Author: "Nicholas Zachariou" / Topic: nuclear and high energy physics - Searchworks@Jio Institute Digital Library Search Results

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46 results on '"Nicholas Zachariou"'

1. Single $$\pi ^0$$ production off neutrons bound in deuteron with linearly polarized photons

Author: M. Günther, D. P. Watts, M. Bashkanov, R. A. Miskimen, S. Abt, C. S. Akondi, N. Jermann, Yu. A. Usov, O. Steffen, I. J. D. MacGregor, P. Pedroni, N. K. Walford, Nicholas Zachariou, Concettina Sfienti, S. N. Prakhov, D. Ghosal, S. Wagner, G. Reicherz, A. Powell, V. L. Kashevarov, A. Braghieri, Z. Ahmed, Th. Strub, Patrick Achenbach, Susanna Costanza, Andy Thomas, I. I. Strakovsky, M. Ostrick, M. Mocanu, Michaela Thiel, I. Supek, B. Krusche, J. Wettig, Lena Heijkenskjöld, J. R. M. Annand, R. Beck, K. Livingston, V. V. Kulikov, S. Lutterer, S. Fegan, S. Gardner, N. S. Borisov, I. Gorodnov, Ron L. Workman, C. Mullen, S. Kay, D. M. Manley, M. Korolija, A. B. Neganov, V. Sokhoyan, D. Hornidge, A. Thiel, A. G. Denig, M. Dieterle, K. Spieker, P. P. Martel, F. Afzal, Durga Paudyal, A. Kaeser, E. J. Downie, A. Lazarev, Lilian Witthauer, E. Mornacchi, W. Gradl, C. Meier, M. Wolfes, D. Werthmüller, M. Biroth, G. Gurevic, C. Collicott, P. B. Otte, P. Drexler, M. A. Martemianov, W. J. Briscoe, M. Unverzagt, T. Rostomyan, F. Cividini, Guy Ron, G. M. Huber, M. Oberle, D. I. Glazier, and M. I. Ferretti-Bondy
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Nuclear Theory, 010308 nuclear & particles physics, media_common.quotation_subject, Hadron, 01 natural sciences, Asymmetry, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Pion, Isospin, 0103 physical sciences, Production (computer science), Center of mass, Nuclear Experiment, 010306 general physics, Crystal Ball, media_common
Abstract: The quasifree $\overrightarrow{\gamma} d\to\pi^0n(p)$ photon beam asymmetry, $\Sigma$, has been measured at photon energies, $E_\gamma$, from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49 to 148$^\circ$. In this kinematic region, polarization observables are sensitive to contributions from the $\Delta (1232)$ and $N(1440)$ resonances. The extracted values of $\Sigma$ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID, and Bonn-Gatchina analyses; while a revised SAID fit, including the new $\Sigma$ measurements, has also been performed. In addition, isospin symmetry is examined as a way to predict $\pi^0n$ photoproduction observables, based on fits to published data in the channels $\pi^0p$, $\pi^+n$, and $\pi^-p$., Comment: 11 pages, 9 figures, 5 tables; fixed 2 glitches
Published: 2021
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2. Measurement of the beam spin asymmetry of e→p→e′p′η in the deep-inelastic regime with CLAS

Author: M. Guidal, C. Djalali, J. A. Tan, A. I. Ostrovidov, K. Park, Z.W. Zhao, G. D. Smith, M. Holtrop, M. Hattawy, D. G. Ireland, Iu. Skorodumina, Volker D. Burkert, K. A. Griffioen, A. S. Biselli, Maxime Defurne, V. Mokeev, D. Marchand, X. Wei, M. Bashkanov, S. Adhikari, V. Crede, Rong Wang, B. McKinnon, P. Lenisa, L. Lanza, Taya Chetry, R. A. Montgomery, C. A. Meyer, N. A. Baltzell, Y. G. Sharabian, P. Chatagnon, M. Ehrhart, W. Kim, D. G. Jenkins, A. Kim, Y. Prok, M. Mirazita, Z. E. Meziani, A. Celentano, R. W. Gothe, R. De Vita, G. Niculescu, Sergey Kuleshov, F. Sabatié, N. Markov, F. X. Girod, V. Batourine, M. Ungaro, N. Dashyan, M. Khachatryan, V. P. Kubarovsky, H. S. Jo, R. Paremuzyan, K. Livingston, O. Pogorelko, L. Barion, G. Rosner, Nicholas M. Harrison, Gerard Gilfoyle, Friedrich Klein, M. Battaglieri, H. Avakian, K. Joo, S. Strauch, H. Hakobyan, D. Sokhan, I. Bedlinskiy, H. Voskanyan, Y. Ghandilyan, Laura Clark, B. S. Ishkhanov, H. Egiyan, Jie Zhang, S. Diehl, C. Salgado, M. Osipenko, K. Hicks, B. Zhao, G. Khachatryan, P. Nadel-Turonski, G. Ciullo, J. P. Ball, S. E. Kuhn, D. S. Carman, Dustin Keller, D. Heddle, Nikos Sparveris, E. De Sanctis, R. A. Schumacher, G. Angelini, P. Eugenio, S. Johnston, L. Guo, Alessandro Rizzo, S. Niccolai, Michael Wood, P. Rossi, C. Munoz Camacho, K. Hafidi, W. J. Briscoe, M. L. Kabir, E. Golovatch, R. Dupre, T. A. Forest, S. Stepanyan, A. Filippi, Avraham Klein, E. L. Isupov, G. Gavalian, I. J. D. MacGregor, M. Contalbrigo, M. Khandaker, I. I. Strakovsky, A. Deur, M. Ripani, S. Boiarinov, M. Taiuti, W. K. Brooks, B. A. Clary, Z. Akbar, Michael Paolone, J. W. Price, A. D'Angelo, D. Protopopescu, E. Voutier, L. El Fassi, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, and P. L. Cole
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, media_common.quotation_subject, Hadron, Virtual particle, Parton, 01 natural sciences, Asymmetry, Nuclear physics, Pseudoscalar, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Spin-½, media_common, Lepton
Abstract: The beam spin asymmetry of the exclusive pseudoscalar channel e → p → e ′ p ′ η was measured for the first time in the deep-inelastic regime ( W > 2 GeV / c 2 and Q 2 > 1 GeV 2 / c 2 ) using a longitudinally polarized 5.78 GeV electron beam at Jefferson Lab with the CEBAF Large Acceptance Spectrometer. The data were accumulated in 144 four-dimensional bins of Q 2 , x B , − t and ϕ over a wide kinematic range, where ϕ is the azimuthal angle between the lepton and hadron scattering planes, The measured azimuthal dependence with large amplitudes of the sin ⁡ ϕ moments is a clear indication of a substantial contribution to the polarized cross-section from transversely polarized virtual photons. In the framework of generalized parton distributions (GPDs) this contribution is expressed via longitudinal-transverse interference between chiral-even and chiral-odd GPDs. The experimental results are compared to the existing theoretical models demonstrating the sensitivity to the product of chiral-odd and chiral-even GPDs and provide new constraints to the existing GPD parameterizations.
Published: 2019
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3. The CLAS12 Forward Tagger

Author: V. Vigo, E. Pasyuk, F. Cipro, A. Ciarma, D. Sokhan, R. Behary, G. Charles, T. Bey, Y. Mouden, A. Filippi, K. L. Giovanetti, T. Lemon, Q. Bertrand, F. Sabatié, A. Manco, H.S. Mann, A. Bersani, I. Mandjavidze, A. Hoebel, David Attié, M. Vandenbroucke, S. Aune, M. Garçon, R. Cereseto, G. Christiaens, E. Delagnes, D. P. Watts, R. Miller, F. Georges, N. Grouas, A. Casale, C. Salgado, C. Rossi, G. Ottonello, T. Lerch, P. Contrepois, A. Trovato, Paolo Musico, L. Zana, F. Parodi, S. M. Hughes, S. Fegan, Fatiha Benmokhtar, J. Ball, J. A. Fleming, P. Campero Rojas, Alessandro Rizzo, P. Black, M. Leffel, M. Riallot, M. Battaglieri, Andrea Celentano, G. Miní, S. Procureur, M. Cook, P. Baron, R. Puppo, O. Meunier, R. Granelli, D. Besin, L. Lanza, M. Osipenko, M. Defurne, P. Pollovio, D. I. Glazier, R. De Vita, F. Bossu, M. Ripani, K. Livingston, C. Lahonde, Nicholas Zachariou, A. Acker, M. Taiuti, P. Bonneau, K. Hicks, C. Wiggins, M. Boyer, G. D. Smith, R. Boudouin, E. Virique, E. Fanchini, F. Pratolongo, A. D'Angelo, I. Stankovic, M. Bashkanov, B. McKinnon, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay
Subjects: tungsten: oxygen, Photon, Physics::Instrumentation and Detectors, Low-Q2 electron scattering, Electron, 01 natural sciences, photon: particle identification, MicroMegas, Instrumentation, Low-Q, Physics, forward spectrometer, PbWO4, Settore FIS/04, MicroMegas detector, PbWO 4, electron scattering, Low-Q 2 electron scattering, performance, Nuclear and High Energy Physics, PbWO, Gas tracking detector, SiPM, Hodoscope, Silicon photomultiplier, Optics, Electromagnetic calorimeter, Hadron spectroscopy, APD, 2, 4, Plastic scintillator, WLS fibers, 0103 physical sciences, scintillation counter: hodoscope, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Low-Q(2) electron scattering, 010306 general physics, detector: design, activity report, Scintillation, lead, Spectrometer, electron: particle identification, 010308 nuclear & particles physics, business.industry, calorimeter: electromagnetic, business
Abstract: This document presents the technical layout and the performance of the CLAS12 Forward Tagger (FT). The FT, composed of an electromagnetic calorimeter based on PbWO4 crystals (FT-Cal), a scintillation hodoscope (FT-Hodo), and several layers of Micromegas trackers (FT-Trk), has been designed to detect electrons and photons scattered at polar angles from 2 ∘ to 5 ∘ and to meet the physics goals of the hadron spectroscopy program and other experiments running with the CLAS12 spectrometer in Hall B.
Published: 2020
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4. Beam–target helicity asymmetry $E$ in $K^+$ $\Sigma^-$ photoproduction on the neutron

Author: R. De Vita, D. Marchand, H. Atac, H. S. Jo, A. Filippi, L. Marsicano, N. K. Walford, O. Soto, M. Khandaker, I. J. D. MacGregor, K. Hicks, W. Phelps, R. A. Schumacher, Michael Paolone, H. Hakobyan, W. Kim, G. Charles, F. Bossu, H. Lu, S. Joosten, J. W. Price, S. Diehl, C. Salgado, William Brooks, L. Venturelli, D. Heddle, V. P. Kubarovsky, I. Bedlinskiy, Z. E. Meziani, V. Mascagna, A. Celentano, R. W. Gothe, N. Markov, Alessandro Rizzo, W. Gohn, G. Asryan, Axel Schmidt, Dustin Keller, M. Ungaro, M. Guidal, M. Contalbrigo, M. Osipenko, Z. W. Zhao, Fatiha Benmokhtar, E. L. Isupov, Y. Prok, J. Poudel, O. Pogorelko, A. I. Ostrovidov, K. Park, M. J. Amaryan, Michael Wood, K. Hafidi, M. Holtrop, M. Ehrhart, C.D. Bass, V. A. Nikonov, A. D'Angelo, D. G. Jenkins, D. G. Ireland, G. Rosner, S. Boiarinov, E. Golovatch, P. Eugenio, K. Livingston, Luciano Pappalardo, K. Joo, M. Leali, Jie Zhang, T. Kageya, Volker D. Burkert, Y. Ghandilyan, A. S. Biselli, C. W. Kim, G. Gavalian, U. Shrestha, F.-X. Girod, Gerard Gilfoyle, M. Ripani, R. G. Fersch, H. Voskanyan, A. El Alaoui, G. Angelini, Nicholas Zachariou, J. C. Carvajal, W. J. Briscoe, P. L. Cole, T. Chetry, N. Gevorgyan, D. Ho, I. I. Strakovsky, A. M. Sandorfi, A. Deur, Victor Mokeev, D. Sokhan, T. R. O'Connell, Chaden Djalali, P. Nadel Turonski, T. Mineeva, M. Bashkanov, S. Adhikari, D. Bulumulla, E. Munevar, B. McKinnon, B. S. Ishkhanov, Aditya R. Khanal, Andrea Bianconi, I. Zonta, X. Wei, P. Peng, Hovanes Egiyan, C. Munoz Camacho, P. Lenisa, M. Hattawy, J. A. Fleming, Friedrich Klein, Brian Raue, Andrew Puckett, E. Voutier, Martin K. Mayer, M. Khachatryan, K. A. Griffioen, Nikolaos Sparveris, K. P. Adhikari, C. S. Whisnant, C. Hanretty, L. Lanza, R. Dupre, M. Battaglieri, M. Lowry, S. Strauch, Eugene Pasyuk, N. Dashyan, Yordanka Ilieva, L. Barion, G. Ciullo, D. S. Carman, S. Fegan, D. P. Watts, A. V. Sarantsev, N. Tyler, J. A. Tan, P. Chatagnon, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: Nuclear and High Energy Physics, Socio-culturale, nucleon resonance, Nucleons, Photoproduction, Mesons, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, K+: photoproduction, Particle identification, Nuclear physics, chemistry.chemical_compound, PE2_2, PE2_1, CLAS, 0103 physical sciences, Neutron, Hydrogen deuteride, n: target, 010306 general physics, Nuclear Experiment, PE2_3, photon: beam, Physics, 010308 nuclear & particles physics, nucleus: target, Settore FIS/04, Resonance, helicity: asymmetry, Observable, Sigma-: photoproduction, Helicity, lcsh:QC1-999, chemistry, Excited state, spectrometer, Nucleon, lcsh:Physics, Jefferson Lab, experimental results
Abstract: We report a measurement of a beam–target double-polarisation observable (E) for the γ→n→(p)→K+Σ−(p) reaction. The data were obtained impinging the circularly-polarised energy-tagged photon beam of Hall B at Jefferson Lab on a longitudinally-polarised frozen-spin hydrogen deuteride (HD) nuclear target. The E observable for an effective neutron target was determined for centre-of-mass energies 1.70≤W≤2.30 GeV, with reaction products detected over a wide angular acceptance by the CLAS spectrometer. These new double-polarisation data give unique constraints on the strange decays of excited neutron states. Inclusion of the new data within the Bonn-Gatchina theoretical model results in significant changes for the extracted photocouplings of a number of established nucleon resonances. Possible improvements in the PWA description of the experimental data with additional “missing” resonance states, including the N(2120)3/2− resonance, are also quantified.
Published: 2020
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5. The CLAS12 Spectrometer at Jefferson Laboratory

Author: C. W. Kim, H. Avakian, D. Protopopescu, D. Heddle, M. Contalbrigo, M. L. Kabir, H. Voskanyan, E. Voutier, T. Chetry, M. Zarecky, J. Poudel, I. Illari, B. A. Clary, M. Osipenko, D. Insley, D. P. Watts, I. Bedlinskiy, Michael Paolone, V. Sergeyeva, D. Kashy, M. Khachatryan, F. Hauenstein, V. Mascagna, Nikolaos Sparveris, F. Bossu, D. Marchand, W. Kim, G. Niculescu, P. Bonneau, G. Charles, P. Hemler, Ruben J. Fair, P. Moran, Dustin Keller, C. Ayerbe Gayoso, Nicholas Zachariou, M. Ungaro, C. Munoz Camacho, M. J. Amaryan, G. Rosner, I. J. D. MacGregor, T. A. Forest, V. Lucherini, S. E. Kuhn, Y. Prok, M. Hattawy, S. Stepanyan, Michael Wood, K. Hafidi, M. D. Mestayer, S. Lee, M. Wiseman, F. Sabatié, R. Paremuzyan, N. Dashyan, A. Deur, K. Hicks, K. Joo, E. L. Isupov, N. A. Baltzell, R. W. Gothe, S. Christo, L. C. Smith, B. S. Ishkhanov, Latifa Elouadrhiri, V. Baturin, Nicholas M. Harrison, Gerard Gilfoyle, M. McMullen, G. E. Dodge, H. S. Jo, R. Johnston, A. Yegneswaran, K. Livingston, A. Lung, P. Stoler, M. Guidal, D. Sokhan, K. Price, Aditya R. Khanal, K. P. Adhikari, Jie Zhang, K. Bruhwel, S. Adhikari, S. Boyarinov, B. McKinnon, M. Ehrhart, M. Leali, Z. W. Zhao, S. Joosten, B. J. Roy, V. P. Kubarovsky, J. Newton, P. Chatagnon, G. V. Fedotov, D. Tilles, M.A. Antonioli, Renuka Rajput-Ghoshal, G. D. Smith, M. Holtrop, C. Cuevas, V. Gyurjyan, Probir K. Ghoshal, Yordanka Ilieva, H. Hakobyan, Alexander Schmidt, Luciano Pappalardo, Andrea Bianconi, W. J. Briscoe, M. Turisini, M. Mirazita, D. I. Glazier, M. Garçon, M. Ripani, F. X. Girod, A. Filippi, K. L. Giovanetti, R. Miller, J. Ritman, S. Diehl, R. De Vita, C. D. Keith, Y. G. Sharabian, M. Lowry, M. Defurne, E. Pasyuk, P. Naidoo, J. Hogan, N. Markov, Or Hen, C. Salgado, M. Taylor, G. Young, S. Strauch, Larry Weinstein, H. Atac, Chaden Djalali, A. Hobart, A. Kim, Z. E. Meziani, S. Schadmand, U. Shrestha, T. Ewing, T. Mineeva, O. Pogorelko, S. Nanda, L. Barion, G. Angelini, J. Rowley, P. Rossi, M. Leffel, William Brooks, I. Mandjavidze, L. Venturelli, Iu. Skorodumina, Y. Gotra, C. Mealer, J. W. Price, S. Aune, C. Wiggins, D. G. Ireland, G. Gavalian, G. Jacobs, V. Crede, Volker D. Burkert, A. S. Biselli, O. Pastor, Victor Mokeev, E.P. Segarra, Ross Milner, N. Tyler, J. A. Tan, E. Golovatch, R. Dupre, W. Phelps, Andrea Celentano, S. Procureur, M. Cook, G. Ciullo, M. Battaglieri, D. S. Carman, B. Raydo, A. Rizzo, X. Wei, R. Cruz-Torres, S. Niccolai, K. A. Griffioen, B. Eng, A. Movsisyan, P. L. Cole, L. Lanza, G. Christiaens, A. D'Angelo, T. Kageya, L. El Fassi, P. Lenisa, V. Ziegler, C. Hanretty, D. Anderson, T. B. Hayward, Brian Raue, Fatiha Benmokhtar, O. Soto, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), 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), 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: Physics::Instrumentation and Detectors, data acquisition, magnet: solenoid, superconductivity: torus, Solenoid, 01 natural sciences, Particle identification, Luminosity, momentum resolution, electron: beam, Nuclear Experiment, Instrumentation, QC, Physics, Luminosity (scattering theory), Settore FIS/04, Detector, Magnetic spectrometer, magnet: torus, performance, Nuclear and High Energy Physics, Meson, vertex detector, nucleon: interaction, CLAS12, Electromagnetic physics, Large acceptance, Socio-culturale, fabrication, beam: energy, Nuclear physics, PE2_1, CLAS, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, PE2_3, scintillation counter, Cherenkov radiation, detector: design, activity report, Spectrometer, 010308 nuclear & particles physics, nucleus, CLAS12, Electromagnetic physics, Large acceptance, Luminosity, Magnetic spectrometer, magnet: superconductivity, magnetic spectrometer, electromagnetic physics, large acceptance, luminosity, neutral particle, Automatic Keywords, calorimeter: electromagnetic, Cherenkov counter, spectrometer, particle identification, Beam (structure)
Abstract: International audience; The CEBAF Large Acceptance Spectrometer for operation at 12 GeV beam energy (CLAS12) in Hall B at Jefferson Laboratory is used to study electro-induced nuclear and hadronic reactions. This spectrometer provides efficient detection of charged and neutral particles over a large fraction of the full solid angle. CLAS12 has been part of the energy-doubling project of Jefferson Lab’s Continuous Electron Beam Accelerator Facility, funded by the United States Department of Energy. An international collaboration of 48 institutions contributed to the design and construction of detector hardware, developed the software packages for the simulation of complex event patterns, and commissioned the detector systems. CLAS12 is based on a dual-magnet system with a superconducting torus magnet that provides a largely azimuthal field distribution that covers the forward polar angle range up to 35 ∘ , and a solenoid magnet and detector covering the polar angles from 35° to 125° with full azimuthal coverage. Trajectory reconstruction in the forward direction using drift chambers and in the central direction using a vertex tracker results in momentum resolutions of < 1% and < 3%, respectively. Cherenkov counters, time-of-flight scintillators, and electromagnetic calorimeters provide good particle identification. Fast triggering and high data-acquisition rates allow operation at a luminosity of 1035 cm −2 s −1 . These capabilities are being used in a broad program to study the structure and interactions of nucleons, nuclei, and mesons, using polarized and unpolarized electron beams and targets for beam energies up to 11 GeV. This paper gives a general description of the design, construction, and performance of CLAS12.
Published: 2020
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6. Semi-inclusive π0 target and beam-target asymmetries from 6 GeV electron scattering with CLAS

Author: P. Lenisa, W. Kim, R. Dupre, M. Battaglieri, G. Niculescu, G. Rosner, K. Livingston, M. Hattawy, Friedrich Klein, Y. Ghandilyan, A. Filippi, X. Wei, Brian Raue, M. Khandaker, M. J. Amaryan, V. I. Mokeev, D. Heddle, K. L. Giovanetti, Larry Weinstein, G. Hollis, R. A. Schumacher, Jie Zhang, K. A. Griffioen, Dustin Keller, C. Hanretty, N. Guler, G. Khachatryan, A. Celentano, R. W. Gothe, D. P. Watts, P. Nadel-Turonski, Michael Wood, Taya Chetry, W. J. Briscoe, H. Egiyan, M. Ungaro, Laura Clark, L. Lanza, S. Bültmann, M. E. McCracken, Sergey Kuleshov, K. P. Adhikari, T. A. Forest, C. Carlin, H. Avakian, F. X. Girod, S. Pisano, B. S. Ishkhanov, Sylvester Joosten, P. Eugenio, F. Cao, P. Bosted, P. Rossi, S. Strauch, D. Adikaram, E. De Sanctis, M. Guidal, M. Taiuti, J. Brock, C. Munoz Camacho, K. Joo, H. Hakobyan, D. Protopopescu, G. D. Smith, M. Holtrop, W. Phelps, V. Crede, C. Salgado, D. I. Sober, M. Garçon, J. Pierce, E. Voutier, S. Adhikari, B. McKinnon, Avraham Klein, R. A. Montgomery, C. Djalali, H. Voskanyan, Maxime Defurne, I. Bedlinskiy, L. Colaneri, O. Cortes, M. Mirazita, E. Phelps, H. Y. Lu, E. L. Isupov, E. Pasyuk, V. Batourine, R. De Vita, A. El Alaoui, S. Boiarinov, Nicholas Zachariou, A. D'Angelo, R. Paremuzyan, S. Anefalos Pereira, Nicholas M. Harrison, Gerard Gilfoyle, A. Kim, D. Sokhan, N. Markov, N. A. Baltzell, L. El Fassi, J. W. Price, I. Niculescu, V. P. Kubarovsky, Z. W. Zhao, K. Hicks, D. Riser, C. D. Keith, A. I. Ostrovidov, L. Guo, Alessandro Rizzo, O. Pogorelko, S. M. Hughes, K. Park, G. Ddoge, D. G. Ireland, I. Stankovic, T. Mineeva, H. Jiang, R. G. Fersch, Volker D. Burkert, A. S. Biselli, William Brooks, P. L. Cole, S. Koirala, A. Fradi, M. Osipenko, M. Contalbrigo, D. G. Jenkins, Iu. Skorodumina, Z. Akbar, G. Charles, A. Simonyan, F. Sabatié, N. K. Walford, S. S. Jawalkar, I. J. D. MacGregor, W. Gohn, E. Golovatch, A. Deur, L. A. Net, Latifa Elouadrhiri, C. A. Meyer, Y. G. Sharabian, G. V. Fedotov, N. Dashyan, S. E. Kuhn, Yordanka Ilieva, J. A. Fleming, Martin K. Mayer, M. Khachatryan, S. Fegan, C. Gleason, G. Ciullo, J. P. Ball, Y. Prok, D. S. Carman, Nikos Sparveris, S. Niccolai, A. Movsisyan, M. Ripani, E. Seder, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), CLAS, 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: Single spin asymmetries, Hadron, fragmentation function, 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, transverse momentum: momentum spectrum, Collins, hadron: production, Nuclear Experiment, Spin-½, Physics, deep inelastic scattering: semi-inclusive reaction, suppression, Collins fragmentation, hadron: energy, lcsh:QC1-999, Double spin asymmetries, Semi-inclusive deep-inelastic scattering, Transverse momentum distributions, High Energy Physics - Phenomenology, transverse, electron: scattering, cryogenics, spin: asymmetry, Jefferson Lab, Nuclear and High Energy Physics, pi: momentum, Quark, Socio-culturale, quark gluon: correlation, lepton: scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], quark, pi: electroproduction, Nuclear physics, Pion, target: spin, deep inelastic scattering, CLAS, 0103 physical sciences, 010306 general physics, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Deep inelastic scattering, Gluon, Automatic Keywords, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, higher-dimensional, lcsh:Physics, experimental results, Lepton
Abstract: We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic $^{14}$NH$_3$ target, and extracted double and single target spin asymmetries for $ep\rightarrow e^\prime\pi^0X$ in multidimensional bins in four-momentum transfer ($1.0, Comment: 18 preprint pages, 3 figures
Published: 2018
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7. 12C(e,e'pN) measurements of short range correlations in the tensor-to-scalar interaction transition region

Author: M. J. Amaryan, P. Lenisa, Jie Zhang, A. Beck, L. Marsicano, T. B. Hayward, U. Shrestha, Larry Weinstein, S. Strauch, Maxime Defurne, K. A. Griffioen, D. P. Watts, Friedrich Klein, R. Paremuzyan, Brian Raue, O. Pogorelko, J. Rowley, A. I. Ostrovidov, R. A. Schumacher, F. X. Girod, M. Duer, A. Denniston, E. Golovatch, R. Dupre, Nicholas M. Harrison, R. De Vita, I. I. Strakovsky, P. Eugenio, A. Deur, W. K. Brooks, A. Filippi, D. Sokhan, B. A. Clary, D. Protopopescu, Volker D. Burkert, A. S. Biselli, L. Lanza, M. Khandaker, N. Tyler, C. Djalali, E. Voutier, Michael Paolone, Y. G. Sharabian, X. Zheng, H. Atac, J. A. Tan, Y. Prok, D. S. Carman, I. Bedlinskiy, W. Phelps, V. Lucherini, M. Battaglieri, A. El Alaoui, Y. Ilieva, E. L. Isupov, Nicholas Zachariou, X. Wei, S. Mey-Tal Beck, S. Boiarinov, Hovanes Egiyan, F. Hauenstein, C. Munoz Camacho, J. W. Price, Taofeng Wang, Fatiha Benmokhtar, M. Khachatryan, Nikolaos Sparveris, N. Markov, A. Movsisyan, R. Cruz-Torres, T. A. Forest, O. Soto, D. Heddle, M. Ungaro, K. P. Adhikari, Douglas Higinbotham, Latifa Elouadrhiri, D. Marchand, P. Nadel-Turonski, S. Adhikari, B. McKinnon, M. Ripani, A. Kim, S. Stepanyan, I. Korover, M. Hattawy, M. Guidal, B. Mustapha, Z. W. Zhao, T. Mineeva, Or Hen, H. Hakobyan, M. Mirazita, J. Ritman, L. Barion, J.R. Pybus, M. Holtrop, S. Diehl, R. G. Fersch, C. Salgado, K. Joo, Luciano Pappalardo, T. Chetry, E.P. Segarra, H. S. Jo, D. G. Jenkins, M. Leali, Eugene Pasyuk, P. L. Cole, M. Ehrhart, G. Rosner, P. Chatagnon, A. D'Angelo, L. El Fassi, V. P. Kubarovsky, L. Venturelli, Krishna Neupane, C. W. Kim, H. Voskanyan, W. J. Briscoe, Dustin Keller, E. Piasetzky, D. Bulumulla, Michael Wood, K. Hafidi, Aditya R. Khanal, Andrea Bianconi, G. Niculescu, Alexander Schmidt, G. Gavalian, M. Osipenko, I. J. D. MacGregor, F. Sabatié, D. G. Ireland, V. Crede, M. Contalbrigo, Laura Clark, G. Angelini, K. Hicks, A. Celentano, R. W. Gothe, Alessandro Rizzo, V. Mascagna, S. Joosten, K. Livingston, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and The Clas Collaboration
Subjects: Nuclear and High Energy Physics, Nuclear Theory, dependence, CLAS, dynamics, isospin, energy, system, Astronomy & Astrophysics, Physics, QC1-999, Scalar (mathematics), FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Astrophysics, 01 natural sciences, Nuclear Theory (nucl-th), Momentum, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, ddc:530, Tensor, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, Nuclear theory, [PHYS]Physics [physics], Range (particle radiation), 010308 nuclear & particles physics, Settore FIS/04, Nuclear interaction, High Energy Physics - Phenomenology, Astronomy &amp, Atomic physics, Nucleon
Abstract: High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the $^{12}$C$(e,e'p)$ and $^{12}$C$(e,e'pN)$ reactions (where $N$ is either $n$ or $p$), at high-$Q^2$ and $x_B>1.1$. The data span a missing-momentum range of 300--1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon ($NN$) interaction models. This agreement suggests that the measured high missing-momentum protons up to $1000$ MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured $^{12}$C$(e,e'pN)$ / $^{12}$C$(e,e'p)$ and $^{12}$C$(e,e'pp)$ / $^{12}$C$(e,e'pn)$ cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor $NN$ interaction at $\sim 400$ MeV/c to an isospin-independent scalar interaction at high-momentum around $\sim 800$ MeV/c as predicted by theoretical calculation., Accepted for publication in Physics Letters B. 7 pages, 3 figures, and online supplementary materials
Published: 2021
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8. Photon beam asymmetry Σ in the reaction γ→p→pω for E= 1.152 to 1.876 GeV

Author: G. Khachatryan, W. Kim, M. Battaglieri, N. K. Walford, G. Niculescu, L. Lanza, Michael Paolone, M. Bashkanov, S. Adhikari, H. Avakian, F. X. Girod, W. J. Briscoe, Laura Clark, B. McKinnon, P. Lenisa, T. Cao, M. Ungaro, I. J. D. MacGregor, F. Sabatié, I. I. Strakovsky, H. Voskanyan, A. Kim, E. De Sanctis, V. A. Nikonov, A. Deur, E. Pasyuk, J. W. Price, N. Dashyan, C. Gleason, G. Rosner, K. Hicks, V. Mokeev, P. Nadel-Turonski, V. Batourine, I. Bedlinskiy, D. I. Sober, S. Strauch, V. Crede, William Brooks, Dustin Keller, M. Defurne, Y. Ghandilyan, D. P. Watts, Barry Ritchie, Brian Raue, Alessandro Rizzo, C. Hanretty, H. Egiyan, E. Golovatch, R. Dupre, R. A. Montgomery, A. Celentano, R. W. Gothe, M. Khachatryan, Sylvester Joosten, B. S. Ishkhanov, G. Charles, Michael Wood, J. Ball, K. Hafidi, W. Phelps, H. S. Jo, A. V. Sarantsev, G. Ciullo, Y. Prok, D. I. Glazier, D. S. Carman, A. Simonyan, O. Cortes, N. A. Baltzell, C. Munoz Camacho, Nikos Sparveris, F. J. Klein, M. Ripani, M. Contalbrigo, Z. E. Meziani, E. L. Isupov, S. Niccolai, D. G. Jenkins, M. Osipenko, K. A. Griffioen, R. Paremuzyan, Eberhard Klempt, S. Boiarinov, N. Markov, V. P. Kubarovsky, A. Movsisyan, R. De Vita, Nicholas M. Harrison, O. Pogorelko, Gerard Gilfoyle, J. Zhang, S. M. Hughes, X. Wei, S. Pisano, D. Sokhan, I. Stankovic, A. V. Anisovich, C. A. Meyer, Z. Akbar, G. V. Fedotov, I. Niculescu, C. Salgado, P. L. Cole, A. I. Ostrovidov, K. Park, R. A. Schumacher, D. G. Ireland, H. Jiang, H. Hakobyan, S. Anefalos Pereira, Volker D. Burkert, A. S. Biselli, L. El Fassi, K. P. Adhikari, S. Stepanyan, E. Munevar, L. A. Net, Avraham Klein, Y. G. Sharabian, J. A. Fleming, Iu. Skorodumina, D. Heddle, G. Hollis, P. Eugenio, M. Taiuti, P. Collins, S. Procureur, K. L. Giovanetti, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, A. Filippi, M. Khandaker, K. Livingston, M. Hattawy, D. Protopopescu, Z. W. Zhao, E. Voutier, Chaden Djalali, Michael Dugger, T. Mineeva, F. Cao, D. Adikaram, M. Guidal, G. D. Smith, M. Holtrop, Taya Chetry, and Sergey Kuleshov
Subjects: Physics, Nuclear and High Energy Physics, Photon, Meson, Proton, 010308 nuclear & particles physics, Partial wave analysis, Bremsstrahlung, Photon energy, 01 natural sciences, Nuclear physics, Pomeron, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: Photon beam asymmetry Σ measurements for ω photoproduction in the reaction γ → p → ω p are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between t-channel meson exchange and s- and u-channel contributions, underscoring sensitivity to the nucleon resonances included in those descriptions. Comparisons with the Bonn–Gatchina partial-wave analysis indicate the Σ data reported here help to fix the magnitudes of the interference terms between the leading amplitudes in that calculation (Pomeron exchange and the resonant portion of the J P = 3 / 2 + partial wave), as well as the resonant portions of the smaller partial waves with J P = 1 / 2 − , 3 / 2 − , and 5 / 2 + .
Published: 2017
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9. Measurement of Nuclear Transparency Ratios for Protons and Neutrons

Author: M. Patsyuk, R. Paremuzyan, Nicholas M. Harrison, Gerard Gilfoyle, P. Eugenio, M. Taiuti, P. Lenisa, O. Soto, D. Sokhan, N. Dashyan, M. Battaglieri, Y. G. Sharabian, T. B. Hayward, X. Zheng, F. X. Girod, S. Kuleshov, J. W. Price, J. A. Tan, Friedrich Klein, V. Crede, Taya Chetry, Brian Raue, D. Marchand, Or Hen, Michael Paolone, S. Strauch, D. Heddle, Iu. Skorodumina, A. Beck, L. Barion, M. Khachatryan, Hovanes Egiyan, C. Munoz Camacho, A. I. Ostrovidov, R. De Vita, H. S. Jo, Nikolaos Sparveris, R. A. Montgomery, D. Payette, D. G. Ireland, K. Livingston, K. A. Griffioen, Volker D. Burkert, R. Cruz Torres, A. S. Biselli, I. Bedlinskiy, P. Nadel-Turonski, S. Adhikari, Eli Piasetzky, B. McKinnon, H. Hakobyan, W. K. Brooks, Dinko Pocanic, P. Chatagnon, F. Sabatié, F. Cao, I. Korover, M. Duer, R. A. Schumacher, S. Diehl, C. Salgado, M. Guidal, S. E. Kuhn, M. Hattawy, M. Mirazita, B. Duran, B. Mustapha, X. Wei, Sylvester Joosten, L. Lanza, G. Laskaris, Jie Zhang, T. A. Forest, E. De Sanctis, S. Mey-Tal Beck, M. Holtrop, A. Filippi, M. Ripani, S. Stepanyan, Avraham Klein, Luciano Pappalardo, M. Khandaker, Axel Schmidt, E. L. Isupov, Chaden Djalali, T. Mineeva, S. Boiarinov, G. Ciullo, Y. Prok, A. Deur, D. S. Carman, Sandra K. Johnston, E.P. Segarra, O. Cortes, Larry Weinstein, Eliahu Cohen, S. Niccolai, E. Golovatch, A. El Alaoui, Y. Ilieva, R. Dupre, Victor Mokeev, A. Movsisyan, Nicholas Zachariou, D. Protopopescu, Z. W. Zhao, E. Voutier, B. Schmookler, G. Angelini, B. S. Ishkhanov, M. Ungaro, P. Rossi, Aditya R. Khanal, K. Joo, A. Kim, M. Ehrhart, Dustin Keller, K. Hafidi, H. Avakian, H. Voskanyan, W. J. Briscoe, E. Pasyuk, V. P. Kubarovsky, D. Riser, O. Pogorelko, G. Khachatryan, G. Rosner, P. L. Cole, L. Guo, Alessandro Rizzo, C. Hanretty, A. D'Angelo, M. Osipenko, W. Kim, G. Niculescu, L. El Fassi, C. Ayerbe Gayoso, Rong Wang, A. Celentano, R. W. Gothe, F. Hauenstein, I. J. D. MacGregor, M. Contalbrigo, 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CLAS, 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: Nuclear and High Energy Physics, Nuclear Theory, Proton, nucleon: pair, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, Socio-culturale, short-range, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear Theory (nucl-th), Nuclear physics, approximation: Glauber, CLAS, fragmentation, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Nuclear theory, Physics, n: momentum, 010308 nuclear & particles physics, Settore FIS/04, Neutron, Nuclear Transparency, Hadron physics, Proton, Breakup, lcsh:QC1-999, Nuclear transparency, kinematics, Nuclear Transparency, Nucleon, Hadron physics, Glauber, nucleus: transparency, lcsh:Physics, experimental results
Abstract: This paper presents, for the first time, measurements of neutron transparency ratios for nuclei relative to C measured using the (e,e'n) reaction, spanning measured neutron momenta of 1.4 to 2.4 GeV/c. The transparency ratios were extracted in two kinematical regions, corresponding to knockout of mean-field nucleons and to the breakup of Short-Range Correlated nucleon pairs. The extracted neutron transparency ratios are consistent with each other for the two measured kinematical regions and agree with the proton transparencies extracted from new and previous (e,e'p) measurements, including those from neutron-rich nuclei such as lead. The data also agree with and confirm the Glauber approximation that is commonly used to interpret experimental data. The nuclear-mass-dependence of the extracted transparencies scales as A^{\alpha} with {\alpha} = -0.289 {\pm} 0.007, which is consistent with nuclear-surface dominance of the reactions., Comment: Accepted for publication in Physics Letters B
Published: 2019
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10. Measurement of the beam-helicity asymmetry in photoproduction of π0η pairs on carbon, aluminum, and lead

Author: R. A. Miskimen, A. G. Denig, Durga Paudyal, M. Wolfes, I. Keshelashvili, Yu. A. Usov, O. Steffen, K. Spieker, P. Pedroni, Susanna Costanza, P. Aguar-Bartolomé, Concettina Sfienti, A. N. Mushkarenkov, M. Ostrick, D. G. Middleton, M. Günther, S. Garni, A. Powell, I. Supek, A. Käser, R. Beck, I. Gorodnov, M. Unverzagt, V. L. Kashevarov, F. Cividini, Roderick M. Macrae, L. V. Fil'kov, P. Adlarson, M. Oberle, S. Abt, E. J. Downie, Patrick Achenbach, D. P. Watts, S. Cherepnya, A. J. Sarty, K. Bantawa, G. M. Huber, Z. Ahmed, S. Kay, I. I. Strakovsky, T. Rostomyan, K. Livingston, S. Lutterer, B. Strandberg, S. Gardner, N. S. Borisov, C. Mullen, Guy Ron, D. I. Glazier, S. Wagner, H. J. Arends, W. J. Briscoe, A. B. Lazarev, Michaela Thiel, A. Neiser, A. Fix, A. Braghieri, Th. Strub, P. Drexler, F. Afzal, A. B. Neganov, Nicholas Zachariou, W. Gradl, J. Wettig, J. C. McGeorge, V. Sokhoyan, P. P. Martel, J. R. M. Annand, D. Hornidge, E. Mornacchi, I. J. D. MacGregor, M. Korolija, David Manley, N. K. Walford, B. Krusche, K. Altangerel, E. Rickert, M. Biroth, P. B. Otte, R. Kondratiev, G. M. Gurevich, S. N. Prakhov, Lilian Witthauer, M. Dieterle, Lena Heijkenskjöld, M. I. Ferretti Bondy, Andy Thomas, A. Thiel, D. Werthmüller, C. Collicott, and M. Bashkanov
Subjects: Nuclear and High Energy Physics, Proton, media_common.quotation_subject, Nuclear Theory, chemistry.chemical_element, 7. Clean energy, 01 natural sciences, Asymmetry, Nuclear physics, Aluminium, 0103 physical sciences, Intermediate state, Nuclear Experiment, 010306 general physics, QC, media_common, Physics, 010308 nuclear & particles physics, Helicity, lcsh:QC1-999, 3. Good health, chemistry, High Energy Physics::Experiment, Nucleon, Carbon, lcsh:Physics, Beam (structure)
Abstract: The beam-helicity asymmetry was measured, for the first time, in photoproduction of $\pi^{0}\eta$ pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The results are compared to an earlier measurement on a free proton and to the corresponding theoretical calculations. The Mainz model is used to predict the beam-helicity asymmetry for the nuclear targets. The present results indicate that the photoproduction mechanism for $\pi^{0}\eta$ pairs on nuclei is similar to photoproduction on a free nucleon. This process is dominated by the $D_{33}$ partial wave with the $\eta\Delta(1232)$ intermediate state., Comment: Accepted for publication in Physics Letters B (2020)
Published: 2020
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11. Differential cross section for γd → ωd using CLAS at Jefferson Lab

Author: R. W. Gothe, I. J. D. MacGregor, M. Contalbrigo, K. A. Griffioen, S. Adhikari, S. Strauch, V. Crede, Taya Chetry, A. Filippi, I. I. Strakovsky, A. Deur, G. Ciullo, J. P. Ball, Y. Prok, D. S. Carman, Nikos Sparveris, E. Voutier, Misak Sargsian, M. Khandaker, L. Lanza, S. Niccolai, A. El Alaoui, Y. Ilieva, N. Compton, A. Movsisyan, M. Khachatryan, E. De Sanctis, Nicholas Zachariou, I. Bedlinskiy, W. K. Brooks, B. McKinnon, E. L. Isupov, M. Battaglieri, Iu. Skorodumina, P. Eugenio, M. Osipenko, M. Taiuti, R. A. Schumacher, Laura Clark, P. Lenisa, D. I. Sober, S. Boiarinov, M. L. Kabir, G. Charles, A. Kim, K. Livingston, M. Hattawy, A. D'Angelo, E. Golovatch, D. G. Jenkins, G. D. Smith, R. Dupre, N. Markov, Jie Zhang, M. Holtrop, Friedrich Klein, K. L. Giovanetti, Andrea Celentano, S. Stepanyan, Larry Weinstein, G. V. Fedotov, R. De Vita, C. Salgado, V. Batourine, L. El Fassi, P. Nadel-Turonski, N. Dashyan, G. Gavalian, V. Mokeev, Z. W. Zhao, R. Paremuzyan, Nicholas M. Harrison, F. X. Girod, L. Barion, S. Johnston, J. W. Price, M. Ripani, B. A. Clary, Michael Paolone, Barry Ritchie, A. I. Ostrovidov, K. Park, D. G. Ireland, Volker D. Burkert, A. S. Biselli, C. Djalali, J. A. Tan, D. Sokhan, W. Kim, C. Munoz Camacho, G. Niculescu, R. G. Fersch, P. L. Cole, M. Ungaro, H. Voskanyan, B. S. Ishkhanov, E. Pasyuk, V. P. Kubarovsky, D. Riser, O. Pogorelko, I. Balossino, G. Khachatryan, Dustin Keller, W. J. Briscoe, Michael Wood, K. Hafidi, L. Guo, Alessandro Rizzo, K. Hicks, W. Phelps, G. Rosner, and Y. Ghandilyan
Subjects: Vector Meson Dominance, Nuclear and High Energy Physics, Meson, Nuclear Theory, Socio-culturale, Double scattering, Photon energy, 01 natural sciences, 7. Clean energy, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Cross section (physics), 0103 physical sciences, 010306 general physics, Nuclear Experiment, Physics, Range (particle radiation), 010308 nuclear & particles physics, Scattering, Momentum transfer, Differential cross section, Single scattering, Vector meson dominance, lcsh:QC1-999, Deuterium, High Energy Physics::Experiment, lcsh:Physics
Abstract: The cross section for coherent ω-meson photoproduction off the deuteron has been measured for the first time as a function of the momentum transfer t=(Pγ−Pω)2 and photon energy Eγ using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cross sections are measured in the energy range 1.4
Published: 2018

12. Measurement of Unpolarized and Polarized Cross Sections for Deeply Virtual Compton Scattering on the Proton at Jefferson Laboratory with CLAS

Author: F. Cao, W. Phelps, M. Guidal, E. Pasyuk, N. Dashyan, P. Lenisa, Andrea Celentano, M. Holtrop, S. Procureur, W. Gohn, S. E. Kuhn, G. Charles, M. J. Amaryan, H. S. Jo, H. Y. Lu, H. Voskanyan, B. McKinnon, Iu. Skorodumina, Friedrich Klein, Z. W. Zhao, A. I. Ostrovidov, R. A. Montgomery, Y. Prok, F. Sabatié, David M. Keller, Maxime Defurne, B. Guegan, K. A. Griffioen, H. Hakobyan, P. Stoler, A. Kim, M. Mirazita, A. El Alaoui, A. Filippi, N. Markov, A. Fradi, Latifa Elouadrhiri, X. Wei, G. Rosner, Taya Chetry, C. A. Meyer, I. Balossino, N. Gevorgyan, S. Johnston, K. L. Giovanetti, E. L. Isupov, G. V. Fedotov, K. Hicks, Y. Ghandilyan, Nicholas Zachariou, P. Eugenio, G. Niculescu, V. Batourine, D. G. Ireland, Sergey Kuleshov, M. Ripani, A. Deur, L. Guo, T. Mineeva, K. P. Adhikari, J. A. Tan, M. L. Kabir, S. Niccolai, Volker D. Burkert, W. K. Brooks, D. P. Watts, B. S. Ishkhanov, S. Adhikari, A. S. Biselli, D. Heddle, M. Battaglieri, C. Gleason, M. Khachatryan, D. G. Jenkins, M. Ungaro, R. De Vita, G. Khachatryan, E. Golovatch, R. Dupre, K. Park, Y. Ilieva, Nikolaos Sparveris, L. Lanza, R. W. Gothe, W. Kim, I. Bedlinskiy, K. Livingston, C. Munoz Camacho, M. Hattawy, R. A. Schumacher, M. Osipenko, P. Rossi, W. J. Briscoe, A. D'Angelo, R. G. Fersch, V. P. Kubarovsky, P. Nadel-Turonski, D. Riser, M. Khandaker, S. Stepanyan, R. Paremuzyan, K. Hafidi, S. Bültmann, T. A. Forest, P. L. Cole, Sylvester Joosten, O. Pogorelko, S. Diehl, S. Anefalos Pereira, Avraham Klein, Nicholas M. Harrison, Gerard Gilfoyle, J. W. Price, I. J. D. MacGregor, M. Contalbrigo, Martin Wood, C. Hanretty, L. Barion, C. Salgado, M. Taiuti, J. Zhang, D. Protopopescu, Victor Mokeev, Z. Akbar, M. Garçon, E. Voutier, Y. G. Sharabian, G. Ciullo, J. P. Ball, D. S. Carman, A. Rizzo, A. Movsisyan, L. El Fassi, Zein-Eddine Meziani, M. E. McCracken, F. X. Girod, O. Cortes, S. Boiarinov, Chaden Djalali, G. D. Smith, S. Strauch, G. Gavalian, B. A. Clary, N. Hirlinger Saylor, Michael Paolone, N. A. Baltzell, K. Joo, H. Egiyan, 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CLAS, 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: electron p: deep inelastic scattering, interference: Bethe-Heitler, Nuclear and High Energy Physics, generalized parton distribution, Proton, accelerator, electron: polarized beam, Hadronic Physics and QCD, FOS: Physical sciences, Socio-culturale, parton: distribution function, Parton, Newport News CEBAF Linac, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], momentum transfer dependence, 01 natural sciences, beam: energy, High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare, x-dependence, Nuclear physics, Cross section (physics), High Energy Physics - Experiment (hep-ex), spectrometer: acceptance, High Energy Physics - Phenomenology (hep-ph), deeply virtual Compton scattering, CLAS, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Quantum chromodynamics, Physics, Spectrometer, 010308 nuclear & particles physics, Compton scattering, cross section: difference, HERA, magnetic spectrometer, photon: electroproduction, High Energy Physics - Phenomenology, kinematics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Nucleon, channel cross section: measured, experimental results
Abstract: This paper reports the measurement of polarized and unpolarized cross sections for the ep -> e'p' reaction, which is comprised of Deeply Virtual Compton Scattering (DVCS) and Bethe-Heitler (BH) processes, at an electron beam energy of 5.88 GeV at the Thomas Jefferson National Accelerator Facility using the Large Acceptance Spectrometer CLAS. The unpolarized cross sections and polarized cross section differences have been measured over broad kinematics, 0.10 < x_B < 0.58, 1.0 < Q^2 < 4.8 GeV^2, and 0.09 < -t < 2.00 GeV^2. The results are found to be consistent with previous CLAS data, and these new data are discussed in the framework of the generalized parton distribution approach. Calculations with two widely used phenomenological models, denoted VGG and KMSC, are approximately compatible with the experimental results over a large portion of the kinematic range of the data., 27 pages, 24 figures, Accepted for publication in PRC
Published: 2018
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13. First measurement of $\Xi^-$ polarization in photoproduction

Author: K. Livingston, M. Hattawy, Taya Chetry, Jie Zhang, A. Kim, L. Guo, Alessandro Rizzo, W. Kim, G. Niculescu, R. Paremuzyan, Lorenzo Zana, N. Dashyan, Nicholas M. Harrison, R. A. Schumacher, Maxime Defurne, Yordanka Ilieva, C. Djalali, J. A. Tan, K. A. Griffioen, C. Salgado, V. Crede, D. Sokhan, D. I. Glazier, L. Barion, P. Eugenio, Michael Dugger, R. A. Montgomery, R. De Vita, E. Golovatch, A. El Alaoui, M. Taiuti, Nicholas Zachariou, M. Osipenko, J. Bono, A. Fradi, M. L. Kabir, H. Egiyan, F. Cao, I. Bedlinskiy, Iu. Skorodumina, S. Stepanyan, G. Charles, M. Ungaro, E. L. Isupov, B. A. Clary, C. Munoz Camacho, G. Rosner, X. Wei, P. Lenisa, Y. Prok, S. Strauch, M. Battaglieri, F. Sabatié, W. Gohn, D. Protopopescu, Z. W. Zhao, N. Markov, K. Hicks, M. Bashkanov, S. Adhikari, B. McKinnon, W. Phelps, G. D. Smith, M. Holtrop, N. Gevorgyan, Avraham Klein, Y. Ghandilyan, Michael Paolone, A. Celentano, R. W. Gothe, I. I. Strakovsky, E. Voutier, Rong Wang, A. Deur, M. Khachatryan, G. Ciullo, J. P. Ball, M. C. Kunkel, A. I. Ostrovidov, K. Park, D. S. Carman, G. V. Fedotov, Nikos Sparveris, D. G. Ireland, Friedrich Klein, V. Batourine, Volker D. Burkert, A. S. Biselli, T. Mineeva, William Brooks, Brian Raue, K. P. Adhikari, F. X. Girod, G. Gavalian, Y. G. Sharabian, S. Johnston, M. Ripani, H. S. Jo, G. Khachatryan, M. Contalbrigo, J. W. Price, Z. Akbar, I. J. D. MacGregor, V. P. Kubarovsky, A. D'Angelo, O. Pogorelko, L. El Fassi, Dustin Keller, Michael Wood, K. Hafidi, M. J. Amaryan, P. L. Cole, H. Voskanyan, D. Heddle, E. Pasyuk, S. Diehl, A. Filippi, M. Khandaker, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), CLAS, Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, 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 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: Nuclear and High Energy Physics, Photon, Meson, Hadron, Nuclear Theory, Cascade, Hyperon spectroscopy, Photoproduction, Polarization, Strange, Xi, Socio-culturale, Elementary particle, Xi-: polarization, Photon energy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Computer Science::Digital Libraries, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, photoproduction: (cascade), Particle decay, polarization: measured, excited state: spectrum, CLAS, meson: exchange, 0103 physical sciences, Xi-: photoproduction, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Hyperon, hyperon: (nucleon resonance), photon: energy, Baryon, Xi-: (recoil), High Energy Physics::Experiment, polarization: induced, hyperon: photoproduction, decay: weak interaction, +K%2B+K-+Xi%22">photon p --> K+ K- Xi, 5.45 GeV, Jefferson Lab
Abstract: Despite decades of studies of the photoproduction of hyperons, both their production mechanisms and their spectra of excited states are still largely unknown. While the parity-violating weak decay of hyperons offers a means of measuring their polarization, which could help discern their production mechanisms and identify their excitation spectra, no such study has been possible for doubly strange baryons in photoproduction, due to low production cross sections. However, by making use of the reaction $\gamma p \to K^+ K^+ \Xi^-$, we have measured, for the first time, the induced polarization, $P$, and the transferred polarization from circularly polarized real photons, characterized by $C_x$ and $C_z$, to recoiling $\Xi^-$s. The data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab for photon energies from just over threshold (2.4 GeV) to 5.45 GeV. These first-time measurements are compared, and are shown to broadly agree, with model predictions in which cascade photoproduction proceeds through the decay of intermediate hyperon resonances that are produced via relativistic meson exchange, offering a new step forward in the understanding of the production and polarization of doubly-strange baryons., Comment: 9 pages, 7 figures
Published: 2018
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14. Double $K_S^0$ Photoproduction off the Proton at CLAS

Author: W. Gohn, Pawel Nadel-Turonski, R. Paremuzyan, R. A. Schumacher, N. Markov, P. Eugenio, Nicholas M. Harrison, D. G. Jenkins, Gerard Gilfoyle, D. Sokhan, E. Golovatch, R. Dupre, I. Bedlinskiy, M. L. Kabir, L. Lanza, C. Munoz Camacho, M. Battaglieri, M. Bashkanov, B. McKinnon, X. Wei, C. A. Meyer, F. X. Girod, Y. Ilieva, G. V. Fedotov, H. Egiyan, L. Guo, A. D'Angelo, C. Hanretty, S. Niccolai, I. I. Strakovsky, P. Lenisa, K. P. Adhikari, Chaden Djalali, Avraham Klein, A. Simonyan, A. Deur, Laura Clark, E. De Sanctis, Iu. Skorodumina, G. Khachatryan, W. Kim, K. Park, W. Phelps, Sylvester Joosten, A. Fradi, K. Joo, W. J. Briscoe, G. Charles, M. Osipenko, Barry Ritchie, W. K. Brooks, S. Adhikari, Friedrich Klein, Brian Raue, J. Zhang, D. Protopopescu, E. Voutier, Y. G. Sharabian, S. Chandavar, S. Strauch, Y. Prok, T. Mineeva, G. Ciullo, J. P. Ball, D. S. Carman, Maxime Defurne, V. Crede, A. Rizzo, G. Rosner, G. Gavalian, F. Sabatié, D. I. Glazier, K. A. Griffioen, M. C. Kunkel, S. Johnston, David M. Keller, V. P. Kubarovsky, Y. Ghandilyan, Carlos A. Salgado, M. Khachatryan, R. De Vita, K. Livingston, M. Hattawy, K. Hicks, A. Movsisyan, E. L. Isupov, D. Riser, H. Hakobyan, Nikolaos Sparveris, Michael Paolone, M. Khandaker, A. I. Ostrovidov, D. G. Ireland, S. Stepanyan, Volker D. Burkert, A. S. Biselli, Andrea Celentano, A. El Alaoui, Nicholas Zachariou, M. Ripani, F. Cao, M. Guidal, G. Niculescu, E. Pasyuk, N. Dashyan, M. Holtrop, D. P. Weygand, I. Balossino, Taya Chetry, George Davey Smith, J. W. Price, M. Ungaro, L. El Fassi, M. Contalbrigo, Z. Akbar, O. Pogorelko, I. J. D. MacGregor, P. L. Cole, Z. W. Zhao, M. E. McCracken, Victor Mokeev, R. W. Gothe, L. Barion, A. Filippi, D. Heddle, K. Hafidi, J. T. Goetz, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), 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), CLAS, 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), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, 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, Meson, Proton, Dalitz plot, FOS: Physical sciences, Socio-culturale, Photon energy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], time-of-flight, 01 natural sciences, Resonance (particle physics), Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, mass spectrum, p: target, background: low, CLAS, 0103 physical sciences, mixing, Invariant mass, Nuclear Experiment (nucl-ex), [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Glueball, background, meson resonance, photon: energy, momentum transfer: measured, Automatic Keywords, glueball, meson: photoproduction, Mass spectrum, baryon: hadron spectroscopy, High Energy Physics::Experiment, missing-mass, photoproduction, experimental results
Abstract: The $f_0$(1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the $f_0$(1500) via decay into the $K_S^0 K_S^0$ channel using the CLAS detector. The reaction $��p$ -> $f_0 p$ -> $K_S^0 K_S^0 p$, where J = 0, 2, was measured with photon energies from 2.7 to 5.1 GeV. A clear peak is seen at 1500 MeV in the background subtracted invariant mass spectra of the two kaons. This is enhanced if the measured 4-momentum transfer to the proton target is restricted to be less than 1.0 GeV2. By comparing data with simulations, it can be concluded that the peak at 1500 MeV is produced primarily at low t, which is consistent with a t-channel production mechanism., 12 pages, 12 figures
Published: 2018
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15. First measurement of the polarization observable E in the p→(γ→,π+)n reaction up to 2.25 GeV

Author: I. Zonta, William Brooks, X. Wei, P. Lenisa, K. Livingston, D. P. Watts, Friedrich Klein, A. V. Sarantsev, D. Rönchen, P. Nadel-Turonski, Z. W. Zhao, Eberhard Klempt, W. Gohn, F. Sabatié, R. A. Badui, H. Y. Lu, I. Niculescu, I. I. Strakovsky, B. A. Raue, R. A. Schumacher, A. El Alaoui, Barry Ritchie, J. W. Price, A. Deur, Nicholas Zachariou, K. A. Griffioen, S. Chandavar, A. V. Anisovich, L. Guo, M. Ungaro, M. Ripani, R. W. Gothe, Michael Döring, T. A. Forest, S. Stepanyan, E. Munevar, Avraham Klein, Iu. Skorodumina, P. Eugenio, C. I. Moody, M. Taiuti, V. Crede, V. A. Nikonov, Latifa Elouadrhiri, G. Khachatryan, C. A. Meyer, G.V. O'Rielly, A. Trivedi, K. Joo, G. V. Fedotov, Andrea Celentano, Andrew Puckett, R. A. Montgomery, A. Kim, E. Golovatch, R. Dupre, S. Procureur, D. Keller, R. De Vita, D. Protopopescu, M. Contalbrigo, D. G. Jenkins, S. Pozdniakov, I. Bedlinskiy, K. P. Adhikari, N. Benmouna, F. X. Girod, J. Brock, H. S. Jo, N. Compton, Jian Zhang, C. Carlin, A. Filippi, Nikolaos Sparveris, N. Gevorgyan, W. Kim, S. Strauch, D. S. Carman, Victor Mokeev, G. Niculescu, D. Ho, K. Park, L. Colaneri, M. Khandaker, John Phillips, A. Simonyan, E. Seder, N. Markov, S. Pisano, N. K. Walford, M. Hattawy, D. I. Glazier, E. Voutier, T. Cao, A. Fradi, O. Pogorelko, D. G. Meekins, Diane Schott, G. Rosner, I. J. D. MacGregor, A. I. Ostrovidov, M. Osipenko, D. G. Ireland, H. Moutarde, M. Battaglieri, Y. Ghandilyan, H. Jiang, B. S. Ishkhanov, Volker D. Burkert, S. E. Kuhn, A. S. Biselli, K. L. Giovanetti, J. A. Fleming, L. El Fassi, P. Peng, Hovanes Egiyan, Chaden Djalali, Michael Dugger, Hrachya Hakobyan, Y. Ilieva, C. Munoz Camacho, R. Tucker, Ron L. Workman, P. L. Cole, B. McKinnon, L. A. Net, S. Fegan, Eugene Pasyuk, S. Anefalos Pereira, Y. G. Sharabian, W. Phelps, V. Batourine, M. L. Seely, D. Sokhan, E. De Sanctis, C. D. Keith, J. P. Ball, Y. Prok, D. I. Sober, A. Rizzo, S. Niccolai, C. Hanretty, V. Sytnik, N. Harrison, A. Movsisyan, N. Dashyan, P. Stoler, I. Senderovich, K. Hicks, G. Charles, P. Roy, D. Adikaram, M. Guidal, S. Joosten, G. D. Smith, M. Holtrop, H. Voskanyan, W. J. Briscoe, V. P. Kubarovsky, Annalisa D'Angelo, S. M. Hughes, Michael Wood, K. Hafidi, O. Cortes, E. L. Isupov, Ye Tian, Lorenzo Zana, and C. Salgado
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Photon, Pion, Meson, Bremsstrahlung, Observable, Photon energy, Nuclear Experiment, Multipole expansion, Nucleon
Abstract: First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction (p) over right arrow((gamma) over right arrow, pi(+))n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn-Gatchina, Jfilich-Bonn, and SAID groups. (C) 2015 The Authors. Published by Elsevier B.V.
Published: 2015
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16. Photon beam asymmetry Σ for η and η′ photoproduction from the proton

Author: K. A. Griffioen, I. I. Strakovsky, S. Strauch, H. Egiyan, Michael Dugger, Sylvester Joosten, Latifa Elouadrhiri, C. A. Meyer, Michael Paolone, P. Eugenio, M. Taiuti, A. Deur, K. Livingston, G. V. Fedotov, R. A. Schumacher, N. Markov, W. Phelps, W. K. Brooks, M. Osipenko, S. Pisano, F. X. Girod, E. Golovatch, R. Dupre, M. Ungaro, A. V. Sarantsev, X. Wei, G. Murdoch, M. Ripani, V. Crede, P. Collins, Iu. Skorodumina, M. Khachatryan, P. Nadel-Turonski, F. Sabatié, L. Lanza, C. Gleason, Michael Döring, D. Heddle, K. P. Adhikari, D. Sadasivan, R. Paremuzyan, N. K. Walford, A. Kim, J. W. Price, V. A. Nikonov, A. I. Ostrovidov, K. Park, Taya Chetry, S. Stepanyan, D. I. Glazier, G. Khachatryan, Barry Ritchie, G. Charles, R. A. Montgomery, Avraham Klein, C. Djalali, A. El Alaoui, Y. Ilieva, J. Ball, W. Kim, D. G. Ireland, G. Niculescu, V. P. Kubarovsky, R. De Vita, Volker D. Burkert, Nicholas Zachariou, H. S. Jo, S. Chandavar, A. V. Anisovich, A. S. Biselli, I. Bedlinskiy, I. J. D. MacGregor, M. Battaglieri, W. J. Briscoe, N. Compton, O. Pogorelko, S. M. Hughes, Nicholas M. Harrison, Gerard Gilfoyle, K. Hicks, B. Torayev, D. G. Jenkins, E. Fanchini, Y. G. Sharabian, H. Avakian, M. J. Amaryan, S. Anefalos Pereira, I. Niculescu, P. Lenisa, D. Sokhan, L. Guo, H. Hakobyan, O. Cortes, E. L. Isupov, Alessandro Rizzo, Laura Clark, H. Voskanyan, Eberhard Klempt, V. Mokeev, Ye Tian, D. Protopopescu, E. De Sanctis, M. Bashkanov, M. Contalbrigo, P. L. Cole, J. A. Fleming, E. Pasyuk, E. Voutier, C. Hanretty, J. Zhang, B. McKinnon, G. Ciullo, Friedrich Klein, Brian Raue, F. Cao, P. Roy, Y. Prok, D. S. Carman, K. L. Giovanetti, Nikos Sparveris, I. Balossino, G. Rosner, D. Rönchen, Dustin Keller, M. Mirazita, S. Niccolai, A. Movsisyan, B. S. Ishkhanov, C. Salgado, N. Dashyan, A. D'Angelo, A. Filippi, Z. Akbar, Y. Ghandilyan, K. Hafidi, M. Khandaker, G. D. Smith, M. Holtrop, A. Celentano, R. W. Gothe, L. El Fassi, C. Munoz Camacho, and L. Colaneri
Subjects: Nuclear and High Energy Physics, Photon, Proton, Meson, Meson photoproduction, Eta photoproduction, Eta-prime photoproduction, Polarization observable, Photon beam asymmetry, Nuclear Theory, Photon energy, 01 natural sciences, Particle identification, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Physics, 010308 nuclear & particles physics, Bremsstrahlung, Particle Data Group, lcsh:QC1-999, High Energy Physics::Experiment, Atomic physics, Nucleon, lcsh:Physics
Abstract: Measurements of the linearly-polarized photon beam asymmetry Σ for photoproduction from the proton of η and η′ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the γp→ηp reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the γp→η′p reaction. For γp→ηp, the data reported here considerably extend the range of measurements to higher energies, and are consistent with the few previously published measurements for this observable near threshold. For γp→η′p, the results obtained are consistent with the few previously published measurements for this observable near threshold, but also greatly expand the incident photon energy coverage for that reaction. Initial analysis of the data reported here with the Bonn–Gatchina model strengthens the evidence for four nucleon resonances – the N(1895)1/2−, N(1900)3/2+, N(2100)1/2+ and N(2120)3/2− resonances – which presently lack the “four-star” status in the current Particle Data Group compilation, providing examples of how these new measurements help refine models of the photoproduction process.
Published: 2017

17. Beam-target double-spin asymmetry in quasielastic electron scattering off the deuteron with CLAS

Author: N. Compton, Chaden Djalali, R. A. Schumacher, F. X. Girod, R. Paremuzyan, S. Bültmann, Gerard Gilfoyle, T. A. Forest, C. D. Keith, I. Zonta, M. Osipenko, G. Khachatryan, Laura Clark, F. Sabatié, D. Sokhan, Marco Contalbrigo, S. Stepanyan, L. Guo, W. J. Briscoe, Avraham Klein, B. McKinnon, G. Asryan, C. Hanretty, S. Strauch, G. Charles, W. Kim, P. Rossi, R. A. Badui, M. Mirazita, G. Niculescu, J. W. Price, S. Niccolai, W. Phelps, P. Eugenio, V. Sytnik, Alessandro Rizzo, Victor Mokeev, G. Rosner, A. Deur, L. Lanza, M. Taiuti, L. Colaneri, M. Ungaro, W. K. Brooks, S. E. Kuhn, Y. Prok, Y. Ghandilyan, A. Celentano, R. W. Gothe, K. A. Griffioen, A. Kim, C. E. Hyde, B. S. Ishkhanov, J. A. Fleming, E. De Sanctis, V. Crede, J. P. Ball, M. H. Wood, R. Dupre, M. Battaglieri, Taya Chetry, D. S. Carman, Hrachya Hakobyan, B. Torayev, I. u. Skorodumina, I. Bedlinskiy, Z. Akbar, E. Fanchini, P. Bosted, K. Hicks, M. Guidal, R. De Vita, K. L. Giovanetti, A. I. Ostrovidov, K. Park, P. L. Cole, M. Holtrop, L. A. Net, E. Voutier, J. Zhang, Paolo Lenisa, D. G. Ireland, H. Jiang, A. Movsisyan, Volker D. Burkert, A. S. Biselli, H. Avakian, S. Anefalos Pereira, N. K. Walford, I. J. D. MacGregor, Latifa Elouadrhiri, George Davey Smith, G. V. Fedotov, Y. G. Sharabian, H. Voskanyan, D. G. Meekins, A. D'Angelo, Andrew Puckett, Martin K. Mayer, L. El Fassi, E. Pasyuk, M. Khachatryan, K. P. Adhikari, E. L. Isupov, N. A. Baltzell, Ye Tian, S. Boiarinov, Nikolaos Sparveris, C. Gleason, M. Ripani, V. P. Kubarovsky, O. Pogorelko, S. M. Hughes, N. Dashyan, Dustin Keller, I. Stankovic, Yordanka Ilieva, Giuseppe Ciullo, A. El Alaoui, Nicholas Zachariou, K. Livingston, M. Hattawy, R. Fersch, N. Guler, Larry Weinstein, A. Filippi, M. Khandaker, Old Dominion University [Norfolk] (ODU), 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), CLAS Collaboration, 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: Particle physics, Nuclear and High Energy Physics, POLARIZED TARGET, media_common.quotation_subject, Hadron, Nuclear Theory, FOS: Physical sciences, Socio-culturale, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Economica, 0103 physical sciences, Neutron, ELECTRODISINTEGRATION, Nuclear Experiment (nucl-ex), 010306 general physics, NUCLEON, Nuclear Experiment, QC, media_common, FORM-FACTOR, NEUTRON, STATE, Physics, 010308 nuclear & particles physics, Scattering, Momentum transfer, Quasielastic neutron scattering, Nucleon
Abstract: Quasi-elastic electron scattering on the deuteron is a benchmark reaction to test our understanding of deuteron structure and the properties and interactions of the two nucleons bound in the deuteron. The experimental data presented here can be used to test state-of-the-art models of the deuteron and the two-nucleon interaction in the final state after two-body breakup of the deuteron. Focusing on polarization degrees of freedom, we gain information on spin-momentum correlations in the deuteron ground state (due to the D-state admixture) and on the limits of the Impulse Approximation (IA) picture as it applies to measurements of spin-dependent observables like spin structure functions for bound nucleons. We measured the beam-target double spin asymmetry for quasi-elastic electron scattering off the deuteron at several beam energies using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. The deuterons were polarized along (or opposite to) the beam direction. The double spin asymmetries were measured as a function of photon virtuality , missing momentum, and the angle between the (inferred) "spectator" neutron and the momentum transfer direction. The results are compared with a recent model that includes Final State Interactions (FSI) using a complete parameterization of nucleon-nucleon scattering, as well as a simplified model using the Plane Wave Impulse Approximation (PWIA). We find overall good agreement with both the PWIA and FSI expectations at low to medium missing momenta, including the change of the asymmetry due to the contribution of the deuteron D-state at higher momenta. At the highest missing momenta, our data clearly agree better with the calculations including FSI., Comment: 19 pages, 17 figures, to be submitted to PRC
Published: 2017
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18. Target and double spin asymmetries of deeply virtual π 0 production with a longitudinally polarized proton target and CLAS

Author: E. Seder, G. V. Fedotov, K. P. Adhikari, D. G. Ireland, V. Sytnik, V. Crede, B. McKinnon, A. Kim, M. Ungaro, Dustin Keller, G. Khachatryan, W. Phelps, M. Contalbrigo, A. Fradi, D. P. Watts, A. D'Angelo, H. Egiyan, P. Nadel-Turonski, H. Y. Lu, P. Mattione, P. Bosted, P. Roy, E. De Sanctis, M. Osipenko, L. Colaneri, L. El Fassi, M. Battaglieri, Sylvester Joosten, H. S. Jo, S. Pisano, K. Hafidi, D. G. Jenkins, N. Compton, Michael Paolone, C. Hanretty, P. Lenisa, M. E. McCracken, V. Batourine, I. I. Strakovsky, I. J. D. MacGregor, B. S. Ishkhanov, Z. Akbar, K. Joo, W. Kim, N. Markov, F. X. Girod, Lorenzo Zana, K. A. Griffioen, R. A. Badui, G. D. Smith, M. Holtrop, S. E. Kuhn, L. Guo, Alessandro Rizzo, C. Djalali, Friedrich Klein, J. A. Fleming, Gerard Gilfoyle, P. Rossi, V. P. Kubarovsky, C. Salgado, D. Sokhan, M. Ripani, O. Pogorelko, E. Golovatch, A. Celentano, R. W. Gothe, L. Lanza, S. Chandavar, M. Garc con, J. W. Price, I. Bedlinskiy, R. G. Fersch, H. Avakian, A. I. Ostrovidov, R. De Vita, K. Park, Y. Prok, D. S. Carman, Iu. Skorodumina, P. L. Cole, J. Zhang, L. A. Net, O. Cortes, Nikos Sparveris, William Brooks, H. Voskanyan, H. Jiang, X. Wei, Taya Chetry, W. J. Briscoe, E. Pasyuk, S. Niccolai, G. Rosner, S. Boiarinov, S. Anefalos Pereira, A. Movsisyan, P. Eugenio, Volker D. Burkert, A. S. Biselli, N. Dashyan, M. Taiuti, Y. G. Sharabian, Y. Ghandilyan, T. Cao, R. A. Schumacher, M. Hattawy, W. Gohn, S. Bültmann, S. Stepanyan, E. Munevar, Avraham Klein, Sergey Kuleshov, V. Mokeev, G. Charles, S. Strauch, P. Stoler, K. Hicks, E. Voutier, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, D. Heddle, B. Torayev, A. Filippi, M. Khandaker, K. L. Giovanetti, Larry Weinstein, 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and CLAS Collaboration
Subjects: Particle physics, Nuclear and High Energy Physics, media_common.quotation_subject, Deeply Virtual Meson Production, Virtual particle, Socio-culturale, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Nucleon structure, 0103 physical sciences, Chiral-odd generalized parton distributions, CLAS collaboration, Longitudinally polarized target, 010306 general physics, Nuclear Experiment, media_common, Physics, Spectrometer, 010308 nuclear & particles physics, lcsh:QC1-999, Pseudoscalar, Transverse plane, Amplitude, Phase space, High Energy Physics::Experiment, lcsh:Physics
Abstract: The target and double spin asymmetries of the exclusive pseudoscalar channel View the MathML source were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of Q2, xB, −t and ϕ . Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs View the MathML source and ET, and complement previous measurements of unpolarized structure functions sensitive to the GPDs HT and View the MathML source. These data provide a crucial input for parametrizations of essentially unknown chiral-odd GPDs and will strongly influence existing theoretical calculations based on the handbag formalism.
Published: 2017
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19. Hard exclusive pion electroproduction at backward angles with CLAS

Author: H. Avakian, B. S. Ishkhanov, K. A. Griffioen, H. Voskanyan, R. Paremuzyan, A. El Alaoui, E. L. Isupov, M. Battaglieri, Nicholas Zachariou, M. Ripani, I. Bedlinskiy, C. Salgado, K. Livingston, M. Hattawy, R. Fersch, S. Stepanyan, M. Ungaro, Nicholas M. Harrison, Gerard Gilfoyle, D. Sokhan, Laura Clark, P. Rossi, Maxime Defurne, Friedrich Klein, P. Eugenio, M. Taiuti, M. L. Kabir, G. Charles, F. Sabatié, A. D'Angelo, David M. Keller, L. Guo, D. Heddle, Chaden Djalali, I. J. D. MacGregor, R. W. Gothe, R. A. Schumacher, W. Kim, O. Pogorelko, F. X. Girod, L. Lanza, C. Munoz Camacho, J. W. Price, C. E. Hyde, C. Hanretty, X. Wei, Y. Prok, M. Khachatryan, K. Hicks, J. Ball, K. Hafidi, M. Osipenko, J. Zhang, D. Protopopescu, Latifa Elouadrhiri, R. De Vita, V. Crede, R. A. Montgomery, Nikolaos Sparveris, E. Voutier, S. Strauch, G. V. Fedotov, Y. G. Sharabian, M. Contalbrigo, Victor Mokeev, B. McKinnon, Taya Chetry, M. Khandaker, Iu. Skorodumina, Andrea Celentano, H. Hakobyan, L. El Fassi, M. Mirazita, J. Poudel, J. M. Laget, S. Niccolai, Z. Akbar, S. Johnston, N. Markov, Kirill M. Semenov-Tian-Shansky, I. I. Strakovsky, G. Niculescu, Y. Ilieva, K. P. Adhikari, A. Deur, E. De Sanctis, S. Adhikari, Y. Ghandilyan, A. Filippi, Michael Paolone, E. Golovatch, R. Dupre, P. L. Cole, D. G. Ireland, S. E. Kuhn, G. Ciullo, G. Khachatryan, D. S. Carman, F. Cao, A. Rizzo, M. Guidal, Volker D. Burkert, W. J. Briscoe, A. S. Biselli, E. Pasyuk, N. Dashyan, William Brooks, G. D. Smith, M. Holtrop, L. Barion, N. A. Baltzell, M. Garçon, H. Egiyan, P. Nadel-Turonski, K. Joo, J. A. Tan, D. G. Jenkins, Bernard Pire, W. Phelps, I. Balossino, K. Park, V. P. Kubarovsky, 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 Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Interactions Fondamentales en Physique et en Astrophysique (IFPA), Université de Liège, Thomas Jefferson National Accelerator Facility (Jefferson Lab), Istituto Nazionale di Fisica Nucleare, Sezione di Torino (INFN, Sezione di Torino), Istituto Nazionale di Fisica Nucleare (INFN), University of Ca’ Foscari [Venice, Italy], 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, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Clemson University, Old Dominion University [Norfolk] (ODU), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Massachusetts Institute of Technology (MIT), 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), Laboratoire d'automatique et de génie des procédés (LAGEP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS), Politecnico di Torino = Polytechnic of Turin (Polito), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), School of Mechanical Engineering, University of Birmingham [Birmingham], School of Geography, 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), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Université de Lyon-Université de Lyon-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Quark, Nuclear and High Energy Physics, Electroproduction, Exclusive single pion, transition distribution amplitudes, Particle physics, Meson, Proton, Nuclear Theory, Hadron, Socio-culturale, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], TDA, 01 natural sciences, Resonance (particle physics), CLAS, Eletroproduction, High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear Theory (nucl-th), High Energy Physics - Experiment (hep-ex), Pion, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, lcsh:QC1-999, Baryon, High Energy Physics - Phenomenology, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, Nucleon, lcsh:Physics
Abstract: We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, $e p \to e^\prime n \pi^+$, above the resonance region at backward pion center-of-mass angles. The $\varphi^*_{\pi}$-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs) and shed new light on nucleon structure., Comment: 7 pages, 6figures
Published: 2017
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20. First measurement of the helicity asymmetry E in η photoproduction on the proton

Author: K. A. Griffioen, K. Livingston, B. McKinnon, H. Hakobyan, C. Hanretty, S. Strauch, Latifa Elouadrhiri, C. A. Meyer, G. V. Fedotov, E. De Sanctis, I. Bedlinskiy, S. Chandavar, L. Colaneri, J. Brock, K. P. Adhikari, E. Golovatch, R. Dupre, D. I. Sober, M. C. Kunkel, V. Batourine, M. L. Seely, I. Zonta, Iu. Skorodumina, X. Wei, V. Crede, S. Pisano, Victor Mokeev, I. I. Strakovsky, E. Voutier, F. Sabatié, M. Ripani, D. I. Glazier, H. Egiyan, M. Ungaro, A. Deur, R. A. Montgomery, P. Stoler, Barry Ritchie, A. Simonyan, I. Senderovich, P. Lenisa, Z. W. Zhao, R. De Vita, Diane Schott, W. K. Brooks, A. El Alaoui, Y. Ilieva, K. Hicks, H. S. Jo, K. L. Giovanetti, Gerard Gilfoyle, K. Joo, C. D. Keith, Nicholas Zachariou, K. Park, N. K. Walford, D. G. Ireland, L. Guo, D. G. Jenkins, H. Jiang, Volker D. Burkert, A. S. Biselli, Sylvester Joosten, Michael Dugger, I. J. D. MacGregor, S. Anefalos Pereira, V. P. Kubarovsky, R. A. Badui, S. Park, N. Dashyan, A. Filippi, F. X. Girod, O. Pogorelko, S. M. Hughes, J. Zhang, W. Phelps, P. Nadel-Turonski, M. Khandaker, O. Cortes, W. Gohn, A. Celentano, R. W. Gothe, Ye Tian, Dustin Keller, Friedrich Klein, S. Boiarinov, D. G. Meekins, A. D'Angelo, J. W. Price, C. Djalali, Michael Wood, K. Hafidi, D. Rönchen, E. Seder, M. Contalbrigo, P. Mattione, P. Peng, L. El Fassi, C. Munoz Camacho, J. T. Goetz, R. Tucker, H. Voskanyan, P. L. Cole, E. Pasyuk, Z. Akbar, Lorenzo Zana, J. P. Ball, Y. Prok, P. Roy, D. Adikaram, M. Guidal, D. S. Carman, A. Rizzo, S. Niccolai, C. Salgado, G. D. Smith, M. Holtrop, A. Movsisyan, M. Battaglieri, S. Fegan, A. Kim, G. Charles, T. Mineeva, B. Morrison, V. Sytnik, P. Eugenio, B. S. Ishkhanov, R. A. Schumacher, P. Collins, B. Garillon, Michael Döring, D. Ho, S. Stepanyan, A. Fradi, H. Y. Lu, Andrew Puckett, Nikolaos Sparveris, I. Niculescu, J. A. Fleming, L. A. Net, C. Carlin, G. Rosner, M. Osipenko, Y. Ghandilyan, G. Khachatryan, W. J. Briscoe, G. Niculescu, M. Hattawy, N. A. Baltzell, 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), 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), CLAS Collaboration, 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: Particle physics, Nuclear and High Energy Physics, Meson, media_common.quotation_subject, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Asymmetry, NO, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, 0103 physical sciences, Eta photoproduction, ddc:530, Helicity asymmetry, Polarization observable, 010306 general physics, Nuclear Experiment, QC, media_common, Physics, Quantitative Biology::Biomolecules, 010308 nuclear & particles physics, Bremsstrahlung, Resonance, Observable, Helicity, lcsh:QC1-999, Baryon, Physics::Accelerator Physics, High Energy Physics::Experiment, Nucleon, lcsh:Physics
Abstract: Results are presented for the first measurement of the double-polarization helicity asymmetry E for the η photoproduction reaction γp→ηp. Data were obtained using the FROzen Spin Target (FROST) with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range of center-of-mass energy W from threshold to 2.15 GeV and a large range in center-of-mass polar angle. As an initial application of these data, the results have been incorporated into the Jülich–Bonn model to examine the case for the existence of a narrow N⁎ resonance between 1.66 and 1.70 GeV. The addition of these data to the world database results in marked changes in the predictions for the E observable from that model. Further comparison with several theoretical approaches indicates these data will significantly enhance our understanding of nucleon resonances. Keywords: Eta photoproduction, Polarization observable, Helicity asymmetry
Published: 2016
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21. Evidence for the onset of color transparency in ρ0 electroproduction off nuclei

Author: G. Niculescu, S. Tkachenko, R. Dupre, M. Battaglieri, L. Guo, P. Khetarpal, R. De Vita, Paolo Rossi, C. Djalali, G. Ricco, Martin K. Mayer, S. Anefalos Pereira, G. E. Dodge, H. Y. Lu, F. X. Girod, V. Mokeev, Barry Ritchie, P. E. Reimer, B. Vernarsky, J. W. Price, V. Kuznetsov, M. S. Saini, E. Voutier, S. Procureur, F. Sabatié, A. Kim, B. Zhao, I. Niculescu, D. G. Ireland, Friedrich Klein, Brian Raue, V. Crede, W. Tang, M. Ripani, K. A. Griffioen, Michael Vineyard, E. De Sanctis, M. Aghasyan, D. I. Sober, J. T. Goetz, W. Gohn, T. Mineeva, D. Schott, P. Nadel-Turonski, M. Osipenko, Y. Mao, V. P. Kubarovsky, S. Niccolai, C. E. Hyde, S. S. Jawalkar, J. Arrington, P. Stoler, Latifa Elouadrhiri, C. A. Meyer, B. Dey, I. J. D. MacGregor, E. Munevar, B. S. Ishkhanov, S. E. Kuhn, C. Hanretty, K. Hicks, G. V. Fedotov, H. Avakian, E. L. Isupov, K. P. Adhikari, A. Celentano, R. W. Gothe, A. Deur, D. P. Weygand, Elton Smith, George Davey Smith, D. J. Tedeschi, H. Voskanyan, R. A. Schumacher, P. Eugenio, M. Taiuti, M. Anghinolfi, W. J. Briscoe, E. Pasyuk, W. K. Brooks, I. Bedlinskiy, H. Seraydaryan, Lorenzo Zana, S. Park, Y. G. Sharabian, A. D'Angelo, H. Hakobyan, S. Bültmann, X. Zheng, A. I. Ostrovidov, K. Park, M. Contalbrigo, R. J. Holt, C. E. Taylor, S. Stepanyan, C. Salgado, Avraham Klein, L. El Fassi, A. Ni, E. Golovatch, M. Ungaro, J. McAndrew, Z. W. Zhao, Michael Wood, Volker D. Burkert, K. Hafidi, A. S. Biselli, B. McKinnon, D. Branford, M. Mirazita, E. Phelps, J. M. Laget, S. S. Stepanyan, N. Gevorgyan, V. Batourine, N. Markov, D. Keller, Sergey Kuleshov, M. Khandaker, Hovanes Egiyan, M. J. Amaryan, R. Paremuzyan, H. Moutarde, K. L. Giovanetti, Larry Weinstein, Gerard Gilfoyle, D. Doughty, D. Heddle, D. Sokhan, D. Adikaram, M. Guidal, B. Mustapha, M. Holtrop, A. Daniel, Luciano Pappalardo, G. Rosner, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, D. Rimal, B. Moreno, R. Dickson, P. L. Cole, D. Protopopescu, S. Pozdniakov, M. Garçon, S. Chandavar, S. Strauch, D. P. Watts, M. Y. Gabrielyan, D. S. Carman, N. Dashyan, H. Baghdasaryan, S. Fegan, C. Bookwalter, and W. Kim
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, Virtual particle, Electron, 01 natural sciences, Coherence length, Nuclear physics, Color model, Deuterium, Nuclear transparency, 0103 physical sciences, Nuclear Experiment, 010306 general physics
Abstract: We have measured the nuclear transparency of the incoherent diffractive A(e,e′ρ0) process in 12C and 56Fe targets relative to 2H using a 5 GeV electron beam. The nuclear transparency, the ratio of the produced ρ0ʼs on a nucleus relative to deuterium, which is sensitive to ρA interaction, was studied as function of the coherence length (lc), a lifetime of the hadronic fluctuation of the virtual photon, and the four-momentum transfer squared (Q2). While the transparency for both 12C and 56Fe showed no lc dependence, a significant Q2 dependence was measured, which is consistent with calculations that included the color transparency effects.
Published: 2012
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22. Determination of the beam-spin asymmetry of deuteron photodisintegration in the energy regionEγ=1.1–2.3 GeV

Author: Alessandra Filippi, Reinhard Schumacher, Eugene Pasyuk, Alessandro Rizzo, Nicholas Zachariou, Philip Cole, Annalisa D'Angelo, Marco Contalbrigo, Franck Sabatie, Andrea Celentano, David Ireland, Mikhail Osipenko, Nikolay Markov, Marco Battaglieri, Eric Voutier, Irene Zonta, Ian MacGregor, Gabriel Charles, and Evgeny Isupov
Subjects: Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Proton, media_common.quotation_subject, Hadron, Bremsstrahlung, Perturbative QCD, 7. Clean energy, Asymmetry, Particle identification, Nuclear physics, Photodisintegration, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, media_common
Abstract: The beam-spin asymmetry, Σ, for the reaction γd→pn has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, θc.m., between 25∘ and 160∘. These are the first measurements of beam-spin asymmetries at θc.m.=90∘ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than θc.m.=90∘. The angular and energy dependence of Σ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.
Published: 2015
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23. Measurements ofep→e′π+nat1.6<W<2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS

Author: B. S. Ishkhanov, I. Zonta, J. Bono, P. Nadel-Turonski, X. Wei, E. De Sanctis, P. Eugenio, M. Taiuti, K. A. Griffioen, B. Garillon, Z. W. Zhao, C. E. Hyde, A. Filippi, D. Protopopescu, A. Kim, M. Garçon, S. Niccolai, A. Trivedi, Andrew Puckett, J. T. Goetz, F. X. Girod, Michael Paolone, I. I. Strakovsky, V. Crede, L. Guo, R. A. Schumacher, Sergey Kuleshov, M. Khandaker, Alessandro Rizzo, S. Chandavar, W. Tang, G. Charles, A. Deur, M. Osipenko, Latifa Elouadrhiri, Gerard Gilfoyle, Nikolaos Sparveris, M. Battaglieri, W. K. Brooks, A. Simonyan, R. De Vita, R. A. Montgomery, D. Martinez, B. Guegan, H. Hakobyan, C. Hanretty, C. E. Taylor, K. Livingston, N. Dashyan, G. V. Fedotov, S. Strauch, V. Sytnik, E. Golovatch, R. Dupre, Avraham Klein, H. S. Jo, Jie Zhang, S. Anefalos Pereira, V. Mokeev, P. Lenisa, V. P. Kubarovsky, H. S. Joo, H. Y. Lu, W. Phelps, Eugene Pasyuk, Inna Aznauryan, O. Pogorelko, S. M. Hughes, K. P. Adhikari, I. Bedlinskiy, C. Salgado, P. Roy, S. E. Kuhn, P. Peng, Hovanes Egiyan, C. Munoz Camacho, W. Kim, J. A. Fleming, M. Guidal, G. Niculescu, Yordanka Ilieva, H. Avakian, C. Djalali, K. Park, M. Ripani, I. Niculescu, B. McKinnon, P. Rossi, M. J. Amaryan, S. Joosten, G. D. Smith, M. Holtrop, Friedrich Klein, A. El Alaoui, M. Hattawy, Brian Raue, L. Zana, G. Rosner, H. Voskanyan, Nicholas Zachariou, Elton Smith, D. G. Jenkins, W. J. Briscoe, E. Seder, F. Sabatié, P. Stoler, D. P. Watts, S. Procureur, H. Moutarde, Dustin Keller, M. Ungaro, Michael Wood, K. Hicks, Y. G. Sharabian, K. Joo, O. Cortes, E. L. Isupov, Ye Tian, J. W. Price, K. L. Giovanetti, S. Fegan, Iu. Skorodumina, Larry Weinstein, D. Doughty, Y. Prok, D. S. Carman, E. Voutier, M. Contalbrigo, R. A. Badui, A. Celentano, R. W. Gothe, N. K. Walford, J. J. Phillips, I. J. D. MacGregor, A. D'Angelo, L. El Fassi, R. G. Fersch, Diane Schott, P. L. Cole, A. I. Ostrovidov, N. Gevorgyan, D. G. Ireland, H. Jiang, Volker D. Burkert, A. S. Biselli, L. Colaneri, N. Markov, and S. Pisano
Subjects: Physics, Quark, Nuclear and High Energy Physics, Particle physics, Amplitude, Isospin, Quark model, Isobar, Resonance, Invariant mass, Nucleon
Abstract: Differential cross sections of the exclusive process $ep\ensuremath{\rightarrow}{e}^{\ensuremath{'}}{\ensuremath{\pi}}^{+}n$ were measured with good precision in the range of the photon virtuality ${Q}^{2}=1.8--4.5$ ${\mathrm{GeV}}^{2}$ and the invariant mass range of the ${\ensuremath{\pi}}^{+}n$ final state $W=1.6--2.0$ GeV using the Continuous Electron Beam Accelerator Facility Large Acceptance Spectrometer. Data were collected with nearly complete coverage in the azimuthal and polar angles of the $n{\ensuremath{\pi}}^{+}$ center-of-mass system. More than 37 000 cross-section points were measured. The contributions of the isospin $I=\frac{1}{2}$ resonances $N(1675){\frac{5}{2}}^{\ensuremath{-}},N(1680){\frac{5}{2}}^{+}$, and $N(1710){\frac{1}{2}}^{+}$ were extracted at different values of ${Q}^{2}$ using a single-channel, energy-dependent resonance amplitude analysis. Two different approaches, the unitary isobar model and the fixed-$t$ dispersion relations, were employed in the analysis. We observe significant strength of the $N(1675){\frac{5}{2}}^{\ensuremath{-}}$ in the ${A}_{1/2}$ amplitude, which is in strong disagreement with quark models that predict both transverse amplitudes to be strongly suppressed. For the $N(1680){\frac{5}{2}}^{+}$ we observe a slow changeover from the dominance of the ${A}_{3/2}$ amplitude at the real photon point $({Q}^{2}=0)$ to a ${Q}^{2}$ where ${A}_{1/2}$ begins to dominate. The scalar amplitude ${S}_{1/2}$ drops rapidly with ${Q}^{2}$ consistent with quark model prediction. For the $N(1710){\frac{1}{2}}^{+}$ resonance our analysis shows significant strength for the ${A}_{1/2}$ amplitude at ${Q}^{2}l2.5$ ${\mathrm{GeV}}^{2}$.
Published: 2015
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24. Single and double spin asymmetries for deeply virtual Compton scattering measured with CLAS and a longitudinally polarized proton target

Author: M. Contalbrigo, R. A. Schumacher, P. Bosted, Andrew Puckett, A. Kim, P. Stoler, S. Chandavar, J. P. Ball, Y. Prok, E. Golovatch, I. Zonta, P. Roy, D. Adikaram, M. Guidal, B. S. Ishkhanov, Nikolaos Sparveris, B. Briscoe, K. Hicks, N. Compton, M. Garçon, Iu. Skorodumina, A. Rizzo, X. Wei, S. Joosten, G. D. Smith, M. Holtrop, V. Sytnik, M. Mirazita, P. Nadel-Turonski, A. El Alaoui, O. Cortes, C. D. Keith, Ye Tian, J. J. Phillips, S. Niccolai, D. G. Crabb, Nicholas Zachariou, P. Lenisa, S. Tkachenko, S. Stepanyan, R. Dupre, L. Guo, M. Ripani, D. P. Watts, I. J. D. MacGregor, E. De Sanctis, J. Brock, R. De Vita, S. Fegan, R. W. Gothe, M. Osipenko, William Brooks, J. T. Goetz, Latifa Elouadrhiri, O. Pogorelko, Z. W. Zhao, Diane Schott, C. A. Meyer, M. Ungaro, D. I. Sober, A. I. Ostrovidov, K. Park, Hovanes Egiyan, M. Battaglieri, C. Munoz Camacho, G. V. Fedotov, A. Deur, K. A. Griffioen, V. Crede, D. G. Ireland, W. Phelps, Lorenzo Zana, C. I. Moody, H. Y. Lu, Volker D. Burkert, A. S. Biselli, B. McKinnon, Friedrich Klein, K. P. Adhikari, D. G. Jenkins, C. Hanretty, R. A. Montgomery, L. Colaneri, C. Salgado, G. Charles, H. S. Jo, A. Fradi, S. E. Kuhn, W. Kim, V. Batourine, M. Hattawy, Chaden Djalali, J. A. Fleming, G. Rosner, I. Bedlinskiy, M. Turisini, F. Sabatié, E. Seder, S. Strauch, K. Joo, K. Livingston, W. Gohn, J. W. Price, Y. Ghandilyan, C. Carlin, S. Pisano, Gerard Gilfoyle, S. Anefalos Pereira, M. Mayer, D. S. Carman, D. Sokhan, Andrea Celentano, R. Fersch, Victor Mokeev, H. Avakian, E. Voutier, P. Rossi, J. Zhang, N. K. Walford, X. Jiang, V. P. Kubarovsky, D. G. Meekins, Annalisa D'Angelo, S. M. Hughes, L. El Fassi, Michael Wood, K. Hafidi, P. L. Cole, P. Eugenio, F. X. Girod, S. Procureur, B. Garillon, Y. Ilieva, M. J. Amaryan, M. MacCormick, K. L. Giovanetti, Larry Weinstein, D. Keller, A. Filippi, 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), 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, CLAS Collaboration, 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: Quark, Nuclear and High Energy Physics, Particle physics, Photon, Meson, FOS: Physical sciences, Parton, Kinematics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, NO, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), GENERALIZED PARTON DISTRIBUTIONS, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), NUCLEON, 010306 general physics, Nuclear Experiment, Quantum chromodynamics, Physics, 010308 nuclear & particles physics, ELECTROPRODUCTION, MESONS, QCD, Compton scattering, High Energy Physics::Experiment, Nucleon
Abstract: Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton $\vec{e}\vec{p} \to e' p'\gamma$ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally polarized ${}^{14}$NH$_3$ target. The three asymmetries were measured in 165 4-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of Generalized Parton Distributions. The measurement of three DVCS spin observables at the same kinematic points allows a quasi-model-independent extraction of the imaginary parts of the $H$ and $\tilde{H}$ Compton Form Factors, which give insight into the electric and axial charge distributions of valence quarks in the proton., Comment: 28 pages, 25 figures
Published: 2015
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25. Publisher's Note: Exclusiveπ0electroproduction atW>2GeV with CLAS [Phys. Rev. C 90, 025205 (2014)]

Author: George Davey Smith, N. A. Baltzell, D. Doughty, M. Khandaker, A. Simonyan, J. P. Ball, A. D'Angelo, Y. Prok, D. S. Carman, I. Zonta, H. Moutarde, K. L. Giovanetti, Larry Weinstein, X. Wei, H. Y. Lu, E. De Sanctis, V. P. Kubarovsky, M. Contalbrigo, Sergey Kuleshov, L. El Fassi, O. Pogorelko, D. I. Sober, D. Protopopescu, M. Garçon, E. Voutier, A. Movsisyan, N. Dashyan, Y. G. Sharabian, S. Chandavar, Frank Klein, A. V. Vlassov, F. X. Girod, D. G. Ireland, Dustin Keller, K. Livingston, C. Munoz Camacho, R. De Vita, K. P. Adhikari, V. Crede, Andrew Puckett, Lorenzo Zana, Martin K. Mayer, K. Hafidi, R. Dupre, S. Anefalos Pereira, V. Sytnik, M. Battaglieri, P. L. Cole, Z. W. Zhao, H. Hakobyan, H. S. Jo, B. McKinnon, S. Strauch, W. Kim, S. Niccolai, H. Avakian, P. Nadel-Turonski, B. Guegan, R. A. Montgomery, M. Mirazita, I. Niculescu, M. Yurov, E. Phelps, Diane Schott, H. Voskanyan, N. Gevorgyan, S. Fegan, S. Koirala, A. I. Ostrovidov, K. Park, G. V. Fedotov, W. J. Briscoe, E. Pasyuk, P. Roy, C. Djalali, A. Celentano, R. W. Gothe, M. Ripani, Volker D. Burkert, M. Guidal, A. S. Biselli, D. P. Watts, H. Egiyan, Nicholas M. Harrison, A. El Alaoui, L. Colaneri, Gerard Gilfoyle, D. Sokhan, D. G. Jenkins, W. I. Levine, M. Holtrop, Nicholas Zachariou, N. Markov, R. A. Schumacher, S. E. Kuhn, M. Hattawy, S. Pisano, Luciano Pappalardo, O. Cortes, I. Bedlinskiy, J. A. Fleming, J. Bono, K. A. Griffioen, E. L. Isupov, N. K. Walford, Andreas Klein, J. J. Phillips, Ye Tian, S. Park, P. Eugenio, Carlos A. Salgado, S. Boiarinov, P. Rossi, W. Tang, Y. Ghandilyan, Barry Ritchie, B. S. Ishkhanov, M. Osipenko, T. A. Forest, S. Stepanyan, B. Garillon, S. Procureur, P. Stoler, A. Kim, E. Seder, K. Hicks, William Brooks, I. J. D. MacGregor, W. Phelps, G. Gavalian, V. Mokeev, I. Senderovich, Alessandro Rizzo, E. Golovatch, L. Elouadrhiri, A. Deur, J. Zhang, J. W. Price, L. Guo, M. Ungaro, K. Joo, V. Batourine, F. Sabatié, C. I. Moody, P. Lenisa, and Brian Raue
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Meson production
Published: 2014
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26. Precision measurements ofg1of the proton and of the deuteron with 6 GeV electrons

Author: P. Lenisa, N. A. Baltzell, D. Meekins, E. De Sanctis, M. Aghasyan, C. Keith, D. I. Sober, Friedrich Klein, K. A. Griffioen, G. Rosner, M. Contalbrigo, L. Elouadrhiri, V. Crede, O. Pogorelko, Y. Ghandilyan, F. Sabatié, P. Roy, C. Smith, Diane Schott, Victor Mokeev, C. Hanretty, D. S. Carman, R. A. Montgomery, M. J. Amaryan, D. Adikaram, A. I. Ostrovidov, K. Park, K. Hicks, J. W. Price, S. Strauch, S. Fegan, H. S. Jo, H. Moutarde, S. Tkachenko, A. V. Vlassov, D. G. Ireland, G. D. Smith, S. Stepanyan, M. Holtrop, D. Protopopescu, K. Joo, W. Tang, A. Movsisyan, E. Voutier, T. Mineeva, K. L. Giovanetti, Larry Weinstein, B. Zhao, S. Pozdniakov, M. Garçon, Nicholas Kvaltine, R. A. Schumacher, I. Zonta, P. Bosted, N. Harrison, Volker D. Burkert, A. S. Biselli, S. Koirala, M. Osipenko, A. Kim, B. Guegan, S. S. Jawalkar, J. J. Phillips, R. De Vita, M. Ungaro, J. Brock, S. Anefalos Pereira, H. Voskanyan, Y. Prok, W. Gohn, S. Bültmann, K. Hafidi, Y. G. Sharabian, C. Carlin, R. G. Fersch, I. I. Strakovsky, S. S. Stepanyan, I. J. D. MacGregor, Andrew Puckett, T. A. Forest, V. Sytnik, P. L. Cole, B. Garillon, K. Livingston, Jie Zhang, Martin K. Mayer, R. W. Gothe, A. Deur, N. Kalantarians, Gerard Gilfoyle, J. Pierce, Avraham Klein, B. Vernarsky, Y. Ilieva, N. K. Walford, S. Chandavar, W. Kim, N. Guler, G. Niculescu, D. Sokhan, L. Colaneri, M. S. Saini, W. J. Briscoe, J. Bono, P. Nadel-Turonski, D. Doughty, Chaden Djalali, B. S. Ishkhanov, L. El Fassi, D. Keller, N. Markov, M. Taiuti, P. Rossi, S. Pisano, A. Simonyan, Sergey Kuleshov, R. Paremuzyan, G. E. Dodge, H. Y. Lu, M. Mirazita, P. Peng, H. Avakian, C. Munoz Camacho, A. El Alaoui, W. K. Brooks, F. X. Girod, Z. W. Zhao, D. P. Watts, I. Niculescu, B. McKinnon, N. Gevorgyan, D. Ho, J. P. Ball, M. Khandaker, Nicholas Zachariou, M. Ripani, L. L. Pappalardo, V. P. Kubarovsky, Andrea Celentano, S. E. Kuhn, A. Rizzo, D. Rimal, S. Procureur, J. A. Fleming, E. Munevar, Annalisa D'Angelo, S. Niccolai, D. G. Crabb, B. A. Raue, N. Dashyan, M. Battaglieri, H. Baghdasaryan, Lorenzo Zana, G. V. Fedotov, K. P. Adhikari, X. Jiang, E. Seder, M. Hattawy, C. Salgado, J. T. Goetz, O. Cortes, E. L. Isupov, R. Dupre, 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), CLAS, 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: Nuclear and High Energy Physics, Particle physics, FOS: Physical sciences, SPIN STRUCTURE, INELASTIC EP, SCATTERING, NUCLEON, CLAS, Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Settore FIS/04 - Fisica Nucleare e Subnucleare, NO, Nuclear physics, Invariant mass, Nuclear Experiment (nucl-ex), Nuclear Experiment, Quantum chromodynamics, Physics, Scattering, Polarization (waves), Deuterium, Quark–gluon plasma, High Energy Physics::Experiment, Nucleon
Abstract: The inclusive polarized structure functions of the proton and deuteron, g(1)(p) and g(1)(d) , were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory. Electrons scattered at laboratory angles between 18 and 45 degrees were detected using the CEBAF Large Acceptance Spectrometer (CLAS). For the usual deep inelastic region kinematics, Q(2) > 1 GeV2 and the final-state invariant mass W > 2 GeV, the ratio of polarized to unpolarized structure functions g(1)/F-1 is found to be nearly independent of Q(2) at fixed x. Significant resonant structure is apparent at values of W up to 2.3 GeV. In the framework of perturbative quantum chromodynamics, the high-W results can be used to better constrain the polarization of quarks and gluons in the nucleon, as well as high-twist contributions.
Published: 2014
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27. Exclusiveπ0electroproduction atW>2 GeV with CLAS

Author: Latifa Elouadrhiri, P. Lenisa, J. P. Ball, Y. Prok, H. Moutarde, D. S. Carman, G. V. Fedotov, E. De Sanctis, K. L. Giovanetti, Larry Weinstein, C. Djalali, A. Movsisyan, Friedrich Klein, D. I. Sober, H. Hakobyan, K. P. Adhikari, W. Phelps, Brian Raue, D. Doughty, W. Tang, P. Roy, E. Voutier, M. Osipenko, V. Crede, P. Eugenio, A. V. Vlassov, E. Golovatch, B. Guegan, S. Fegan, R. A. Montgomery, K. Livingston, Y. Ghandilyan, F. Sabatié, J. Bono, B. S. Ishkhanov, R. De Vita, I. Bedlinskiy, H. Y. Lu, A. D'Angelo, C. I. Moody, G. D. Smith, M. Holtrop, S. E. Kuhn, N. Dashyan, B. Garillon, M. Hattawy, J. A. Fleming, Z. W. Zhao, Barry Ritchie, Luciano Pappalardo, I. Zonta, S. Anefalos Pereira, S. Chandavar, H. Avakian, L. El Fassi, P. Stoler, W. J. Briscoe, W. Kim, X. Wei, S. Procureur, Lorenzo Zana, I. Niculescu, I. Senderovich, K. Hicks, M. Khandaker, N. K. Walford, H. Voskanyan, A. Kim, P. Rossi, L. Guo, W. I. Levine, R. A. Schumacher, S. Strauch, S. Park, Y. G. Sharabian, E. Seder, D. P. Watts, S. Niccolai, H. S. Jo, D. Protopopescu, H. Egiyan, A. Deur, P. L. Cole, N. Harrison, Andrew Puckett, T. A. Forest, M. Garçon, W. K. Brooks, R. Dupre, Alessandro Rizzo, Martin K. Mayer, Avraham Klein, P. Nadel-Turonski, M. Battaglieri, Sergey Kuleshov, A. El Alaoui, J. J. Phillips, Nicholas Zachariou, G. Gavalian, Dustin Keller, M. Ripani, K. Hafidi, A. Simonyan, C. Salgado, I. J. D. MacGregor, M. Yurov, S. S. Stepanyan, V. P. Kubarovsky, O. Pogorelko, V. Sytnik, M. Contalbrigo, Gerard Gilfoyle, L. Colaneri, N. Markov, D. Sokhan, A. Celentano, R. W. Gothe, S. Pisano, O. Cortes, E. L. Isupov, Ye Tian, Diane Schott, S. Boiarinov, A. I. Ostrovidov, K. Park, D. G. Ireland, Volker D. Burkert, A. S. Biselli, C. Munoz Camacho, B. McKinnon, M. Mirazita, E. Phelps, N. Gevorgyan, V. Batourine, F. X. Girod, J. W. Price, S. Koirala, D. G. Jenkins, Eugene Pasyuk, N. A. Baltzell, K. A. Griffioen, Victor Mokeev, M. Ungaro, K. Joo, and J. Zhang
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, Structure function, Magnitude (mathematics), Parton, Helicity, Nuclear physics, Transverse plane, Pi, High Energy Physics::Experiment, Vector meson, Nuclear Experiment
Abstract: Exclusive neutral-pion electroproduction (ep-->e'p'pi0) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections d4sigma/dtdQ2dxBdphipi and structure functions sigmaT+epsilonsigmaL,sigmaTT and σLT as functions of t were obtained over a wide range of Q2 and xB. The data are compared with Regge and handbag theoretical calculations. Analyses in both frameworks find that a large dominance of transverse processes is necessary to explain the experimental results. For the Regge analysis it is found that the inclusion of vector meson rescattering processes is necessary to bring the magnitude of the calculated and measured structure functions into rough agreement. In the handbag framework, there are two independent calculations, both of which appear to roughly explain the magnitude of the structure functions in terms of transversity generalized parton distributions.
Published: 2014
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28. Induced polarization of {\Lambda}(1116) in kaon electroproduction

Author: B. S. Ishkhanov, A. Simonyan, W. Phelps, H. Hakobyan, H. S. Jo, C. A. Meyer, G. V. Fedotov, K. P. Adhikari, S. Strauch, P. Eugenio, S. E. Kuhn, M. Hattawy, J. A. Fleming, C. Salgado, F. X. Girod, V. P. Kubarovsky, Eugene Pasyuk, J. Bono, I. Bedlinskiy, P. Nadel-Turonski, N. Dashyan, S. Chandavar, O. Pogorelko, S. M. Hughes, F. Sabatié, M. J. Amaryan, S. Procureur, William Brooks, I. Zonta, X. Wei, H. Avakian, V. Baturin, Sergey Kuleshov, J. W. Price, N. K. Walford, B. Garillon, L. Zana, H. Voskanyan, H. Moutarde, R. Dupre, I. I. Strakovsky, M. Battaglieri, D. Ho, D. P. Watts, W. J. Briscoe, A. Deur, Yordanka Ilieva, S. Koirala, S. Niccolai, K. L. Giovanetti, S. S. Stepanyan, V. Sytnik, C. Djalali, Larry Weinstein, K. A. Griffioen, Alessandro Rizzo, Y. Ghandilyan, C. I. Moody, G. Charles, E. Golovatch, Dustin Keller, W. I. Levine, D. Adikaram, M. Guidal, G. Niculescu, D. G. Jenkins, R. A. Schumacher, G. D. Smith, M. Holtrop, M. Y. Gabrielyan, K. Hafidi, Luciano Pappalardo, M. Khandaker, J. P. Ball, T. A. Forest, D. S. Carman, M. Ripani, S. Stepanyan, E. Voutier, A. Movsisyan, E. Munevar, S. Fegan, V. Crede, A. V. Vlassov, R. De Vita, S. Anefalos Pereira, W. Tang, E. De Sanctis, M. Osipenko, D. I. Sober, W. Kim, Victor Mokeev, M. Ungaro, K. Joo, L. Guo, M. D. Mestayer, O. Cortes, Martin K. Mayer, S. Boiarinov, J. T. Goetz, K. Hicks, P. Lenisa, D. Doughty, Friedrich Klein, Brian Raue, A. D'Angelo, K. Livingston, L. El Fassi, R. Paremuzyan, Gerard Gilfoyle, J. J. Phillips, Jie Zhang, T. Cao, I. J. D. MacGregor, D. Sokhan, M. Contalbrigo, B. McKinnon, A. Celentano, R. W. Gothe, P. L. Cole, M. Mirazita, N. Gevorgyan, D. Protopopescu, S. Pozdniakov, P. Peng, C. Munoz Camacho, Diane Schott, N. A. Baltzell, K. Park, D. G. Ireland, H. Jiang, Volker D. Burkert, A. S. Biselli, Nicholas Zachariou, L. Colaneri, D. Rimal, S. Pisano, 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), CLAS, 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: Quark, Nuclear and High Energy Physics, Particle physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Induced polarization, DECAYS, Settore FIS/04 - Fisica Nucleare e Subnucleare, NO, Nuclear physics, CLAS, 0103 physical sciences, GAMMA-P, SIGMA(0), 010306 general physics, NUCLEON, Nuclear Experiment, PHOTON ENERGIES, PHOTOPRODUCTION, K+LAMBDA, SYSTEM, Physics, Spectrometer, 010308 nuclear & particles physics, Momentum transfer, Hyperon, Interaction model, Cathode ray, High Energy Physics::Experiment, Nucleon
Abstract: We have measured the induced polarization of the ${\Lambda}(1116)$ in the reaction $ep\rightarrow e'K^+{\Lambda}$, detecting the scattered $e'$ and $K^+$ in the final state along with the proton from the decay $\Lambda\rightarrow p\pi^-$.The present study used the CEBAF Large Acceptance Spectrometer (CLAS), which allowed for a large kinematic acceptance in invariant energy $W$ ($1.6\leq W \leq 2.7$ GeV) and covered the full range of the kaon production angle at an average momentum transfer $Q^2=1.90$ GeV$^2$.In this experiment a 5.50 GeV electron beam was incident upon an unpolarized liquid-hydrogen target. We have mapped out the $W$ and kaon production angle dependencies of the induced polarization and found striking differences from photoproduction data over most of the kinematic range studied. However, we also found that the induced polarization is essentially $Q^2$ independent in our kinematic domain, suggesting that somewhere below the $Q^2$ covered here there must be a strong $Q^2$ dependence. Along with previously published photo- and electroproduction cross sections and polarization observables, these data are needed for the development of models, such as effective field theories, and as input to coupled-channel analyses that can provide evidence of previously unobserved $s$-channel resonances., Comment: 13 figures
Published: 2014
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29. Data analysis techniques, differential cross sections, and spin density matrix elements for the reaction γp→ϕp

Author: D. P. Watts, A. V. Vlassov, E. Munevar, A. El Alaoui, Y. Ilieva, D. I. Glazier, R. Paremuzyan, B. S. Ishkhanov, A. Celentano, Nicholas Zachariou, R. W. Gothe, R. De Vita, Gerard Gilfoyle, D. Sokhan, K. Hafidi, H. Y. Lu, D. Rimal, A. Kim, W. Kim, S. Anefalos Pereira, H. S. Jo, B. McKinnon, G. Niculescu, C. Munoz Camacho, M. Mirazita, C. E. Hyde, M. Contalbrigo, N. Gevorgyan, S. Chandavar, A. Simonyan, F. Sabatié, N. A. Baltzell, E. De Sanctis, D. Protopopescu, M. Ungaro, J. P. Ball, D. S. Carman, D. Schott, R. A. Schumacher, M. Aghasyan, D. Keller, S. Pozdniakov, M. Garçon, J. W. Price, O. Cortes, J. J. Phillips, Michael L. Williams, D. I. Sober, B. Vernarsky, L. Colaneri, I. J. D. MacGregor, A. D'Angelo, I. Bedlinskiy, L. Zana, I. Zonta, R. Dupre, S. Boiarinov, P. Lenisa, V. P. Kubarovsky, K. A. Griffioen, N. Markov, M. Khandaker, I. I. Strakovsky, S. Pisano, V. Mokeev, K. Livingston, K. Joo, A. Deur, O. Pogorelko, Y. Ghandilyan, V. Sytnik, Avraham Klein, K. Park, N. Dashyan, M. J. Amaryan, L. El Fassi, D. G. Ireland, V. Crede, W. K. Brooks, Volker D. Burkert, A. S. Biselli, J. T. Goetz, T. Mineeva, C. Hanretty, H. Moutarde, D. Ho, Friedrich Klein, M. Bellis, I. Niculescu, R. A. Montgomery, K. L. Giovanetti, W. Tang, N. K. Walford, S. Niccolai, H. Voskanyan, M. Ripani, E. Voutier, M. Osipenko, M. Taiuti, D. Doughty, J. Zhang, Alessandro Rizzo, W. J. Briscoe, E. Pasyuk, P. Peng, Michael Dugger, P. Rossi, S. Procureur, M. Battaglieri, P. L. Cole, S. Fegan, M. E. McCracken, E. Seder, S. Strauch, Latifa Elouadrhiri, Kei Moriya, C. A. Meyer, G. V. Fedotov, K. P. Adhikari, Andrew Puckett, Martin K. Mayer, Barry Ritchie, M. S. Saini, S. E. Kuhn, M. Hattawy, S. Tkachenko, J. A. Fleming, Elton Smith, P. Roy, Y. G. Sharabian, N. Harrison, D. Adikaram, M. Guidal, C. Djalali, P. Stoler, M. Holtrop, B. Dey, I. Senderovich, K. Hicks, Luciano Pappalardo, Sergey Kuleshov, S. S. Stepanyan, J. Bono, P. Nadel-Turonski, F. X. Girod, S. Koirala, Z. W. Zhao, and D. G. Jenkins
Subjects: Physics, Nuclear and High Energy Physics, Scattering, Detector, Bremsstrahlung, Vector meson dominance, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Momentum, Matrix (mathematics), Vector meson, Atomic physics, Nuclear Experiment, Event (particle physics)
Abstract: High-statistics measurements of differential cross sections and spin density matrix elements for the reaction γ p → ϕ p have been made using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ( s ) from 1.97 to 2.84 GeV, with an extensive coverage in the ϕ production angle. The high statistics of the data sample made it necessary to carefully account for the interplay between the ϕ natural lineshape and effects of the detector resolution, that are found to be comparable in magnitude. We study both the charged- ( ϕ → K + K − ) and neutral- ( ϕ → K S 0 K L 0 ) K K ¯ decay modes of the ϕ . Further, for the charged mode, we differentiate between the cases where the final K − track is directly detected or its momentum reconstructed as the total missing momentum in the event. The two charged-mode topologies and the neutral-mode have different resolutions and are calibrated against each other. Extensive usage is made of kinematic fitting to improve the reconstructed ϕ mass resolution. Our final results are reported in 10- and mostly 30-MeV-wide s bins for the charged- and the neutral-modes, respectively. Possible effects from K + Λ * channels with p K K ¯ final states are discussed. These present results constitute the most precise and extensive ϕ photoproduction measurements to date and in conjunction with the ω photoproduction results recently published by CLAS, will greatly improve our understanding of low energy vector meson photoproduction.
Published: 2014
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30. Publisher's Note: Beam asymmetryΣforπ+andπ0photoproduction on the proton for photon energies from 1.102 to 1.862 GeV [Phys. Rev. C88, 065203 (2013)]

Author: L. Elouadrhiri, N. A. Baltzell, I. I. Strakovsky, C. S. Nepali, George Davey Smith, A. Deur, M. Contalbrigo, R. Paremuzyan, S. Fegan, D. Adikaram, M. Guidal, F. X. Girod, E. De Sanctis, A. D'Angelo, V. Mokeev, G. Niculescu, M. Khandaker, W. Tang, M. Aghasyan, M. Osipenko, Nicholas M. Harrison, Gerard Gilfoyle, M. Holtrop, D. I. Sober, A. El Alaoui, Nicholas Zachariou, L. El Fassi, D. Martinez, I. J. D. MacGregor, S. Park, D. Sokhan, S. Strauch, N. Dashyan, Luciano Pappalardo, P. Nadel-Turonski, P. Rossi, D. Rimal, I. Zonta, C. Djalali, A. Celentano, R. W. Gothe, D. P. Watts, W. Gohn, H. Y. Lu, S. Koirala, H. Egiyan, M. J. Amaryan, K. Livingston, Frank Klein, D. G. Ireland, Dustin Keller, Yordanka Ilieva, Diane Schott, E. Munevar, A. I. Ostrovidov, K. Park, R. De Vita, B. S. Ishkhanov, Michael Dugger, Sergey Kuleshov, Yakov I. Azimov, Brian Raue, H. Moutarde, V. Crede, E. Golovatch, A. Kubarovsky, K. A. Griffioen, N. K. Walford, I. Niculescu, N. Guler, K. L. Giovanetti, J. J. Phillips, K. Hafidi, S. Anefalos Pereira, R. A. Montgomery, P. Stoler, Ron L. Workman, V. Batourine, D. Doughty, G. Rosner, P. L. Cole, Z. W. Zhao, Volker D. Burkert, A. S. Biselli, R. A. Schumacher, S. Niccolai, D. Heddle, J. P. Ball, Y. Prok, D. S. Carman, F. Sabatié, K. Hicks, C. Hanretty, J. Zhang, S. Chandavar, S. Tkachenko, T. Mineeva, D. Protopopescu, J. W. Price, H. Avakian, P. Peng, B. Torayev, S. Pozdniakov, I. Senderovich, Alessandro Rizzo, E. Voutier, L. Guo, M. Ungaro, C. Munoz Camacho, S. Stepanyan, I. Bedlinskiy, Andreas Klein, M. Ripani, A. Kim, B. McKinnon, H. Voskanyan, K. Joo, Carlos A. Salgado, M. Mirazita, E. Phelps, W. J. Briscoe, E. Pasyuk, N. Gevorgyan, S. Procureur, S. Pisano, R. Dupre, M. Battaglieri, J. A. Fleming, V. P. Kubarovsky, P. Collins, O. Pogorelko, S. Lewis, Martin K. Mayer, M. S. Saini, J. T. Goetz, H. Seraydaryan, Y. G. Sharabian, P. Eugenio, M. Taiuti, D. Ho, E. Seder, Barry Ritchie, O. Cortes, E. L. Isupov, Ye Tian, S. Boiarinov, G. V. Fedotov, D. P. Weygand, K. P. Adhikari, Lorenzo Zana, H. Hakobyan, H. S. Jo, and W. Kim
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Meson production, Photon, Proton, Partial wave analysis, media_common.quotation_subject, Asymmetry, Beam (structure), media_common
Published: 2014
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31. $\phi$-meson photoproduction on Hydrogen in the neutral decay mode

Author: D. Doughty, Michael Wood, D. Heddle, K. Livingston, K. Hafidi, Jie Zhang, W. Kim, Victor Mokeev, N. Guler, Y. Ilieva, R. De Vita, W. J. Briscoe, P. Rossi, H. Y. Lu, M. J. Amaryan, S. Lewis, D. S. Carman, E. Munevar, N. A. Baltzell, H. Moutarde, P. Eugenio, E. Seder, N. Dashyan, M. Ungaro, K. L. Giovanetti, C. E. Hyde, K. A. Griffioen, Larry Weinstein, J. Bono, P. Nadel-Turonski, D. Protopopescu, W. Gohn, S. Pozdniakov, I. Niculescu, B. S. Ishkhanov, D. Keller, A. Kim, F. X. Girod, Z. W. Zhao, D. Ho, L. Weinstein, V. P. Kubarovsky, K. Joo, Barry Ritchie, P. Stoler, I. I. Strakovsky, Annalisa D'Angelo, H. Hakobyan, C. Hanretty, Andrea Celentano, R. Paremuzyan, M. Khandaker, A. Deur, K. Hicks, Nicholas Zachariou, H. Avakian, M. Ripani, W. Tang, S. E. Kuhn, W. K. Brooks, D. P. Watts, J. A. Fleming, J. J. Phillips, D. Rimal, M. Osipenko, C. E. Taylor, H. Baghdasaryan, S. Tkachenko, L. Guo, N. K. Walford, G. V. Fedotov, H. Voskanyan, G. Rosner, R. Nasseripour, I. J. D. MacGregor, E. Pasyuk, K. P. Adhikari, E. Golovatch, E. Voutier, Andrew Puckett, Martin K. Mayer, S. Strauch, D. Martinez, R. P. Bennett, E. De Sanctis, N. Harrison, R. G. Fersch, S. Fegan, M. Aghasyan, D. Adikaram, M. Guidal, Friedrich Klein, M. S. Saini, I. Bedlinskiy, R. A. Schumacher, D. I. Sober, G. D. Smith, M. Holtrop, D. Sokhan, J. P. Ball, S. Chandavar, Luciano Pappalardo, A. Rizzo, S. Park, R. W. Gothe, R. Dupre, M. Battaglieri, S. Niccolai, T. Mineeva, O. Pogorelko, P. Collins, M. F. Vineyard, Diane Schott, L. El Fassi, S. Bültmann, Sergey Kuleshov, A. I. Ostrovidov, K. Park, H. Seraydaryan, S. Anefalos Pereira, Y. G. Sharabian, A. Kubarovsky, S. Stepanyan, D. G. Ireland, V. Crede, Volker D. Burkert, M. Contalbrigo, A. S. Biselli, R. A. Montgomery, J. T. Goetz, H. S. Jo, S. Pisano, C. Munoz Camacho, Lorenzo Zana, B. McKinnon, M. Mirazita, C. Salgado, E. Phelps, N. Gevorgyan, V. Batourine, O. Cortes, E. L. Isupov, Ye Tian, S. Boiarinov, F. Sabatié, J. W. Price, G. Gavalian, S. Koirala, Chaden Djalali, Michael Dugger, Old Dominion University [Norfolk] (ODU), 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), 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, CLAS, 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: Nuclear and High Energy Physics, Particle physics, Meson, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Settore FIS/04 - Fisica Nucleare e Subnucleare, High Energy Physics - Experiment, Nuclear physics, Pion, LARGE MOMENTUM-TRANSFER, DRIFT CHAMBER SYSTEM, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], PERTURBATIVE QCD, SPECTROMETER, Invariant mass, NEAR-THRESHOLD, Nuclear Experiment, DETECTOR, Physics, Spectrometer, Perturbative QCD, Phi meson, Baryon, BARYON RESONANCES, High Energy Physics::Experiment, Energy (signal processing)
Abstract: See paper for full list of authors; We report the first measurement of the photoproduction cross section of the $\phi$ meson in its neutral decay mode in the reaction $\gamma p \to p\phi(K_SK_L)$. The experiment was performed with a tagged photon beam of energy $1.6 \le E_\gamma \le 3.6$ GeV incident on a liquid hydrogen target of the CLAS spectrometer at the Thomas Jefferson National Accelerator Facility. The $p \phi$ final state is identified via reconstruction of $K_S$ in the invariant mass of two oppositely charged pions and by requiring the missing particle in the reaction $\gamma p \to p K_S X$ to be $K_L$. The presented results significantly enlarge the existing data on $\phi$-photoproduction. These data, combined with the data from the charged decay mode, will help to constrain different mechanisms of $\phi$ photoproduction.
Published: 2014
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32. Beam-spin Asymmetries from Semi-inclusive Pion Electroproduction

Author: P. Lenisa, R. Dupre, J. Bono, P. Nadel-Turonski, M. Battaglieri, I. Zonta, G. V. Fedotov, V. Crede, Friedrich Klein, C. Hanretty, S. Niccolai, H. Avakian, S. Strauch, Brian Raue, F. X. Girod, R. Paremuzyan, K. P. Adhikari, B. S. Ishkhanov, P. Eugenio, N. K. Walford, M. Ungaro, H. Voskanyan, George Davey Smith, S. Chandavar, C. E. Hyde, H. Y. Lu, W. Kim, E. Pasyuk, W. J. Briscoe, G. Charles, P. Khetarpal, I. I. Strakovsky, S. Pisano, Gerard Gilfoyle, S. Procureur, C. Djalali, I. Niculescu, K. Joo, F. Sabatié, H. Seraydaryan, D. Sokhan, E. Seder, J. J. Phillips, Y. G. Sharabian, D. Ho, B. Vernarsky, D. S. Carman, Y. Prok, Dustin Keller, N. A. Baltzell, A. D'Angelo, L. El Fassi, O. Cortes, B. McKinnon, A. Movsisyan, M. Garçon, I. J. D. MacGregor, W. K. Brooks, E. Voutier, P. Roy, Barry Ritchie, M. Contalbrigo, L. Zana, G. Rosner, J. W. Price, Victor Mokeev, J. Ball, Michael Wood, W. Tang, D. P. Watts, K. Hafidi, T. Mineeva, Y. Ghandilyan, H. S. Jo, E. De Sanctis, B. Guegan, M. Mirazita, M. Holtrop, M. Osipenko, R. A. Schumacher, Diane Schott, A. I. Ostrovidov, M. Aghasyan, Luciano Pappalardo, K. Park, A. Simonyan, S. Koirala, D. G. Ireland, D. I. Sober, S. E. Kuhn, T. A. Forest, N. Markov, Volker D. Burkert, A. S. Biselli, S. Stepanyan, J. A. Fleming, Sergey Kuleshov, A. Celentano, R. De Vita, R. W. Gothe, V. P. Kubarovsky, Mohammad Hattawy, S. Anefalos Pereira, N. Dashyan, P. L. Cole, P. Peng, K. A. Griffioen, Andrew Puckett, Martin K. Mayer, W. Gohn, P. Stoler, K. Hicks, S. Tkachenko, L. Guo, Alessandro Rizzo, N. Harrison, K. Livingston, Jie Zhang, P. Rossi, S. Pozdniakov, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, M. Ripani, M. Khandaker, C. Salgado, M. J. Amaryan, K. L. Giovanetti, Larry Weinstein, D. Doughty, University of Connecticut (UCONN), 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), 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, CLAS, 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, Particle physics, Scattering, FOS: Physical sciences, Large range, Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Deep inelastic scattering, High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare, High Energy Physics - Experiment (hep-ex), Pion, Reaction model, Statistical precision, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We have measured the moment $A_{LU}^{\sin\phi}$ corresponding to the polarized electron beam-spin asymmetry in SIDIS. $A_{LU}^{\sin\phi}$ is a twist-3 quantity providing information about quark-gluon correlations. Data were taken with the CLAS Spectrometer at Jefferson Lab using a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target. All three pion channels ($\pi^+$, $\pi^0$ and $\pi^-$) were measured simultaneously over a large range of kinematics within the virtuality range $Q^2 \approx$ 1.0-4.5 GeV$^2$. The observable was measured with better than 1% statistical precision over a large range of $z$, $P_T$, $x_B$, and $Q^{2}$, which permits comparison with several reaction models. The discussed measurements provide an upgrade in statistics over previous measurements, and serve as the first evidence for the negative sign of the $\pi^{-}$ $\sin\phi$ moment., Comment: 16 pages, 18 figures
Published: 2014
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33. Beam asymmetryΣforπ+andπ0photoproduction on the proton for photon energies from 1.102 to 1.862 GeV

Author: C. Hanretty, I. Bedlinskiy, Martin K. Mayer, Ron L. Workman, G. Rosner, M. S. Saini, O. Cortes, E. L. Isupov, Ye Tian, Sergey Kuleshov, B. S. Ishkhanov, S. Boiarinov, F. X. Girod, S. Strauch, E. De Sanctis, A. El Alaoui, Y. Ilieva, D. P. Watts, H. Egiyan, M. Aghasyan, Nicholas Zachariou, I. Zonta, D. I. Sober, P. Nadel-Turonski, D. Rimal, Friedrich Klein, Brian Raue, J. W. Price, C. Munoz Camacho, M. Contalbrigo, G. V. Fedotov, S. Chandavar, Michael Dugger, K. Joo, Yakov I. Azimov, K. P. Adhikari, D. P. Weygand, S. S. Stepanyan, S. Niccolai, H. Seraydaryan, M. Taiuti, W. Tang, Y. G. Sharabian, A. Kubarovsky, R. Dupre, N. A. Baltzell, M. Battaglieri, M. Osipenko, M. Ripani, F. Sabatié, George Davey Smith, T. Mineeva, P. Eugenio, D. Martinez, D. G. Ireland, V. Crede, K. Livingston, S. Koirala, E. Seder, I. I. Strakovsky, I. J. D. MacGregor, R. A. Montgomery, D. Adikaram, M. Guidal, M. Khandaker, A. Deur, A. D'Angelo, V. Mokeev, M. Holtrop, J. T. Goetz, J. A. Fleming, R. De Vita, Barry Ritchie, Luciano Pappalardo, M. J. Amaryan, L. El Fassi, C. Djalali, Lorenzo Zana, P. Collins, N. K. Walford, E. Golovatch, H. Hakobyan, H. Moutarde, H. S. Jo, J. J. Phillips, S. Park, E. Voutier, S. Anefalos Pereira, Z. W. Zhao, C. Salgado, P. Rossi, K. L. Giovanetti, J. Zhang, D. Ho, W. Kim, D. Doughty, K. A. Griffioen, G. Niculescu, D. Heddle, V. P. Kubarovsky, H. Y. Lu, W. Gohn, O. Pogorelko, S. Lewis, P. L. Cole, C. S. Nepali, B. Torayev, D. Protopopescu, Dustin Keller, S. Pozdniakov, I. Niculescu, S. Procureur, K. Hafidi, A. Celentano, R. W. Gothe, R. A. Schumacher, E. Munevar, Avraham Klein, H. Avakian, H. Voskanyan, W. J. Briscoe, E. Pasyuk, P. Stoler, K. Hicks, S. Tkachenko, L. Guo, N. Harrison, S. Pisano, Diane Schott, A. I. Ostrovidov, K. Park, Volker D. Burkert, A. S. Biselli, N. Dashyan, S. Fegan, R. Paremuzyan, Gerard Gilfoyle, J. P. Ball, Y. Prok, D. S. Carman, D. Sokhan, B. McKinnon, M. Mirazita, E. Phelps, N. Gevorgyan, and V. Batourine
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Proton, 010308 nuclear & particles physics, Scattering, media_common.quotation_subject, Partial wave analysis, 01 natural sciences, 7. Clean energy, Asymmetry, Nuclear physics, Pion, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Energy (signal processing), Beam (structure), media_common
Abstract: Beam asymmetries for the reactions $\ensuremath{\gamma}p\ensuremath{\rightarrow}p{\ensuremath{\pi}}^{0}$ and $\ensuremath{\gamma}p\ensuremath{\rightarrow}n{\ensuremath{\pi}}^{+}$ have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged, linearly polarized photon beam with energies from 1.102--1.862 GeV. A Fourier moment technique for extracting beam asymmetries from experimental data is described. The results reported here possess greater precision and finer energy resolution than previous measurements. Our data for both pion reactions appear to favor the SAID and Bonn-Gatchina scattering analyses over the older Mainz MAID predictions. After incorporating the present set of beam asymmetries into the world database, exploratory fits made with the SAID analysis indicate that the largest changes from previous fits are for properties of the $\ensuremath{\Delta}(1700)3/{2}^{\ensuremath{-}}$ and $\ensuremath{\Delta}(1905)5/{2}^{+}$ states.
Published: 2013
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34. First observation of the Lambda(1405) line shape in electroproduction

Author: B. McKinnon, D. Adikaram, M. Guidal, E. Golovatch, G. Niculescu, M. Ripani, Andrew Puckett, Martin K. Mayer, S. Strauch, M. Mirazita, E. Phelps, N. Gevorgyan, M. Holtrop, Eugene Pasyuk, M. S. Saini, V. Batourine, P. Collins, S. Koirala, Luciano Pappalardo, D. Doughty, Friedrich Klein, K. A. Griffioen, H. Y. Lu, V. Crede, S. Procureur, Diane Schott, A. I. Ostrovidov, K. Park, C. E. Hyde, G. Rosner, B. S. Ishkhanov, P. Peng, Hovanes Egiyan, F. X. Girod, J. A. Fleming, C. Munoz Camacho, V. P. Kubarovsky, D. G. Ireland, I. Niculescu, R. De Vita, W. Kim, A. Deur, D. Heddle, Volker D. Burkert, S. Tkachenko, Sergey Kuleshov, R. A. Montgomery, O. Pogorelko, B. A. Raue, A. S. Biselli, R. Paremuzyan, S. Anefalos Pereira, J. W. Price, M. Y. Gabrielyan, R. A. Schumacher, P. Nadel-Turonski, S. Fegan, R. Dupre, M. Battaglieri, Gerard Gilfoyle, P. Eugenio, C. S. Nepali, M. Taiuti, N. K. Walford, S. S. Stepanyan, H. Voskanyan, Lorenzo Zana, S. Chandavar, D. Sokhan, H. Seraydaryan, W. J. Briscoe, N. Harrison, E. De Sanctis, W. Tang, M. Aghasyan, D. I. Sober, W. Gohn, Y. G. Sharabian, N. Dashyan, E. Munevar, Avraham Klein, P. L. Cole, F. Sabatié, George Davey Smith, A. Kubarovsky, Z. W. Zhao, D. Ho, D. Protopopescu, S. Pozdniakov, M. Osipenko, D. Martinez, S. Niccolai, H. S. Jo, William Brooks, B. Vernarsky, A. D'Angelo, C. Djalali, P. Stoler, S. Park, H. Hakobyan, Michael Wood, David M. Keller, L. El Fassi, K. Livingston, P. Rossi, K. Hicks, K. Hafidi, J. P. Ball, Y. Prok, D. S. Carman, C. Salgado, E. Seder, S. Pisano, I. Bedlinskiy, Jie Zhang, E. Voutier, T. Mineeva, Kei Moriya, C. A. Meyer, G. V. Fedotov, A. El Alaoui, Nicholas Zachariou, K. P. Adhikari, S. Lewis, D. P. Weygand, J. T. Goetz, D. Rimal, O. Cortes, E. L. Isupov, Ye Tian, S. Boiarinov, M. Khandaker, V. I. Mokeev, Y. Ilieva, B. Torayev, M. J. Amaryan, H. Moutarde, K. L. Giovanetti, L. Guo, K. Joo, A. Celentano, R. W. Gothe, M. Contalbrigo, J. J. Phillips, I. J. D. MacGregor, 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), 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), CLAS, 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: Nuclear and High Energy Physics, Photon, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Proton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Lambda, 01 natural sciences, High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], SCATTERING, Nuclear Experiment, 010306 general physics, Line (formation), Physics, BARYONS, Mass distribution, 010308 nuclear & particles physics, QUARK-MODEL, HYPERFINE INTERACTIONS, NUCLEON INTERACTIONS, CHIRAL DYNAMICS, CONSTRAINTS, STATES, Hyperon, Resonance, Particle Data Group, 3. Good health, High Energy Physics::Experiment, Atomic physics
Abstract: We report the first observation of the line shape of the $\Lambda(1405)$ from electroproduction, and show that it is not a simple Breit-Wigner resonance. Electroproduction of $K^+ \Lambda(1405)$ off the proton was studied by using data from CLAS at Jefferson Lab in the range $1.0, Comment: 8 pages, 8 figures. Version 2 has some added references; submitted to Phys. Rev. C
Published: 2013
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35. Differential photoproduction cross sections of theΣ0(1385),Λ(1405), andΛ(1520)

Author: H. Y. Lu, Jie Zhang, H. Avakian, M. F. Vineyard, R. Fersch, N. Guler, M. J. Amaryan, N. K. Walford, S. Fegan, H. Voskanyan, H. Seraydaryan, J. P. Ball, D. S. Carman, I. Zonta, R. De Vita, W. J. Briscoe, E. Pasyuk, E. Voutier, Friedrich Klein, H. Moutarde, I. Niculescu, Brian Raue, K. L. Giovanetti, Y. G. Sharabian, A. Kubarovsky, S. Anefalos Pereira, Larry Weinstein, A. Deur, R. A. Schumacher, F. Sabatié, B. Vernarsky, V. P. Kubarovsky, D. Doughty, S. Tkachenko, P. Eugenio, L. Guo, G. Niculescu, Andrew Puckett, Martin K. Mayer, O. Pogorelko, D. Adikaram, W. K. Brooks, D. Heddle, D. Protopopescu, M. Guidal, S. Pozdniakov, S. Park, E. Munevar, S. Niccolai, S. Chandavar, E. Seder, B. S. Ishkhanov, E. De Sanctis, C. E. Taylor, J. J. Phillips, P. Rossi, M. S. Saini, Michael Wood, M. Aghasyan, Z. W. Zhao, David M. Keller, D. I. Sober, M. Holtrop, S. Stepanyan, I. J. D. MacGregor, H. Hakobyan, D. Ho, V. Crede, Y. Ilieva, Kei Moriya, C. A. Meyer, G. V. Fedotov, E. Golovatch, C. Hanretty, Nicholas Zachariou, M. Khandaker, M. Contalbrigo, C. S. Nepali, Luciano Pappalardo, S. Strauch, D. P. Watts, R. A. Montgomery, S. Lewis, M. D. Mestayer, B. McKinnon, J. A. Fleming, O. Cortes, T. Mineeva, D. Rimal, P. Stoler, M. Taiuti, E. L. Isupov, W. Tang, J. Bono, P. Nadel-Turonski, Ye Tian, Michael L. Williams, K. P. Adhikari, B. Dey, M. Osipenko, Diane Schott, G. Rosner, R. Nasseripour, A. I. Ostrovidov, K. Park, S. Boiarinov, K. Hicks, I. Bedlinskiy, D. G. Ireland, D. Martinez, Volker D. Burkert, A. S. Biselli, M. Mirazita, Barry Ritchie, F. X. Girod, A. Celentano, R. W. Gothe, Sergey Kuleshov, J. T. Goetz, V. Mokeev, W. Gohn, N. Gevorgyan, V. Batourine, C. Djalali, J. W. Price, S. Koirala, R. Paremuzyan, Lorenzo Zana, E. Phelps, S. Pisano, H. S. Jo, Gerard Gilfoyle, C. Salgado, D. Sokhan, Hovanes Egiyan, C. Munoz Camacho, R. P. Bennett, P. Collins, N. A. Baltzell, K. A. Griffioen, S. Taylor, Avraham Klein, M. Ungaro, M. Ripani, Michael Dugger, K. Joo, M. Bellis, R. Dupre, M. Battaglieri, S. Procureur, George Davey Smith, A. D'Angelo, L. El Fassi, M. E. McCracken, K. Livingston, and N. Dashyan
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Current (mathematics), 010308 nuclear & particles physics, Theoretical models, Hyperon, Sigma, Lambda, 01 natural sciences, Nuclear physics, Isospin, 0103 physical sciences, Effective lagrangian, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Differential (mathematics)
Abstract: We report the exclusive photoproduction cross sections for the Sigma(1385), Lambda(1405), and Lambda(1520) in the reactions gamma + p -> K+ + Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective Lagrangian approach and fitted to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Lambda(1405) region are strikingly different for the Sigma+pi-, Sigma0 pi0, and Sigma- pi+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.
Published: 2013
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36. Demonstration of a novel technique to measure two-photon exchange effects in elastice±pscattering

Author: R. P. Bennett, P. Eugenio, J. Bono, N. A. Baltzell, K. A. Griffioen, Andrew Puckett, S. Strauch, Martin K. Mayer, H. Y. Lu, M. MacCormick, A. Deur, R. Paremuzyan, M. Battaglieri, M. S. Saini, I. Zonta, H. Egiyan, Gerard Gilfoyle, R. De Vita, D. Sokhan, I. Niculescu, J. T. Goetz, B. McKinnon, P. Collins, S. Tkachenko, E. Seder, M. Mirazita, E. Phelps, S. Anefalos Pereira, L. Guo, Z. W. Zhao, G. Rosner, R. Nasseripour, N. Gevorgyan, S. Chandavar, W. Gohn, D. Ho, V. Batourine, Kei Moriya, C. E. Taylor, William Brooks, S. E. Kuhn, O. Cortes, V. P. Kubarovsky, G. V. Fedotov, E. L. Isupov, Ye Tian, J. A. Fleming, S. Park, J. Zhang, Andrei Afanasev, E. De Sanctis, E. Golovatch, O. Pogorelko, S. Boiarinov, A. Celentano, R. Dupre, R. W. Gothe, P. Rossi, M. Aghasyan, R. A. Schumacher, C. Munoz Camacho, K. P. Adhikari, Lorenzo Zana, H. Avakian, J. Lachniet, D. I. Sober, H. Hakobyan, C. Hanretty, S. Procureur, N. Harrison, Maryam Moteabbed, E. Munevar, B. S. Ishkhanov, V. Crede, C. Salgado, N. K. Walford, M. Ungaro, H. Voskanyan, R. A. Montgomery, Chaden Djalali, Elton Smith, M. R. Niroula, H. Seraydaryan, Y. G. Sharabian, A. Kubarovsky, S. Lewis, F. Sabatié, S. Stepanyan, G. Niculescu, W. J. Briscoe, I. Bedlinskiy, H. S. Jo, K. Joo, T. Mineeva, J. J. Phillips, George Davey Smith, Dustin Keller, S. Fegan, S. Pisano, I. J. D. MacGregor, S. Koirala, A. Kim, W. Tang, Michael Wood, M. Contalbrigo, A. D'Angelo, M. Osipenko, K. Hafidi, Victor Mokeev, K. Hicks, D. Martinez, F. X. Girod, N. Dashyan, L. El Fassi, J. W. Price, D. Protopopescu, P. Nadel-Turonski, S. Pozdniakov, E. Voutier, Diane Schott, A. I. Ostrovidov, K. Park, D. G. Ireland, N. Guler, Volker D. Burkert, A. S. Biselli, Y. Ilieva, Nicholas Zachariou, J. P. Ball, D. Rimal, R. G. Fersch, D. S. Carman, P. L. Cole, D. Doughty, S. Niccolai, D. Heddle, M. J. Amaryan, H. Moutarde, K. L. Giovanetti, Sergey Kuleshov, D. Adikaram, Larry Weinstein, M. Guidal, M. Holtrop, Luciano Pappalardo, M. Khandaker, C. E. Hyde, Friedrich Klein, J. Arrington, Brian Raue, and M. Ripani
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, Photon, Proton, 010308 nuclear & particles physics, Scattering, Electron, 01 natural sciences, Nuclear physics, Positron, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Atomic physics, 010306 general physics, Electron scattering, Beam (structure)
Abstract: Background: The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations of TPE corrections have significant model dependence, and there is limited direct experimental evidence for such corrections. Purpose: The TPE contributions depend on the sign of the lepton charge in e(+/-)p scattering, but the luminosities of secondary positron beams limited past measurement at large scattering angles, where the TPE effects are believe to be most significant. We present the results of a new experimental technique for making direct e(+/-)p comparisons, which has the potential to make precise measurements over a broad range in Q(2) and scattering angles. Methods: We use the Jefferson Laboratory electron beam and the Hall B photon tagger to generate a clean but untagged photon beam. The photon beam impinges on a converter foil to generate a mixed beam of electrons, positrons, and photons. A chicane is used to separate and recombine the electron and positron beams while the photon beam is stopped by a photon blocker. This provides a combined electron and positron beam, with energies from 0.5 to 3.2 GeV, which impinges on a liquid hydrogen target. The large acceptance CLAS detector is used to identify and reconstruct elastic scattering events, determining both the initial lepton energy and the sign of the scattered lepton. Results: The data were collected in two days with a primary electron beam energy of only 3.3 GeV, limiting the data from this run to smaller values of Q(2) and scattering angle. Nonetheless, this measurement yields a data sample for e(+/-)p with statistics comparable to those of the best previous measurements. We have shown that we can cleanly identify elastic scattering events and correct for the difference in acceptance for electron and positron scattering. Because we ran with only one polarity for the chicane, we are unable to study the difference between the incoming electron and positron beams. This systematic effect leads to the largest uncertainty in the final ratio of positron to electron scattering: R = 1.027 +/- 0.005 +/- 0.05 for = 0.206 GeV2 and 0.830
Published: 2013
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37. Cross sections for theγp→K+Λandγp→K+Σ0reactions measured at CLAS

Author: N. K. Walford, H. Voskanyan, W. J. Briscoe, E. Pasyuk, V. Mokeev, P. Khetarpal, Michael Wood, K. Hafidi, A. V. Vlassov, Diane Schott, I. I. Strakovsky, V. P. Kubarovsky, O. Pogorelko, P. Eugenio, R. Dupre, Y. Prok, M. Battaglieri, D. S. Carman, A. I. Ostrovidov, R. De Vita, K. Park, A. Deur, C. A. Meyer, F. X. Girod, G. V. Fedotov, I. Zonta, D. G. Ireland, E. Voutier, S. Strauch, D. P. Watts, P. Collins, C. Munoz Camacho, Volker D. Burkert, A. S. Biselli, R. Paremuzyan, W. Kim, G. Niculescu, M. Ungaro, R. A. Schumacher, S. H. Kim, S. Anefalos Pereira, S. Fegan, Friedrich Klein, B. Vernarsky, C. S. Nepali, George Davey Smith, K. P. Adhikari, Gerard Gilfoyle, P. Stoler, D. P. Weygand, D. Sokhan, Z. W. Zhao, E. De Sanctis, D. Ho, W. Tang, K. Joo, Brian Raue, J. W. Price, G. Rosner, M. Aghasyan, Hyun-Chul Kim, M. Osipenko, D. I. Sober, A. D'Angelo, B. McKinnon, S. Stepanyan, W. Gohn, J. J. Phillips, C. E. Hyde, F. Sabatié, D. Martinez, N. Markov, M. Y. Gabrielyan, E. Munevar, S. Koirala, N. Dashyan, I. J. D. MacGregor, K. Hicks, C. E. Taylor, S. Pisano, L. El Fassi, H. Y. Lu, M. Contalbrigo, S. Niccolai, N. A. Baltzell, J. Bono, P. Nadel-Turonski, E. Golovatch, S. Tkachenko, Barry Ritchie, A. Kim, N. Gevorgyan, David M. Keller, K. A. Griffioen, E. Phelps, G. Charles, S. Chandavar, L. Guo, Y. Mao, H. Hakobyan, C. Hanretty, D. Protopopescu, I. Niculescu, B. S. Ishkhanov, P. L. Cole, A. Celentano, R. W. Gothe, I. Bedlinskiy, S. Pozdniakov, N. Harrison, S. Procureur, C. Djalali, M. Khandaker, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, M. J. Amaryan, H. Moutarde, D. Rimal, K. L. Giovanetti, Larry Weinstein, D. Doughty, K. Livingston, D. Heddle, Jie Zhang, B. Torayev, M. Guidal, M. Holtrop, S. Park, P. Rossi, Luciano Pappalardo, V. Crede, M. Ripani, S. S. Stepanyan, A. Kubarovsky, Andrew Puckett, Sergey Kuleshov, Martin K. Mayer, M. S. Saini, J. A. Fleming, H. Seraydaryan, Y. G. Sharabian, Lorenzo Zana, H. S. Jo, C. Salgado, O. Cortes, E. L. Isupov, Ye Tian, and S. Boiarinov
Subjects: Physics, Nuclear and High Energy Physics, Meson production, Photon, 010308 nuclear & particles physics, Hyperon, 7. Clean energy, 01 natural sciences, Nuclear physics, Cross section (physics), 0103 physical sciences, Isobar, Atomic physics, 010306 general physics, Legendre polynomials
Abstract: The first high-statistics cross sections for the reactions γp→K*+Λ and γp→K*+Σ0 were measured using the CLAS detector at photon energies between threshold and 3.9 GeV at the Thomas Jefferson National Accelerator Facility. Differential cross sections are presented over the full range of the center-of-mass angles, and then fitted to Legendre polynomials to extract the total cross section. Results for the K*+Λ final state are compared with two different calculations in an isobar and a Regge model, respectively. Theoretical calculations significantly underestimate the K*+Λ total cross sections between 2.1 and 2.6 GeV, but are in better agreement with present data at higher photon energies.
Published: 2013
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38. Transverse polarization ofΣ+(1189)in photoproduction on a hydrogen target in CLAS

Author: M. Taiuti, B. S. Ishkhanov, H. Hakobyan, C. Hanretty, V. Mokeev, A. Kim, K. Hafidi, Z. W. Zhao, P. Khetarpal, M. Khandaker, I. Bedlinskiy, D. Ho, G. Charles, E. De Sanctis, F. X. Girod, S. E. Kuhn, Friedrich Klein, M. Aghasyan, Brian Raue, D. I. Sober, D. Protopopescu, V. Crede, R. A. Schumacher, Barry Ritchie, S. S. Stepanyan, B. Vernarsky, J. A. Fleming, S. Pozdniakov, F. Sabatié, D. Doughty, I. Zonta, J. W. Price, A. V. Vlassov, G. Rosner, N. K. Walford, H. Voskanyan, W. J. Briscoe, D. I. Glazier, George Davey Smith, E. Pasyuk, S. Fegan, C. E. Hyde, D. Heddle, R. A. Montgomery, S. Koirala, R. De Vita, S. Bültmann, W. Tang, M. Osipenko, David M. Keller, S. Anefalos Pereira, K. Hicks, S. Stepanyan, E. Munevar, B. Torayev, S. Tkachenko, T. Mineeva, E. Phelps, Avraham Klein, L. El Fassi, C. E. Taylor, S. Niccolai, Jie Zhang, M. J. Amaryan, E. Golovatch, W. Kim, N. Dashyan, N. Harrison, H. Seraydaryan, G. Niculescu, N. Guler, E. Seder, S. Park, R. W. Gothe, V. P. Kubarovsky, R. G. Fersch, P. Rossi, I. I. Strakovsky, H. Y. Lu, Y. G. Sharabian, P. L. Cole, O. Pogorelko, A. Deur, H. Baghdasaryan, C. S. Nepali, G. V. Fedotov, I. Niculescu, A. El Alaoui, Y. Ilieva, K. L. Giovanetti, Andrew Puckett, Martin K. Mayer, Nicholas Zachariou, K. P. Adhikari, D. P. Weygand, N. D. Kvaltine, C. Munoz Camacho, Larry Weinstein, M. S. Saini, J. P. Ball, D. Rimal, M. Ripani, D. S. Carman, J. J. Phillips, N. Markov, I. J. D. MacGregor, W. Gohn, B. McKinnon, M. Contalbrigo, S. Pisano, Sergey Kuleshov, M. Guidal, M. Mirazita, M. Holtrop, N. Gevorgyan, V. Batourine, Luciano Pappalardo, Diane Schott, A. I. Ostrovidov, K. Park, R. Paremuzyan, D. G. Ireland, Volker D. Burkert, A. S. Biselli, D. Sokhan, Lorenzo Zana, H. S. Jo, Andrea Celentano, S. Procureur, C. Salgado, S. Strauch, D. P. Watts, M. Y. Gabrielyan, E. L. Isupov, Ye Tian, S. Chandavar, C. Djalali, K. A. Griffioen, S. Boiarinov, R. Dupre, E. Voutier, M. Battaglieri, J. T. Goetz, P. Collins, J. Bono, and P. Nadel-Turonski
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Quark model, Hyperon, Photon energy, Lambda, 01 natural sciences, Baryon, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment, 010306 general physics
Abstract: Experimental results on the $$\Sigma^+(1189)$$ hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson laboratory are presented. The $$\Sigma^+(1189)$$ was reconstructed in the exclusive reaction $$\gamma+p\rightarrow K^{0}_{S} + \Sigma^+(1189)$$ via the $$\Sigma^{+} \to p \pi^{0}$$ decay mode. The $$K^{0}_S$$ was reconstructed in the invariant mass of two oppositely charged pions with the $$\pi^0$$ identified in the missing mass of the detected $$p\pi^+\pi^-$$ final state. Experimental data were collected in the photon energy range $$E_{\gamma}$$ = 1.0-3.5 GeV ($$\sqrt{s}$$ range 1.66-2.73 GeV). We observe a large negative polarization of up to 95%. As the mechanism of transverse polarization of hyperons produced in unpolarized photoproduction experiments is still not well understood, these results will help to distinguish between different theoretical models on hyperon production and provide valuable information for the searches of missing baryon resonances.
Published: 2013
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39. Measurement of theΣπphotoproduction line shapes near theΛ(1405)

Author: P. Eugenio, B. S. Ishkhanov, R. A. Schumacher, P. Collins, C. E. Taylor, F. X. Girod, C. E. Hyde, H. Hakobyan, W. Tang, M. D. Mestayer, E. Golovatch, P. Khetarpal, N. A. Baltzell, K. A. Griffioen, J. P. Ball, D. S. Carman, C. Hanretty, M. Osipenko, E. L. Isupov, D. Adikaram, M. Guidal, Barry Ritchie, R. Paremuzyan, S. Taylor, Diane Schott, Ye Tian, Michael L. Williams, P. L. Cole, A. I. Ostrovidov, K. Park, M. Holtrop, S. Stepanyan, E. Munevar, Gerard Gilfoyle, D. Protopopescu, J. W. Price, S. Pozdniakov, Avraham Klein, D. G. Ireland, Z. W. Zhao, G. Charles, M. E. McCracken, S. Tkachenko, D. Ho, B. Vernarsky, Volker D. Burkert, A. S. Biselli, I. Bedlinskiy, A. Kim, R. Dupre, N. K. Walford, M. Battaglieri, S. Strauch, S. S. Stepanyan, S. Koirala, H. Voskanyan, D. P. Watts, L. L. Pappalardo, I. Zonta, A. Celentano, R. W. Gothe, W. J. Briscoe, E. Pasyuk, N. Harrison, George Davey Smith, N. D. Kvaltine, A. Kubarovsky, K. Livingston, V. Mokeev, J. Bono, P. Nadel-Turonski, H. Y. Lu, S. Park, Jie Zhang, A. D'Angelo, W. Gohn, S. Niccolai, Sergey Kuleshov, Friedrich Klein, R. Fersch, E. Seder, S. Chandavar, T. Mineeva, Hovanes Egiyan, P. Rossi, C. Munoz Camacho, I. Niculescu, L. El Fassi, S. Fegan, N. Pivnyuk, R. Nasseripour, P. Stoler, I. I. Strakovsky, V. P. Kubarovsky, Kei Moriya, B. Dey, C. A. Meyer, F. Sabatié, O. Pogorelko, K. Hicks, W. Kim, G. V. Fedotov, V. Crede, C. Djalali, B. McKinnon, Y. Ilieva, G. Niculescu, S. Procureur, Nicholas Zachariou, A. Deur, R. A. Montgomery, G. Rosner, M. Taiuti, Dustin Keller, E. Voutier, N. Markov, D. Rimal, K. P. Adhikari, D. P. Weygand, S. Pisano, C. S. Nepali, K. Hafidi, M. Mirazita, N. Dashyan, E. Phelps, N. Gevorgyan, V. Batourine, M. Bellis, J. J. Phillips, I. J. D. MacGregor, Elton Smith, M. Ripani, H. Seraydaryan, Y. G. Sharabian, Martin K. Mayer, M. S. Saini, M. Khandaker, D. Doughty, J. A. Fleming, D. Heddle, B. Torayev, A. V. Vlassov, K. L. Giovanetti, R. De Vita, S. Anefalos Pereira, E. De Sanctis, M. Aghasyan, D. I. Sober, M. Ungaro, S. Boiarinov, J. T. Goetz, Lorenzo Zana, H. S. Jo, and C. Salgado
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Quark model, Sigma, Lambda, 01 natural sciences, Baryon, Amplitude, Isospin, 0103 physical sciences, Invariant mass, Production (computer science), Atomic physics, 010306 general physics
Abstract: The reaction {gamma} + p -> K{sup +} + {Sigma} + {p}i was used to determine the invariant mass distributions or "line shapes" of the {Sigma}{sup +} {pi}{sup -}, {Sigma}{sup -} {pi}{sup +} and {Sigma}{sup 0} {pi}{sup 0} final states, from threshold at 1328 MeV/c^2 through the mass range of the {Lambda}(1405) and the {Lambda}(1520). The measurements were made with the CLAS system at Jefferson Lab using tagged real photons, for center-of-mass energies 1.95 < W < 2.85 GeV. The three mass distributions differ strongly in the vicinity of the I=0 {Lambda}(1405), indicating the presence of substantial I=1 strength in the reaction. Background contributions to the data from the {Sigma}{sup 0}(1385) and from K* {Sigma} production were studied and shown to have negligible influence. To separate the isospin amplitudes, Breit-Wigner model fits were made that included channel-coupling distortions due to the Nkbar threshold. A best fit to all the data was obtained after including a phenomenological I=1, J{sup P} = 1/2{sup -} amplitude with a centroid at 1394\pm20 MeV/c^2 and a second I=1 amplitude at 1413\pm10 MeV/c^2. The centroid of the I=0 {Lambda}(1405) strength was found at the {Sigma} {pi} threshold, with the observed shape determined largely by channel-coupling, leadingmore » to an apparent overall peak near 1405 MeV/c^2.« less
Published: 2013
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40. Separated structure functions for exclusiveK+ΛandK+Σ0electroproduction at 5.5 GeV measured with CLAS

Author: N. A. Baltzell, E. De Sanctis, M. Aghasyan, H. Y. Lu, M. D. Mestayer, S. Strauch, G. Charles, D. I. Sober, O. Cortes, E. L. Isupov, Ye Tian, S. Procureur, Y. Prok, M. Ungaro, Eugene Pasyuk, D. P. Watts, P. Stoler, F. X. Girod, S. Boiarinov, M. Anghinolfi, H. Seraydaryan, M. Contalbrigo, V. P. Kubarovsky, D. Doughty, C. Hanretty, A. Fradi, Y. G. Sharabian, M. Ripani, I. Niculescu, R. De Vita, A. El Alaoui, V. Mokeev, O. Pogorelko, K. Joo, J. T. Goetz, K. Hicks, D. Heddle, J. W. Price, S. Anefalos Pereira, M. Y. Gabrielyan, Andrew Puckett, Martin K. Mayer, Dustin Keller, C. Munoz Camacho, J. P. Ball, S. Lewis, R. A. Schumacher, D. S. Carman, S. Pisano, B. McKinnon, M. S. Saini, S. Koirala, Sergey Kuleshov, R. Dupre, Nicholas Zachariou, D. Rimal, P. L. Cole, C. Djalali, Michael Wood, I. Bedlinskiy, S. Chandavar, M. Mirazita, E. Phelps, K. Hafidi, S. Park, M. Battaglieri, N. Gevorgyan, George Davey Smith, S. Tkachenko, V. Batourine, E. Voutier, E. Seder, L. Guo, Lorenzo Zana, I. Zonta, Diane Schott, H. Avakian, A. I. Ostrovidov, K. Park, R. Nasseripour, K. Livingston, J. A. Fleming, W. Kim, N. K. Walford, T. Mineeva, N. Harrison, A. D'Angelo, S. Stepanyan, H. Hakobyan, H. S. Jo, E. Munevar, C. A. Meyer, H. Voskanyan, R. Paremuzyan, G. V. Fedotov, I. I. Strakovsky, B. Guegan, Avraham Klein, K. A. Griffioen, D. G. Ireland, Y. Ilieva, Jie Zhang, G. Niculescu, S. Fegan, W. J. Briscoe, J. Bono, P. Nadel-Turonski, V. Crede, C. Salgado, P. Eugenio, J. J. Phillips, L. El Fassi, A. Deur, M. Taiuti, K. P. Adhikari, D. Sokhan, S. Niccolai, William Brooks, Volker D. Burkert, A. S. Biselli, R. Fersch, Y. Mao, S. S. Stepanyan, P. Khetarpal, I. J. D. MacGregor, N. Dashyan, C. S. Nepali, C. E. Taylor, R. A. Montgomery, N. A. Saylor, A. Trivedi, N. D. Kvaltine, H. Baghdasaryan, W. Tang, P. Rossi, A. Celentano, R. W. Gothe, Z. W. Zhao, A. Kubarovsky, M. Osipenko, B. Vernarsky, D. Ho, D. Adikaram, M. Khandaker, M. Guidal, B. S. Ishkhanov, D. Protopopescu, D. Martinez, S. Pozdniakov, W. Gohn, M. Holtrop, Luciano Pappalardo, M. J. Amaryan, H. Moutarde, K. L. Giovanetti, G. Rosner, Larry Weinstein, F. Sabatié, G. Ricco, Friedrich Klein, Brian Raue, and A. Kim
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Structure function, Hyperon, Sigma, Polarization (waves), Lambda, 01 natural sciences, Baryon, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract: We report measurements of the exclusive electroproduction of K{sup +}{Lambda} and K{sup +}{Sigma}{sup 0} final states from an unpolarized proton target using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The separated structure functions {sigma}{sub U}, {sigma}{sub LT}, {sigma}{sub TT}, and {sigma}{sub LT'} were extracted from the {Phi}-dependent differential cross sections acquired with a longitudinally polarized 5.499~GeV electron beam. The data span a broad range of momentum transfers Q{sup 2} from 1.4 to 3.9 GeV{sup 2}, invariant energy W from threshold to 2.6 GeV, and nearly the full center-of-mass angular range of the kaon. The separated structure functions provide an unprecedented data sample, which in conjunction with other meson photo- and electroproduction data, will help to constrain the higher-level analyses being performed to search for missing baryon resonances.
Published: 2013
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41. Near-threshold neutral pion electroproduction at high momentum transfers and generalized form factors

Author: S. Tkachenko, L. Guo, E. De Sanctis, N. Harrison, M. Aghasyan, D. I. Sober, I. Zonta, A. Celentano, R. W. Gothe, F. X. Girod, G. Charles, F. Sabatié, R. A. Schumacher, W. Tang, P. Stoler, C. E. Hyde, M. Osipenko, J. T. Goetz, N. D. Kvaltine, K. Hicks, David M. Keller, M. Ungaro, D. Martinez, M. Ripani, M. Contalbrigo, W. Gohn, S. Stepanyan, T. Mineeva, P. Eugenio, C. E. Taylor, Andrew Puckett, E. Munevar, Martin K. Mayer, R. De Vita, E. Seder, H. Y. Lu, Michael Wood, K. Hafidi, W. Kim, E. Golovatch, G. Niculescu, M. Taiuti, M. S. Saini, K. Joo, R. Nasseripour, G. Ricco, P. Khetarpal, S. Niccolai, C. A. Meyer, I. Niculescu, E. L. Isupov, S. Anefalos Pereira, G. Rosner, G. V. Fedotov, S. Lewis, K. A. Griffioen, N. A. Saylor, H. Avakian, Y. Mao, S. Boiarinov, I. I. Strakovsky, K. P. Adhikari, H. Hakobyan, D. P. Weygand, R. Dupre, C. Hanretty, J. W. Price, J. Bono, M. Battaglieri, Michael Dugger, R. G. Fersch, N. K. Walford, A. Deur, Friedrich Klein, J. J. Phillips, P. Nadel-Turonski, H. Voskanyan, B. Vernarsky, Brian Raue, W. K. Brooks, I. J. D. MacGregor, S. Park, H. S. Jo, P. L. Cole, W. J. Briscoe, E. Pasyuk, George Davey Smith, Z. W. Zhao, C. Salgado, B. S. Ishkhanov, J. A. Fleming, D. Ho, I. Bedlinskiy, P. Rossi, A. D'Angelo, L. El Fassi, M. Anghinolfi, H. Seraydaryan, V. Crede, V. P. Kubarovsky, S. Koirala, C. Djalali, O. Pogorelko, Y. G. Sharabian, Victor Mokeev, R. A. Montgomery, S. Procureur, E. Phelps, Diane Schott, A. I. Ostrovidov, K. Park, D. G. Ireland, Volker D. Burkert, A. S. Biselli, A. Fradi, S. Pisano, A. Kim, N. A. Baltzell, M. Khandaker, D. Doughty, M. J. Amaryan, H. Moutarde, K. L. Giovanetti, Larry Weinstein, S. S. Stepanyan, A. Kubarovsky, D. Adikaram, M. Guidal, M. Holtrop, Luciano Pappalardo, Sergey Kuleshov, R. Paremuzyan, Gerard Gilfoyle, D. Sokhan, C. Munoz Camacho, B. McKinnon, M. Mirazita, N. Gevorgyan, V. Batourine, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, D. Rimal, K. Livingston, Jie Zhang, Inna Aznauryan, S. Strauch, H. Egiyan, D. Protopopescu, S. Pozdniakov, M. Garçon, M. Y. Gabrielyan, N. Dashyan, H. Baghdasaryan, B. Guegan, S. Fegan, J. P. Ball, D. S. Carman, E. Voutier, 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, 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), CLAS, 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, Particle physics, Proton, 010308 nuclear & particles physics, Structure function, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, High momentum, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Near threshold, Pion, CLAS, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, SYSTEM
Abstract: We report the measurement of near threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range $Q^2$ from 2 to 4.5 GeV$^2$ and $W$ from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles $E_{0+}$ and $S_{0+}$ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors $G_1^{\pi^0 p}(Q^2)$ and $G_2^{\pi^0 p}(Q^2)$. The data are compared to these generalized form factors and the results for $G_1^{\pi^0 p}(Q^2)$ are found to be in good agreement with the LCSR predictions, but the level of agreement with $G_2^{\pi^0 p}(Q^2)$ is poor., Comment: 17 pages, 18 figures, Journal article (Physical Review C)
Published: 2013
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42. Measurement of transparency ratios for protons from short-range correlated pairs

Author: V. Crede, John Arrington, S. Strauch, D. P. Watts, B. McKinnon, I. Zonta, M. Contalbrigo, C. E. Taylor, Barry Ritchie, R. A. Montgomery, A. El Alaoui, P. Eugenio, A. Kim, Y. Ilieva, E. Phelps, R. Nasseripour, S. Tkachenko, G. V. Fedotov, M. Taiuti, K. P. Adhikari, Nicholas Zachariou, S. E. Kuhn, J. A. Fleming, M. J. Amaryan, E. Golovatch, L. Guo, V. Batourine, Eli Piasetzky, Dustin Keller, S. Procureur, D. Rimal, J. T. Goetz, S. Niccolai, M. Y. Gabrielyan, S. Fegan, Michael Wood, N. Harrison, H. Moutarde, K. Hafidi, Victor Mokeev, K. L. Giovanetti, A. Celentano, R. W. Gothe, H. Seraydaryan, I. Korover, Larry Weinstein, R. Dupre, M. Battaglieri, M. Ripani, Y. G. Sharabian, X. Zheng, N. Gevorgyan, S. Chandavar, J. P. Ball, E. L. Isupov, Andrew Puckett, George Davey Smith, Ye Tian, Martin K. Mayer, D. S. Carman, Gerard Gilfoyle, D. Protopopescu, D. Sokhan, S. Pozdniakov, S. Park, B. Mustapha, M. Holtrop, Diane Schott, Chaden Djalali, N. K. Walford, M. Khandaker, S. Boiarinov, R. Shneor, H. Hakobyan, A. I. Ostrovidov, E. De Sanctis, K. Park, M. S. Saini, E. Pasyuk, Lorenzo Zana, P. Rossi, K. Livingston, D. Doughty, Luciano Pappalardo, F. Sabatié, R. A. Schumacher, D. G. Ireland, H. S. Jo, W. J. Briscoe, D. Heddle, Jie Zhang, E. Voutier, N. Dashyan, L. El Fassi, M. Ungaro, I. Bedlinskiy, W. Gohn, Volker D. Burkert, A. S. Biselli, M. Aghasyan, K. Hicks, K. A. Griffioen, Hovanes Egiyan, D. I. Sober, C. Munoz Camacho, S. Stepanyan, S. S. Stepanyan, E. Munevar, R. Paremuzyan, P. L. Cole, Or Hen, G. E. Dodge, H. Y. Lu, G. Rosner, K. Joo, H. Baghdasaryan, V. P. Kubarovsky, J. Bono, P. Nadel-Turonski, A. Deur, J. J. Phillips, O. Pogorelko, I. Niculescu, S. Pisano, N. Pivnyuk, W. K. Brooks, A. Kubarovsky, H. Voskanyan, I. J. D. MacGregor, A. V. Vlassov, R. De Vita, Shalev Gilad, S. Anefalos Pereira, Friedrich Klein, Brian Raue, F. X. Girod, C. E. Hyde, A. DʼAngelo, J. W. Price, S. Koirala, P. Khetarpal, B. Vernarsky, B. S. Ishkhanov, T. Mineeva, W. Tang, M. Osipenko, A. Beck, D. Martinez, G. Niculescu, S. May-Tal Beck, 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), CLAS, 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: Nuclear reaction, Nuclear and High Energy Physics, Proton, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, PROPAGATION, HIGH Q(2), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Nuclear Theory (nucl-th), 0103 physical sciences, SCATTERING, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, NUCLEAR TRANSPARENCY, Physics, Momentum (technical analysis), 010308 nuclear & particles physics, Momentum transfer, Carbon-12, Baryon, Nuclear transparency, Atomic physics, Nucleon
Abstract: Nuclear transparency, Tp(A), is a measure of the average probability for a struck proton to escape the nucleus without significant re-interaction. Previously, nuclear transparencies were extructed for quasi-elastic A(e,e'p) knockout of protons with momentum below the Fermi momentum, where the spectral functions are well known. In this paper we extract a novel observable, the transparency ratio, Tp(A)/T_p(12C), for knockout of high-missing-momentum protons from the breakup of short range correlated pairs (2N-SRC) in Al, Fe and Pb nuclei relative to C. The ratios were measured at momentum transfer Q^2 > 1.5 (GeV/c)^2 and x_B > 1.2 where the reaction is expected to be dominated by electron scattering from 2N-SRC. The transparency ratios of the knocked-out protons coming from 2N-SRC breakup are 20 - 30% lower than those of previous results for low missing momentum. They agree with Glauber calculations and agree with renormalization of the previously published transparencies as proposed by recent theoretical investigations. The new transparencies scale as A^-1/3, which is consistent with dominance of scattering from nucleons at the nuclear surface., 6 pages, 4 figures
Published: 2013
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43. Comment on 'Observation of a narrow structure in1H(γ,KS0)Xvia interference withϕ-meson production'

Author: A. Celentano, B. McKinnon, M. Ungaro, B. Zhao, G. Ricco, D. Doughty, A. I. Ostrovidov, K. Park, A. El Alaoui, P. Stoler, Nicholas Zachariou, D. Heddle, B. Dey, Volker D. Burkert, Sergey Kuleshov, R. De Vita, K. Hicks, M. Mirazita, F. X. Girod, R. A. Schumacher, M. Guidal, S. Anefalos Pereira, Michael Dugger, J. T. Goetz, S. Park, R. Dickson, S. Niccolai, S. S. Stepanyan, E. Seder, A. Ni, M. Holtrop, Elton Smith, J. W. Price, M. Bellis, L. Guo, E. De Sanctis, M. Anghinolfi, H. Y. Lu, D. G. Ireland, V. Crede, D. I. Sober, Y. G. Sharabian, N. A. Baltzell, Gerard Gilfoyle, I. Niculescu, P. L. Cole, R. Dupre, D. Schott, Paolo Rossi, M. Battaglieri, M. E. McCracken, P. Eugenio, J. P. Ball, I. Bedlinskiy, D. S. Carman, Michael Wood, K. Hafidi, S. Pozdniakov, M. Garçon, B. Morrison, K. L. Giovanetti, M. Ripani, B. S. Ishkhanov, Barry Ritchie, L. El Fassi, P. Khetarpal, Latifa Elouadrhiri, Kei Moriya, C. A. Meyer, B. Vernarsky, G. V. Fedotov, V. P. Kubarovsky, D. P. Weygand, O. Pogorelko, A. S. Biselli, P. Bosted, C. Bookwalter, N. Markov, S. Pisano, A. Kim, E. Golovatch, W. Tang, Michael Vineyard, M. Osipenko, H. Hakobyan, I. J. D. MacGregor, H. S. Jo, W. Kim, G. Niculescu, H. Egiyan, M. Y. Gabrielyan, M. D. Mestayer, V. Mokeev, E. L. Isupov, S. Chandavar, and S. Boiarinov
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Meson production, Meson, Structure (category theory), Mass spectrum, Interference (wave propagation), Pentaquark, Interpretation (model theory)
Abstract: In Ref. [1], the authors claim to observe a narrow structure in the mass spectrum constructed from the (pK_L) system using data from the CLAS detector. The interpretation of this narrow structure given in Ref. [1] is as follows: “It may be due to the photoproduction of the Theta+ pentaquark or some unknown Sigma∗ resonance.” The authors go on to say that “it is unlikely for the observed structure to be due to a Sigma∗ resonance.” This analysis was reviewed by the CLAS Collaboration, following the established procedures for all CLAS papers, and did not receive approval. The purpose of this Comment is to explain the reasons why that analysis was not approved for publication.
Published: 2012
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44. Measurement of the generalized form factors near threshold viaγ*p→nπ+at highQ2

Author: R. Paremuzyan, Gerard Gilfoyle, R. A. Schumacher, George Davey Smith, A. D'Angelo, R. Nasseripour, L. El Fassi, I. I. Strakovsky, A. Fradi, C. Bookwalter, K. A. Griffioen, L. Graham, W. Kim, Martin K. Mayer, C. E. Hyde, M. Contalbrigo, A. Deur, N. Kalantarians, D. Sokhan, V. P. Kubarovsky, H. Hakobyan, C. Hanretty, P. Eugenio, M. Taiuti, G. Niculescu, P. L. Cole, M. S. Saini, S. Pozdniakov, W. K. Brooks, E. Munevar, B. S. Ishkhanov, B. McKinnon, O. Pogorelko, N. Markov, S. Pisano, K. Livingston, D. Doughty, E. De Sanctis, J. P. Ball, I. Bedlinskiy, Y. Prok, J. T. Goetz, S. S. Stepanyan, S. Park, S. Stepanyan, D. Heddle, D. I. Sober, D. Branford, M. Mirazita, R. Dupre, M. Battaglieri, D. S. Carman, Avraham Klein, A. I. Ostrovidov, K. Park, A. Kubarovsky, P. Rossi, W. Tang, Z. W. Zhao, P. Stoler, D. G. Ireland, E. Phelps, N. Gevorgyan, W. Gohn, V. Batourine, H. S. Jo, W. J. Briscoe, C. E. Taylor, N. D. Kvaltine, S. Chandavar, V. Crede, F. Sabatié, H. Y. Lu, A. V. Vlassov, D. G. Jenkins, Volker D. Burkert, A. S. Biselli, M. Osipenko, C. Salgado, S. E. Kuhn, E. Golovatch, N. Dashyan, G. Ricco, Y. Ilieva, B. Zhao, A. Kim, C. A. Meyer, G. V. Fedotov, Sergey Kuleshov, F. X. Girod, T. Mineeva, K. Hicks, A. El Alaoui, R. De Vita, H. Baghdasaryan, D. Adikaram, M. Guidal, P. Khetarpal, I. Niculescu, M. Ripani, S. Strauch, Nicholas Zachariou, S. Niccolai, D. P. Watts, M. Holtrop, I. J. D. MacGregor, S. Anefalos Pereira, Friedrich Klein, A. Daniel, D. Schott, Michael Wood, K. Hafidi, J. W. Price, Elton Smith, Luciano Pappalardo, M. Khandaker, D. Rimal, A. Celentano, R. W. Gothe, M. Paolone, M. Y. Gabrielyan, B. Vernarsky, M. D. Mestayer, E. L. Isupov, S. Tkachenko, K. P. Adhikari, G. Charles, D. P. Weygand, Ye Tian, G. Rosner, S. Procureur, R. P. Bennett, L. Guo, S. Boiarinov, M. Anghinolfi, H. Moutarde, K. L. Giovanetti, H. Seraydaryan, Y. G. Sharabian, Barry Ritchie, C. Djalali, E. Voutier, P. Nadel-Turonski, M. Ungaro, K. Joo, Victor Mokeev, and A. Trivedi
Subjects: Physics, Nuclear and High Energy Physics, Proton, Spectrometer, 010308 nuclear & particles physics, Momentum transfer, Form factor (quantum field theory), 01 natural sciences, Transverse plane, Light cone, 0103 physical sciences, Cathode ray, Atomic physics, Nuclear Experiment, 010306 general physics, Multipole expansion
Abstract: We report the first extraction of the pion-nucleon multipoles near the production threshold for the nπ+ channel at relatively high momentum transfer (Q2 up to 4.2 GeV2). The dominance of the s-wave transverse multipole (E0+), expected in this region, allowed us to access the generalized form factor G1 within the light-cone sum-rule (LCSR) framework as well as the axial form factor GA. The data analyzed in this work were collected by the nearly 4π CEBAF Large Acceptance Spectrometer (CLAS) using a 5.754-GeV electron beam on a proton target. The differential cross section and the π-N multipole E0+/GD were measured using two different methods, the LCSR and a direct multipole fit. The results from the two methods are found to be consistent and almost Q2 independent.
Published: 2012
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45. Branching ratio of the electromagnetic decay of the Σ+(1385)

Author: S. S. Stepanyan, V. Mokeev, R. Nasseripour, A. El Alaoui, Y. Ilieva, A. V. Vlassov, M. Paolone, N. Dashyan, Nicholas Zachariou, A. Kubarovsky, R. Dupre, M. Battaglieri, R. De Vita, V. Crede, D. Keller, P. Eugenio, Latifa Elouadrhiri, S. Tkachenko, L. Guo, D. Rimal, G. Ricco, C. A. Meyer, M. Taiuti, S. Strauch, M. Ripani, G. V. Fedotov, P. L. Cole, P. Nadel-Turonski, D. Adikaram, M. Guidal, B. McKinnon, S. Anefalos Pereira, H. Baghdasaryan, D. P. Watts, R. A. Schumacher, M. Khandaker, Michael Wood, K. P. Adhikari, C. E. Taylor, K. Hafidi, Elton Smith, K. Joo, E. Golovatch, G. D. Smith, M. Holtrop, S. Niccolai, N. Markov, A. D'Angelo, Friedrich Klein, E. De Sanctis, C. Djalali, Brian Raue, T. Mineeva, D. Protopopescu, Barry Ritchie, A. Daniel, Luciano Pappalardo, S. Pisano, S. Pozdniakov, W. Tang, D. I. Sober, L. Graham, F. Sabatié, P. Khetarpal, C. Bookwalter, M. J. Amaryan, M. Anghinolfi, M. Osipenko, A. Celentano, R. W. Gothe, Z. W. Zhao, S. Procureur, D. Branford, L. El Fassi, Michael Vineyard, H. Seraydaryan, H. Hakobyan, V. P. Kubarovsky, M. Y. Gabrielyan, O. Pogorelko, H. Moutarde, Lorenzo Zana, A. I. Ostrovidov, K. Park, M. Mirazita, E. Voutier, Y. G. Sharabian, S. Stepanyan, K. L. Giovanetti, J. P. Ball, B. Vernarsky, N. Gevorgyan, W. Gohn, S. Park, Y. Prok, D. S. Carman, M. Contalbrigo, P. Stoler, H. S. Jo, N. Guler, D. G. Ireland, D. Doughty, Sergey Kuleshov, E. Munevar, Martin K. Mayer, G. Rosner, P. Rossi, H. Voskanyan, I. Bedlinskiy, B. S. Ishkhanov, K. Hicks, H. Y. Lu, K. A. Griffioen, Volker D. Burkert, A. S. Biselli, C. Salgado, W. J. Briscoe, M. S. Saini, E. Pasyuk, S. Chandavar, Y. Mao, W. Kim, I. Niculescu, E. L. Isupov, B. Zhao, G. Niculescu, D. Schott, S. Boiarinov, R. Paremuzyan, William Brooks, Gerard Gilfoyle, I. J. D. MacGregor, D. Sokhan, A. Kim, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), CLAS, 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: Nuclear and High Energy Physics, Particle physics, STRANGENESS, TRANSITIONS, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, QUARK-MODEL, RADIATIVE DECAYS, HYPERFINE INTERACTIONS, BARYONS, HYPERONS, 0103 physical sciences, Fitting algorithm, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Photon beam, Nuclear Experiment, 010306 general physics, Physics, Partial width, 010308 nuclear & particles physics, Branching fraction, Hyperon, Symmetry test, Photon beams, High Energy Physics::Experiment, Energy (signal processing)
Abstract: The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the ${\ensuremath{\Sigma}}^{*+}(1385)$ from the reaction $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\Sigma}}^{*+}(1385)$. A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and ${\ensuremath{\Sigma}}^{*}$ hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the measured decay widths ratio ${\ensuremath{\Sigma}}^{+}(1385)\ensuremath{\rightarrow}{\ensuremath{\Sigma}}^{+}\ensuremath{\gamma}/{\ensuremath{\Sigma}}^{+}(1385)\ensuremath{\rightarrow}{\ensuremath{\Sigma}}^{+}{\ensuremath{\pi}}^{0}=11.95\ifmmode\pm\else\textpm\fi{}2.21(\mathrm{stat}{)}_{\ensuremath{-}1.21}^{+0.53}(\mathrm{sys})%$ and a deduced partial width of $250.0\ifmmode\pm\else\textpm\fi{}56.9(\mathrm{stat}{)}_{\ensuremath{-}41.2}^{+34.3}(\mathrm{sys})\text{ }\text{ }\mathrm{keV}$. A U-spin symmetry test using the SU(3) flavor-multiplet representation yields predictions for the ${\ensuremath{\Sigma}}^{*+}(1385)\ensuremath{\rightarrow}{\ensuremath{\Sigma}}^{+}\ensuremath{\gamma}$ and ${\ensuremath{\Sigma}}^{*0}(1385)\ensuremath{\rightarrow}\ensuremath{\Lambda}\ensuremath{\gamma}$ partial widths that agree with the experimental measurements.
Published: 2012
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46. Electromagnetic decay of theΣ0(1385)toΛγ

Author: P. Nadel-Turonski, L. Casey, R. Dupre, R. Dickson, M. Battaglieri, J. P. Ball, D. S. Carman, E. De Sanctis, Y. G. Sharabian, V. Kuznetsov, M. Aghasyan, D. I. Sober, P. Eugenio, R. De Vita, A. M. Micherdzinska, S. Anefalos Pereira, G. Gavalian, M. Taiuti, E. Voutier, E. L. Isupov, D. Keller, H. Y. Lu, M. Ripani, S. Niccolai, M. Amarian, Kei Moriya, C. A. Meyer, G. V. Fedotov, M. Khandaker, B. Guegan, S. Fegan, I. Niculescu, D. Protopopescu, H. Hakobyan, Z. W. Zhao, George Davey Smith, K. P. Adhikari, D. G. Jenkins, S. Pozdniakov, A. D'Angelo, D. Doughty, M. S. Saini, D. Schott, R. P. Bennett, B. Morrison, R. A. Schumacher, R. Paremuzyan, L. El Fassi, S. Strauch, Michael Vineyard, Barry Ritchie, L. Graham, F. X. Girod, F. Sabatié, N. Dashyan, P. Konczykowski, D. P. Watts, C. Djalali, S. Procureur, I. Bedlinskiy, Elton Smith, N. Markov, Lorenzo Zana, P. L. Cole, A. Ni, A. El Alaoui, Y. Ilieva, S. Pisano, Sergey Kuleshov, T. A. Forest, Friedrich Klein, H. Seraydaryan, H. S. Jo, Brian Raue, A. Kim, Avraham Klein, Nicholas Zachariou, C. Salgado, H. Baghdasaryan, S. L. Careccia, M. Y. Gabrielyan, E. Seder, J. W. Price, S. Park, P. Khetarpal, K. L. Giovanetti, B. McKinnon, P. Rossi, Larry Weinstein, D. Adikaram, M. Guidal, D. Branford, V. Crede, M. Mirazita, M. Holtrop, B. Moreno, A. Daniel, N. Gevorgyan, C. Hanretty, G. Rosner, V. Batourine, Luciano Pappalardo, A. I. Ostrovidov, K. Park, D. G. Ireland, S. S. Stepanyan, Volker D. Burkert, A. S. Biselli, Victor Mokeev, Hovanes Egiyan, H. Moutarde, B. Vernarsky, K. Joo, E. Munevar, I. I. Strakovsky, A. Deur, W. K. Brooks, C. E. Taylor, E. Golovatch, W. Gohn, W. Kim, G. Niculescu, W. Tang, M. Osipenko, B. Zhao, S. S. Jawalkar, I. J. D. MacGregor, M. Contalbrigo, V. P. Kubarovsky, O. Pogorelko, R. W. Gothe, J. McAndrew, Michael Wood, K. Hafidi, W. J. Briscoe, E. Pasyuk, P. Stoler, B. Dey, and K. Hicks
Subjects: Physics, Nuclear and High Energy Physics, Meson, 010308 nuclear & particles physics, Hadron, Elementary particle, Lambda, Lambda baryon, 01 natural sciences, Sigma baryon, Nuclear physics, Particle decay, 0103 physical sciences, High Energy Physics::Experiment, Atomic physics, 010306 general physics, Nucleon
Abstract: The electromagnetic decay $\Sigma^0(1385) \to \Lambda \gamma$ was studied using the CLAS detector at the Thomas Jefferson National Accelerator Facility. A real photon beam with a maximum energy of 3.8 GeV was incident on a proton target, producing an exclusive final state of $K^+\Sigma^{*0}$. We report the decay widths ratio $\Sigma^0(1385) \to \Lambda\gamma$/ $\Sigma^0(1385) \to \Lambda\pi^0$ = $1.42 \pm 0.12(\text{stat})_{-0.07}^{+0.11}(\text{sys})$%. This ratio is larger than most theoretical predictions by factors ranging from 1.5-3, but is consistent with the only other experimental measurement. From the reported ratio we calculate the partial width and electromagnetic transition magnetic moment for $\Sigma^0(1385) \to \Lambda\gamma$.
Published: 2011
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