Watson, F. Renard, L. Cardman, B. D. Anderson, G. J. Lolos, M. B. Epstein, F. T. Baker, F. Merchez, P. Y. Bertin, Haiyan Gao, M. Liang, G. Quéméner, D. Neyret, N. d'Hose, S. Frullani, Charles Glashausser, M. Khayat, H. Breuer, D. M. Manley, J. Gao, L. Van Hoorebeke, G. G. Petratos, Z. E. Meziani, V. A. Punjabi, L. A. Ewell, Ronald Gilman, K. McCormick, H. Fonvieille, Z. L. Zhou, A. V. Glamazdin, S. Kox, Jing Zhao, C. F. Perdrisat, R. Michaels, C. Marchand, M. K. Jones, C. Furget, P. E. Ulmer, Kevin Fissum, M. Kuss, James J. Kelly, E. J. Brash, Laird Kramer, Shalev Gilad, C. W. de Jager, K. A. Aniol, E. A.J.M. Offermann, C. Cavata, S.S. Kamalov, G. J. Kumbartzki, A. J. Sarty, W. M. Zhang, R. Suleiman, J. Domingo, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), HALL A, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
Elastic scattering, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Scattering, Compton scattering, Resonance, FOS: Physical sciences, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Deep inelastic scattering, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Pion, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment
Abstract

We have made the first measurements of the virtual Compton scattering (VCS) process via the H$(e,e'p)\gamma$ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the $W$-dependence at fixed $Q^2=1$ GeV$^2$, and for the $Q^2$-dependence at fixed $W$ near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed $Q^2$-dependence is smooth. The measured ratio of H$(e,e'p)\gamma$ to H$(e,e'p)\pi^0$ cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared to Real Compton Scattering (RCS) at high energy and large angles, our VCS data at the highest $W$ (1.8-1.9 GeV) show a striking $Q^2$- independence, which may suggest a transition to a perturbative scattering mechanism at the quark level., Comment: 20 pages, 8 figures. To appear in Phys.Rev.C

Published
2009

34. Charged particle detection at GRAAL

Author

V. Bellini, G. Giardina, A. Giusa, C. Schaerf, M. L. Sperduto, C. Randieri, D. Franco, P. Levi Sandri, R. Di Salvo, M. C. Sutera, V. Vegna, G.V. Russo, A. Fantini, F. Mammoliti, Giuseppe Mandaglio, D. Moricciani, and A. D'Angelo

Subjects
Nuclear and High Energy Physics, Proton, BGO calorimeter, BGO CALORIMETER, PI(0) PHOTOPRODUCTION, MONITORING-SYSTEM, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Pion, photonuclear reaction, General Materials Science, SRIM simulation, Fermi momentum, Photon beam, Nuclear Experiment, Physics, deuterium target, +np plus - channel reaction, Radiation, Calorimeter (particle physics), Linear polarization, Solid angle, Condensed Matter Physics, Charged particle, Deuterium, Atomic physics
Abstract

Experimental results on proton and charged pion detection obtained from a study of the γ+n→p+π− reaction are reported in detail. Data have been collected using the tagged and linearly polarized photon beam, impinging on a deuterium target, and the large solid angle apparatus of the GRAAL facility in Grenoble (France). The energy of the charged particles was measured using a BGO calorimeter. A comparison of the experimental data with a GEANT3-based simulation is also presented.

Published
2009

35. Simultaneous Photoproduction ofηandπ0Mesons on the Proton

Author

L. Fichen, N. V. Rudnev, Y. Assafiri, J. Ajaka, E. Oset, F. Ghio, M. Guidal, R. Di Salvo, E. Hourany, B. Girolami, A. N. Mushkarenkov, D. Moricciani, A. Fantini, P. Levi Sandri, S. Bouchigny, G.V. Russo, V. G. Nedorezov, A. Turinge, Michael Döring, V. Bellini, O. Bartalini, C. Schaerf, C. Randieri, J. P. Didelez, A. Giusa, M. L. Sperduto, R. Kunne, M. Castoldi, M. C. Sutera, A. D'Angelo, G. Gervino, and A. M. Lapik

Subjects
Baryon, Nuclear physics, Physics, Particle decay, Particle physics, Pion, Meson, Proton, Hadron, General Physics and Astronomy, Nuclear Experiment, Nucleon, Delta baryon
Abstract

The analysis of the gammap-->etapi(0)p reaction has been performed using data from the GRAAL experiment. The total and differential cross sections and the beam asymmetry have been obtained from threshold up to 1.5 GeV of beam energy. The two resonances S11(1535) and Delta(1700) are expected to be excited in the intermediate states of this reaction. The results are used to test predictions based on the assumption that both resonances are dynamically generated from the meson-baryon interaction provided by chiral Lagrangians. The term involving the Delta(1700) excitation, followed by the decay into etaDelta(1232), is found to be dominant.

Published
2008

36. First measurement of the Sigma beam asymmetry in eta photoproduction on the neutron

Author

M. C. Sutera, V. G. Nedorezov, V. Vegna, M. L. Sperduto, D. Moricciani, G. Gervino, L. Casano, V. Bellini, Annick Lleres, A. Fix, G. Giardina, V. Kuznetsov, Marina Manganaro, D. Franco, J. P. Bocquet, M. Castoldi, S.S. Kamalov, C. Schaerf, A. Turinge, B. Girolami, A. N. Mushkarenkov, G.V. Russo, P. Levi Sandri, L. Nicoletti, L. Tiator, N. V. Rudnev, F. Ghio, A. Giusa, F. Renard, A. Lapik, O. Bartalini, C. Randieri, R. Di Salvo, A. Fantini, F. Mammoliti, A. D'Angelo, D. Rebreyend, Giuseppe Mandaglio, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
deuteron, Nuclear reaction, Nuclear and High Energy Physics, Particle physics, BGO calorimeter, Proton, GRAAL, media_common.quotation_subject, Hadron, Nuclear Theory, Elementary particle, Photon energy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, 0103 physical sciences, monitoring-system, energy region, Neutron, 010306 general physics, Nuclear Experiment, media_common, 25.20.Lj, 13.60.Le, 13.88.+e, Physics, near-threshold photoproduction, meson photoproduction, proton, electroproduction, photoexcitation, 010308 nuclear & particles physics, NEAR-THRESHOLD PHOTOPRODUCTION, BGO CALORIMETER, MESON PHOTOPRODUCTION, MONITORING-SYSTEM, ENERGY REGION, PROTON, DEUTERON, ELECTROPRODUCTION, PHOTOEXCITATION, Physics::Accelerator Physics, High Energy Physics::Experiment, Nucleon
Abstract

We present the first measurement of the {sigma} beam asymmetry in {eta} photoproduction on the neutron in the photon energy range from threshold to 1.5 GeV. Data have been collected by using the tagged and linearly polarized photon beam and the large solid angle apparatus of the GRAAL facility. Neutron data have been selected among {eta} photoproduction events on the deuteron in the quasi-free kinematics approximation. Proton data, extracted in the same way, are within errors identical to those previously obtained on free protons at the GRAAL facility, except for a few points falling in certain energy bins. This difference is, however, well understood in terms of the Fermi motion of the nucleons in the deuteron. We take the consistency of free and quasi-free proton data as an indication that nuclear effects are negligible also for neutron data. The ETAMAID model, in which a strong coupling of the D{sub 15}(1675) resonance to the {eta}-neutron channel is introduced, can explain the proton data very well, but it cannot describe the beam asymmetry for the neutron.

Published
2008

37. Measurement of the total photoabsorption cross section on a proton in the energy range 600-1500 MeV at the GRAAL

Author

O. Bartalini, A. N. Mushkarenkov, A. Fantini, C. Schaerf, G.V. Russo, P. Levi Sandri, V. Bellini, A. M. Lapik, R. Kunne, P. Calvat, J. P. Didelez, V. G. Nedorezov, M. C. Sutera, A. D'Angelo, J. P. Bocquet, D. Rebreyend, M. Guidal, D. Moricciani, E. Hourany, T. Russew, A. S. Ignatov, Annick Lleres, F. Ghio, A. Giusa, F. Renard, N. V. Rudnev, A. A. Turinge, M. L. Sperduto, C. Perrin, B. Girolami, and R. Di Salvo

Subjects
Nuclear reaction, Physics, Elastic scattering, Nuclear and High Energy Physics, Range (particle radiation), Proton, Hadron, Compton scattering, GAMMA-RAYS, BEAM, Atomic and Molecular Physics, and Optics, REGION, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Cross section (physics), BGO CALORIMETER, PHOTOPRODUCTION, NEUTRON, Nucleon
Abstract

The total photoabsorption cross section on a free proton was measured at the GRAAL facility in the energy range Eγ = 600−1500 MeV. The large-aperture LAGRANγE detector and a liquid hydrogen target were used in the experiment performed with a back-scattered Compton gamma beam. To improve the accuracy, two alternative methods were employed. First, a subtraction method of using empty-target measurements allowed the cross section σtot to be evaluated directly because of a low level of the electromagnetic background. Second, an algorithm for evaluating σtot on the basis of summing the dominating partial cross sections was developed. Experimental results obtained for σtot by the two methods are compared with existing data.

Published
2008

38. New experimental and simulated results on nuclear media effects in meson photoproduction off nuclei

Author

N. V. Rudnev, T. Russew, O. Bartalini, V. G. Nedorezov, A. D'Angelo, D. Moricciani, D. Rebreyend, R. Kunne, G. Gervino, J. P. Bocquet, A. Fantini, M. L. Sperduto, C. Perrin, M. Casano, Annick Lleres, A. Turinge, R. Di Salvo, M. Castoldi, A. M. Lapik, G.V. Russo, C. Schaerf, F. Renard, P. Calvat, V. Bellini, E. Hourany, M. Guidal, V. Kouznetsov, A. S. Ignatov, A. N. Mushkarenkov, P. Levi Sandri, L. Nicoletti, J. P. Didelez, B. Girolami, F. Ghio, A. Giusa, Marco Capogni, M. C. Sutera, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, medicine.anatomical_structure, Recoil, Deuterium, Cascade, 0103 physical sciences, medicine, High Energy Physics::Experiment, 010306 general physics, Nucleon, Nuclear Experiment, Nucleus
Abstract

International audience; New experimental approach to study meson photoproduction in nuclei is discussed. It is based on the measurement of the recoil nucleon as a tagger for identification of the initial step of reaction. Propagation of mesons and nucleons within a nucleus is described by the Intra-Nuclear Cascade (INC) model. Simulations and preliminary experimental data for the deuteron target obtained at GRAAL are presented.

Published
2008

39. PERFORMANCE OF FROZEN-SPIN POLARIZED HD TARGETS FOR NUCLEON SPIN EXPERIMENTS

Author

T. KAGEYA, K. ARDASHEV, C. BADE, M. BLECHER, A. CARACAPPA, A. D'ANGELO, R. DI SALVO, A. FANTINI, C. GIBSON, H. GLÜCKLER, K. HICKS, S. HOBLIT, A. HONIG, M. KHANDAKAR, S. KIZIGUL, O. KISTNER, S. KUCUKER, A. LEHMANN, F. LINCOLN, R. LINDGREN, M. LOWRY, M. LUCAS, J. MAHON, L. MICELI, D. MORICCIANI, B. NORUM, M. PAP, B. PREEDOM, A. M. SANDORFI, C. SCHAERF, H. SEYFARTH, H. STRÖHER, C. THORN, K. WANG, X. WEI, and C. WHISNANT

Subjects
Physics, Nuclear physics, Nucleon, Spin (physics)
Published
2007

40. Double $\pi^0$ photoproduction on the neutron at GRAAL

Author

O. Bartalini, C. Randieri, A. N. Mushkarenkov, V. Bellini, G. Gervino, M. Castoldi, G.V. Russo, Sylvain Bouchigny, M. Guidal, J. P. Didelez, E. Hourany, A. M. Lapik, D. Moricciani, Y. Assafiri, V. G. Nedorezov, L. Fichen, F. Ghio, J. Ajaka, A. Giusa, P. Levi Sandri, A. D'Angelo, A. Fantini, R. Di Salvo, M. C. Sutera, B. Girolami, A. Turinge, C. Schaerf, N. V. Rudnev, M. L. Sperduto, R. Kunne, Institut de Physique Nucléaire d'Orsay (IPNO), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Polarization observables, Proton, Meson, Baryon resonances, Hadron, Nuclear Theory, 01 natural sciences, 7. Clean energy, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Pion, 0103 physical sciences, 13.60.Le, 13.88.+e, 14.40.Aq, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Neutron, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Neutron target, Deuterium, Double π0 photoproduction, Photon beam asymmetry, Double $\pi^0$ photoproduction, Physics::Accelerator Physics, High Energy Physics::Experiment, Atomic physics, Nucleon, Beam (structure)
Abstract

The photoproduction of double π 0 on the neutron is studied in the beam energy range of 0.6 up to 1.5 GeV, using a liquid deuterium target. The cross section and the beam asymmetry are extracted and compared to those previously obtained on a proton target. The theoretical interpretation of these results is given using different models.

Published
2007

41. Neutron detection efficiency of BGO calorimeter at GRAAL

Author

G.V. Russo, M. Casano, A. N. Mushkarenkov, G. Gervino, J. P. Bocquet, T. Russew, E. Hourany, D. Moricciani, P. Levi Sandri, A. D'Angelo, M. C. Sutera, D. Rebreyend, P. Calvat, V. Bellini, V. Kouznetsov, C. Perrin, C. Schaerf, F. Renard, Marco Capogni, L. Nicoletti, A. Fantini, A. M. Lapik, R. Kunne, N. V. Rudnev, Annick Lleres, R. Di Salvo, V. G. Nedorezov, J. P. Didelez, M. Castoldi, F. Ghio, A. Turinge, A. Giusa, M. Guidal, O. Bartalini, B. Girolami, M. L. Sperduto, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
Nuclear and High Energy Physics, 29.40.Mc, 29.40.Vj, 28.20.−v, BAF2, Physics::Instrumentation and Detectors, BGO, neutrons, detection efficiency, GEANT simulation, MONITORING-SYSTEM, PHOTON-BEAM, SCINTILLATORS, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Spectral line, Detection efficiency, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, 0103 physical sciences, Neutron detection, Neutron, 010306 general physics, Nuclear Experiment, Instrumentation, Pulse height, Physics, Neutrons, Calorimeter (particle physics), 010308 nuclear & particles physics
Abstract

Experimental results on the neutron detection efficiency of the GRAAL BGO calorimeter obtained from a study of γ p → π + n reaction are reported. Pulse height spectra were measured for neutron energies from 80 to 650 MeV. A comparison of the experimental data with a GEANT-based simulation is presented.

Published
2006

42. Recent results from GRAAL

Author

A. Fantini, G. Gervino, M. Guidal, E. Hourany, J. P. Bocquet, R. Kunne, B. Girolami, A. M. Lapik, F. Ghio, P. Levi Sandri, M. L. Sperduto, V. Kouznetsov, A. Turinge, A. Giusa, A. D'Angelo, D. Moricciani, D. Rebreyend, G. Russo, O. Bartalini, M. C. Sutera, C. Schaerf, N. V. Rudnev, Alessandro Zucchiatti, R. Di Salvo, Annick Lleres, D. V. Nedorezov, J. P. Didelez, V. Bellini, M. Castoldi, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
POSITIVE PION-PHOTOPRODUCTION, Nuclear and High Energy Physics, Angular range, Hydrogen, Meson, Nuclear Theory, chemistry.chemical_element, Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], PROTON, 01 natural sciences, SIGMA-BEAM ASYMMETRY, CROSS-SECTION MEASUREMENT, THRESHOLD, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, ETA-PHOTOPRODUCTION, 0103 physical sciences, PRECISE MEASUREMENT, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Compton scattering, ELECTROPRODUCTION, Astronomy and Astrophysics, MESONS, meson photoproduction, Atomic and Molecular Physics, and Optics, MODEL, Deuterium, chemistry, polarized gamma beam, Storage ring, Beam (structure)
Abstract

A polarised and tagged [Formula: see text] ray beam is produced at GRAAL by the Compton scattering of laser light on the high energy electron of the ESRF storage ring. We present results on the beam polarisation asymmetries and cross sections in the photoproduction of mesons on hydrogen and deuterium target in the energy region 500-1500 MeV. These very precise results cover the angular range 30°-150°, providing stringent constraints to theoretical models.

Published
2005

43. η and π° Photoproduction on the Deuteron: Beam Asymmetries

Author

M. Guidal, J. P. Bocquet, A. Turige, A. Fantini, R. Di Salvo, R. Kunne, Alessandro Zucchiatti, M. C. Sutera, A. D'Angelo, D. Rebreyend, M. Castoldi, G. Gervino, M. L. Sperduto, F. Ghio, V. Bellini, N. V. Rudven, V. Kuznetsov, P. Levi Sandri, V. G. Nedorezov, C. Schaerf, D. Franco, A. M. Lapik, E. Hourany, O. Bartalini, Annick Lleres, B. Girolami, J. P. Didelez, F. Renard, and D. Moricciani

Subjects
Physics, Range (particle radiation), Particle physics, Photon, Proton, media_common.quotation_subject, Nuclear Theory, Asymmetry, Nuclear physics, Deuterium, High Energy Physics::Experiment, Neutron, Nuclear Experiment, Beam (structure), media_common
Abstract

Preliminary results on the beam asymmetry for the eta and pi degrees photoproduction off the quasi-free proton and the quasi-free neutron in the deuteron were obtained in the energy range 0.65-1.5 GeV of the incoming photon.

Published
2004

44. Measurement of the Generalized Polarizabilities of the Proton in Virtual Compton Scattering atQ2=0.92and1.76 GeV2

Author

G. Laveissière, L. Todor, N. Degrande, S. Jaminion, C. Jutier, 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, 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, J. Gao, F. Garibaldi, A. Gasparian, S. Gilad, R. Gilman, 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, 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, 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, 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, D. Rowntree, G. Rutledge, P. M. Rutt, A. Saha, T. Saito, A. J. Sarty, A. Serdarevic, T. Smith, G. Smirnov, K. Soldi, P. Sorokin, P. A. Souder, R. Suleiman, J. A. Templon, T. Terasawa, R. Tieulent, E. Tomasi-Gustaffson, H. Tsubota, H. Ueno, P. E. Ulmer, G. M. Urciuoli, M. Vanderhaeghen, R. Van De Vyver, R. L. J. Van der Meer, 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

Subjects
Physics, Proton, 010308 nuclear & particles physics, Scattering, Momentum transfer, Compton scattering, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Nuclear physics, Paramagnetism, Dipole, Pion, Polarizability, 0103 physical sciences, Atomic physics, 010306 general physics
Abstract

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.

Published
2004

45. Backward electroproduction ofπ0mesons on protons in the region of nucleon resonances at four momentum transfer squaredQ2=1.0GeV2

Author

P.Y. Bertin, M. K. Jones, B. D. Anderson, G. J. Lolos, M. B. Epstein, S. Frullani, R. W. Lourie, Jing Zhao, W. Kahl, M. Kuss, J. W. Watson, Y. Roblin, Bogdan Wojtsekhowski, William Bertozzi, L. S. Cardman, D. Neyret, S. Jaminion, R. Michaels, S. Platchkov, F. T. Baker, H. Ueno, Pete Markowitz, R. Di Salvo, T. Terasawa, Vincent Breton, M. Khayat, J. Martino, Raphael Noel Tieulent, Sebastien Incerti, A. Saha, L. B. Auerbach, E. J. Brash, G. E. Dodge, V. A. Punjabi, R. A. Lindgren, Richard Madey, G. J. Kumbartzki, G. Laveissière, Z. Papandreou, J. J. LeRose, P. M. Rutt, O. Ravel, Roberto Perrino, R. De Leo, D. J. Margaziotis, J. A. Templon, Ronald Ransome, D. Rowntree, M. Baylac, J. P. Chen, A. Deur, P. Vernin, B. Frois, G. G. Petratos, Z. E. Meziani, K. Kino, E. Chudakov, J. O. Hansen, Justin I. McIntyre, R. I. Pomatsalyuk, K. Wijesooriya, Hiroaki Tsubota, A. Ketikyan, Z. L. Zhou, K. Soldi, A. Serdarevic, L. Bimbot, H. Breuer, M. Liang, R. Van de Vyver, G. M. Urciuoli, A. T. Katramatou, L. C. Alexa, G. Quéméner, V. Gorbenko, F. Renard, N. d'Hose, S. K. Nanda, S. Malov, E. Burtin, J. Domingo, C. R. Howell, J. R. Calarco, J. M. Finn, S. Kerhoas, M. Holtrop, J. Gomez, Thomas E. Smith, C. F. Perdrisat, C. Glashausser, E. Cisbani, W. U. Boeglin, Philippe Grenier, Latifa Elouadrhiri, G. Audit, A. Gasparian, C. E. Hyde-Wright, L. Todor, A. Leone, L. Tiator, S. Mehrabyan, L. A. Ewell, Kazushige Maeda, C. Furget, D. M. Manley, Kevin Fissum, D. G. Zainea, J. Jardillier, J. Gao, K. Arundell, R. Holmes, G. Rutledge, C. C. Chang, L. Van Hoorebeke, K. S. Kumar, Ronald Gilman, K. McCormick, Mauro Iodice, Nilanga Liyanage, H. Fonvieille, Pierre A.M. Guichon, Pavel Sorokin, Larry Weinstein, P. E. Ulmer, Paul Souder, A. V. Glamazdin, Haiyan Gao, R. L.J. van der Meer, S. Kox, G. M. Huber, F. Garibaldi, T. Saito, Richard Wilson, Laird Kramer, J. Y. Mougey, E. Voutier, Branislav Vlahovic, F. Merchez, G. Fournier, James J. Kelly, C. Marchand, Seigo Kato, G. W. Miller, H. Voskanyan, C. Jutier, David L. Prout, T. Pussieux, W. M. Zhang, J. Berthot, R. Suleiman, C. Cavata, S.S. Kamalov, G. Smirnov, A. J. Sarty, Shalev Gilad, C. W. de Jager, K. A. Aniol, E. A.J.M. Offermann, N. Degrande, J. Marroncle, D. Marchand, E. Tomasi-Gustaffson, J. S. Real, and D. S. Dale

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Momentum transfer, Sigma, 01 natural sciences, Nuclear physics, Baryon, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, Lepton
Abstract

Exclusive electroproduction of pi{sup 0} mesons on protons in the backward hemisphere has been studied at Q2 = 1.0 GeV2 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{sub T} + epsilon sigma{sub L}, sigma{sub TL}, and sigma{sub TT} were separated from the azimuthal distribution and are presented together with the MAID and SAID parameterizations.

Published
2004

46. Compton scattering of polarized photons on the proton at GRAAL

Author

A. Guisa, M. L. Sperduto, G. Gervino, F. Ghio, V. Bellini, J. P. Didelez, B. Girolami, Annick Lleres, C. Schaerf, M. Guidal, P. Levi Sandri, A. M. Lapik, R. Kunne, V. G. Nedorezov, E. Hourany, A. D'Angelo, D. Rebreyend, A. Fantini, J. P. Bocquet, M. Castoldi, A. Turinge, N. V. Rudnev, C. M. Sutera, Alessandro Zucchiatti, G.V. Russo, O. Bartalini, D. Moricciani, R. Di Salvo, V. Kouznetsov, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), J.P. Bocquet, V. Kuznetsov, D. Rebreyend, and GRAAL

Subjects
Physics, Photon, Proton, 010308 nuclear & particles physics, Scattering, Nuclear Theory, Compton scattering, Electron, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Baryon, 0103 physical sciences, BGO CALORIMETER, Atomic physics, 010306 general physics, Nuclear Experiment, Storage ring
Abstract

PHASE; Compton scattering of polarized photons on the proton has been investigated in the energy range 0.8-1.5 GeV, where the non-resonance double-pion photoproduction and the excitations of high baryon resonances play an important role among the photoabsorption mechanisms. Data have been collected by the GRAAL facility, whose polarized photon beam is obtained by the backward scattering of laser light onto the ultrarelativistic electrons circulating in the Grenoble's ESRF storage ring. The main background contribution is due to the in-flight decay of $\pi^0$ where the two photons are emitted with a small opening angle. We present some preliminary results about the method for the separation of Compton scattering events from the aforesaid background.

Published
2004

47. Basic instrumentation for Hall A at Jefferson Lab

Author

T. Pussieux, Paul Souder, J. H. Mitchell, Y. Roblin, O. Ravel, E. Chudakov, K. A. Griffioen, C. Cavata, J. A. Templon, H. F. Ibrahim, J. S. McCarthy, M. A. Stevens, D. P. Watts, B. Frois, W. J. Schneider, Dipangkar Dutta, R. Di Salvo, R. I. Pomatsalyuk, A. Soldi, G. J. Kumbartzki, Arijit Saha, N. Colombel, J. Berthot, Jing Zhao, A. J. Sarty, B. D. Anderson, J. Martine, M. Coman, R. Michaels, M. B. Epstein, R. W. Lourie, J. O. Hansen, N. Degrande, J. Mclntyre, John Arrington, L. Zhu, W. Kahl, Bogdan Wojtsekhowski, P. Djawotho, M. Leuschner, William Bertozzi, K. A. Aniol, A. Gasparian, Karl Slifer, Jrm Annand, C. F. Perdrisat, D. Pripstein, M. Baylac, S. Kox, X. Jiang, K. Kramer, H. Breuer, David Hamilton, Jian-Ping Chen, T. Averett, L. B. Auerbach, G. A. Rutledge, G. Quéméner, Stephanie Escoffier, P.Y. Bertin, R. Suleiman, R. Carr, Pete Markowitz, A. Deur, Z. Papandreou, R. L. Walter, R. D. McKeown, T. P. Gorringe, M. Rvachev, R. Holmes, S. Churchwell, J. Marroncle, S. Platchkov, M. Khandaker, M. Liang, L. Pierangeli, K. Kino, A. Ketikyan, Kevin Fissum, F. W. Hersman, J. LeRose, F. Giuliani, P. E. Ulmer, Roberto Perrino, R. De Leo, J. Gao, L. A. Ewell, S. Jensen, R. Crateri, Shalev Gilad, C. W. de Jager, D. Lhuillier, J.E. Ducret, M. Gricia, R. Iommi, F. Sabatavenere, P. A. Zolnierczuk, K. Wijesooriya, Alan M. Nathan, D. Rowntree, E. Voutier, H. Holmgren, S. K. Nanda, D. G. Meekins, K. S. Egiyan, C. R. Howell, A. Serdarevic-Offermann, Hiroaki Tsubota, D. G. Zainea, J. R. Calarco, S. Esp, T. Terasawa, Vincent Breton, C. C. Chang, J. Domingo, T. Black, A. T. Katramatou, S. Kerhoas, F. Santavenere, J. Y. Mougey, R. Van de Vyver, G. M. Urciuoli, Seigo Kato, G. M. Huber, B. Reitz, E. J. Beise, K. S. Kumar, F. Garibaldi, Pavel Sorokin, G. J. Lolos, M. Lucentini, J. Segal, H. Xiang, D. V. Boykin, W. U. Boeglin, C. Glashausser, E. Cisbani, A. Leone, R. D. Ransomez, Gordon D. Cates, Sonja Dieterich, H. Voskanyan, C. Jutier, R. L.J. van der Meer, Olivier Gayou, James A. Miller, L. Van Hoorebeke, Sebastien Incerti, J. Jardillier, L. Cardman, James J. Kelly, F. Xiong, S. Jaminion, I. K. Kominis, K. McCormick, P. Vernin, P. M. Rutt, A. Petrosyan, David L. Prout, Nilanga Liyanage, L. Lagamba, X. Zheng, S. L. Spiegel, Branislav Vlahovic, Leonid Levchuk, Mauro Iodice, Larry Weinstein, F. Marie, D. G. Ireland, N. S. Chant, David Manley, V. A. Punjabi, C. E. Jones, J. Gomez, Wolfgang Korsch, W. Xu, J. W. Watson, M. Roedelbronn, F. T. Baker, Z. E. Meziani, T. Saito, S. Frullani, H. Ueno, E. J. Brash, R. Roche, E. Hovhannisyan, C. E. Hyde-Wright, N. d'Hose, L. Bimbot, G. Laveissière, R. Madey, Kazushige Maeda, A. Gavalya, W. Miller, D. Neyret, T. P. Smith, B. Diederich, E. Burtin, M. Holtrop, L. Todor, G. Dezern, Z. L. Zhou, K. Livingston, D. S. Dale, V. Zeps, S. Mayilyan, E. Folts, B. D. Milbrath, Haiyan Gao, J. M. Finn, O. Rondon-Aramayo, R. A. Lindgren, V. Gorbenko, A. V. Glamazdin, Z. Chai, E. A.J.M. Offermann, S. Malov, J. Alcorn, S. Strauch, A. Shahinyan, G. Rosner, H. Fonvieille, P. G. Roos, E. W. Hughes, K. Joo, D. S. Brown, P. Brindza, G. G. Petratos, S. van Verst, M. Khayat, S. Colilli, Douglas Higinbotham, M. K. Jones, D. J. Margaziotis, M. Kuss, Seonho Choi, Ronald Gilman, Thomas Jefferson National Accelerator Facility (Jefferson Lab), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), HALL A, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Cryogenics, Scintillator, 7. Clean energy, 01 natural sciences, Particle identification, Magnetic field, Nuclear physics, Cardinal point, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment, 010306 general physics, Nucleon, Instrumentation, Cherenkov radiation
Abstract

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 x 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 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.

Published
2004

48. FIRST PION PHOTOPRODUCTION DOUBLE-POLARIZATION RESULTS WITH POLARIZED $ \vec H\vec D $ AT LEGS

Author

A. LEHMANN, C.S. WHISNANT, C. CACACE, A. CARACAPPA, S. HOBLIT, O.C. KISTNER, A. KUCZEWSKI, F. LINCOLN, M. LOWRY, L. MICELI, A.M. SANDORFI, C. THORN, X. WEI, M. KHANDAKER, K. ARDASHEV, C. BADE, R. DEININGER, K. HICKS, M. LUCAS, J. MAHON, A. HONIG, A. D’ANGELO, A. d’ANGELO, R. DI SALVO, D. MORICCIANNI, C. SCHAERF, C. COMMEAUX, J.P DIDELEZ, I. DANCHEV, C. GIBSON, B.M. PREEDOM, A. CICHOCKI, B. NORUM, K. WANG, M. BLECHER, T. KAGEYA, H. MEYER, and T. SAITOH

Subjects
Nuclear physics, Physics, Pion, Spectrometer, Nuclear Theory, Solid angle, Neutron, Nucleon spin structure, Photon beam, Nuclear Experiment, Polarization (waves), Polarized target
Abstract

A new polarized target using HD in the solid phase has been developed for studies of the nucleon spin structure at Q(2) = 0 using pion photo-production. In combination with the high quality LEGS photon beam and a large solid angle spectrometer this target allows practically background-free measurements on the proton and on the neutron. The first beam-target double-polarization data taken with this target are reported here.

Published
2003

49. GDH at GRAAL with polarized H D target

Author

S. BOUCHIGNY, C. COMMEAUX, J-P. DIDELEZ, M. GUIDAL, E. HOURANY, R. KUNNE, G. ROUILLE, M. BASSAN, A. D’ANGELO, R. DI SALVO, A. FANTINI, D. MORICCIANI, C. SCHAERF, J-P. BOCQUET, A. LLERES, D. REBREYEND, V. KUZNETSOV, A. LAPIK, V. NEDOREZOV, N.V. ROUDNEV, A. TURINGE, P. LEVI SANDRI, F. GHIO, B. GIROLAMI, V. BELLINI, M. SPERDUTO, M. SUTERA, M. CASTOLDI, A. ZUCCHIATTI, G. GERVINO, and O. BARTALINI

Subjects
Physics, Isovector, Proton, Nuclear Theory, Polarization (waves), PROTON, SUM-RULE, MAGNETIC MOMENTS, PHOTOPRODUCTION, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Deuterium, Physics::Accelerator Physics, Photon beams, Neutron, Sum rule in quantum mechanics, Nuclear Experiment, Circular polarization
Abstract

Within the GRAAL collaboration, we have constructed a Polarized HD Target Factory, implanted at IPN Orsay. The expected properties of the HD targets and the results already obtained for the polarization of HD samples and the relaxation times are given. New possibilities to perform GDH experiments on polarized proton, neutron and deuteron are now opened, by using the high circular polarization of the GRAAL backscattered photon beams and the large effective longitudinal polarization of the HD target, resulting essentially from its good dilution factors. Polarized total cross sections concerning the isovector Drell-Hearn Gerasimov Sum Rule related to the proton neutron difference, could be measured with minimum systematic uncertainties: the target containing both polarized protons and neutrons. An experimental method, taking advantage of the 4pi GRAAL experimental set-up is described.

Published
2003

50. Double pi(0) photoproduction on the proton at GRAAL

Author

D. Moricciani, N. V. Rudnev, V. Kouznetsov, Marco Capogni, L. Fichen, Alessandro Zucchiatti, V. Bellini, J. P. Didelez, R. Kunne, C. Schaerf, Y. Assafiri, G. Gervino, M. Guidal, P. Levi Sandri, O. Bartalini, A. D'Angelo, C. Randieri, M. L. Sperduto, D. Rebreyend, E. Hourany, S. Bouchigny, F. Ghio, A. Turinge, R. Di Salvo, V. G. Nedorezov, A. Giusa, J. P. Bocquet, M. Castoldi, A. M. Lapik, M. C. Sutera, F. Renard, J. M. Laget, A. Fantini, Annick Lleres, B. Girolami, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and GRAAL

Subjects
double-pion-photoproduction, sigma-beam asymmetry, cross-section measurement, precise measurement, threshold, Proton, media_common.quotation_subject, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Cross section (physics), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment, 010306 general physics, media_common, Physics, Range (particle radiation), 010308 nuclear & particles physics, Resonance, Sigma, Physics::Accelerator Physics, High Energy Physics::Experiment, Nucleon, Beam (structure)
Abstract

The double ${\ensuremath{\pi}}^{0}$ photoproduction off the proton has been measured in the beam energy range of 0.65--1.5 GeV. The total and differential cross sections and the $\ensuremath{\Sigma}$ beam asymmetry were extracted. The total cross section measured for the first time in the third resonance region of the nucleon shows a prominent peak. The interpretation of these results by two independent theoretical models infers mostly the selective excitation of ${P}_{11}$- and ${D}_{13}$-nucleon resonances.

Published
2003

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