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91 results on '"H. Moutarde"'

1. EpIC: novel Monte Carlo generator for exclusive processes

Author: E. C. Aschenauer, V. Batozskaya, S. Fazio, K. Gates, H. Moutarde, D. Sokhan, H. Spiesberger, P. Sznajder, and K. Tezgin
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract We present the EpIC Monte Carlo event generator for exclusive processes based on generalised parton distributions. EpIC utilises the PARTONS framework, which provides a flexible software architecture and a variety of modelling options for the partonic description of the nucleon. The generator offers a comprehensive set of features, including simulation of a variety of exclusive processes and radiative corrections. It may be used both in the analysis of experimental data, as well as for impact studies, especially for the future electron-ion colliders.
Published: 2022
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2. Artificial neural network modelling of generalised parton distributions

Author: H. Dutrieux, O. Grocholski, H. Moutarde, and P. Sznajder
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract We discuss the use of machine learning techniques in effectively nonparametric modelling of generalised parton distributions (GPDs) in view of their future extraction from experimental data. Current parameterisations of GPDs suffer from model dependency that lessens their impact on phenomenology and brings unknown systematics to the estimation of quantities like Mellin moments. The new strategy presented in this study allows to describe GPDs in a way fulfilling theory-driven constraints, keeping model dependency to a minimum. Getting a better grip on the control of systematic effects, our work will help the GPD phenomenology to achieve its maturity in the precision era commenced by the new generation of experiments.
Published: 2022
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3. Phenomenological assessment of proton mechanical properties from deeply virtual Compton scattering

Author: H. Dutrieux, C. Lorcé, H. Moutarde, P. Sznajder, A. Trawiński, and J. Wagner
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract A unique feature of generalised parton distributions is their relation to the QCD energy–momentum tensor. In particular, they provide access to the mechanical properties of the proton i.e. the distributions of pressure and shear stress induced by its quark and gluon structure. In principle the pressure distribution can be experimentally determined in a model-independent way from a dispersive analysis of deeply virtual Compton scattering data through the measurement of the subtraction constant. In practice the kinematic coverage and accuracy of existing experimental data make this endeavour a challenge. Elaborating on recent global fits of deeply virtual Compton scattering measurements using artificial neural networks, our analysis presents the current knowledge on this subtraction constant and assesses the impact of the most frequent systematic assumptions made in this field of research. This study will pave the way for future works when more precise data will become available, e.g. obtained in the foreseen electron-ion colliders EIC and EIcC.
Published: 2021
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4. Data-driven study of timelike Compton scattering

Author: O. Grocholski, H. Moutarde, B. Pire, P. Sznajder, and J. Wagner
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract In the framework of collinear QCD factorization, the leading twist scattering amplitudes for deeply virtual Compton scattering (DVCS) and timelike Compton scattering (TCS) are intimately related thanks to analytic properties of leading and next-to-leading order amplitudes. We exploit this welcome feature to make data-driven predictions for TCS observables to be measured in near future experiments. Using a recent extraction of DVCS Compton form factors from most of the existing experimental data for that process, we derive TCS amplitudes and calculate TCS observables only assuming leading-twist dominance. Artificial neural network techniques are used for an essential reduction of model dependency, while a careful propagation of experimental uncertainties is achieved with replica methods. Our analysis allows for stringent tests of the leading twist dominance of DVCS and TCS amplitudes. Moreover, this study helps to understand quantitatively the complementarity of DVCS and TCS measurements to test the universality of generalized parton distributions, which is crucial e.g. to perform the nucleon tomography.
Published: 2020
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5. Erratum to: Artificial neural network modelling of generalised parton distributions

Author: H. Dutrieux, O. Grocholski, H. Moutarde, and P. Sznajder
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Published: 2022
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6. Unbiased determination of DVCS Compton form factors

Author: H. Moutarde, P. Sznajder, and J. Wagner
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract The extraction of Compton form factors (CFFs) in a global analysis of almost all deeply virtual Compton scattering (DVCS) proton data is presented. The extracted quantities are DVCS sub-amplitudes and the most basic observables which are unambiguously accessible from this process. The parameterizations of CFFs are constructed utilizing the artificial neural network technique allowing for an important reduction of model dependency. The analysis consists of such elements as feasibility studies, training of neural networks with the genetic algorithm and a careful regularization to avoid over-fitting. The propagation of experimental uncertainties to extracted quantities is done with the replica method. The resulting parameterizations of CFFs are used to determine the subtraction constant through dispersion relations. The analysis is done within the PARTONS framework.
Published: 2019
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7. Border and skewness functions from a leading order fit to DVCS data

Author: H. Moutarde, P. Sznajder, and J. Wagner
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract We propose new parameterizations for the border and skewness functions appearing in the description of 3D nucleon structure in the language of generalized parton distributions (GPDs). These parameterizations are constructed in a way to fulfill the basic properties of GPDs, like their reduction to parton density functions and elastic form factors. They also rely on the power behavior of GPDs in the $$x \rightarrow 1$$ x→1 limit and the propounded analyticity property of Mellin moments of GPDs. We evaluate compton form factors (CFFs), the sub-amplitudes of the deeply virtual compton scattering (DVCS) process, at the leading order and leading twist accuracy. We constrain the restricted number of free parameters of these new parameterizations in a global CFF analysis of almost all existing proton DVCS measurements. The fit is performed within the PARTONS framework, being the modern tool for generic GPD studies. A distinctive feature of this CFF fit is the careful propagation of uncertainties based on the replica method. The fit results genuinely permit nucleon tomography and may give some insight into the distribution of forces acting on partons.
Published: 2018
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8. PARTONS: PARtonic Tomography Of Nucleon Software

Author: B. Berthou, D. Binosi, N. Chouika, L. Colaneri, M. Guidal, C. Mezrag, H. Moutarde, J. Rodríguez-Quintero, F. Sabatié, P. Sznajder, and J. Wagner
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract We describe the architecture and functionalities of a C++ software framework, coined PARTONS, dedicated to the phenomenology of Generalized Parton Distributions. These distributions describe the three-dimensional structure of hadrons in terms of quarks and gluons, and can be accessed in deeply exclusive lepto- or photo-production of mesons or photons. PARTONS provides a necessary bridge between models of Generalized Parton Distributions and experimental data collected in various exclusive production channels. We outline the specification of the PARTONS framework in terms of practical needs, physical content and numerical capacity. This framework will be useful for physicists – theorists or experimentalists – not only to develop new models, but also to interpret existing measurements and even design new experiments.
Published: 2018
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9. A Nakanishi-based model illustrating the covariant extension of the pion GPD overlap representation and its ambiguities

Author: N. Chouika, C. Mezrag, H. Moutarde, and J. Rodríguez-Quintero
Subjects: Physics, QC1-999
Abstract: A systematic approach for the model building of Generalized Parton Distributions (GPDs), based on their overlap representation within the DGLAP kinematic region and a further covariant extension to the ERBL one, is applied to the valence-quark pion's case, using light-front wave functions inspired by the Nakanishi representation of the pion Bethe–Salpeter amplitudes (BSA). This simple but fruitful pion GPD model illustrates the general model building technique and, in addition, allows for the ambiguities related to the covariant extension, grounded on the Double Distribution (DD) representation, to be constrained by requiring a soft-pion theorem to be properly observed. Keywords: π-meson, Generalized parton distributions, Bethe-Salepeter, Light-front wave-functions, Radon transform, Double distributions
Published: 2018
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10. Covariant extension of the GPD overlap representation at low Fock states

Author: N. Chouika, C. Mezrag, H. Moutarde, and J. Rodríguez-Quintero
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract We present a novel approach to compute generalized parton distributions within the lightfront wave function overlap framework. We show how to systematically extend generalized parton distributions computed within the DGLAP region to the ERBL one, fulfilling at the same time both the polynomiality and positivity conditions. We exemplify our method using pion lightfront wave functions inspired by recent results of non-perturbative continuum techniques and algebraic nucleon lightfront wave functions. We also test the robustness of our algorithm on reggeized phenomenological parameterizations. This approach paves the way to a better understanding of the nucleon structure from non-perturbative techniques and to a unification of generalized parton distributions and transverse momentum dependent parton distribution functions phenomenology through lightfront wave functions.
Published: 2017
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11. First measurement of the polarization observable E in the p→(γ→,π+)n reaction up to 2.25 GeV

Author: S. Strauch, W.J. Briscoe, M. Döring, E. Klempt, V.A. Nikonov, E. Pasyuk, D. Rönchen, A.V. Sarantsev, I. Strakovsky, R. Workman, K.P. Adhikari, D. Adikaram, M.D. Anderson, S. Anefalos Pereira, A.V. Anisovich, R.A. Badui, J. Ball, V. Batourine, M. Battaglieri, I. Bedlinskiy, N. Benmouna, A.S. Biselli, J. Brock, W.K. Brooks, V.D. Burkert, T. Cao, C. Carlin, D.S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P.L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, N. Dashyan, A. D'Angelo, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, J.A. Fleming, T.A. Forest, A. Fradi, N. Gevorgyan, Y. Ghandilyan, K.L. Giovanetti, F.X. Girod, D.I. Glazier, W. Gohn, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, K. Hicks, D. Ho, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H. Jiang, H.S. Jo, K. Joo, S. Joosten, C.D. Keith, D. Keller, G. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, S.E. Kuhn, P. Lenisa, K. Livingston, H.Y. Lu, I.J.D. MacGregor, N. Markov, B. McKinnon, D.G. Meekins, C.A. Meyer, V. Mokeev, R.A. Montgomery, C.I. Moody, H. Moutarde, A. Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, L.A. Net, S. Niccolai, G. Niculescu, I. Niculescu, G. O'Rielly, M. Osipenko, A.I. Ostrovidov, K. Park, P. Peng, W. Phelps, J.J. Phillips, S. Pisano, O. Pogorelko, S. Pozdniakov, J.W. Price, S. Procureur, Y. Prok, D. Protopopescu, A.J.R. Puckett, B.A. Raue, M. Ripani, B.G. Ritchie, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, D. Schott, R.A. Schumacher, E. Seder, M.L. Seely, I. Senderovich, Y.G. Sharabian, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, P. Stoler, S. Stepanyan, V. Sytnik, M. Taiuti, Ye Tian, A. Trivedi, R. Tucker, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, D.P. Watts, X. Wei, M.H. Wood, N. Zachariou, L. Zana, J. Zhang, Z.W. Zhao, and I. Zonta
Subjects: Baryon spectroscopy, Pion photoproduction, Polarization observables, FROST experiment, Physics, QC1-999
Abstract: First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction γ→p→→π+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, Jülich–Bonn, and SAID groups.
Published: 2015
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12. Sketching the pion's valence-quark generalised parton distribution

Author: C. Mezrag, L. Chang, H. Moutarde, C.D. Roberts, J. Rodríguez-Quintero, F. Sabatié, and S.M. Schmidt
Subjects: Physics, QC1-999
Abstract: In order to learn effectively from measurements of generalised parton distributions (GPDs), it is desirable to compute them using a framework that can potentially connect empirical information with basic features of the Standard Model. We sketch an approach to such computations, based upon a rainbow-ladder (RL) truncation of QCD's Dyson–Schwinger equations and exemplified via the pion's valence dressed-quark GPD, Hπv(x,ξ,t). Our analysis focuses primarily on ξ=0, although we also capitalise on the symmetry-preserving nature of the RL truncation by connecting Hπv(x,ξ=±1,t) with the pion's valence-quark parton distribution amplitude. We explain that the impulse-approximation used hitherto to define the pion's valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for Hπv(x,0,t), expressed as the Radon transform of a single amplitude. Therewith we obtain results for Hπv(x,0,t) and the associated impact-parameter dependent distribution, qπv(x,|b→⊥|), which provide a qualitatively sound picture of the pion's dressed-quark structure at a hadronic scale. We evolve the distributions to a scale ζ=2 GeV, so as to facilitate comparisons in future with results from experiment or other nonperturbative methods. Keywords: Deeply virtual Compton scattering, Dynamical chiral symmetry breaking, Dyson–Schwinger equations, Generalised parton distribution functions, π-meson
Published: 2015
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13. Shadow generalized parton distributions: a practical approach to the deconvolution problem of DVCS

Author: V. Bertone, H. Dutrieux, C. Mezrag, H. Moutarde, P. Sznajder
Subjects: Physics, QC1-999
Abstract: Deeply virtual Compton scattering (DVCS) attracts a lot of interest due to its sensitivity to generalized parton distributions (GPDs) which provide a rich access to the partonic structure of hadrons. However, the practical extraction of GPDs for this channel requires a deconvolution procedure, whose feasibility has been disputed. We provide a practical approach to this problem based on a next-to-leading order analysis and a careful study of evolution effects, by exhibiting shadow GPDs with arbitrarily small imprints on DVCS observables at current and future experimental facilities. This shows that DVCS alone will not allow for a model independent extraction of GPDs and a multi-channel analysis is required for this purpose.
Published: 2022
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14. Shadow generalized parton distributions: a practical approach to the deconvolution problem of DVCS

Author: Valerio Bertone, Hervé Dutrieux, Cédric Mezrag, H. Moutarde, Paweł Sznajder, 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: data analysis method, generalized parton distribution, [PHYS.HLAT]Physics [physics]/High Energy Physics - Lattice [hep-lat], High Energy Physics - Lattice (hep-lat), higher-order: 1, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], hadron: structure, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Lattice, deeply virtual Compton scattering, evolution equation, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment, talk
Abstract: Deeply virtual Compton scattering (DVCS) attracts a lot of interest due to its sensitivity to generalized parton distributions (GPDs) which provide a rich access to the partonic structure of hadrons. However, the practical extraction of GPDs for this channel requires a deconvolution procedure, whose feasibility has been disputed. We provide a practical approach to this problem based on a next-to-leading order analysis and a careful study of evolution effects, by exhibiting shadow GPDs with arbitrarily small imprints on DVCS observables at current and future experimental facilities. This shows that DVCS alone will not allow for a model independent extraction of GPDs and a multi-channel analysis is required for this purpose., 7 pages, 2 figures, Submission to SciPost Proceedings DIS2021
Published: 2021
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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. First Exclusive Measurement of Deeply Virtual Compton Scattering off He4 : Toward the 3D Tomography of Nuclei

Author: M. J. Amaryan, Laura Clark, C. Gleason, P. Lenisa, W. Phelps, H. Moutarde, X. Wei, K. A. Griffioen, B. S. Ishkhanov, K. L. Giovanetti, Taya Chetry, M. Hattawy, Hovanes Egiyan, Larry Weinstein, G. Ciullo, J. P. Ball, Y. Prok, D. S. Carman, P. Eugenio, E. Golovatch, S. Strauch, J. W. Price, Friedrich Klein, L. Guo, Alessandro Rizzo, C. Munoz Camacho, D. G. Ireland, E. Voutier, Latifa Elouadrhiri, R. De Vita, V. Crede, M. Taiuti, C. Djalali, Michael Paolone, A. Movsisyan, O. Cortes, E. L. Isupov, S. Niccolai, Z. W. Zhao, C. A. Meyer, H. Y. Lu, L. Lanza, Whitney Armstrong, A. I. Ostrovidov, K. Park, G. V. Fedotov, D. P. Watts, G. Rosner, R. A. Montgomery, A. Celentano, Martin K. Mayer, R. W. Gothe, K. Livingston, A. Deur, H. Jiang, Volker D. Burkert, A. S. Biselli, D. G. Jenkins, R. Paremuzyan, Sergey Kuleshov, M. Khachatryan, A. Simonyan, Y. Ghandilyan, V. I. Mokeev, D. Heddle, H. Hakobyan, M. H. Wood, R. Dupre, S. Boiarinov, L. Colaneri, Iu. Skorodumina, S. Adhikari, S. Anefalos Pereira, S. Fegan, Jie Zhang, I. Niculescu, F. Cao, E. Pasyuk, Nikolaos Sparveris, N. Markov, K. Hicks, D. Adikaram, B. Torayev, M. Guidal, G. Charles, F. X. Girod, Z. E. Meziani, Nicholas M. Harrison, Gerard Gilfoyle, I. Bedlinskiy, N. A. Baltzell, C. Hanretty, W. Kim, P. Nadel-Turonski, William Brooks, A. Filippi, G. D. Smith, M. Holtrop, Lorenzo Zana, G. Khachatryan, M. Battaglieri, G. Niculescu, E. Seder, R. G. Fersch, F. Sabatié, W. Gohn, P. Rossi, V. P. Kubarovsky, D. Sokhan, P. L. Cole, M. Khandaker, O. Pogorelko, D. Protopopescu, B. G. Ritchie, M. Bashkanov, R. A. Schumacher, M. Ungaro, S. M. Hughes, M. Garçon, N. Dashyan, A. D'Angelo, E. De Sanctis, Sylvester Joosten, B. McKinnon, M. E. McCracken, L. A. Net, L. El Fassi, C. Salgado, M. Osipenko, Dustin Keller, A. El Alaoui, N. K. Walford, Y. Perrin, T. Mineeva, Nicholas Zachariou, S. Bültmann, M. Mirazita, E. Phelps, K. P. Adhikari, T. A. Forest, K. Hafidi, N. Gevorgyan, I. J. D. MacGregor, V. Batourine, H. Avakian, S. Stepanyan, Y. G. Sharabian, S. Pisano, K. Joo, Simonetta Liuti, Avraham Klein, M. Contalbrigo, H. Voskanyan, A. Kim, W. J. Briscoe, A. Fradi, S. E. Kuhn, J. A. Fleming, Z. Akbar, and M. Ripani
Subjects: Physics, Particle physics, Time projection chamber, Photon, Proton, Meson, 010308 nuclear & particles physics, Compton scattering, General Physics and Astronomy, Electron, HERA, 01 natural sciences, 7. Clean energy, Nuclear physics, Recoil, 0103 physical sciences, Physics::Accelerator Physics, Nuclear Experiment, 010306 general physics
Abstract: We report on the first measurement of the beam-spin asymmetry in the exclusive process of coherent deeply virtual Compton scattering off a nucleus. The experiment uses the 6 GeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) accelerator at Jefferson Lab incident on a pressurized $^{4}\mathrm{He}$ gaseous target placed in front of the CEBAF Large Acceptance Spectrometer (CLAS). The scattered electron is detected by CLAS and the photon by a dedicated electromagnetic calorimeter at forward angles. To ensure the exclusivity of the process, a specially designed radial time projection chamber is used to detect the recoiling $^{4}\mathrm{He}$ nuclei. We measure beam-spin asymmetries larger than those observed on the free proton in the same kinematic domain. From these, we are able to extract, in a model-independent way, the real and imaginary parts of the only $^{4}\mathrm{He}$ Compton form factor, ${\mathcal{H}}_{A}$. This first measurement of coherent deeply virtual Compton scattering on the $^{4}\mathrm{He}$ nucleus, with a fully exclusive final state via nuclear recoil tagging, leads the way toward 3D imaging of the partonic structure of nuclei.
Published: 2017
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17. 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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18. Precise measurements of beam spin asymmetries in semi-inclusive π0 production

Author: J. McAndrew, E. De Sanctis, E. Voutier, Michael Wood, K. Hafidi, Y. Prok, M. Aghasyan, D. I. Sober, S. Strauch, S. S. Stepanyan, D. P. Watts, R. Dupre, P. Eugenio, H. Egiyan, D. Keller, N. D. Kvaltine, F. Sabatié, M. Battaglieri, W. Gohn, M. Taiuti, S. Tkachenko, L. Guo, M. Khandaker, G. E. Dodge, H. Y. Lu, M. Y. Gabrielyan, D. Adikaram, M. Guidal, H. Avakian, M. Anghinolfi, E. Munevar, M. Holtrop, R. De Vita, Victor Mokeev, H. Seraydaryan, G. Rosner, C. E. Taylor, I. Niculescu, N. Guler, M. Ungaro, Y. G. Sharabian, A. Daniel, P. Nadel-Turonski, Luciano Pappalardo, W. J. Briscoe, V. Crede, S. Anefalos Pereira, D. Schott, J. P. Ball, S. Chandavar, D. S. Carman, A. M. Micherdzinska, E. Pasyuk, V. Kuznetsov, E. Seder, E. Golovatch, A. El Alaoui, H. Voskanyan, Y. Ilieva, A. I. Ostrovidov, K. Park, M. J. Amaryan, E. L. Isupov, Z. W. Zhao, N. Gevorgyan, K. Joo, George Davey Smith, D. G. Ireland, R. A. Schumacher, A. Ni, Sergey Kuleshov, S. E. Kuhn, S. Procureur, L. Graham, C. Djalali, V. P. Kubarovsky, B. McKinnon, C. E. Hyde, O. Pogorelko, Volker D. Burkert, A. S. Biselli, S. Bültmann, S. Park, B. Guegan, R. W. Gothe, Lorenzo Zana, S. Stepanyan, S. Fegan, P. Rossi, D. Branford, H. S. Jo, K. L. Giovanetti, Avraham Klein, M. Mirazita, I. I. Strakovsky, P. Khetarpal, C. Salgado, A. Fradi, S. Niccolai, A. Deur, W. Kim, Larry Weinstein, V. Batourine, Martin K. Mayer, P. L. Cole, N. Dashyan, G. Niculescu, H. Moutarde, B. Moreno, M. S. Saini, P. Stoler, K. Livingston, D. Doughty, H. Baghdasaryan, Gerard Gilfoyle, M. Contalbrigo, R. Dickson, Jie Zhang, G. Ricco, I. Bedlinskiy, N. Markov, B. Dey, R. Paremuzyan, M. Paolone, Friedrich Klein, S. Pisano, D. Protopopescu, Brian Raue, S. Pozdniakov, M. Garçon, K. Hicks, A. Kim, D. Rimal, W. Tang, M. Osipenko, B. Zhao, S. S. Jawalkar, I. J. D. MacGregor, D. Hasch, E. Phelps, D. G. Jenkins, F. X. Girod, A. DʼAngelo, J. W. Price, M. Ripani, C. Hanretty, J. T. Goetz, R. P. Bennett, Latifa Elouadrhiri, C. A. Meyer, G. V. Fedotov, D. P. Weygand, K. A. Griffioen, P. Collins, 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), 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, Angular momentum, Particle physics, DEEP-INELASTIC SCATTERING, FINAL-STATE INTERACTIONS, PION ELECTROPRODUCTION, PARTON DISTRIBUTIONS, DRELL-YAN, LEPTOPRODUCTION, DEPENDENCE, Meson, media_common.quotation_subject, Nuclear Theory, Inelastic scattering, 01 natural sciences, Asymmetry, Settore FIS/04 - Fisica Nucleare e Subnucleare, High Energy Physics - Experiment, Nuclear physics, Pion, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment, 010306 general physics, QC, media_common, Physics, 010308 nuclear & particles physics, Deep inelastic scattering, Amplitude, Physics::Accelerator Physics, High Energy Physics::Experiment, Lepton
Abstract: We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial $\sin \phi_h$ amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle $\phi_h$ of the produced neutral pion. The dependence of this amplitude on Bjorken $x$ and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations., Comment: to be submitted PLB
Published: 2011
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19. Differential cross section of γn→K+Σ− on bound neutrons with incident photons from 1.1 to 3.6 GeV

Author: A. I. Ostrovidov, K. Park, M. E. McCracken, D. G. Ireland, Michael Dugger, Volker D. Burkert, A. S. Biselli, V. P. Kubarovsky, Lorenzo Zana, Sergey Kuleshov, H. S. Jo, C. Salgado, K. A. Griffioen, O. Pogorelko, D. Protopopescu, L. Guo, P. Nadel-Turonski, S. Fegan, R. De Vita, M. Osipenko, S. S. Stepanyan, S. Pozdniakov, W. Gohn, S. Procureur, C. Bookwalter, S. Anefalos Pereira, K. Mikhailov, F. Sabatié, M. Guidal, S. Dhamija, V. Crede, N. Dashyan, W. J. Briscoe, E. Pasyuk, Y. Perrin, T. Mineeva, R. W. Gothe, E. De Sanctis, S. L. Careccia, R. Dupre, M. Holtrop, A. Daniel, Gerard Gilfoyle, G. Ricco, M. Aghasyan, P. Eugenio, M. Battaglieri, J. Salamanca, Friedrich Klein, Brian Raue, K. Joo, D. Sokhan, E. Munevar, D. I. Sober, S. Pisano, B. S. Ishkhanov, B. Morrison, G. Gavalian, S. Tkachenko, W. Kim, B. Zhao, H. Baghdasaryan, M. Ripani, P. L. Cole, B. McKinnon, C. Djalali, G. Niculescu, A. El Alaoui, F. X. Girod, Y. Ilieva, K. L. Giovanetti, Michael Wood, D. Branford, P. Collins, D. Keller, M. Mirazita, E. Voutier, P. Khetarpal, G. Rosner, B. L. Berman, A. D'Angelo, S. S. Jawalkar, I. Niculescu, J. P. Ball, Y. Prok, M. Khandaker, C. Hanretty, D. S. Carman, J. W. Price, N. Hassall, R. A. Schumacher, S. Park, V. Mokeev, P. Rossi, T. A. Forest, S. Stepanyan, H. Moutarde, S. Strauch, P. Stoler, D. P. Watts, B. Dey, B. Moreno, K. Hicks, B. Vernarsky, K. Livingston, J. Zhang, R. Dickson, N. Guler, M. Y. Gabrielyan, H. Hakobyan, D. J. Tedeschi, V. Kuznetsov, S. Niccolai, E. Seder, M. Anghinolfi, H. Seraydaryan, Y. G. Sharabian, Martin K. Mayer, M. S. Saini, Barry Ritchie, J. T. Goetz, I. I. Strakovsky, A. Deur, W. K. Brooks, Kei Moriya, C. A. Meyer, K. P. Adhikari, Michael Vineyard, D. P. Weygand, and D. Doughty
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Meson, 010308 nuclear & particles physics, Hadron, Photon energy, Strangeness, 7. Clean energy, 01 natural sciences, Nuclear physics, Baryon, 0103 physical sciences, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: Differential cross sections of the reaction γd → K+Σ–(p) have been measured with the CLAS detector at Jefferson Lab using incident photons with energies between 1.1 and 3.6 GeV. This is the first complete set of strangeness photoproduction data on the neutron covering a broad angular range. At energies close to threshold and up to Eγ ~ 1.8 GeV, the shape of the angular distribution is suggestive of the presence of s -channel production mechanisms. For Eγ > 1.8 GeV, a clear forward peak appears and becomes more prominent as the photon energy increases, suggesting contributions from t-channel production mechanisms. Furthermore, these data can be used to constrain future analysis of this reaction.
Published: 2010
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20. 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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21. DSE inspired model for the pion's valence dressed-quark GPD

Author: Craig D. Roberts, F. Sabatié, Lei Chang, Jose Rodríguez-Quintero, C. Mezrag, and H. Moutarde
Subjects: Quark, History, Particle physics, High Energy Physics::Lattice, Hadron, Nuclear Theory, FOS: Physical sciences, DSE, Parton, 01 natural sciences, Education, High Energy Physics - Phenomenology (hep-ph), Pion, 0103 physical sciences, 010306 general physics, Nuclear Experiment, Quantum chromodynamics, Physics, Valence (chemistry), Radon transform, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Dressed-quark, Computer Science Applications, Gluon, High Energy Physics - Phenomenology, GPD, High Energy Physics::Experiment, Pion's valence
Abstract: We sketch here an approach to the computation of generalised parton distributions (GPDs), based upon a rainbow-ladder (RL) truncation of QCD's Dyson-Schwinger equations and exemplified via the pion's valence dressed-quark GPD, $H_\pi^{\rm v}(x,\xi,t)$. Our analysis focuses on the case of zero skewness, $\xi=0$, and underlines that the impulse-approximation used hitherto to define the pion's valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for $H_\pi^{\rm v}(x,0,t)$, expressed as the Radon transform of a single amplitude. Therewith we obtain results for $H_\pi^{\rm v}(x,0,t)$ and the associated impact-parameter dependent distribution, $q_\pi^{\rm v}(x,|\vec{b}_\perp|)$, which provide a qualitatively sound picture of the pion's dressed-quark structure at an hadronic scale., Comment: 4th Symposium on Prospects in the Physics of Discrete Symmetries (DISCRETE 2014); CNUM: C14-12-02.1
Published: 2015

22. Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions

Author: H S, Jo, F X, Girod, H, Avakian, V D, Burkert, M, Garçon, M, Guidal, V, Kubarovsky, S, Niccolai, P, Stoler, K P, Adhikari, D, Adikaram, M J, Amaryan, M D, Anderson, S, Anefalos Pereira, J, Ball, N A, Baltzell, M, Battaglieri, V, Batourine, I, Bedlinskiy, A S, Biselli, S, Boiarinov, W J, Briscoe, W K, Brooks, D S, Carman, A, Celentano, S, Chandavar, G, Charles, L, Colaneri, P L, Cole, N, Compton, M, Contalbrigo, V, Crede, A, D'Angelo, N, Dashyan, R, De Vita, E, De Sanctis, A, Deur, C, Djalali, R, Dupre, A El, Alaoui, L El, Fassi, L, Elouadrhiri, G, Fedotov, S, Fegan, A, Filippi, J A, Fleming, B, Garillon, N, Gevorgyan, Y, Ghandilyan, G P, Gilfoyle, K L, Giovanetti, J T, Goetz, E, Golovatch, R W, Gothe, K A, Griffioen, B, Guegan, N, Guler, L, Guo, K, Hafidi, H, Hakobyan, N, Harrison, M, Hattawy, K, Hicks, N, Hirlinger Saylor, D, Ho, M, Holtrop, S M, Hughes, Y, Ilieva, D G, Ireland, B S, Ishkhanov, D, Jenkins, K, Joo, S, Joosten, D, Keller, G, Khachatryan, M, Khandaker, A, Kim, W, Kim, A, Klein, F J, Klein, S E, Kuhn, S V, Kuleshov, P, Lenisa, K, Livingston, H Y, Lu, I J D, MacGregor, B, McKinnon, Z E, Meziani, M, Mirazita, V, Mokeev, R A, Montgomery, H, Moutarde, A, Movsisyan, E, Munevar, C, Munoz Camacho, P, Nadel-Turonski, L A, Net, G, Niculescu, M, Osipenko, A I, Ostrovidov, M, Paolone, K, Park, E, Pasyuk, J J, Phillips, S, Pisano, O, Pogorelko, J W, Price, S, Procureur, Y, Prok, A J R, Puckett, B A, Raue, M, Ripani, A, Rizzo, G, Rosner, P, Rossi, P, Roy, F, Sabatié, C, Salgado, D, Schott, R A, Schumacher, E, Seder, A, Simonyan, Iu, Skorodumina, G D, Smith, D, Sokhan, N, Sparveris, S, Stepanyan, I I, Strakovsky, S, Strauch, V, Sytnik, Ye, Tian, S, Tkachenko, M, Ungaro, H, Voskanyan, E, Voutier, N K, Walford, D P, Watts, X, Wei, L B, Weinstein, M H, Wood, N, Zachariou, L, Zana, J, Zhang, Z W, Zhao, I, Zonta, 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), Thomas Jefferson National Accelerator Facility (Jefferson Lab), 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, Rensselaer Polytechnic Institute (RPI), Old Dominion University [Norfolk] (ODU), Argonne National Laboratory [Lemont] (ANL), Universidad Tecnica Federico Santa Maria [Valparaiso] (UTFSM), University of Connecticut (UCONN), Ohio University, Carnegie Mellon University [Pittsburgh] (CMU), 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, Photon, Proton, HERA, General Physics and Astronomy, Socio-culturale, FOS: Physical sciences, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, High Energy Physics - Experiment (hep-ex), CLAS, virtual compton scattering, Twist, Nuclear Experiment (nucl-ex), VIRTUAL COMPTON-SCATTERING, NUCLEON, Nuclear Experiment, Quantum chromodynamics, Physics, 3. Good health, Phase space, virtual compton scattering, nucleon, High Energy Physics::Experiment, Nucleon
Abstract: Unpolarized and beam-polarized four-fold cross sections $\frac{d^4 \sigma}{dQ^2 dx_B dt d\phi}$ for the $ep\to e^\prime p^\prime \gamma$ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 ($Q^2,x_B,t$) bins over the widest phase space ever explored in the valence-quark region. Several models of Generalized Parton Distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD $H$, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton Form Factors, these results reveal a tomographic image of the nucleon., Comment: 7 pages, 5 figures
Published: 2015
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23. Gauge-dependent O.P.E. power corrections on the QCD coupling

Author: Ph. Boucaud, H. Moutarde, Andrea Donini, J. P. Leroy, Jose Rodríguez-Quintero, F. De Soto, A. Le Yaouanc, Jacques Micheli, and O. Pène
Subjects: Coupling constant, Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Instanton, Particle physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, QCD vacuum, Lattice QCD, Gluon condensate, Atomic and Molecular Physics, and Optics, Gluon, Quantum electrodynamics, Lattice (order)
Abstract: The running coupling constant can be estimated by computing gluon two- and three-point Green functions from the lattice. Computing in lattice implies working in a fixed gauge sector (Landau). A source of systematic uncertainty is then the contribution of non gauge-invariant condensates, as 〈A2〉, generating power corrections that might still be important at very high energies. We study the impact of this gluon condensate on the analysis of lattice data and the estimate of ΛMS. We finally try the relationship of this condensate with topological properties of QCD through the instanton picture.
Published: 2003
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24. O.P.E. and Power Corrections to the QCD coupling constant

Author: J. Rodríguez-Quintero, J. P. Leroy, Andrea Donini, F. De Soto, A. Le Yaouanc, H. Moutarde, Jacques Micheli, O. Pène, and Ph. Boucaud
Subjects: Quantum chromodynamics, Coupling constant, Physics, Nuclear and High Energy Physics, Instanton, Particle physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, FOS: Physical sciences, Gluon condensate, Atomic and Molecular Physics, and Optics, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Lattice (order), Operator product expansion
Abstract: Lattice data seems to show that power corrections should be convoked to describe appropriately the transition of the QCD coupling constant running from U.V. to I.R. domains. Those power corrections for the Landau-gauge MOM coupling constant in a pure Yang-Mills theory (N_f=0) are analysed in terms of Operator Product Expansion (O.P.E.) of two- and three-point Green functions, the gluon condensate emerging from this study. The semi-classical picture given by instantons can be also used to look for into the nature of the power corrections and gluon condensate., Comment: 5 pages, talk given at XXX International Meeting on Fundamental Physics, Jaca 2002
Published: 2003
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25. Sketching the pion's valence-quark generalised parton distribution

Author: Jose Rodríguez-Quintero, Sebastian M. Schmidt, H. Moutarde, F. Sabatié, Craig D. Roberts, Lei Chang, C. Mezrag, 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, Physics Department [Adelaide], University of Adelaide, Argonne National Laboratory (ANL) - Physics Division (PHY), Universidad de Huelva, Dip. di Fisica Applicada e, Ingenieria Electrica, Carretera Palos - La Radida s/n, 21819 Palos Fra (Huelva), Forschungszentrum Julich, Institut fur Kernphysik, and Universidad de Huelva
Subjects: Quark, Nuclear and High Energy Physics, Particle physics, Nuclear Theory, High Energy Physics::Lattice, Lattice field theory, Hadron, FOS: Physical sciences, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Theory (nucl-th), High Energy Physics - Phenomenology (hep-ph), Pion, High Energy Physics - Lattice, Deeply virtual compton scattering, Generalised parton distribution functions, Nuclear Experiment (nucl-ex), Nuclear Experiment, Quantum chromodynamics, Physics, High Energy Physics - Lattice (hep-lat), High Energy Physics::Phenomenology, lcsh:QC1-999, π-meson, Gluon, High Energy Physics - Phenomenology, Amplitude, Dyson–Schwinger equations, Dynamical chiral symmetry breaking, High Energy Physics::Experiment, lcsh:Physics
Abstract: In order to learn effectively from measurements of generalised parton distributions (GPDs), it is desirable to compute them using a framework that can potentially connect empirical information with basic features of the Standard Model. We sketch an approach to such computations, based upon a rainbow-ladder (RL) truncation of QCD's Dyson-Schwinger equations and exemplified via the pion's valence dressed-quark GPD, $H_\pi^{\rm v}(x,\xi,t)$. Our analysis focuses primarily on $\xi=0$, although we also capitalise on the symmetry-preserving nature of the RL truncation by connecting $H_\pi^{\rm v}(x,\xi=\pm 1,t)$ with the pion's valence-quark parton distribution amplitude. We explain that the impulse-approximation used hitherto to define the pion's valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for $H_\pi^{\rm v}(x,0,t)$, expressed as the Radon transform of a single amplitude. Therewith we obtain results for $H_\pi^{\rm v}(x,0,t)$ and the associated impact-parameter dependent distribution, $q_\pi^{\rm v}(x,|\vec{b}_\perp|)$, which provide a qualitatively sound picture of the pion's dressed-quark structure at an hadronic scale. We evolve the distributions to a scale $\zeta=2\,$GeV, so as to facilitate comparisons in future with results from experiment or other nonperturbative methods., Comment: 7 pages, 4 figures
Published: 2014
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26. Strangeness Suppression ofqq¯Creation Observed in Exclusive Reactions

Author: V. Sytnik, M. Ungaro, R. Paremuzyan, Gerard Gilfoyle, S. Chandavar, K. Livingston, D. Sokhan, B. McKinnon, M. Aghasyan, M. Mirazita, V. Batourine, M. Battaglieri, I. Zonta, M. Garçon, X. Wei, K. Joo, Jie Zhang, C. E. Hyde, E. Golovatch, S. Koirala, P. Peng, C. Munoz Camacho, J. Ball, D. S. Carman, Diane Schott, A. I. Ostrovidov, K. Park, R. A. Schumacher, M. Khandaker, V. Crede, S. Strauch, Victor Mokeev, S. Niccolai, D. G. Ireland, A. Movsisyan, Latifa Elouadrhiri, C. Djalali, H. Jiang, D. P. Watts, Volker D. Burkert, A. S. Biselli, C. A. Meyer, N. K. Walford, A. V. Vlassov, H. Voskanyan, A. Kim, W. I. Levine, J. A. Fleming, G. V. Fedotov, H. Hakobyan, C. Hanretty, T. A. Forest, Sergey Kuleshov, P. L. Cole, E. Voutier, R. A. Montgomery, W. J. Briscoe, C. I. Moody, R. De Vita, P. Lenisa, P. Eugenio, K. P. Adhikari, M. D. Mestayer, D. Protopopescu, N. Dashyan, P. Roy, Andrew Puckett, O. Cortes, F. X. Girod, I. Bedlinskiy, Ye Tian, Martin K. Mayer, K. L. Giovanetti, B. Garillon, J. W. Price, S. Pozdniakov, S. Boiarinov, M. Guidal, R. Dupre, H. Y. Lu, L. Colaneri, A. Simonyan, Larry Weinstein, S. Anefalos Pereira, Brian Raue, M. S. Saini, F. Sabatié, Z. W. Zhao, K. A. Griffioen, D. Doughty, M. Holtrop, A. D'Angelo, H. S. Jo, A. El Alaoui, J. T. Goetz, L. El Fassi, Luciano Pappalardo, M. Hattawy, Y. Ilieva, G. Charles, A. Deur, S. Pisano, Nicholas Zachariou, W. K. Brooks, V. P. Kubarovsky, P. Nadel-Turonski, G. Rosner, D. Rimal, I. Niculescu, O. Pogorelko, S. M. Hughes, Y. Ghandilyan, H. Moutarde, B. Guegan, M. Ripani, Dustin Keller, B. Vernarsky, Michael Wood, Alessandro Rizzo, W. Phelps, W. Tang, M. Osipenko, W. Kim, G. Niculescu, I. J. D. MacGregor, A. Celentano, R. W. Gothe, and M. Contalbrigo
Subjects: Physics, Quark, Particle physics, High energy, Meson production, Proton, 010308 nuclear & particles physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, General Physics and Astronomy, Strangeness, 01 natural sciences, Hadronization, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract: In this study, we measured the ratios of electroproduction cross sections from a proton target for three exclusive meson-baryon final states: ΛK+, pπ0, and nπ+, with the CLAS detector at Jefferson Lab. Using a simple model of quark hadronization, we extract qq¯ creation probabilities for the first time in exclusive two-body production, in which only a single qq¯ pair is created. We observe a sizable suppression of strange quark-antiquark pairs compared to nonstrange pairs, similar to that seen in high-energy production.
Published: 2014
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27. 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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28. 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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29. 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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30. 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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31. 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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32. Measurement of the structure function of the nearly free neutron using spectator tagging in inelasticH2(e,e′ps)Xscattering with CLAS

Author: W. Kim, G. Niculescu, P. Lenisa, P. Nadel-Turonski, F. X. Girod, I. Zonta, X. Wei, B. McKinnon, A. Kim, S. Koirala, N. Dashyan, S. E. Kuhn, J. A. Fleming, M. Hattawy, B. S. Ishkhanov, Friedrich Klein, M. Mirazita, R. A. Schumacher, M. J. Amaryan, D. Dutta, N. A. Baltzell, J. Arrington, C. Djalali, S. Chandavar, Andrew Puckett, Martin K. Mayer, N. Gevorgyan, J. Zhang, L. Zana, V. Mokeev, K. A. Griffioen, H. Hakobyan, C. Hanretty, A. V. Vlassov, M. MacCormick, P. Eugenio, R. Paremuzyan, S. Bültmann, A. Simonyan, Latifa Elouadrhiri, G. Charles, S. Tkachenko, C. E. Hyde, K. L. Giovanetti, M. Ungaro, Larry Weinstein, M. Ripani, W. K. Brooks, R. Ent, I. Bedlinskiy, Gerard Gilfoyle, B. Garillon, D. Sokhan, Sergey Kuleshov, S. Stepanyan, Avraham Klein, G. V. Fedotov, V. P. Kubarovsky, K. P. Adhikari, D. Ho, Diane Schott, W. Tang, P. Roy, M. Osipenko, O. Pogorelko, Andrea Celentano, R. De Vita, S. Strauch, D. P. Watts, P. L. Cole, C. E. Keppel, D. Doughty, M. Guidal, D. G. Ireland, George Davey Smith, K. Park, V. Crede, M. Ispiryan, I. J. D. MacGregor, S. Lewis, H. Avakian, G. Rosner, R. A. Montgomery, R. Dupre, M. Battaglieri, C. Munoz Camacho, J. P. Ball, M. Holtrop, N. K. Walford, D. S. Carman, H. Voskanyan, M. Khandaker, Y. Ghandilyan, Volker D. Burkert, A. S. Biselli, S. Anefalos Pereira, Eugene Pasyuk, E. Seder, H. S. Jo, W. J. Briscoe, S. Niccolai, A. D'Angelo, Luciano Pappalardo, G. E. Dodge, H. Y. Lu, N. Markov, Dustin Keller, E. De Sanctis, S. S. Stepanyan, S. Pisano, M. Aghasyan, Michael Wood, K. Hafidi, D. I. Sober, I. Niculescu, L. El Fassi, K. Hicks, H. Egiyan, T. Mineeva, P. Bosted, M. E. Christy, L. Guo, I. Senderovich, Alessandro Rizzo, J. T. Goetz, O. Cortes, N. Harrison, H. Fenker, P. M. King, E. Golovatch, N. Baillie, A. Deur, N. Kalantarians, J. W. Price, D. Protopopescu, S. Pozdniakov, E. Voutier, K. Livingston, Y. G. Sharabian, F. Sabatié, P. Rossi, A. El Alaoui, Y. Ilieva, D. Rimal, M. Contalbrigo, W. Melnitchouk, V. Tvaskis, S. Procureur, R. W. Gothe, H. Moutarde, and J. J. Phillips
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Proton, Dynamic structure factor, Nuclear Theory, EMC effect, Momentum transfer, Neutron, Nuclear Experiment, Nucleon, Inelastic neutron scattering, Neutron time-of-flight scattering
Abstract: Background: Much less is known about neutron structure than that of the proton due to the absence of free neutron targets. Neutron information is usually extracted from data on nuclear targets such as deuterium, requiring corrections for nuclear binding and nucleon off-shell effects. These corrections are model dependent and have significant uncertainties, especially for large values of the Bjorken scaling variable x . As a consequence, the same data can lead to different conclusions, for example, about the behavior of the d quark distribution in the proton at large x . Purpose: The Barely Off-shell Nucleon Structure experiment at Jefferson Lab measured the inelastic electron-deuteron scattering cross section, tagging spectator protons in coincidence with the scattered electrons. This method reduces nuclear binding uncertainties significantly and has allowed for the first time a (nearly) model-independent extraction of the neutron structure function F 2 ( x , Q 2 ) in the resonance and deep-inelastic regions. Method: A novel compact radial time projection chamber was built to detect protons with momentum between 70 and 150 MeV / c and over a nearly 4 π angular range. For the extraction of the free-neutron structure function F 2 n , spectator protons at backward angles ( > 100 ∘ relative to the momentum transfer) and with momenta below 100 MeV / c were selected, ensuring that the scattering took place on a nearly free neutron. The scattered electrons were detected with Jefferson Lab's CLAS spectrometer, with data taken at beam energies near 2, 4, and 5 GeV. Results: The extracted neutron structure function F 2 n and its ratio to the inclusive deuteron structure function F 2 d are presented in both the resonance and the deep-inelastic regions for momentum transfer squared Q 2 between 0.7 and 5 GeV 2 / c 2 , invariant mass W between 1 and 2.7 GeV / c 2 , and Bjorken x between 0.25 and 0.6 (in the deep-inelastic scattering region). The dependence of the semi-inclusive cross section on the spectator proton momentum and angle is investigated, and tests of the spectator mechanism for different kinematics are performed. Conclusions: Our data set on the structure function ratio F 2 n / F 2 d can be used to study neutron resonance excitations, test quark-hadron duality in the neutron, develop more precise parametrizations of structure functions, and investigate binding effects (including possible mechanisms for the nuclear EMC effect) and provide a first glimpse of the asymptotic behavior of d / u at x → 1 .
Published: 2014
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33. 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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34. Exclusive π0 electroproduction at W>2 GeV with CLAS

Author: I. BedlinskiyInstitute of Theoretical and Experimental Physics, V. Kubarovsky(Thomas Jefferson National Accelerator Facility), S. Niccolai(Institut de Physique Nucléaire ORSAY), P. Stoler(Rensselaer Polytechnic Institute), K. P. Adhikari(Old Dominion University), M. D. Anderson(University of Glasgow), S. Anefalos Pereira(INFN), H. Avakian(Thomas Jefferson National Accelerator Facility), J. Ball(CEA), N. A. Baltzell(Argonne National Laboratory), M. Battaglieri(INFN), V. Batourine(Thomas Jefferson National Accelerator Facility), A. S. Biselli(Thomas Jefferson National Accelerator Facility), S. Boiarinov(Thomas Jefferson National Accelerator Facility), J. Bono(Florida International University), W. J. Briscoe(The George Washington University), W. K. Brooks(Universidad Técnica Federico Santa María), V. D. Burkert(Thomas Jefferson National Accelerator Facility), D. S. Carman(Thomas Jefferson National Accelerator Facility), A. Celentano(INFN), S. Chandavar(Ohio University), L. Colaneri(INFN), P. L. Cole(Idaho State University), M. Contalbrigo(INFN), O. Cortes(Idaho State University), V. Crede(Florida State University), A. D'Angelo(INFN), N. Dashyan(Yerevan Physics Institute), R. De Vita(INFN), E. De Sanctis(INFN), A. Deur(Thomas Jefferson National Accelerator Facility), C. Djalali(University of South Carolina), D. Doughty(Christopher Newport University), R. Dupre(Institut de Physique Nucléaire ORSAY), H. Egiyan(Thomas Jefferson National Accelerator Facility), A. El Alaoui(Argonne National Laboratory), L. El Fassi(Old Dominion University), L. Elouadrhiri(Thomas Jefferson National Accelerator Facility), P. Eugenio(Florida State University), G. Fedotov(University of South Carolina), S. Fegan(INFN), J. A. Fleming(Edinburgh University), T. A. Forest(Idaho State University), B. Garillon(Institut de Physique Nucléaire ORSAY), M. Gar\c con(CEA), G. Gavalian(Old Dominion University), N. Gevorgyan(Yerevan Physics Institute), Y. Ghandilyan(Yerevan Physics Institute), G. P. Gilfoyle(University of Richmond), K. L. Giovanetti(James Madison University), F. X. Girod(Thomas Jefferson National Accelerator Facility), E. Golovatch(Skobeltsyn Institute of Nuclear Physics), R. W. Gothe(University of South Carolina), K. A. Griffioen(Institut de Physique Nucléaire ORSAY), B. Guegan(Institut de Physique Nucléaire ORSAY), L. Guo(Florida International University), K. Hafidi(Argonne National Laboratory), H. Hakobyan(Universidad Técnica Federico Santa María), N. Harrison(University of Connecticut), M. Hattawy(Institut de Physique Nucléaire ORSAY), K. Hicks(Ohio University), M. Holtrop(University of New Hampshire), D. G. Ireland(University of Glasgow), B. S. Ishkhanov(Skobeltsyn Institute of Nuclear Physics), E. L. Isupov(Skobeltsyn Institute of Nuclear Physics), D. Jenkins(Institut de Physique Nucléaire ORSAY), H. S. Jo(Institut de Physique Nucléaire ORSAY), K. Joo(University of Connecticut), D. Keller(University of Virginia), M. Khandaker(Idaho State University), A. Kim(University of Connecticut), W. Kim(Kyungpook National University), A. Klein(Old Dominion University), F. J. Klein(Catholic University of America), S. Koirala(Old Dominion University), S. E. Kuhn(Old Dominion University), S. V. Kuleshov(Universidad Técnica Federico Santa María), P. Lenisa(INFN), W. I. Levine(Carnegie Mellon University), K. Livingston(University of Glasgow), H. Y. Lu(University of South Carolina), I . J . D. MacGregor(University of Glasgow), N. Markov(University of Connecticut), M. Mayer(Old Dominion University), B. McKinnon(University of Glasgow), M. Mirazita(INFN), V. Mokeev(Thomas Jefferson National Accelerator Facility), R. A. Montgomery(INFN), C. I. Moody(Argonne National Laboratory), H. Moutarde(CEA), A Movsisyan(INFN), C. Munoz Camacho(Institut de Physique Nucléaire ORSAY), P. Nadel-Turonski(Thomas Jefferson National Accelerator Facility), I. Niculescu(James Madison University), M. Osipenko(INFN), A. I. Ostrovidov(Florida State University), L. L. Pappalardo(INFN), K. Park(Thomas Jefferson National Accelerator Facility), S. Park(Florida State University), E. Pasyuk(Thomas Jefferson National Accelerator Facility), E. Phelps(University of South Carolina), W. Phelps(Florida International University), J. J. Phillips(University of Glasgow), S. Pisano(INFN), O. Pogorelko(Institute of Theoretical and Experimental Physics), J. W. Price(California State University), Y. Prok(Old Dominion University), D. Protopopescu(University of Glasgow), S. Procureur(CEA), A. J. R. Puckett(University of Connecticut), B. A. Raue(Florida International University), M. Ripani(INFN), B. G. Ritchie(Arizona State University), A. Rizzo(INFN), P. Rossi(INFN), P. Roy(Florida State University), F. Sabatié(CEA), C. Salgado(Norfolk State University), D. Schott(The George Washington University), R. A. Schumacher(Carnegie Mellon University), E. Seder(University of Connecticut), I. Senderovich(Arizona State University), Y. G. Sharabian(Thomas Jefferson National Accelerator Facility), A. Simonyan(Yerevan Physics Institute), G. D. Smith(Edinburgh University), D. I. Sober(Catholic University of America), D. Sokhan(University of Glasgow), S. S. Stepanyan(Kyungpook National University), S. Strauch(University of South Carolina), V. Sytnik(Universidad Técnica Federico Santa María), W. Tang(Ohio University), Ye Tian(University of South Carolina), M. Ungaro(Thomas Jefferson National Accelerator Facility), A. V. Vlassov(Institute of Theoretical and Experimental Physics), H. Voskanyan(Yerevan Physics Institute), E. Voutier(LPSC), N. K. Walford(Catholic University of America), D. Watts(University of Glasgow), X. Wei(Thomas Jefferson National Accelerator Facility), L. B. Weinstein(Old Dominion University), M. Yurov(University of Virginia), N. Zachariou(University of South Carolina), L. Zana(Edinburgh University), J. Zhang(Thomas Jefferson National Accelerator Facility), Z. W. Zhao(University of Virginia), I. Zonta(INFN), and for the CLAS Collaboration()
Subjects: hep-ex, High Energy Physics::Experiment, Nuclear Experiment, nucl-ex, NO
Abstract: Exclusive neutral-pion electroproduction ($ep\to e^\prime p^\prime \pi^0$) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\pi$ and structure functions $\sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$ as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. 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

35. $\phi$-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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36. 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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37. Publisher's Note: Differential photoproduction cross sections of theΣ0(1385),Λ(1405), andΛ(1520)[Phys. Rev. C88, 045201 (2013)]

Author: K. Moriya, R. A. Schumacher, K. P. Adhikari, D. Adikaram, M. Aghasyan, M. J. Amaryan, M. D. Anderson, S. Anefalos Pereira, H. Avakian, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, M. Bellis, R. P. Bennett, A. S. Biselli, J. Bono, S. Boiarinov, W. J. Briscoe, W. K. Brooks, V. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, P. Collins, M. Contalbrigo, O. Cortes, V. Crede, A. D’Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, B. Dey, C. Djalali, D. Doughty, M. Dugger, R. Dupre, H. Egiyan, L. El Fassi, P. Eugenio, G. Fedotov, S. Fegan, R. Fersch, J. A. Fleming, N. Gevorgyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, J. T. Goetz, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, N. Guler, L. Guo, H. Hakobyan, C. Hanretty, D. Heddle, K. Hicks, D. Ho, M. Holtrop, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, H. S. Jo, K. Joo, D. Keller, M. Khandaker, A. Klein, F. J. Klein, S. Koirala, A. Kubarovsky, V. Kubarovsky, S. V. Kuleshov, S. Lewis, K. Livingston, H. Y. Lu, I. J. D. MacGregor, D. Martinez, M. Mayer, M. McCracken, B. McKinnon, M. D. Mestayer, C. A. Meyer, T. Mineeva, M. Mirazita, V. Mokeev, R. A. Montgomery, H. Moutarde, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, R. Nasseripour, C. S. Nepali, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, L. L. Pappalardo, R. Paremuzyan, K. Park, S. Park, E. Pasyuk, E. Phelps, J. J. Phillips, S. Pisano, O. Pogorelko, S. Pozdniakov, J. W. Price, S. Procureur, D. Protopopescu, A. J. R. Puckett, B. A. Raue, D. Rimal, M. Ripani, B. G. Ritchie, G. Rosner, P. Rossi, F. Sabatié, M. S. Saini, C. Salgado, D. Schott, E. Seder, H. Seraydaryan, Y. G. Sharabian, G. D. Smith, D. I. Sober, D. Sokhan, S. Stepanyan, P. Stoler, S. Strauch, M. Taiuti, W. Tang, C. E. Taylor, S. Taylor, Y. Tian, S. Tkachenko, M. Ungaro, B. Vernarsky, M. F. Vineyard, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, L. B. Weinstein, M. Williams, M. H. Wood, N. Zachariou, L. Zana, J. Zhang, Z. W. Zhao, and I. Zonta
Subjects: Physics, Nuclear and High Energy Physics, Differential (mathematics), Mathematical physics
Published: 2013
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38. 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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39. 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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40. 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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41. Test of two new parametrizations of the generalized parton distribution H

Author: F. Sabatié, C. Mezrag, H. Moutarde, Département de Physique Nucléaire (ex SPhN) (DPHN), 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-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay
Subjects: Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Compton scattering, FOS: Physical sciences, Observable, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Formalism (philosophy of mathematics), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Statistical physics, 010306 general physics
Abstract: In 2011 Radyushkin outlined the practical implementation of the One-Component Double Distribution formalism in realistic Generalized Parton Distribution models. We compare the One-Component Double Distribution framework to the standard one and compute Deeply Virtual Compton Scattering observables for both. In particular the new implementation is more flexible, offering a greater range of variation of the real and imaginary parts of the associated Compton Form Factor while still allowing to recover results similar to the classical approach. Moreover the polynomiality property is satisfied up to the highest order. Although the comparison to experimental data may be improved, the One-Component Double Distribution modeling is thus an attractive alternative., 38 pages, 12 figures
Published: 2013
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42. 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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43. 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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44. Deep exclusive π+ electroproduction off the proton at CLAS

Author: K. Park, M. Guidal, R. W. Gothe, J. M. Laget, M. Garçon, K. P. Adhikari, M. Aghasyan, M. J. Amaryan, M. Anghinolfi, H. Avakian, H. Baghdasaryan, J. Ball, N. A. Baltzell, M. Battaglieri, I. Bedlinsky, R. P. Bennett, A. S. Biselli, C. Bookwalter, S. Boiarinov, W. J. Briscoe, W. K. Brooks, V. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, M. Contalbrigo, V. Crede, A. D’Angelo, A. Daniel, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, G. E. Dodge, D. Doughty, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, S. Fegan, J. A. Fleming, T. A. Forest, A. Fradi, N. Gevorgyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, W. Gohn, E. Golovatch, L. Graham, K. A. Griffioen, B. Guegan, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, D. Heddle, K. Hicks, D. Ho, M. Holtrop, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, D. Jenkins, H. S. Jo, D. Keller, M. Khandaker, P. Khetarpal, A. Kim, W. Kim, F. J. Klein, S. Koirala, A. Kubarovsky, V. Kubarovsky, S. E. Kuhn, S. V. Kuleshov, K. Livingston, H. Y. Lu, I. J. D. MacGregor, Y. Mao, N. Markov, D. Martinez, M. Mayer, B. McKinnon, C. A. Meyer, T. Mineeva, M. Mirazita, V. Mokeev, H. Moutarde, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, C. S. Nepali, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, L. L. Pappalardo, R. Paremuzyan, S. Park, E. Pasyuk, S. Anefalos Pereira, E. Phelps, S. Pisano, O. Pogorelko, S. Pozdniakov, J. W. Price, S. Procureur, D. Protopopescu, A. J. R. Puckett, B. A. Raue, G. Ricco, D. Rimal, M. Ripani, G. Rosner, P. Rossi, F. Sabatié, M. S. Saini, C. Salgado, D. Schott, R. A. Schumacher, E. Seder, H. Seraydaryan, Y. G. Sharabian, E. S. Smith, G. D. Smith, D. I. Sober, D. Sokhan, S. S. Stepanyan, P. Stoler, I. I. Strakovsky, S. Strauch, M. Taiuti, W. Tang, C. E. Taylor, Ye Tian, S. Tkachenko, A. Trivedi, M. Ungaro, B. Vernarsky, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, L. B. Weinstein, D. P. Weygand, M. H. Wood, N. Zachariou, J. Zhang, Z. W. Zhao, I. Zonta, 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: Particle physics, Nuclear and High Energy Physics, Hadron, Theoretical models, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, SCALING LAWS, 0103 physical sciences, VIRTUAL COMPTON-SCATTERING, PION FORM-FACTOR, CROSS-SECTION, HIGH-ENERGIES, PHOTOPRODUCTION, DEUTERON, MESONS, PHOTODISINTEGRATION, MOMENTUM, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Scattering, Phenomenology (particle physics)
Abstract: The exclusive electroproduction of $\pi^+$ above the resonance region was studied using the $\rm{CEBAF}$ Large Acceptance Spectrometer ($\rm{CLAS}$) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of $\rm{CLAS}$, together with the high luminosity, allowed us to measure the cross section for the $\gamma^* p \to n \pi^+$ process in 140 ($Q^2$, $x_B$, $t$) bins: $0.16, Comment: 18pages, 21figures,2tables
Published: 2013
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45. Hard Two-body Photodisintegration of 3He

Author: G. Niculescu, N. Dashyan, D. Protopopescu, E. Cisbani, S. Pozdniakov, G. Rosner, S. Tkachenko, C. Djalali, Yujie Qiang, C. S. Nepali, X. Yan, Idaykis Rodriguez, F. X. Girod, Yordanka Ilieva, L. Guo, Andrew Puckett, G. Charles, Yingxiao Wang, H. Baghdasaryan, Victor Mokeev, S. Beck, Martin K. Mayer, M. S. Saini, Nikolaos Sparveris, X. Zhan, E. Voutier, J. A. Fleming, Ronald Gilman, E. L. Isupov, J. T. Goetz, E. De Sanctis, Dustin Keller, E. Piasetzky, Diane Schott, R. Shneor, G. Ricco, C. W. de Jager, W. Tang, Franco Garibaldi, M. Aghasyan, A. I. Ostrovidov, K. Park, G. G. Petratos, Bryan J. Moffit, Michael Wood, K. Hafidi, T. Mineeva, N. Harrison, A. Deur, Barry Ritchie, P. L. Cole, M. Osipenko, M. Contalbrigo, N. A. Saylor, J. Bono, P. Nadel-Turonski, S. Boiarinov, D. G. Ireland, M. Anghinolfi, H. Seraydaryan, X. Zheng, D. Doughty, I. Zonta, B. S. Ishkhanov, H. Yao, W. K. Brooks, C. E. Taylor, R. A. Schumacher, R. Dupre, N. Bubis, X. Jiang, A. El Alaoui, D. Martinez, M. Battaglieri, V. Crede, B. Lee, K. Joo, Volker D. Burkert, A. S. Biselli, George Davey Smith, D. Heddle, S. Koirala, Guy Ron, V. P. Kubarovsky, K. A. Griffioen, R. De Vita, A. Kim, E. Golovatch, A. Beck, N. A. Baltzell, O. Pogorelko, M. Ungaro, N. D. Kvaltine, Xin Qian, W. J. Briscoe, J. P. Ball, R. A. Montgomery, S. Chandavar, Y. Mao, Friedrich Klein, K. Chirapatpimol, P. Khetarpal, D. S. Carman, P. Stoler, O. Geagla, Nicholas Zachariou, A. Camsonne, S. Anefalos Pereira, Michael Vineyard, A. J. Sarty, N. K. Walford, P. Eugenio, D. G. Meekins, A. D'Angelo, H. Voskanyan, A. T. Katramatou, R. Michaels, Douglas Higinbotham, M. Taiuti, K. Hicks, C. Dutta, Vincent Sulkosky, S. Stepanyan, E. Schulte, E. Munevar, Bogdan Wojtsekhowski, D. Rimal, E. Seder, A. Fradi, B. Vernarsky, S. Lewis, M. J. Amaryan, B. Guegan, C. E. Hyde, F. Sabatié, L. El Fassi, W. U. Boeglin, G. E. Dodge, S. Procureur, R. Nasseripour, C. Munoz Camacho, H. Y. Lu, S. Fegan, R. A. Lindgren, S. Strauch, H. S. Jo, Ishay Pomerantz, J. J. LeRose, C. A. Meyer, S. Pisano, G. V. Fedotov, H. Moutarde, D. P. Watts, H. Egiyan, C. Bookwalter, F. Cusanno, K. Livingston, K. L. Giovanetti, I. Niculescu, I. J. D. MacGregor, K. P. Adhikari, D. P. Weygand, Larry Weinstein, W. Gohn, R. Paremuzyan, Jie Zhang, A. Celentano, R. W. Gothe, Z. W. Zhao, D. Ho, Emily M. McCullough, R. Subedi, D. Sokhan, M. Khandaker, B. McKinnon, B. L. Berman, J. Glister, M. Mirazita, E. Phelps, N. Gevorgyan, V. Batourine, S. Park, S. Niccolai, P. Rossi, H. Hakobyan, M. Guidal, M. Holtrop, A. Daniel, Luciano Pappalardo, S. S. Stepanyan, Mustafa Canan, Kalyan Allada, I. Bedlinskiy, A. Kubarovsky, Sergey Kuleshov, E. Khrosinkova, B. Sawatzky, M. Ripani, A. Saha, W. Kim, 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: Particle physics, Photon, Nuclear Theory, FOS: Physical sciences, General Physics and Astronomy, Few-body systems, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Cross section (physics), ANGLE ELASTIC-SCATTERING, CROSS-SECTION, DEUTERON, 0103 physical sciences, medicine, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Scaling, Physics, 010308 nuclear & particles physics, medicine.anatomical_structure, Deuterium, Photodisintegration, Nucleus
Abstract: We have measured cross sections for the {gamma}+{sup 3}He->p+d reaction at photon energies of 0.4 - 1.4 GeV and a center-of-mass angle of 90 deg. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.
Published: 2013
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46. 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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47. 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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48. Measurement of Exclusiveπ0Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

Author: A. Kim, R. A. Schumacher, D. Doughty, D. Heddle, L. Graham, F. X. Girod, V. Mokeev, K. A. Griffioen, Y. Mao, S. Strauch, T. A. Forest, P. Nadel-Turonski, D. P. Watts, H. Egiyan, R. P. Bennett, S. Stepanyan, E. Munevar, M. Ungaro, A. V. Vlassov, I. Zonta, Eugene Pasyuk, A. I. Ostrovidov, K. Park, S. Tkachenko, D. G. Ireland, L. Guo, A. El Alaoui, Y. Ilieva, Volker D. Burkert, C. Munoz Camacho, Andrew Puckett, Martin K. Mayer, Nicholas Zachariou, A. S. Biselli, R. De Vita, W. Gohn, K. Joo, M. Khandaker, M. S. Saini, G. Ricco, C. E. Taylor, B. McKinnon, D. Rimal, W. Tang, E. Seder, I. J. D. MacGregor, M. Osipenko, S. Procureur, G. Charles, S. Anefalos Pereira, M. J. Amaryan, M. Mirazita, N. Markov, V. Crede, Latifa Elouadrhiri, S. Pisano, K. Livingston, N. Gevorgyan, N. A. Saylor, S. E. Kuhn, D. Martinez, B. Guegan, C. A. Meyer, A. Celentano, R. W. Gothe, J. A. Fleming, Friedrich Klein, G. V. Fedotov, H. Moutarde, M. Ripani, S. Fegan, Jie Zhang, Brian Raue, R. Paremuzyan, W. Kim, K. L. Giovanetti, G. Niculescu, F. Sabatié, N. D. Kvaltine, E. De Sanctis, H. Hakobyan, C. Djalali, R. Dupre, Larry Weinstein, M. Contalbrigo, M. Battaglieri, C. Hanretty, M. Aghasyan, A. Deur, K. P. Adhikari, D. I. Sober, M. Taiuti, David M. Keller, D. P. Weygand, W. K. Brooks, H. S. Jo, D. Sokhan, C. Bookwalter, P. Stoler, J. W. Price, Michael Wood, I. Bedlinskiy, K. Hafidi, K. Hicks, D. Protopopescu, S. Pozdniakov, M. Garçon, E. Voutier, S. Koirala, G. Rosner, S. Chandavar, E. Phelps, S. Park, N. Dashyan, P. Rossi, E. L. Isupov, V. P. Kubarovsky, A. Kubarovsky, Ye Tian, George Davey Smith, A. D'Angelo, O. Pogorelko, L. El Fassi, H. Avakian, H. Baghdasaryan, S. Boiarinov, M. Guidal, M. Holtrop, A. Daniel, Luciano Pappalardo, N. K. Walford, H. Voskanyan, W. J. Briscoe, J. P. Ball, Y. Prok, D. S. Carman, S. Niccolai, B. S. Ishkhanov, Sergey Kuleshov, H. Y. Lu, P. Khetarpal, N. A. Baltzell, A. Fradi, I. Niculescu, P. Eugenio, D. Schott, T. Mineeva, C. Salgado, Z. W. Zhao, M. F. Vineyard, M. Anghinolfi, H. Seraydaryan, and Y. G. Sharabian
Subjects: Physics, Particle physics, 010308 nuclear & particles physics, Structure function, General Physics and Astronomy, Sigma, Parton, 01 natural sciences, Helicity, Transverse plane, 0103 physical sciences, Sensitivity (control systems), 010306 general physics, Nucleon, Phenomenology (particle physics)
Abstract: Exclusive $$\pi^0$$ electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in $Q^2$, $x_B$, $t$, and $$\phi_\pi$$, in the $Q^2$ range from 1.0 to 4.6 GeV$^2$$,\ $$-t$ up to 2 GeV$^2$, and $x_B$ from 0.1 to 0.58. Structure functions $$\sigma_T +\epsilon \sigma_L, \sigma_{TT}$$ and $$\sigma_{LT}$$ were extracted as functions of $t$ for each of 17 combinations of $Q^2$ and $x_B$. The data were compared directly with two handbag-based calculations including both longitudinal and transversity GPDs. Inclusion of only longitudinal GPDs very strongly underestimates $$\sigma_T +\epsilon \sigma_L$$ and fails to account for $$\sigma_{TT}$$ and $$\sigma_{LT}$$, while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity flip and helicity non-flip processes. The results confirm that exclusive $$\pi^0$$ electroproduction offers direct experimental access to the transversity GPDs.
Published: 2012
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49. Comparison of forward and backwardpppair knockout in3He(e,e′pp)n

Author: V. Crede, S. Strauch, M. Contalbrigo, M. Paolone, H. Egiyan, M. J. Amaryan, S. Niccolai, M. Taiuti, N. Dashyan, D. G. Jenkins, N. A. Saylor, S. Procureur, S. V. Kuleshov, Michael Wood, D. Sokan, B. S. Ishkhanov, K. Hafidi, W. Tang, M. Y. Gabrielyan, K. L. Giovanetti, B. McKinnon, H. S. Jo, K. A. Griffioen, M. Osipenko, Larry Weinstein, A. D'Angelo, A. Celentano, R. W. Gothe, E. Voutier, E. De Sanctis, D. Doughty, P. Khetarpal, G. Charles, S. Pisano, F. X. Girod, H. Baghdasaryan, J. Ball, A. El Alaoui, S. Chandavar, M. Aghasyan, L. El Fassi, V. Mokeev, Lorenzo Zana, M. Mirazita, J. M. Laget, S. Park, H. Moutarde, S. S. Stepanyan, K. Park, V. P. Kubarovsky, W. Gohn, D. Rimal, P. Rossi, D. I. Sober, D. G. Ireland, S. Tkachenko, H. Voskanyan, R. Dupre, N. Gevorgyan, K. Joo, M. Battaglieri, R. A. Schumacher, Volker D. Burkert, A. S. Biselli, Latifa Elouadrhiri, A. Kim, B. Zhao, W. Kim, A. Kubarovsky, G. Rosner, G. V. Fedotov, G. Niculescu, P. L. Cole, W. K. Brooks, R. Paremuzyan, W. J. Briscoe, M. Guidal, S. Pozdniakov, K. P. Adhikari, D. S. Carman, M. Khandaker, S. Stepanyan, E. Munevar, Gerard Gilfoyle, R. De Vita, G. E. Dodge, H. Y. Lu, N. D. Kvaltine, A. Daniel, I. Niculescu, Luciano Pappalardo, I. J. D. MacGregor, D. Schott, K. Hicks, C. E. Hyde, G. Ricco, Brian Raue, B. Guegan, M. Ripani, Chaden Djalali, S. E. Kuhn, Elton Smith, M. Anghinolfi, H. Seraydaryan, and M. S. Saini
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Momentum (technical analysis), Proton, 010308 nuclear & particles physics, Nuclear Theory, Momentum transfer, EMC effect, Few-body systems, 01 natural sciences, Nuclear physics, 0103 physical sciences, Nuclear force, Neutron, Nuclear Experiment, 010306 general physics, Wave function
Abstract: Measuring nucleon-nucleon Short Range Correlations (SRC) has been a goal of the nuclear physics community for many years. They are an important part of the nuclear wavefunction, accounting for almost all of the high-momentum strength. They are closely related to the EMC effect. While their overall probability has been measured, measuring their momentum distributions is more difficult. In order to determine the best configuration for studying SRC momentum distributions, we measured the 3He(e,e'pp)n reaction, looking at events with high momentum protons (pp > 0.35 GeV/c) and a low momentum neutron (pn < 0.2 GeV/c). We examined two angular configurations: either both protons emitted forward or one proton emitted forward and one backward (with respect to the momentum transfer, →q). Thus, the measured relative momentum distribution of the events with one forward and one backward proton was much closer to the calculated initial-state pp relative momentum distribution, indicating that this is the preferred configuration for measuring SRC.
Published: 2012
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50. Publisher’s Note: Measurement of the NeutronF2Structure Function via Spectator Tagging with CLAS [Phys. Rev. Lett.108, 142001 (2012)]

Author: C. E. Hyde, D. G. Ireland, V. Crede, D. Protopopescu, S. Pozdniakov, H. C. Fenker, D. Adikaram, M. Guidal, Nicholas Kvaltine, G. Niculescu, P. Stoler, Wolodymyr Melnitchouk, G. V. Fedotov, N. Kalantarians, B. Dey, K. Hicks, A. Celentano, R. W. Gothe, M. J. Amaryan, H. Avakian, M. Holtrop, D. P. Weygand, E. De Sanctis, A. Daniel, A. El Alaoui, E. L. Isupov, M. Aghasyan, Luciano Pappalardo, B. Guegan, D. I. Sober, H. Moutarde, M. Contalbrigo, W. Kim, G. Charles, M. Ripani, S. Fegan, K. L. Giovanetti, C. E. Keppel, S. Bültmann, E. Seder, W. J. Briscoe, E. Pasyuk, Larry Weinstein, D. Rimal, Alexei V. Klimenko, D. Doughty, P. Khetarpal, P. E. Bosted, Carlos A. Salgado, Andreas Klein, K. Livingston, M. Ispiryan, Michael Vineyard, D. Heddle, K. P. Adhikari, S. Park, Brian Raue, N. Baillie, Y. Prok, D. S. Carman, B. Zhao, Lorenzo Zana, N. Guler, P. Rossi, H. S. Jo, B. McKinnon, W. Tang, S. E. Kuhn, P. Eugenio, M. Taiuti, R. De Vita, E. Voutier, M. Osipenko, N. Dashyan, D. Branford, V. P. Kubarovsky, M. Khandaker, F. Sabatié, S. S. Jawalkar, S. Niccolai, M. Gabrielyan, N. Gevorgyan, Frank Klein, I. J. D. MacGregor, Sergey Kuleshov, Yordanka Ilieva, M. Anghinolfi, S. Tkachenko, Y. G. Sharabian, S. Anefalos Pereira, Michael Wood, E. V. Hungerford, K. Hafidi, Gerard Gilfoyle, G. Ricco, F. X. Girod, D. Sokhan, M. S. Saini, T. Mineeva, M. E. Christy, Diane Schott, A. I. Ostrovidov, K. Park, Hovhannes Baghdasaryan, S. Strauch, Volker D. Burkert, A. S. Biselli, J. Domingo, A. Fradi, S. Pisano, B. Morrison, C. Djalali, K. A. Griffioen, Dipangkar Dutta, L. Guo, M. Ungaro, J. Arrington, R. A. Schumacher, L. Graham, S. S. Stepanyan, R. Dupre, M. Battaglieri, S. Stepanyan, William Brooks, Rolf Ent, G. E. Dodge, H. Y. Lu, S. Procureur, I. Niculescu, A. Kim, J. Zhang, G. Rosner, Y. Mao, S. Chandavar, J. W. Price, A. Ni, V. Tvaskis, D. P. Watts, H. Egiyan, P. Nadel-Turonski, N. Markov, E. Munevar, P. M. King, E. Golovatch, W. Gohn, L. Elouadrhiri, A. Deur, P. L. Cole, A. D'Angelo, and L. El Fassi
Subjects: Physics, Nuclear physics, Structure function, General Physics and Astronomy, Neutron
Published: 2012
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