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121 results on '"R. A. Miskimen"'

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

Author: M. Günther, D. P. Watts, M. Bashkanov, R. A. Miskimen, S. Abt, C. S. Akondi, N. Jermann, Yu. A. Usov, O. Steffen, I. J. D. MacGregor, P. Pedroni, N. K. Walford, Nicholas Zachariou, Concettina Sfienti, S. N. Prakhov, D. Ghosal, S. Wagner, G. Reicherz, A. Powell, V. L. Kashevarov, A. Braghieri, Z. Ahmed, Th. Strub, Patrick Achenbach, Susanna Costanza, Andy Thomas, I. I. Strakovsky, M. Ostrick, M. Mocanu, Michaela Thiel, I. Supek, B. Krusche, J. Wettig, Lena Heijkenskjöld, J. R. M. Annand, R. Beck, K. Livingston, V. V. Kulikov, S. Lutterer, S. Fegan, S. Gardner, N. S. Borisov, I. Gorodnov, Ron L. Workman, C. Mullen, S. Kay, D. M. Manley, M. Korolija, A. B. Neganov, V. Sokhoyan, D. Hornidge, A. Thiel, A. G. Denig, M. Dieterle, K. Spieker, P. P. Martel, F. Afzal, Durga Paudyal, A. Kaeser, E. J. Downie, A. Lazarev, Lilian Witthauer, E. Mornacchi, W. Gradl, C. Meier, M. Wolfes, D. Werthmüller, M. Biroth, G. Gurevic, C. Collicott, P. B. Otte, P. Drexler, M. A. Martemianov, W. J. Briscoe, M. Unverzagt, T. Rostomyan, F. Cividini, Guy Ron, G. M. Huber, M. Oberle, D. I. Glazier, and M. I. Ferretti-Bondy
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Nuclear Theory, 010308 nuclear & particles physics, media_common.quotation_subject, Hadron, 01 natural sciences, Asymmetry, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Pion, Isospin, 0103 physical sciences, Production (computer science), Center of mass, Nuclear Experiment, 010306 general physics, Crystal Ball, media_common
Abstract: The quasifree $\overrightarrow{\gamma} d\to\pi^0n(p)$ photon beam asymmetry, $\Sigma$, has been measured at photon energies, $E_\gamma$, from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49 to 148$^\circ$. In this kinematic region, polarization observables are sensitive to contributions from the $\Delta (1232)$ and $N(1440)$ resonances. The extracted values of $\Sigma$ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID, and Bonn-Gatchina analyses; while a revised SAID fit, including the new $\Sigma$ measurements, has also been performed. In addition, isospin symmetry is examined as a way to predict $\pi^0n$ photoproduction observables, based on fits to published data in the channels $\pi^0p$, $\pi^+n$, and $\pi^-p$., Comment: 11 pages, 9 figures, 5 tables; fixed 2 glitches
Published: 2021
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2. Measurement of beam asymmetry for π−Δ++ photoproduction on the proton at Eγ=8.5GeV

Author: E. S. Smith, T. Erbora, Ilya Larin, V. V. Tarasov, J. Schwiening, K. Luckas, B. E. Cannon, A. Austregesilo, C. Fanelli, A. Hurley, H. Marukyan, J. Fitches, R.S. Pedroni, W. McGinley, C. A. Meyer, L. Guo, J. Reinhold, A. Ali, T. D. Beattie, S. Furletov, M. M. Dalton, A. Smith, Z. Zhao, M. M. Ito, G. Rodriguez, F. Barbosa, D. Romanov, W. J. Briscoe, V. A. Matveev, A. M. Schertz, D. G. Ireland, V. Crede, T. Daniels, L. Gan, H. Egiyan, B. C.L. Sumner, A. LaDuke, G. J. Lolos, C. S. Akondi, V. Lyubovitskij, S. Somov, S. Fegan, R. Barsotti, S. Adhikari, M. R. Shepherd, A. Gasparian, E. Pooser, T. Whitlatch, N. Wickramaarachchi, Xiang Zhou, T. Britton, Sergey Kuleshov, B. Liu, M. Khatchatryan, H. Hakobyan, A. I. Ostrovidov, D. I. Lersch, K. Suresh, H. Li, P. Eugenio, W. B. Li, J. Barlow, Stephen Taylor, W. Phelps, J. Ritman, J. R. Stevens, M. McCaughan, Haiyan Gao, Mark Richard James Williams, Michael Dugger, Q. Zhou, Barry Ritchie, G. M. Huber, D. I. Sober, C. Gleason, K. Livingston, A. Thiel, A. Hamdi, I. I. Strakovsky, A. Schick, E. Barriga, V. S. Goryachev, A. Deur, Carlos A. Salgado, P. Pauli, V. Neelamana, Z. Baldwin, Z. Papandreou, O. Soto, R. Dzhygadlo, S. Schadmand, I. Jaegle, V. Khachatryan, J. Zarling, R. Dotel, Krisztian Peters, K. Goetzen, M. J. Amaryan, A. Asaturyan, F. Nerling, R. A. Schumacher, X. Shen, Christine Kourkoumelis, R. E. Mitchell, R. A. Miskimen, B. Zihlmann, L. Ng, A. Ernst, Zhiyong Zhang, V. V. Berdnikov, G. Vasileiadis, W.U. Boeglin, V. Kakoyan, D. J. Mack, D. Lawrence, Sean A Dobbs, A. Somov, William Brooks, Lubomir Pentchev, C. Paudel, A. M. Foda, G. Kalicy, N. S. Jarvis, A. Dolgolenko, S. Cole, O. Cortes, C.P. Romero, T. C. Black, R. T. Jones, M. E. McCracken, J. Zhou, K. Mizutani, M. Kamel, A. Teymurazyan, Y. Yang, and E. Chudakov
Subjects: Physics, Range (particle radiation), GlueX, Proton, Meson, 010308 nuclear & particles physics, media_common.quotation_subject, Momentum transfer, 01 natural sciences, Asymmetry, Pseudoscalar, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, media_common
Abstract: We report a measurement of the π − photoproduction beam asymmetry for the reaction → γ p → π − Δ + + using data from the GlueX experiment in the photon beam energy range 8.2–8.8 GeV. The asymmetry Σ is measured as a function of four-momentum transfer t to the Δ + + and compared to phenomenological models. We find that Σ varies as a function of t : negative at smaller values and positive at higher values of | t | . The reaction can be described theoretically by t -channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy.
Published: 2021
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3. The GlueX beamline and detector

Author: T. Whitlatch, N. Wickramaarachchi, N. Cao, Ilya Larin, Michael Dugger, N. K. Walford, V. V. Tarasov, Gerard Visser, W. Phelps, J. Frye, B. Liu, J. Stewart, V. Razmyslovich, S. Schadmand, B. E. Cannon, C.P. Romero, O. Cortes, F. Nerling, S. Adhikari, M. M. Dalton, G. Voulgaris, C. S. Akondi, W. J. Briscoe, J. R. Stevens, W. D. Crahen, G.H. Biallas, H. Marukyan, R.S. Pedroni, C. Gleason, W. McGinley, P. Eugenio, E. Wolin, V. Crede, C. Carlin, L. A. Teigrob, F. Mokaya, T. C. Black, A. Toro, D. G. Meekins, I. A. Semenova, Elton Smith, A. Thiel, Kamal K. Seth, G. J. Lolos, A. M. Schertz, Todd Satogata, G. Kalicy, T. Daniels, N. S. Jarvis, A. Hamdi, I. I. Strakovsky, N. Qin, Mark Richard James Williams, I. Vega, A. Tsaris, Y. Yang, K. Goetzen, T. Erbora, J. Leckey, W. U. Boeglin, R. T. Jones, S. Fegan, D. S. Carman, K. Suresh, V. V. Berdnikov, Barry Ritchie, G. Vasileiadis, T. Carstens, E. Barriga, H. Al Ghoul, K. Moriya, J. Hardin, A. Gerasimov, M. E. McCracken, A. Deur, C. D. Keith, M. J. Staib, Hovanes Egiyan, A. Ali, Vladimir Popov, Jay Benesch, A. Hurley, C. Dickover, Viktor Matveev, Dmitri Romanov, A. Dolgolenko, B. Pratt, Justin I. McIntyre, C. A. Meyer, R. Mendez, A. R. Dzierba, C. Hutton, N. Sandoval, G. M. Huber, L. Guo, Z. Papandreou, Zhiyong Zhang, D. I. Sober, E. Pooser, J. Foote, J. Zarling, M. M. Ito, O. Chernyshov, Blake Leverington, S. Cole, P. Brindza, H. Hakobyan, A. Barnes, Sean A Dobbs, E. G. Anassontzis, T. D. Beattie, D. Werthmüller, X. Shen, Amiran Tomaradze, M. Patsyuk, J. Ritman, M. McCaughan, C. Fanelli, Yujie Qiang, R. A. Miskimen, A. Somov, R. Kliemt, F. Barbosa, A. Austregesilo, R. Dzhygadlo, C. Salgado, B. C.L. Sumner, L. Robison, Joerg Reinhold, Ting Xiao, A. Schick, V. Kakoyan, William Brooks, D. J. Mack, W. I. Levine, N. Gevorgyan, S. Katsaganis, E. Chudakov, Pavlos Ioannou, Lubomir Pentchev, A. Goncalves, A. Yu. Semenov, A. I. Ostrovidov, A. M. Foda, R. Dotel, M. Kamel, R. A. Schumacher, D. G. Ireland, W. B. Li, M. R. Shepherd, Ashot Gasparian, A. Teymurazyan, Krisztian Peters, J. Barlow, B. Zihlmann, Xiang Zhou, J. Pierce, S. Taylor, N. Sparks, L. Gan, S. Somov, L. Ng, A. Ernst, D. Kolybaba, K. Livingston, V. S. Goryachev, Cornelius Schwarz, P. Mattione, Y. Van Haarlem, P. Pauli, I. Tolstukhin, J. Schwiening, M. J. Amaryan, D. Lawrence, J. Brock, H. Ni, C. Stanislav, V. Lyubovitskij, S. Furletov, T. Britton, R. Barsotti, C. Paudel, Christine Kourkoumelis, Sergey Kuleshov, R. E. Mitchell, D. I. Lersch, C. L. Henschel, Q. Zhou, O. Soto, Friedrich Klein, and S.T. Krueger
Subjects: Nuclear and High Energy Physics, GlueX, детектор, Physics - Instrumentation and Detectors, Photon, Physics::Instrumentation and Detectors, фотонный пучок, FOS: Physical sciences, Scintillator, 01 natural sciences, Optics, Hodoscope, 0103 physical sciences, ddc:530, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation, Physics, GlueX, Spectrometer, Calorimeter (particle physics), 010308 nuclear & particles physics, business.industry, Detector, Instrumentation and Detectors (physics.ins-det), Beamline, High Energy Physics::Experiment, business
Abstract: The GlueX experiment at Jefferson Lab has been designed to study photoproduction reactions with a 9-GeV linearly polarized photon beam. The energy and arrival time of beam photons are tagged using a scintillator hodoscope and a scintillating fiber array. The photon flux is determined using a pair spectrometer, while the linear polarization of the photon beam is determined using a polarimeter based on triplet photoproduction. Charged-particle tracks from interactions in the central target are analyzed in a solenoidal field using a central straw-tube drift chamber and six packages of planar chambers with cathode strips and drift wires. Electromagnetic showers are reconstructed in a cylindrical scintillating fiber calorimeter inside the magnet and a lead-glass array downstream. Charged particle identification is achieved by measuring energy loss in the wire chambers and using the flight time of particles between the target and detectors outside the magnet. The signals from all detectors are recorded with flash ADCs and/or pipeline TDCs into memories allowing trigger decisions with a latency of 3.3 $\mu$s. The detector operates routinely at trigger rates of 40 kHz and data rates of 600 megabytes per second. We describe the photon beam, the GlueX detector components, electronics, data-acquisition and monitoring systems, and the performance of the experiment during the first three years of operation., Comment: Accepted by Nuclear Instruments and Methods A, 78 pages, 54 figures
Published: 2021
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4. Extracting the spin polarizabilities of the proton by measurement of Compton double-polarization observables

Author: Susanna Costanza, A. G. Denig, V. L. Kashevarov, V. Metag, C. Sfienti, W. Gradl, G. M. Huber, M. Oberle, D. Werthmüller, J. Wettig, M. Biroth, F. Afzal, P. B. Otte, V. Lisin, A. Polonski, V. Sokhoyan, A. B. Lazarev, Anthony W. Thomas, D. I. Glazier, K. Livingston, S. Lutterer, K. Spieker, J. Mancell, S. Gardner, N. S. Borisov, A. Käser, D. Hornidge, C. Collicott, A. Braghieri, A. B. Neganov, Th. Strub, A. Rajabi, D. P. Watts, Patrick Achenbach, J. R. M. Annand, H. J. Arends, P. Drexler, M. Ostrick, R. Kondratiev, Michaela Thiel, Lena Heijkenskjöld, M. I. Ferretti-Bondy, D. Glowa, M. Bashkanov, R. A. Miskimen, M. Korolija, S. N. Prakhov, Yu. A. Usov, O. Steffen, A. Thiel, G. M. Gurevich, David Manley, P. Pedroni, Lorenzo Zana, P. P. Martel, S. Garni, A. Neiser, I. Keshelashvili, David Hamilton, W. Meyer, B. Krusche, J. Linturi, M. Dieterle, Lilian Witthauer, S. Kay, S. Günther, S. Wagner, G. Reicherz, S. Abt, C. S. Akondi, A. J. Sarty, Reinhard Beck, I. Supek, I. Gorodnov, M. H. Sikora, Roderick M. Macrae, W. J. Briscoe, A. N. Mushkarenkov, T. Rostomyan, Guy Ron, E. J. Downie, M. Unverzagt, F. Cividini, P. Adlarson, Z. Ahmed, I. I. Strakovsky, C. Mullen, Durga Paudyal, M. Wolfes, A. Powell, N. K. Walford, E. Mornacchi, and I. J. D. MacGregor
Subjects: Nuclear reaction, Physics, Chiral perturbation theory, Proton, 010308 nuclear & particles physics, Resonance, 16. Peace & justice, 01 natural sciences, Baryon, 0103 physical sciences, Proton spin crisis, Atomic physics, 010306 general physics, Microtron, Spin-½
Abstract: The Compton double-polarization observable \ud Σ\ud 2\ud z\ud has been measured for the first time in the \ud Δ\ud (\ud 1232\ud )\ud resonance region using a circularly polarized photon beam incident on a longitudinally polarized proton target at the Mainz Microtron. This paper reports these results, together with the model-dependent extraction of four proton spin polarizabilities from fits to additional asymmetry data using either a dispersion relation calculation or a baryon chiral perturbation theory calculations with the weighted average of these two fits resulting in \ud γ\ud E\ud 1\ud E\ud 1\ud =\ud −\ud 2.87\ud ±\ud 0.52\ud ,\ud \ud γ\ud M\ud 1\ud M\ud 1\ud =\ud 2.70\ud ±\ud 0.43\ud ,\ud \ud γ\ud E\ud 1\ud M\ud 2\ud =\ud −\ud 0.85\ud ±\ud 0.72\ud , and \ud γ\ud M\ud 1\ud E\ud 2\ud =\ud 2.04\ud ±\ud 0.43\ud , in units of \ud 10\ud −\ud 4\ud fm\ud 4\ud .
Published: 2020
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5. Measurement of the photon beam asymmetry in γ⃗p→K+Σ0 at Eγ=8.5 GeV

Author: T. D. Beattie, K. Goetzen, W. J. Briscoe, P. Pauli, G. M. Huber, D. I. Sober, M. J. Amaryan, V. Crede, M. M. Dalton, V. S. Goryachev, Christine Kourkoumelis, A. Hurley, R. E. Mitchell, G. Kalicy, N. S. Jarvis, C. A. Meyer, L. Ng, D. Lawrence, A. Ernst, H. Hakobyan, V. Lyubovitskij, G. J. Lolos, I. Larin, C. Salgado, R. Barsotti, S. Adhikari, O. Cortes, Sean A Dobbs, T. Britton, A. Somov, A. Ali, Sergey Kuleshov, C.P. Romero, P. Eugenio, R. A. Schumacher, D. I. Lersch, K. Livingston, M. M. Ito, Barry Ritchie, N. Cao, Ashot Gasparian, A. Hamdi, Krisztian Peters, Michael Dugger, T. C. Black, I. I. Strakovsky, J. Barlow, Joerg Reinhold, S. Fegan, A. Deur, S. Cole, J. Frye, E. Pooser, V. A. Matveev, N. Qin, J. Schwiening, O. Soto, A. M. Schertz, T. Whitlatch, L. Robison, T. Daniels, B. E. Cannon, T. Erbora, H. Ni, Z. Papandreou, Ting Xiao, V. V. Berdnikov, William Brooks, J. R. Stevens, M. McCaughan, Mark Richard James Williams, Lubomir Pentchev, C. Gleason, S. Furletov, Q. Zhou, A. M. Foda, Dmitri Romanov, H. Marukyan, R.S. Pedroni, W. U. Boeglin, W. McGinley, E. Chudakov, N. Wickramaarachchi, A. Thiel, K. K. Seth, C. Fanelli, M. Kamel, W. Phelps, F. Nerling, Elton Smith, B. Liu, G. Vasileiadis, A. Austregesilo, Zhiyong Zhang, M. R. Shepherd, A. Teymurazyan, R. T. Jones, Y. Yang, M. E. McCracken, Xiang Zhou, S. Taylor, L. Gan, S. Somov, L. Guo, J. Zarling, C. Paudel, A. Dolgolenko, V. V. Tarasov, E. Barriga, M. Patsyuk, J. Foote, X. Shen, K. Suresh, Hovanes Egiyan, R. A. Miskimen, R. Dzhygadlo, F. Barbosa, V. Kakoyan, D. J. Mack, A. Goncalves, R. Dotel, B. Zihlmann, A. I. Ostrovidov, H. Li, D. G. Ireland, and W. B. Li
Subjects: Physics, Range (particle radiation), GlueX, Spectrometer, 010308 nuclear & particles physics, Linear polarization, media_common.quotation_subject, Theoretical models, 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Photon beam, Nuclear Experiment, 010306 general physics, Beam (structure), media_common
Abstract: We report measurements of the photon beam asymmetry Σ for the reaction γp→K+Σ0 (1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected by using a linearly polarized photon beam in the energy range of 8.2–8.8 GeV incident on a liquid hydrogen target. The beam asymmetry Σ was measured as a function of the Mandelstam variable t , and a single value of Σ was extracted for events produced in the u channel. These are the first exclusive measurements of the photon beam asymmetry Σ for the reaction in this energy range. For the t channel, the measured beam asymmetry is close to unity over the t range studied, − t = ( 0.1 – 1.4 ) ( GeV / c ) 2 , with an average value of Σ = 1.00 ± 0.05 . This agrees with theoretical models that describe the reaction via the natural-parity exchange of the K ∗ (892) Regge trajectory. A value of Σ = 0.41 ± 0.09 is obtained for the u channel integrated up to − u = 2.0 ( GeV / c ) 2 .
Published: 2020
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6. Precision measurement of the neutral pion lifetime

Author: V. P. Kubarovsky, M. Wood, A. Dolgolenko, Haiyan Gao, D. Lawrence, Dipangkar Dutta, S. Danagoulian, L. Guo, M. Khandaker, S. Kowalski, E. Clinton, J. Feng, E. L. Isupov, P. Ambrozewicz, A. Kubarovsky, L. Gan, D. I. Sober, S. Taylor, V. Baturin, Ashot Gasparian, D. Romanov, A. Shahinyan, I. Nakagawa, C. Salgado, S. Stepanyan, V. V. Tarasov, L. Ma, B. Morrison, H. Y. Lu, Andrey Vasiliev, G. V. Fedotov, B. Zihlmann, R.S. Pedroni, W. Phelps, Eugene Pasyuk, A. M. Micherdzinska, M. M. Ito, Yuelin Zhang, L. Ye, A. V. Glamazdin, Friedrich Klein, D. Protopopescu, D. Rimal, D. S. Dale, V. Matveev, I. Larin, R. A. Miskimen, S. R. Gevorkyan, K. Park, Volker D. Burkert, A. Deur, and A. Ahmidouch
Subjects: Quantum chromodynamics, Chiral anomaly, Physics, Systematic error, Particle physics, Multidisciplinary, Photon, Pion, High Energy Physics::Experiment, Anomaly (physics), Axial symmetry, Quantum fluctuation
Abstract: Testing the chiral anomaly Pi mesons, also known as pions, consist of a quark and an antiquark and are extremely unstable. Neutral pions have a lifetime of only ∼80 attoseconds, decaying into two photons. Quantum chromodynamics (QCD), the theory of quarks and gluons, predicts this decay and the associated lifetime using the mechanism of broken chiral symmetry—the so-called chiral anomaly. Measuring the lifetime to high precision then provides a benchmark for theories that aim to improve on this original prediction. Larin et al. measured this lifetime with an uncertainty that was half that of the previous most precise result (see the Perspective by Meyer). The measured value was consistent with the original QCD prediction and less consistent with other theoretical approaches. Science , this issue p. 506 ; see also p. 469
Published: 2020

7. Signatures of the d*(2380) Hexaquark in d(γ,pn→)

Author: M. Bashkanov, R. A. Miskimen, M. Biroth, Yu. A. Usov, O. Steffen, P. Pedroni, P. B. Otte, Michaela Thiel, S. Abt, C. S. Akondi, A. B. Lazarev, A. Braghieri, Th. Strub, Concettina Sfienti, L.A. Zana, M. Korolija, K. Livingston, S. Lutterer, David Manley, V. L. Kashevarov, W. Gradl, S. Gardner, N. S. Borisov, D. Hornidge, P. P. Martel, Z. Ahmed, N. K. Walford, J. Wettig, S. Fegan, I. I. Strakovsky, F. Cividini, Susanna Costanza, H. J. Arends, D. Ghosal, Guy Ron, S. Wagner, K. Spieker, A. Käser, V. Sokhoyan, C. Mullen, R. Beck, P. Adlarson, A. Fix, A. G. Denig, M. Ostrick, Durga Paudyal, Nicholas Zachariou, D. P. Watts, Patrick Achenbach, A. Neiser, E. J. Downie, D. Gurevich, M. Wolfes, I. Supek, C. Collicott, I. Gorodnov, A. Thiel, F. Afzal, W. J. Briscoe, A. B. Neganov, D. Werthmüller, M. Günther, Lena Heijkenskjöld, I. J. D. MacGregor, P. Drexler, S. N. Prakhov, J. R. M. Annand, Andy Thomas, G. M. Huber, D. I. Glazier, S. Kay, A. Powell, A. Sarty, E. Mornacchi, and B. Krusche
Subjects: Physics, Photon, Spin polarization, Nuclear Theory, General Physics and Astronomy, Photon energy, 01 natural sciences, Nuclear physics, Recoil, Photodisintegration, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Nucleon, Crystal Ball
Abstract: We report a measurement of the spin polarization of the recoiling neutron in deuterium photodisintegration, utilizing a new large acceptance polarimeter within the Crystal Ball at MAMI. The measured photon energy range of 300-700 MeV provides the first measurement of recoil neutron polarization at photon energies where the quark substructure of the deuteron plays a role, thereby providing important new constraints on photodisintegration mechanisms. A very high neutron polarization in a narrow structure centered around E_{γ}∼570 MeV is observed, which is inconsistent with current theoretical predictions employing nucleon resonance degrees of freedom. A Legendre polynomial decomposition suggests this behavior could be related to the excitation of the d^{*}(2380) hexaquark.
Published: 2020
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8. Cross section for γn→π0n measured at the Mainz A2 experiment

Author: K. Livingston, S. Lutterer, S. Gardner, N. S. Borisov, M. Unverzagt, V. V. Kulikov, H. J. Arends, A. B. Lazarev, A. Neiser, Alfred Švarc, F. Cividini, A. Braghieri, F. Afzal, D. G. Middleton, B. Oussena, C. Collicott, D. P. Watts, K. Spieker, K. Bantawa, M. Bashkanov, R. A. Miskimen, M. Ostrick, S. Kay, C. Sfienti, V. E. Tarasov, Patrick Achenbach, Yu. A. Usov, G. M. Huber, A. E. Kudryavtsev, A. Käser, O. Steffen, P. Aguar-Bartolomé, V. L. Kashevarov, A. G. Denig, E. J. Downie, N. K. Walford, J. Wettig, E. Mornacchi, A. Thiel, J. Stahov, S. Fegan, Durga Paudyal, J. C. McGeorge, Nicholas Zachariou, V. Sokhoyan, I. J. D. MacGregor, M. I. Ferretti Bondy, M. A. Martemianov, D. Gurevich, D. Hornidge, D. Ghosal, S. Wagner, M. Wolfes, Anthony W. Thomas, D. I. Glazier, Guy Ron, Z. Ahmed, Susanna Costanza, Michaela Thiel, W. J. Briscoe, A. Powell, M. Günther, L. Tiator, I. I. Strakovsky, A. N. Mushkarenkov, S. A. Bulychjov, D. M. Manley, Lena Heijkenskjöld, P. P. Martel, R. Omerović, M. Korolija, R. Beck, C. Mullen, J. R. M. Annand, D. Werthmüller, M. Biroth, M. Hadžimehmedović, P. B. Otte, A. B. Neganov, P. Pedroni, W. Gradl, S. N. Prakhov, B. Krusche, P. Drexler, H. Osmanović, T. Rostomyan, I. Supek, I. Gorodnov, Ron L. Workman, Roderick M. Macrae, S. Abt, C. S. Akondi, and A. J. Sarty
Subjects: Physics, 010308 nuclear & particles physics, Nuclear Theory, 7. Clean energy, 01 natural sciences, Resonance (particle physics), Nuclear physics, Cross section (physics), Pion, Amplitude, Deuterium, Reaction dynamics, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Microtron
Abstract: The γ n → π 0 n differential cross section evaluated for 27 energy bins span the photon-energy range 290–813 MeV ( W = 1.195 –1.553 GeV) and the pion c.m. polar production angles, ranging from 18 ∘ to 162 ∘ , making use of model-dependent nuclear corrections to extract π 0 production data on the neutron from measurements on the deuteron target. Additionally, the total photoabsorption cross section was measured. The tagged photon beam produced by the 883 MeV electron beam of the Mainz Microtron MAMI was used for the π 0 -meson production. Our accumulation of 3.6 × 10 6 γ n → π 0 n events allowed a detailed study of the reaction dynamics. Our data are in reasonable agreement with previous A2 measurements and extend them to lower energies. The data are compared with predictions of previous said, maid, and BnGa partial-wave analyses and to the latest said fit MA19 that included our data. Selected photon-decay amplitudes N ∗ → γ n at the resonance poles are determined for the first time.
Published: 2019
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9. Beam asymmetry Σ for the photoproduction of η and η′ mesons at Eγ=8.8GeV

Author: A. Hurley, L. Gan, C. A. Meyer, J. Frye, C. Paudel, V. V. Tarasov, A. Dolgolenko, H. Hakobyan, C. Salgado, A. M. Schertz, E. Barriga, T. Daniels, C. Fanelli, R. T. Jones, W. Phelps, F. Nerling, M. E. McCracken, Krisztian Peters, Michael Dugger, V. Kakoyan, M. J. Staib, B. E. Cannon, T. Erbora, E. Pooser, I. A. Semenova, Z. Zhang, V. A. Matveev, A. Barnes, Dmitri Romanov, Sean A Dobbs, V. V. Berdnikov, A. Hamdi, J. Barlow, I. I. Strakovsky, Mark Richard James Williams, K. Suresh, T. Whitlatch, A. Somov, T. C. Black, D. Lawrence, A. Thiel, M. M. Dalton, H. Marukyan, Hovanes Egiyan, L. Ng, A. Ernst, M. McCaughan, R.S. Pedroni, W. McGinley, G. M. Huber, D. I. Sober, L. Robison, K. Livingston, V. Lyubovitskij, A. Deur, Ting Xiao, Q. Zhou, R. A. Miskimen, William Brooks, X. Zhou, P. Eugenio, G. Zhao, N. Wickramaarachchi, O. Cortes, N. Qin, L. Guo, E. Chudakov, R. Barsotti, Lubomir Pentchev, N. Cao, O. Soto, K. K. Seth, R. Dzhygadlo, F. Barbosa, B. Zihlmann, S. Fegan, M. Kamel, A. M. Foda, D. J. Mack, R. A. Schumacher, N. Gevorgyan, T. Britton, A. I. Ostrovidov, B. Liu, V. Crede, C.P. Romero, G. J. Lolos, I. Larin, G. Vasileiadis, H. Li, Ashot Gasparian, Sergey Kuleshov, D. I. Lersch, D. G. Ireland, A. Goncalves, Z. Papandreou, V. S. Goryachev, M. J. Amaryan, P. Mattione, S. Adhikari, M. Patsyuk, W. B. Li, A. Yu. Semenov, R. Dotel, Elton Smith, J. Schwiening, Barry Ritchie, J. R. Stevens, S. Somov, M. Boer, J. Foote, J. Zarling, M. R. Shepherd, A. Teymurazyan, C. Gleason, G. Kalicy, N. S. Jarvis, X. Shen, A. Austregesilo, S. Cole, Christine Kourkoumelis, Joerg Reinhold, A. Ali, R. E. Mitchell, W. U. Boeglin, Y. Yang, M. M. Ito, P. Pauli, S. Furletov, W. J. Briscoe, T. D. Beattie, and K. Goetzen
Subjects: Physics, GlueX, Meson, 010308 nuclear & particles physics, Linear polarization, media_common.quotation_subject, Momentum transfer, Parity (physics), 01 natural sciences, 7. Clean energy, Asymmetry, 0103 physical sciences, Quasiparticle, Atomic physics, Photon beam, 010306 general physics, media_common
Abstract: We report on the measurement of the beam asymmetry Σ for the reactions → γ p → p η and → γ p → p η ′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer − t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η ′ in this energy range. We compare the results to theoretical predictions based on t -channel quasiparticle exchange. We also compare the ratio of Σ η to Σ η ′ to these models as this ratio is predicted to be sensitive to the amount of s ¯ s exchange in the production. We find that photoproduction of both η and η ′ is dominated by natural parity exchange with little dependence on − t .
Published: 2019
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10. High precision measurement of Compton scattering in the 5 GeV region

Author: M. Konchatnyi, D. McNulty, Ashot Gasparian, K. Hardy, S. Stepanyan, L. Guo, S. Kowalski, R. A. Miskimen, P. P. Martel, A. Sitnikov, E. Clinton, L. Benton, H. Y. Lu, D. Lawrence, L. Ye, Dipangkar Dutta, A. M. Micherdzinska, M. Wood, A. Shahinyan, R. Demirchyan, A. Deur, A. Ahmidouch, X. Li, S. R. Gevorkyan, S. Mtingwa, V. V. Mochalov, A. Dolgolenko, J. Feng, D. Kashy, B. Zihlmann, S. Overby, A. Evdokimov, Brian D. Milbrath, Y. Zhang, M. Levillain, W. Phelps, B. Morrison, D. I. Sober, P. Collins, I. Nakagawa, A. V. Glamazdin, H. Kang, Aron M. Bernstein, B. A. Mecking, L. Jiang, Wolfgang Korsch, G. Dzyubenko, Haiyan Gao, V. Baturin, M. M. Ito, V. Gyurjyan, K. Park, S. Taylor, P. L. Cole, Volker D. Burkert, S. Zhou, L. Gan, O. Kosinov, V. Goryachev, C. Salgado, I. Larin, N. Gevorkyan, A. Kolarkar, Andrey Vasiliev, J. Underwood, R. C. Minehart, A. Teymurazyan, G. V. Fedotov, G. Davidenko, W. A. Stephens, Dmitri Romanov, J. He, K. Baker, S. Danagoulian, E. Pasyuk, Friedrich Klein, E. L. Isupov, P. Ambrozewicz, D. P. Weygand, O. Korchin, A. Kubarovsky, Y. Prok, Barry Ritchie, V. P. Kubarovsky, V. Vishnyakov, M. Payen, P. Kingsberry, V. E. Tarasov, L. Ma, D. Protopopescu, D. Rimal, D. S. Dale, V. Matveev, M. Khandaker, R.S. Pedroni, M. Gabrielyan, and M. A. Kubantsev
Subjects: Nuclear and High Energy Physics, Nuclear Theory, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Electron, 01 natural sciences, 7. Clean energy, Nuclear Theory (nucl-th), Nuclear physics, Cross section (physics), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Radiative transfer, Nuclear Experiment (nucl-ex), Photon beam, 010306 general physics, Nuclear Experiment, Nuclear theory, Physics, 010308 nuclear & particles physics, Compton scattering, lcsh:QC1-999, High Energy Physics - Phenomenology, Beam energy, Beam (structure), lcsh:Physics
Abstract: The cross section of atomic electron Compton scattering $\gamma + e \rightarrow \gamma^\prime + e^\prime $ was measured in the 4.40--5.475 GeV photon beam energy region by the {\em PrimEx} collaboration at Jefferson Lab with an accuracy of 2\% and less. The results are consistent with theoretical predictions that include next-to-leading order radiative corrections. The measurements provide the first high precision test of this elementary QED process at beam energies greater than 0.1 GeV., Comment: 6 pages, 4 figures
Published: 2019

11. Measurement of the beam-helicity asymmetry in photoproduction of π0η pairs on carbon, aluminum, and lead

Author: R. A. Miskimen, A. G. Denig, Durga Paudyal, M. Wolfes, I. Keshelashvili, Yu. A. Usov, O. Steffen, K. Spieker, P. Pedroni, Susanna Costanza, P. Aguar-Bartolomé, Concettina Sfienti, A. N. Mushkarenkov, M. Ostrick, D. G. Middleton, M. Günther, S. Garni, A. Powell, I. Supek, A. Käser, R. Beck, I. Gorodnov, M. Unverzagt, V. L. Kashevarov, F. Cividini, Roderick M. Macrae, L. V. Fil'kov, P. Adlarson, M. Oberle, S. Abt, E. J. Downie, Patrick Achenbach, D. P. Watts, S. Cherepnya, A. J. Sarty, K. Bantawa, G. M. Huber, Z. Ahmed, S. Kay, I. I. Strakovsky, T. Rostomyan, K. Livingston, S. Lutterer, B. Strandberg, S. Gardner, N. S. Borisov, C. Mullen, Guy Ron, D. I. Glazier, S. Wagner, H. J. Arends, W. J. Briscoe, A. B. Lazarev, Michaela Thiel, A. Neiser, A. Fix, A. Braghieri, Th. Strub, P. Drexler, F. Afzal, A. B. Neganov, Nicholas Zachariou, W. Gradl, J. Wettig, J. C. McGeorge, V. Sokhoyan, P. P. Martel, J. R. M. Annand, D. Hornidge, E. Mornacchi, I. J. D. MacGregor, M. Korolija, David Manley, N. K. Walford, B. Krusche, K. Altangerel, E. Rickert, M. Biroth, P. B. Otte, R. Kondratiev, G. M. Gurevich, S. N. Prakhov, Lilian Witthauer, M. Dieterle, Lena Heijkenskjöld, M. I. Ferretti Bondy, Andy Thomas, A. Thiel, D. Werthmüller, C. Collicott, and M. Bashkanov
Subjects: Nuclear and High Energy Physics, Proton, media_common.quotation_subject, Nuclear Theory, chemistry.chemical_element, 7. Clean energy, 01 natural sciences, Asymmetry, Nuclear physics, Aluminium, 0103 physical sciences, Intermediate state, Nuclear Experiment, 010306 general physics, QC, media_common, Physics, 010308 nuclear & particles physics, Helicity, lcsh:QC1-999, 3. Good health, chemistry, High Energy Physics::Experiment, Nucleon, Carbon, lcsh:Physics, Beam (structure)
Abstract: The beam-helicity asymmetry was measured, for the first time, in photoproduction of $\pi^{0}\eta$ pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The results are compared to an earlier measurement on a free proton and to the corresponding theoretical calculations. The Mainz model is used to predict the beam-helicity asymmetry for the nuclear targets. The present results indicate that the photoproduction mechanism for $\pi^{0}\eta$ pairs on nuclei is similar to photoproduction on a free nucleon. This process is dominated by the $D_{33}$ partial wave with the $\eta\Delta(1232)$ intermediate state., Comment: Accepted for publication in Physics Letters B (2020)
Published: 2020
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12. Deuteron photodisintegration by polarized photons in the region of the $d^*(2380)$

Author: A. Powell, I. Gorodnov, Roderick M. Macrae, W. J. Briscoe, M. Biroth, P. B. Otte, S. Abt, C. S. Akondi, A. Käser, A. B. Lazarev, Concettina Sfienti, A. Thiel, E. J. Downie, D. P. Watts, E. Mornacchi, W. Gradl, Z. Ahmed, David Manley, Lena Heijkenskjöld, A. Braghieri, Th. Strub, A. Sarty, I. J. D. MacGregor, I. I. Strakovsky, S. Wagner, K. Livingston, S. Lutterer, M. Ostrick, V. L. Kashevarov, M. Günther, P. P. Martel, N. S. Borisov, Michaela Thiel, T. Rostomyan, F. Cividini, N. K. Walford, J. Wettig, M. Bashkanov, R. A. Miskimen, H. J. Arends, M. Korolija, P. Adlarson, Yu. A. Usov, O. Steffen, C. Collicott, F. Afzal, C. Mullen, S. Kay, B. Krusche, V. Sokhoyan, A. B. Neganov, S. Costanza, P. Pedroni, A. G. Denig, Reinhard Beck, Durga Paudyal, A. Neiser, Guy Ron, S. Garni, D. Gurevich, M. Wolfes, K. Spieker, L.A. Zana, J. R. M. Annand, D. I. Glazier, G. M. Huber, D. Werthmüller, Patrick Achenbach, D. Hornidge, S. N. Prakhov, Andy Thomas, P. Drexler, and I. Supek
Subjects: Nuclear and High Energy Physics, Photon, media_common.quotation_subject, Nuclear Theory, Hexaquark, FOS: Physical sciences, Photon energy, 01 natural sciences, Asymmetry, Resonance (particle physics), Nuclear physics, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, media_common, Physics, Range (particle radiation), 010308 nuclear & particles physics, lcsh:QC1-999, Deuterium, Photodisintegration, lcsh:Physics, proton polarization, cross-section, disintegration, asymmetry, energies
Abstract: We report the first large-acceptance measurement of the beam–spin asymmetry for deuteron photodisintegration (γ→d→pn) in the photon energy range 420
Published: 2018
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13. High precision photon flux determination for photon tagging experiments

Author: R. Demirchyan, B. A. Mecking, D. Lawrence, Brian D. Milbrath, A. Evdokimov, Y. Prok, Barry Ritchie, P. P. Martel, K. Hardy, Rolf Ent, P. Collins, A. Kolarkar, M. A. Kubantsev, J. Underwood, R. C. Minehart, J. J. He, S. Danagoulian, D. Kashy, A. Deur, D. S. Dale, A. Ahmidouch, A. Dolgolenko, P. Ambrozewicz, Andrey Vasiliev, A. V. Glamazdin, R.S. Pedroni, A. Korchin, L. Jiang, S. Kowalski, A. Shahinyan, D. McNulty, S. Overby, A. Asratyan, V. V. Mochalov, M. Gabrielyan, L. Benton, I. Nakagawa, M. Khandaker, X. Li, Ashot Gasparian, G. Dzyubenko, I. Larin, S. Stepanyan, Volker D. Burkert, Wolfgang Korsch, M. M. Ito, R. A. Miskimen, A. Sitnikov, E. Clinton, E. Pasyuk, O. Kosinov, C. Salgado, K. Baker, V. Goryachev, Viktor Matveev, V. P. Kubarovsky, D. I. Sober, J. Feng, P. L. Cole, W. Stevens, S. Zhou, A. Teymurazyan, M. Wood, V. Vishnyakov, M. Payen, L. Gan, M. Konchatnyi, and G. Davidenko
Subjects: Physics, Nuclear and High Energy Physics, Photon, Spectrometer, Astrophysics::High Energy Astrophysical Phenomena, Bremsstrahlung, Flux, Photon energy, Particle detector, Nuclear physics, Measuring instrument, Nuclear Experiment, Absorption (electromagnetic radiation), Instrumentation
Abstract: The Jefferson Laboratory PrimEx Collaboration has developed and implemented a method to control the tagged photon flux in photoprocluction experiments at the 1% level over the photon energy range from 4.9 to 5.5 GeV. This method has been successfully implemented in a high precision measurement of the neutral pion lifetime. Here, we outline the experimental equipment and the analysis techniques used to accomplish this. These include the use of a total absorption counter for absolute flux calibration, a pair spectrometer for online relative flux monitoring, and a new method for post-bremsstrahlung electron counting. (C) 2014 Elsevier B.V. All rights reserved.
Published: 2014
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14. Measurement of the ω→π0e+e− and η→e+e−γ Dalitz decays with the A2 setup at the Mainz Microtron

Author: S. N. Prakhov, Lilian Witthauer, P. Pedroni, Andy Thomas, J. Wettig, S. Garni, E. J. Downie, I. Keshelashvili, K. Spieker, E. F. McNicoll, J. Robinson, P. Drexler, V. Sokhoyan, T. Rostomyan, Michaela Thiel, A. Polonski, Z. Ahmed, R. Kondratiev, G. Rosner, D. M. Manley, G. M. Gurevich, S. Wagner, C. Mullen, C. Collicott, A. Rajabi, D. P. Watts, Lorenzo Zana, A. G. Denig, G. M. Huber, V. L. Kashevarov, Durga Paudyal, M. I. Ferretti Bondy, K. Bantawa, N. K. Walford, E. Mornacchi, V. Metag, Guy Ron, C. Sfienti, M. H. Sikora, Igor Strakovsky, W. J. Briscoe, I. J. D. MacGregor, M. Wolfes, P. P. Martel, A. N. Mushkarenkov, Roderick M. Macrae, I. V. Danilkin, J. C. McGeorge, D. Glowa, M. Unverzagt, V. Lisin, M. Ostrick, A. Neiser, D. I. Glazier, F. Cividini, K. Livingston, T. C. Jude, I. Supek, B. Strandberg, M. Korolija, S. Gardner, S. Kay, N. S. Borisov, P. Adlarson, A. B. Neganov, B. Krusche, R. A. Miskimen, P. Aguar-Bartolomé, H. J. Arends, A. Thiel, P. Ott, W. Gradl, David Hamilton, L. V. Fil'kov, H. Berghäuser, A. Käser, Yu. A. Usov, J. Linturi, D. Werthmüller, M. Dieterle, O. Steffen, A. B. Lazarev, A. Braghieri, Th. Strub, M. Biroth, D. G. Middleton, P. B. Otte, A. Nikolaev, J. R. M. Annand, F. Afzal, S. Cherepnya, D. Hornidge, M. Oberle, Susanna Costanza, and R. Beck
Subjects: Physics, 010308 nuclear & particles physics, business.industry, Scattering, Form factor (quantum field theory), Value (computer science), 01 natural sciences, Nuclear physics, Optics, 0103 physical sciences, 010306 general physics, business, Microtron, Crystal Ball
Abstract: The Dalitz decays η→e+e-γ and ω→π0e+e- have been measured in the γp→ηp and γp→ωp reactions, respectively, with the A2 tagged-photon facility at the Mainz Microtron. The value obtained for the slope parameter of the electromagnetic transition form factor of η, Λη-2=(1.97±0.11tot)GeV-2, is in good agreement with previous measurements of the η→e+e-γ and η→μ+μ-γ decays. The uncertainty obtained in the value of Λη-2 is lower than in previous results based on the η→e+e-γ decay. The value obtained for the ω slope parameter, Λωπ0-2=(1.99±0.21tot)GeV-2, is somewhat lower than previous measurements based on ω→π0μ+μ-, but the results for the ω transition form factor are in better agreement with theoretical calculations, compared to earlier experiments.
Published: 2017
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15. Measurement of the π0→e+e−γ Dalitz decay at the Mainz Microtron

Author: N. K. Walford, E. Mornacchi, C. Collicott, K. Spieker, K. Livingston, T. C. Jude, B. Strandberg, S. Gardner, N. S. Borisov, H. J. Arends, S. Cherepnya, D. P. Watts, V. Metag, E. J. Downie, M. I. Ferretti Bondy, K. Bantawa, C. Sfienti, H. Berghäuser, J. Robinson, J. Wettig, P. Pedroni, D. Hornidge, P. B. Otte, G. M. Huber, G. Rosner, R. A. Miskimen, V. Sokhoyan, Igor Strakovsky, M. Unverzagt, S. Garni, C. S. Akondi, A. Käser, S. Kay, J. Linturi, M. Ostrick, M. Dieterle, I. Keshelashvili, Yu. A. Usov, P. Drexler, P. Aguar-Bartolomé, O. Steffen, P. Adlarson, Michaela Thiel, V. L. Kashevarov, D. I. Glazier, M. Biroth, F. Cividini, A. Thiel, M. Oberle, R. Kondratiev, G. M. Gurevich, Guy Ron, Z. Ahmed, V. Lisin, D. M. Manley, D. Werthmüller, F. Afzal, E. F. McNicoll, S. Wagner, V. V. Kulikov, A. B. Neganov, Susanna Costanza, A. Rajabi, P. Ott, B. Krusche, M. A. Martemianov, C. Mullen, W. J. Briscoe, A. N. Mushkarenkov, A. Nikolaev, J. C. McGeorge, W. Gradl, P. P. Martel, Lilian Witthauer, A. G. Denig, M. Korolija, R. Beck, Lorenzo Zana, D. Glowa, Durga Paudyal, L. V. Fil'kov, M. Wolfes, A. B. Lazarev, I. Supek, A. Braghieri, A. Neiser, Th. Strub, D. G. Middleton, I. J. D. MacGregor, T. Rostomyan, J. R. M. Annand, A. Polonski, S. N. Prakhov, David Hamilton, Andy Thomas, M. H. Sikora, and Roderick M. Macrae
Subjects: Nuclear physics, Physics, Particle physics, Meson, 010308 nuclear & particles physics, 0103 physical sciences, Form factor (quantum field theory), 010306 general physics, 01 natural sciences, Microtron, Dark photon
Abstract: The Dalitz decay π0→e+e−γ has been measured in the γp→π0p reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The value obtained for the slope parameter of the π0 electromagnetic transition form factor, aπ=0.030±0.010tot, is in agreement with existing measurements of this decay and with recent theoretical calculations. The uncertainty obtained in the value of aπ is lower than in previous results based on the π0→e+e−γ decay.
Published: 2017
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16. Determination of the scalar polarizabilities of the proton using beam asymmetry $\Sigma_{3}$ Σ 3 in Compton scattering

Author: A. Käser, C. S. Akondi, Michaela Thiel, D. Hornidge, I. J. D. MacGregor, P. Ott, A. J. Sarty, D. M. Manley, R. Kondratiev, G. M. Gurevich, B. Krusche, M. Korolija, J. Ahrens, Durga Paudyal, M. Unverzagt, N. Krupina, M. Wolfes, M. Ostrick, P. P. Martel, Judith A. McGovern, S. N. Prakhov, F. Cividini, T. Rostomyan, J. Wettig, H. Ortega Spina, D. I. Glazier, D. Werthmüller, V. Sokhoyan, Lilian Witthauer, B. Oussena, A. Polonski, C. Collicott, A. Rajabi, A. G. Denig, I. Supek, V. Lensky, D. P. Watts, V. L. Kashevarov, I. Keshelashvili, Roderick M. Macrae, S. Schumann, M. Oberle, Andy Thomas, P. B. Otte, I. I. Strakovsky, S. Wagner, D. Glowa, V. Polyansky, E. Mornacchi, W. J. Briscoe, A. N. Mushkarenkov, M. Ferretti, J. Linturi, F. Afzal, P. Pedroni, M. Dieterle, W. Gradl, V. Lisin, A. Braghieri, Th. Strub, E. J. Downie, D. G. Middleton, G. M. Huber, S. Garni, R. A. Miskimen, K. Livingston, O. Steffen, B. Strandberg, S. Gardner, H. J. Arends, David Hamilton, Lorenzo Zana, A. Neiser, J. R. M. Annand, Susanna Costanza, and R. Beck
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, media_common.quotation_subject, Nuclear Theory, Scalar (physics), Compton scattering, Sigma, 01 natural sciences, Asymmetry, Nuclear physics, Dipole, Pion, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Nucleon, Microtron, media_common
Abstract: The scalar dipole polarizabilities, $\alpha_{E1}$ and $\beta_{M1}$, are fundamental properties related to the internal dynamics of the nucleon. The currently accepted values of the proton polarizabilities were determined by fitting to unpolarized proton Compton scattering cross section data. The measurement of the beam asymmetry $\Sigma_{3}$ in a certain kinematical range provides an alternative approach to the extraction of the scalar polarizabilities. At the Mainz Microtron (MAMI) the beam asymmetry was measured for Compton scattering below pion photoproduction threshold for the first time. The results are compared with model calculations and the influence of the experimental data on the extraction of the scalar polarizabilities is determined.
Published: 2017
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17. TandFasymmetries inπ0photoproduction on the proton

Author: A. Nikolaev, I. J. D. MacGregor, G. Reicherz, P. Ott, D. Hornidge, J. R. M. Annand, B. Oussena, S. Cherepnya, D. I. Glazier, Reinhard Beck, P. Pedroni, A. B. Lazarev, V. L. Kashevarov, I. I. Strakovsky, E. F. McNicoll, M. Dieterle, T. Rostomyan, D. M. Manley, S. Garni, M. Korolija, L. V. Fil'kov, L. Tiator, D. G. Middleton, D. Howdle, C. Collicott, K. Livingston, I. Keshelashvili, D. P. Watts, W. Gradl, M. Oberle, N. S. Borisov, A. Braghieri, Th. Strub, M. Wolfes, A. J. Sarty, I. Supek, H. J. Arends, S. N. Prakhov, S. Schumann, M. Ostrick, David Hamilton, P. B. Otte, A. Fix, Andy Thomas, R. A. Miskimen, V. Lisin, W. Meyer, B. Krusche, H. Ortega, A. B. Neganov, G. M. Huber, Yu. A. Usov, O. Steffen, P. Hall Barrientos, W. J. Briscoe, A. N. Mushkarenkov, M. Unverzagt, E. J. Downie, R. Kondratiev, G. M. Gurevich, V. V. Polyanski, A. Polonski, Lilian Witthauer, D. Werthmüller, P. P. Martel, J. Mancel, and S. Costanza
Subjects: Physics, Particle physics, Photon, 010308 nuclear & particles physics, media_common.quotation_subject, Bremsstrahlung, Photon energy, 01 natural sciences, Asymmetry, Resonance (particle physics), Baryon, Nuclear physics, 0103 physical sciences, Physics::Accelerator Physics, Nuclear Experiment, 010306 general physics, Microtron, Crystal Ball, media_common
Abstract: The γp→π0p reaction was studied at laboratory photon energies from 425 to 1445 MeV with a transversely polarized target and a longitudinally polarized beam. The beam-target asymmetry F was measured for the first time and new high precision data for the target asymmetry T were obtained. The experiment was performed at the photon tagging facility of the Mainz Microtron (MAMI) using the Crystal Ball and TAPS photon spectrometers. The polarized cross sections were expanded in terms of associated Legendre functions and compared to recent predictions from several partial-wave analyses. The impact of the new data on our understanding of the underlying partial-wave amplitudes and baryon resonance contributions is discussed.
Published: 2016
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18. Development of a superconducting transverse holding magnet for the HIγS frozen spin target

Author: H. R. Weller, M. Seely, P.-N. Seo, R. A. Miskimen, and D. G. Crabb
Subjects: Physics, Superconductivity, Quantitative Biology::Biomolecules, Nuclear and High Energy Physics, Condensed matter physics, Superconducting wire, Physics::Medical Physics, Superconducting magnet, engineering.material, Transverse plane, Electromagnetic coil, Magnet, Homogeneity (physics), engineering, Instrumentation, Saddle
Abstract: We describe the design, construction, and performance of a set of saddle coils used to maintain the spin of a polarized proton target in the transverse direction with respect to the incident gamma-ray beam direction. The transverse coil assembly consists of two racetrack shaped coils formed from a single strand of thin NbTi superconducting wire. Four layers of NbTi per saddle coil were wet wound in a racetrack shape and then installed on a cylindrical support tube and epoxyed to prevent them from moving when the coils were energized. As expected from our model calculation, a set of two saddle coils produced 0.36 T in the middle of the coils with a 25 A current at 4 K, which is 63% of the critical current of the wire. The measured homogeneity of the field over the target volume has a maximum variation from the average value of 0.6%.
Published: 2010
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19. Moments of the spin structure functions g1p and g1d for 0.05<Q2<3.0 GeV2

Author: R. A. Schumacher, G. V. O'Rielly, C. D. Keith, Cynthia Marie Hadjidakis, Z. W. Zhao, Chaden Djalali, D. G. Jenkins, Michael Dugger, S. Tkachenko, H. O. Funsten, A. I. Ostrovidov, A. C S Lima, S. Bültmann, L. Morand, M. R. Niroula, T. A. Forest, D. G. Ireland, G. Asryan, Volker D. Burkert, A. S. Biselli, J. Pierce, Elton Smith, M. J. Amaryan, M. MacCormick, O. P. Dzyubak, R. A. Niyazov, I. Hleiqawi, S. L. Careccia, Larry Weinstein, Avraham Klein, E. Golovatch, H. G. Juengst, K. Moriya, Daniel S. Carman, J. Kuhn, Philip L. Cole, S. McAleer, H. Hakobyan, S. Anefalos Pereira, P. D. Rubin, L. Blaszczyk, P. Corvisiero, Y. G. Sharabian, A. Fradi, L. Cheng, G. Audit, A.V. Stavinsky, C. E. Hyde-Wright, F. Sabatié, Nikolay Shvedunov, D. Heddle, P. Stoler, Friedrich Klein, J. P. Cummings, R. De Vita, N. Markov, V. Sapunenko, C. Salgado, Dinko Pocanic, L. Elouadrhiri, N. Kalantarians, S. Stepanyan, K. S. Egiyan, R. C. Minehart, C. A. Meyer, J. Ball, M. Taiuti, S. E. Kuhn, I. I. Strakovsky, M. Bektasoglu, M. Kossov, K. Mikhailov, K.H. Hicks, R. J. Feuerbach, G. V. Fedotov, M. Nozar, A. Deur, I. Popa, V. Crede, J. W. Price, Shifeng Chen, M. Anghinolfi, Laird Kramer, D. P. Watts, H. Egiyan, G. Gavalian, John A. Mueller, L. Casey, B. L. Berman, P. Mattione, B. B. Niczyporuk, G. Rosner, N. Benmouna, N. Pivnyuk, Kwangsoo Kim, J. T. Goetz, M. Mirazita, G. Riccardi, J. R. Calarco, R. A. Miskimen, B. A. Raue, B. McKinnon, W. J. Briscoe, L. M. Qin, R. G. Fersh, P. Eugenio, J. Langheinrich, C. Butuceanu, C. Hanretty, S. S. Stepanyan, E. Pasyuk, S. A. Philips, M. Ripani, G. Ricco, S. A. Morrow, C. Paterson, Y. Ilieva, Michael Vineyard, Victor Mokeev, M. Klusman, B. M. Preedom, D. Branford, P. Collins, B. Moreno, J. R. Johnstone, Lorenzo Zana, J. P. Santoro, Tsutomu Mibe, Gerald Feldman, J. M. Laget, L. Todor, D. Protopopescu, K. L. Giovanetti, S. V. Kuleshov, C. Marchand, S. Pozdniakov, M. Garçon, M. L. Seely, Ji Li, D. J. Tedeschi, G. E. Dodge, H. Y. Lu, J. Lachniet, I. Bedlinskiy, Marco A. Huertas, A. Tkabladze, M. D. Mestayer, E. L. Isupov, P. V. Degtyarenko, D. Rowntree, K. Livingston, Michael L. Williams, M. Holtrop, R. Suleiman, V. Kuznetsov, D. S. Dale, J. Zhang, S. Boiarinov, D. I. Sober, Gerard Gilfoyle, F. X. Girod, G. S. Mutchler, N. A. Baltzell, I. Niculescu, D. Sokhan, J. Salamanca, K. A. Griffioen, D. Lawrence, M. Guillo, N. Guler, R. De Masi, L. El Fassi, J. W C McNabb, Sylvain Bouchigny, H. Denizli, M. Guidal, M. Battaglieri, J. Hardie, S. Strauch, J. D. Kellie, Z. Krahn, R. Nasseripour, S. Barrow, P. Rossi, R. Dickson, N. Baillie, D. Doughty, V. Gyurjyan, R. Bradford, K. Lukashin, B. E. Stokes, G. S. Adams, H. Bagdasaryan, P. Nadel-Turonski, A. V. Skabelin, K. Joo, A. Cazes, S. Procureur, Maryam Moteabbed, Bernhard Mecking, K. V. Dharmawardane, L. Guo, M. Ungaro, D. P. Weygand, E. Wolin, N. Hassall, M. Bellis, D. G. Crabb, J. Yun, D. Cords, P. Bosted, A. Yegneswaran, N. Dashyan, Y. Prok, Barry Ritchie, E. De Sanctis, H. S. Jo, S. Niccolai, R. Fatemi, A. V. Vlassov, P. Coltharp, R. W. Gothe, M. M. Ito, K. Y. Kim, M. Osipenko, K. Beard, L. C. Smith, E. Munevar, Kalvir S. Dhuga, B. S. Ishkhanov, O. Pogorelko, M. Khandaker, B. Zhao, F. W. Hersman, W. Kim, G. Niculescu, N. Gevorgyan, L. C. Dennis, B. E. Bonner, H. Avakian, D. Sharov, S. A. Dytman, W. K. Brooks, K. Park, V. P. Kubarovsky, J. Shaw, Michael Wood, K. Hafidi, and V. S. Serov
Subjects: Physics, Nuclear and High Energy Physics, Chiral perturbation theory, Heavy baryon chiral perturbation theory, Proton, 010308 nuclear & particles physics, Nuclear Theory, Hadron, 01 natural sciences, Baryon, Nuclear physics, Polarizability, 0103 physical sciences, Sum rule in quantum mechanics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: The spin structure functions g 1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q 2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH3 and ND3 targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for 0.05 Q 2 5 GeV 2 and W 3 GeV . The first moments of g 1 for the proton and deuteron are presented – both have a negative slope at low Q 2 , as predicted by the extended Gerasimov–Drell–Hearn sum rule. The first extraction of the generalized forward spin polarizability of the proton γ 0 p is also reported. This quantity shows strong Q 2 dependence at low Q 2 . Our analysis of the Q 2 evolution of the first moment of g 1 shows agreement in leading order with Heavy Baryon Chiral Perturbation Theory. However, a significant discrepancy is observed between the γ 0 p data and Chiral Perturbation calculations for γ 0 p , even at the lowest Q 2 .
Published: 2009
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20. Exclusive ρ0 electroproduction on the proton at CLAS

Author: J. Langheinrich, S. S. Stepanyan, E. Pasyuk, S. A. Philips, N. Dashyan, V. Sapunenko, G. Ricco, Alexei V. Klimenko, N. A. Baltzell, C. Salgado, Dinko Pocanic, Barry Ritchie, H. Denizli, A. V. Skabelin, K. A. Griffioen, B. Zhao, V. Gyurjyan, A. I. Ostrovidov, R. Fatemi, K. Park, S. E. Kuhn, Latifa Elouadrhiri, R. C. Minehart, Kei Moriya, C. A. Meyer, H. G. Juengst, B. E. Stokes, G. S. Adams, G. V. Fedotov, V. P. Kubarovsky, J. Zhang, P. Eugenio, K. P. Adhikari, A. V. Vlassov, D. P. Weygand, G. E. Dodge, H. Y. Lu, M. J. Amaryan, G. V. O'Rielly, S. Niccolai, Z. W. Zhao, V. Mokeev, Y. Ilieva, Ji Li, D. G. Jenkins, C. Tur, Gerard Gilfoyle, Elton Smith, H. Hakobyan, A.V. Stavinsky, J. D. Kellie, M. Guidal, M. MacCormick, I. Hleiqawi, S. L. Careccia, R. De Vita, Friedrich Klein, Brian Raue, P. V. Degtyarenko, M. D. Mestayer, J. P. Didelez, R. Nasseripour, L. Todor, F. W. Hersman, P. Coltharp, E. L. Isupov, J. P. Cummings, W. Gohn, S. A. Morrow, S. McAleer, M. Anghinolfi, P. Nadel-Turonski, D. Sokhan, D. Protopopescu, D. J. Tedeschi, M. Holtrop, Michael L. Williams, P. Collins, K. L. Giovanetti, I. Niculescu, F. X. Girod, L. Blaszczyk, B. Carnahan, James Mueller, D. Lawrence, R. G. Fersch, R. A. Miskimen, B. McKinnon, S. Pozdniakov, M. Garçon, J. J. Melone, M. M. Ito, S. Boiarinov, Larry Weinstein, L. Zana, P. D. Rubin, R. De Masi, D. Keller, I. Bedlinskiy, B. M. Preedom, S. Anefalos Pereira, D. Schott, Y. G. Sharabian, R. A. Schumacher, P. L. Cole, M. Yurov, M. Taiuti, S. Mehrabyan, D. Branford, L. C. Smith, E. Munevar, G. S. Mutchler, B. S. Ishkhanov, Michael Wood, K. Hafidi, L. Graham, M. Kossov, M. E. McCracken, C. I O Gordon, J. M. Laget, V. Kuznetsov, J. Kuhn, E. Hourany, M. Khandaker, V. S. Serov, L. C. Dennis, B. E. Bonner, J. W. Price, Tsutomu Mibe, S. Bültmann, G. Audit, Shifeng Chen, C. Bookwalter, N. Gevorgyan, M. Osipenko, C. E. Hyde-Wright, J. P. Santoro, H. S. Jo, H. Avakian, L. Morand, I. Popa, D. Sharov, T. A. Forest, G. Riccardi, M. R. Niroula, E. De Sanctis, O. Pogorelko, S. Stepanyan, P. Mattione, C. Butuceanu, M. S. Saini, D. Doughty, J. Pierce, M. Ripani, B. L. Berman, Avraham Klein, L. M. Qin, M. Aghasyan, E. Wolin, Sergey Kuleshov, W. J. Briscoe, D. Heddle, J. T. Goetz, D. I. Sober, Kalvir S. Dhuga, M. Bektasoglu, S. A. Dytman, S. Dhamija, M. Nozar, E. Polli, M. Mirazita, C. Paterson, J. P. Ball, R. W. Gothe, Y. Prok, B. Moreno, W. Kim, J. Hardie, Hall Crannell, D. S. Carman, K. Livingston, G. Rosner, C. Marchand, G. Niculescu, D. S. Dale, N. Baillie, S. Park, Sylvain Bouchigny, J. Lachniet, A. Tkabladze, D. G. Crabb, R. Dickson, Michael Vineyard, D. G. Ireland, V. Crede, J. R. Calarco, P. Khetarpal, N. Guler, J. Salamanca, L. El Fassi, J. W C McNabb, S. Barrow, P. Rossi, L. Casey, H. Bagdasaryan, Volker D. Burkert, A. S. Biselli, B. B. Niczyporuk, N. Pivnyuk, P. Stoler, C. Hanretty, Laird Kramer, J. R. Johnstone, L. Guo, M. Ungaro, A. Fradi, K. Joo, D. Cords, N. Markov, A. Yegneswaran, K. Hicks, M. Battaglieri, R. Bradford, K. S. Egiyan, A. Cazes, S. Procureur, Maryam Moteabbed, Bernhard Mecking, K. V. Dharmawardane, N. Hassall, M. Bellis, K. Mikhailov, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. Corvisiero, S. Strauch, D. P. Watts, H. Egiyan, I. I. Strakovsky, A. Deur, W. K. Brooks, R. J. Feuerbach, Cynthia Marie Hadjidakis, M. Guillo, Chaden Djalali, Michael Dugger, L. Cheng, F. Sabatié, Nikolay Shvedunov, N. Kalantarians, G. Gavalian, S. Tkachenko, and N. Benmouna
Subjects: Quark, Physics, REPRESENTATION, Nuclear and High Energy Physics, Particle physics, Valence (chemistry), Proton, Hadron, Parton, VECTOR-MESON ELECTROPRODUCTION, Approx, PHOTONS, QCD, EVOLUTION, High Energy Physics - Experiment, Regge theory, Nuclear physics, Scattering amplitude, GENERALIZED PARTON DISTRIBUTIONS, VIRTUAL COMPTON-SCATTERING, VECTOR-MESON ELECTROPRODUCTION, LARGE MOMENTUM-TRANSFER, DIFFRACTIVE PRODUCTION, PHOTOPRODUCTION, PHOTONS, QCD, REPRESENTATION, EVOLUTION, LARGE MOMENTUM-TRANSFER, GENERALIZED PARTON DISTRIBUTIONS, DIFFRACTIVE PRODUCTION, PHOTOPRODUCTION, Nuclear Experiment, VIRTUAL COMPTON-SCATTERING
Abstract: The $e p\to e^\prime p \rho^0$ reaction has been measured, using the 5.754 GeV electron beam of Jefferson Lab and the CLAS detector. This represents the largest ever set of data for this reaction in the valence region. Integrated and differential cross sections are presented. The $W$, $Q^2$ and $t$ dependences of the cross section are compared to theoretical calculations based on $t$-channel meson-exchange Regge theory on the one hand and on quark handbag diagrams related to Generalized Parton Distributions (GPDs) on the other hand. The Regge approach can describe at the $\approx$ 30% level most of the features of the present data while the two GPD calculations that are presented in this article which succesfully reproduce the high energy data strongly underestimate the present data. The question is then raised whether this discrepancy originates from an incomplete or inexact way of modelling the GPDs or the associated hard scattering amplitude or whether the GPD formalism is simply inapplicable in this region due to higher-twists contributions, incalculable at present., Comment: 29 pages, 29 figures
Published: 2008
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21. First measurement of target and beam-target asymmetries in theγp→π0ηpreaction

Author: A. Nikolaev, S. N. Prakhov, Andy Thomas, P. P. Martel, V. L. Kashevarov, J. R. M. Annand, I. I. Strakovsky, C. Collicott, L. V. Fil'kov, D. P. Watts, T. Rostomyan, D. I. Glazier, Lilian Witthauer, D. M. Manley, M. Korolija, M. Ostrick, D. Howdle, D. G. Middleton, M. Oberle, B. Krusche, V. Lisin, V. V. Polyanski, D. Hornidge, M. Wolfes, A. B. Neganov, I. J. D. MacGregor, D. Werthmüller, A. J. Sarty, I. Supek, E. F. McNicoll, E. J. Downie, G. M. Huber, W. Gradl, G. Reicherz, J. Mancel, A. Polonski, R. Beck, H. Ortega, I. Keshelashvili, R. Kondratiev, S. Cherepnya, M. Unverzagt, S. Costanza, G. M. Gurevich, P. Pedroni, S. Schumann, David Hamilton, S. Garni, M. Dieterle, B. Oussena, K. Livingston, W. Meyer, P. B. Otte, N. S. Borisov, W. J. Briscoe, A. N. Mushkarenkov, H. J. Arends, A. Fix, L. Tiator, P. Hall Barrientos, A. B. Lazarev, A. Braghieri, Th. Strub, P. Ott, R. A. Miskimen, Yu. A. Usov, and O. Steffen
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Photon, Meson, Partial wave analysis, Bremsstrahlung, Physics::Accelerator Physics, Photon energy, Nuclear Experiment, Nucleon, Microtron, Crystal Ball
Abstract: The first data on target and beam-target asymmetries for the gamma p -> pi(0)eta p reaction at photon energies from 1050 up to 1450 MeV are presented. The measurements were performed using the Crystal Ball and TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. The general assumption that the reaction is dominated by the Delta 3/2-amplitude is confirmed. The data are in particular sensitive to small contributions from other partial waves.
Published: 2015
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22. Measurement of the x- and Q2-dependence of the asymmetry A1 on the nucleon

Author: L. Elouadrhiri, R. A. Miskimen, M. Khandaker, B. McKinnon, G. Rosner, I. I. Strakovsky, R. W. Gothe, M. Bellis, D. Branford, P. Rossi, K. Y. Kim, A. Deur, S. V. Kuleshov, H. G. Juengst, K. S. Egiyan, P. V. Degtyarenko, P. Dragovitsch, M. Battaglieri, M. Nozar, D. J. Tedeschi, M. Taiuti, I. Bedlinskiy, L. Todor, J. P. Cummings, D. Doughty, F. X. Girod, S. Niccolai, D. Protopopescu, Laird Kramer, J. Hardie, V. Gyurjyan, R. De Masi, B. E. Stokes, F. Ronchetti, R. A. Schumacher, P. Corvisiero, V. P. Kubarovsky, G. S. Adams, D. Heddle, Brian Raue, M. Mirazita, G. Ricco, Dinko Pocanic, L. C. Smith, S. Tkachenko, R. Bradford, K. Lukashin, Y. G. Sharabian, O. Pogorelko, E. Wolin, S. McAleer, S. E. Kuhn, V. Sapunenko, B. S. Ishkhanov, Ji Li, Jean Laget, N. Benmouna, N. Pivnyuk, Rakhsha Nasseripour, B. Carnahan, L. C. Dennis, B. E. Bonner, M. Guillo, C. Tur, J. Napolitano, A. I. Ostrovidov, R. Fatemi, A. C S Lima, Gerard Gilfoyle, D. Cords, Marco A. Huertas, H. Avakian, E. S. Smith, K. Park, A. V. Vlassov, D. G. Ireland, M. R. Niroula, V. Batourine, B. Zhao, Y. Ilieva, E. L. Isupov, R. Suleiman, I. Hleiqawi, L. Guo, S. Bültmann, Volker D. Burkert, A. S. Biselli, H. S. Jo, E. Golovatch, Michael L. Williams, P. Bosted, S. L. Careccia, James Mueller, G. S. Mutchler, R. DeVita, M. Ripani, S. A. Morrow, Atilla Gonenc, M. MacCormick, C. Djalali, F. W. Hersman, T. A. Forest, M. Anghinolfi, P. D. Rubin, S. Stepanyan, A. Cazes, G. Gavalian, J. W. Price, S. Boiarinov, Maryam Moteabbed, B. M. Preedom, N. A. Baltzell, Sylvain Bouchigny, J. P. Ball, Y. Prok, K. L. Giovanetti, Michael Dugger, A. Yegneswaran, Shifeng Chen, K. V. Dharmawardane, J. Pierce, M. Kossov, Avraham Klein, Jens H. Kuhn, A. Stavinsky, Larry Weinstein, P. Ambrozewicz, E. Pasyuk, L. M. Qin, K. A. Griffioen, H. O. Funsten, P. Coltharp, U. Thoma, C. Keith, Lorenzo Zana, D. P. Weygand, S. A. Dytman, Hall Crannell, M. M. Ito, N. Baillie, J. T. Goetz, G. V. O'Rielly, C. Paterson, M. Klusman, K. Livingston, V. Crede, Z. W. Zhao, Frank Klein, D. G. Crabb, J. R. Calarco, S. Strauch, D. G. Jenkins, C. Salgado, J. D. Kellie, G. E. Dodge, S. Pozdniakov, N. Guler, J. W C McNabb, M. D. Mestayer, I. Niculescu, Nikolay Shvedunov, D. Lawrence, M. Guidal, D. I. Sober, S. S. Stepanyan, M. Osipenko, S. Barrow, F. Sabatié, Michael Vineyard, K. Beard, M. Garçon, B. Mecking, G. Riccardi, J. Shaw, C. Butuceanu, Michael Wood, W. K. Brooks, K. Hafidi, V. S. Serov, Victor Mokeev, M. Ungaro, K. Joo, J. Yun, J. P. Santoro, Roy Thompson, K. Kim, J. J. Manak, P. Eugenio, J. Zhang, H. Bagdasaryan, P. Collins, Daniel S. Carman, C. Hadjidakis, C. E. Hyde-Wright, M. Bektasoglu, J. Langheinrich, S. A. Philips, G. Niculescu, M. Holtrop, Hong Lu, P. L. Cole, P. Nadel-Turonski, Tsutomu Mibe, B. B. Niczyporuk, J. Lachniet, A. Tkabladze, D. Rowntree, R. S. Hakobyan, J. Donnelly, O. P. Dzyubak, R. A. Niyazov, R. J. Feuerbach, L. Morand, P. Stoler, E. De Sanctis, K. Hicks, W. Kim, Susan Taylor, K. Mikhailov, H. Egiyan, N. Markov, Barry Ritchie, G. Asryan, H. Denizli, A. V. Skabelin, R. C. Minehart, C. A. Meyer, G. V. Fedotov, and E. Polli
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Proton, 010308 nuclear & particles physics, media_common.quotation_subject, Momentum transfer, Quark model, Parton, 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, Invariant mass, 010306 general physics, Nucleon, media_common
Abstract: We report results for the virtual photon asymmetry A{sub 1} on the nucleon from new Jefferson Lab measurements. The experiment, which used the CEBAF Large Acceptance Spectrometer and longitudinally polarized proton ({sup 15}NH{sub 3}) and deuteron ({sup 15}ND{sub 3}) targets, collected data with a longitudinally polarized electron beam at energies between 1.6 GeV and 5.7 GeV. In the present paper, we concentrate on our results for A{sub 1}(x,Q{sup 2}) and the related ratio g{sub 1}/F{sub 1}(x,Q{sup 2}) in the resonance and the deep inelastic regions for our lowest and highest beam energies, covering a range in momentum transfer Q{sup 2} from 0.05 to 5.0 GeV{sup 2} and in final-state invariant mass W up to about 3 GeV. Our data show detailed structure in the resonance region, which leads to a strong Q{sup 2}--dependence of A{sub 1}(x,Q{sup 2}) for W below 2 GeV. At higher W, a smooth approach to the scaling limit, established by earlier experiments, can be seen, but A{sub 1}(x,Q{sup 2}) is not strictly Q{sup 2}--independent. We add significantly to the world data set at high x, up to x = 0.6. Our data exceed the SU(6)-symmetric quark model expectation for both the proton and the deuteron whilemore » being consistent with a negative d-quark polarization up to our highest x. This data set should improve next-to-leading order (NLO) pQCD fits of the parton polarization distributions.« less
Published: 2006
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23. Performance of a compact detector package for the out-of-plane spectrometer system

Author: Nilanga Liyanage, Ricardo Alarcon, S. Dolfini, J. R. Comfort, S. Kowalski, J. Zhao, Shalev Gilad, C. Vellidis, S. Sobczynski, K. Joo, P. Bourgeois, K. A. Dow, J. Kirkpatrick, R. S. Hicks, T. McIlvain, A. Dooley, Costas N. Papanicolas, D. S. Dale, S. Georgakopoulos, C. Mertz, C. Tschalaer, S. B. Soong, I. Nakagawa, Jian-Ping Chen, E. Six, R. A. Miskimen, M. Farkhondeh, D. J. Margaziotis, J. R. Calarco, G. A. Peterson, W. Turchinetz, C. Kunz, Nikolaos Sparveris, M. O. Distler, D. R. Tieger, N. I. Kaloskamis, A. Hotta, Glen A. Warren, D. Jordan, J. Shaw, A. J. Sarty, Ross Milner, S. Stiliaris, F. Casagrande, T. Zwart, Tancredi Botto, M. Pavan, Aron M. Bernstein, Z.-L. Zhou, Joseph B. Mandeville, S. E. Williamson, Tadaaki Tamae, X. Jiang, M. Holtrop, S. Širca, W. Boeglin, Larry Weinstein, William Bertozzi, G. Tsentalovich, A. F. Ramirez, G. W. Dodson, Yutaro Sato, S. Stave, A. Karabarbounis, R. Beck, M. B. Epstein, A. Young, and D. Rowntree
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Pion, Spectrometer, Detector, Compton scattering, Electron, Nuclear Experiment, Instrumentation, Electron scattering, Linear particle accelerator, Particle identification
Abstract: We report on the design and performance of compact detector packages currently installed in the four magnetic out-of-plane spectrometers for electron scattering experiments at the MIT-Bates Linear Accelerator Center. The detector packages have been designed to meet the mechanical requirements arising from out-of-plane particle detection. They offer good trajectory and momentum reconstruction, particle identification and time-of-flight measurements for electrons, pions, protons, and deuterons with large momentum bites and in broad kinematical ranges and high luminosities. The detectors have so far been used with great success in out-of-plane measurements of 12 C ( e → , e ′ p ) , 2 H ( e → , e ′ p ) , virtual Compton scattering below pion threshold and in studies of the N → Δ transition in both exclusive reaction channels 1 H ( e → , e ′ p ) π 0 and 1 H ( e → , e ′ π + )n .
Published: 2002
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24. Measurements of Double-Polarized Compton Scattering Asymmetries and Extraction of the Proton Spin Polarizabilities

Author: B. Oussena, D. P. Watts, I. Keshelashvili, I. I. Strakovsky, A. B. Lazarev, A. Nikolaev, I. Supek, D. Howdle, A. Braghieri, S. N. Prakhov, G. Reicherz, K. Livingston, T. C. Jude, M. H. Sikora, B. M. K. Nefkens, Th. Strub, M. Unverzagt, S. Schrauf, N. S. Borisov, Michaela Thiel, V. L. Kashevarov, David Hamilton, C. S. Akondi, D. M. Manley, M. Korolija, L. Tiator, W. J. Briscoe, P. Hall Barrientos, Anthony W. Thomas, D. Hornidge, M. Ostrick, D. I. Glazier, W. Meyer, P. P. Martel, P. Pedroni, I. J. D. MacGregor, A. Starostin, A. J. Sarty, A. Rajabi, S. Garni, R. Kondratiev, R. A. Miskimen, A. Kaeser, A. N. Mushkarenkov, S. Schumann, B. Krusche, J. Ahrens, G. M. Gurevich, G. M. Huber, J. R. M. Annand, A. G. Denig, Yu. A. Usov, E. J. Downie, Lilian Witthauer, P. Aguar-Bartolomé, P. B. Otte, A. B. Neganov, T. Rostomyan, L. V. Fil'kov, W. Barnes, C. Collicott, D. Werthmüller, S. Cherepnya, M. Wolfes, A. Polonski, W. Gradl, J. Mancell, Susanna Costanza, M. Oberle, R. Beck, M. Dieterle, Aron M. Bernstein, H. J. Arends, D. G. Middleton, O. Steffen, V. Polyansky, V. Lisin, H. Ortega Spina, and P. Ott
Subjects: Physics, Photon, Proton, Nuclear Theory, Compton scattering, General Physics and Astronomy, FOS: Physical sciences, 7. Clean energy, 3. Good health, Baryon, Nuclear physics, Proton spin crisis, spin polarizabilities, nucleon, photon, ∆(1232) region, MAMI, Nuclear Experiment (nucl-ex), Nucleon, Nuclear Experiment, Microtron, Spin-½
Abstract: The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to measure the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the $\Delta(1232)$ region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields $\gamma_{E1E1} = -3.5 \pm 1.2$, $\gamma_{M1M1}= 3.16 \pm 0.85$, $\gamma_{E1M2} = -0.7 \pm 1.2$, and $\gamma_{M1E2} = 1.99 \pm 0.29$, in units of $10^{-4}$ fm$^4$., Comment: 5 pages, 3 figures, 2 tables
Published: 2014

25. Measurement of the transverse target and beam-target asymmetries in η meson photoproduction at MAMI

Author: M. Oberle, P. P. Martel, M. Dieterle, B. Oussena, Aron M. Bernstein, C. Collicott, D. P. Watts, A. B. Neganov, E. F. McNicoll, S. Cherepnya, H. Ortega, David Hamilton, W. Gradl, A. N. Mushkarenkov, W. Meyer, W. J. Briscoe, J. Mancel, D. Hornidge, G. Reicherz, P. Hall Barrientos, B. Krusche, V. Lisin, E. J. Downie, I. J. D. MacGregor, V. L. Kashevarov, Lothar Tiator, K. Livingston, N. S. Borisov, P. Pedroni, D. Werthmüller, R. A. Miskimen, R. Kondratiev, G. M. Gurevich, A. Fix, D. M. Manley, M. Korolija, P. Ott, A. Polonski, S. Costanza, S. N. Prakhov, Yu. A. Usov, O. Steffen, V. V. Polyanski, R. Beck, M. Wolfes, A. B. Lazarev, A. Braghieri, Th. Strub, S. Garni, I. I. Strakovsky, H. J. Arends, D. G. Middleton, Lilian Witthauer, G. M. Huber, Anthony W. Thomas, D. I. Glazier, I. Keshelashvili, J. R. M. Annand, S. Schumann, P. B. Otte, A. Nikolaev, B. M. K. Nefkens, D. Howdle, L. V. Fil'kov, C. S. Akondi, M. Ostrick, A. J. Sarty, I. Supek, T. Rostomyan, and M. Unverzagt
Subjects: Physics, Particle physics, Photon, Proton, Meson, Nuclear Theory, media_common.quotation_subject, Partial wave analysis, General Physics and Astronomy, Asymmetry, High Energy Physics - Experiment, Nuclear physics, beam-target asymmetry F, γ⃗ p⃗ →ηp reaction, Mainz Microtron MAMI, High Energy Physics::Experiment, Nucleon, Nuclear Experiment, Microtron, Crystal Ball, media_common
Abstract: We present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the $\vec \gamma \vec p\to\eta p$ reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. All existing model predictions fail to reproduce the new data indicating a significant impact on our understanding of the underlying dynamics of $\eta$ meson photoproduction. The peculiar nodal structure observed in existing T data close to threshold is not confirmed., Comment: 5 pages, 3 figures, accepted for publication in PRL
Published: 2014
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26. Measurement of the Elastic Magnetic Form Factor of3Heat High Momentum Transfer

Author: M. C. Berisso, X. Jiang, P. Bosted, R. S. Hicks, T. Kobayashi, A. Cichocki, A. Hotta, R. A. Miskimen, W. Turchinetz, J. Shaw, I. Nakagawa, F. Casagrande, B. Asavapibhop, S. E. Rock, K. Burchesky, Tadaaki Tamae, Toshio Suda, S. Churchwell, K. Wang, and G. A. Peterson
Subjects: Physics, Transfer (group theory), Scattering, Magnetic form factor, Momentum transfer, General Physics and Astronomy, Electron, Atomic physics, High momentum, Electron scattering
Abstract: New electron scattering measurements have been made that extend data on the ${}^{3}\mathrm{He}$ elastic magnetic form factor up to ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}42.6{\mathrm{fm}}^{\ensuremath{-}2}$. These new data test theoretical conjectures regarding non-nucleonic effects in the three-body system. The very small cross sections, as low as ${10}^{\ensuremath{-}40}{\mathrm{cm}}^{2}/\mathrm{sr}$, required the use of a high-pressure cryogenic gas target and a detector system with excellent background rejection capability. No existing theoretical calculation satisfactorily accounts for all the available data.
Published: 2001
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27. Theep→e′pηReaction at and above theS11(1535)Baryon Resonance

Author: M. J. Amaryan, M. Taiuti, S. K. Matthews, J. Ficenec, Gyurjyan, W. Kim, A. Longhi, R. A. Schumacher, B. E. Bonner, L. Elouadrhiri, A. P. Freyberger, R. Magahiz, Robert E. Welsh, S. Dytman, S. Whisnant, B. M. Preedom, Federico Ronchetti, R. J. Feuerbach, K. L. Giovanetti, B. Asavapibhop, Michael Dugger, Shalev Gilad, De Sanctis E, A. V. Vlassov, G. Ricco, J. R. Kane, H. Avakian, Philip L. Cole, J. P. Cummings, G. S. Adams, Larry Weinstein, R. A. Miskimen, K. Joo, J. Shaw, R. W. Major, Moshe Gai, M. Kossov, W. J. Briscoe, D. Rowntree, D. Doughty, K. Beard, W. K. Brooks, Friedrich Klein, R. S. Hicks, Brian Raue, Kevin Fissum, Kalvir S. Dhuga, Barry Ritchie, A. Coleman, K. A. Griffioen, M. M. Ito, G. Riccardi, L. M. Qin, J. J. Manak, M. Mirazita, J. M. Laget, C. E. Hyde-Wright, J. W C McNabb, M. S. Ohandjanyan, D. Heddle, C. Salgado, H. R. Weller, Roy Thompson, Curtis Smith, D. P. Weygand, Herbert O. Funsten, S. A. Philips, Patrick Girard, Y. Kuang, H. Egiyan, M. Witkowski, Bernhard Mecking, Mestayer, A. J. Sarty, Jing Zhao, S. Stepanyan, De Vita R, D. G. Jenkins, C. Djalali, Z. L. Zhou, M. Lucas, Airton Deppman, D. I. Sober, A. Shafi, D. Hancock, Avraham Klein, Leskin Ga, M. Battaglieri, S. McAleer, William Bertozzi, E. Polli, E. Anciant, L. Farhi, G. E. Dodge, Daniel S. Carman, V. B. Gavrilov, O. Pogorelko, A. K. Opper, G. Audit, J. W. Price, M. Khandaker, E. Wolin, P. V. Degtyarenko, Y. Patois, Gerard Gilfoyle, Dinko Pocanic, L.C. Dennis, K. Loukachine, N. Pivnyuk, M. Bektasoglu, S. E. Kuhn, S. M. Shuvalov, D. Lawrence, M. Eckhause, J. Napolitano, M. Ripani, M. Guillo, Jochen Heisenberg, Y. V. Efremenko, Volker D. Burkert, M. Sanzone, J. Connelly, Donal Day, M. Sargsyan, G. A. Peterson, M. Guidal, A. V. Skabelin, J. Yun, D. Cords, A. Yegneswaran, A. S. Biselli, Elton Smith, S. Barrow, M. Holtrop, Thomas E. Smith, G. S. Mutchler, M. Anghinolfi, Hall Crannell, D. G. Crabb, James Mueller, S. Taylor, P. D. Rubin, G. Capitani, F. Roudot, D. J. Tedeschi, Y. G. Sharabian, M. Spraker, Sapunenko, R. C. Minehart, M. Klusman, Nicola Bianchi, S. Boiarinov, C. A. Meyer, J. S. McCarthy, B. Carnahan, Thierry Auger, A. R. Reolon, Michael Vineyard, C. Marchand, P. Rossi, P. Dragovitsch, F. W. Hersman, R. A. Demirchyan, T. Y. Tung, J. Hardie, K. Y. Kim, Muccifora, R. A. Niyazov, John T. O'Brien, P. Corvisiero, K. S. Egiyan, Calarco, P. Stoler, and K. Hicks
Subjects: Baryon, Physics, Nuclear physics, Particle physics, Photon, Amplitude, Angular distribution, Meson, Momentum transfer, General Physics and Astronomy, Resonance, Invariant (physics), Nuclear Experiment
Abstract: New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.
Published: 2001
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28. Measurement of the interference structure functionRLTfor the12C(e,e′p)reaction in the quasielastic region

Author: V. Bhushan, D. S. Dale, S. Dolfini, Joseph B. Mandeville, T. McIlvain, D. J. Margaziotis, William Bertozzi, D. Martinez, Glen A. Warren, J. Görgen, W. W. Sapp, D. R. Tieger, G. W. Dodson, D. Jordan, Shalev Gilad, K. A. Dow, M. Holtrop, M. B. Epstein, Jiahao Chen, W. Turchinetz, J. Kelsey, J. Dzengeleski, W. Boeglin, C. Tschalaer, A. J. Sarty, Costas N. Papanicolas, K. Joo, Ricardo Alarcon, R. M. Laszewski, W. Kim, M. Farkhondeh, R. Beck, R.W. Lourie, Larry Weinstein, S. Penn, R. A. Miskimen, and S. E. Williamson
Subjects: Physics, Nuclear and High Energy Physics, Nuclear Theory, Structure function, Momentum transfer, Hartree–Fock method, Hartree, Atomic physics
Abstract: The coincidence cross section and the interference structure function, ${R}_{\mathrm{LT}},$ were measured for the ${}^{12}\mathrm{C}{(e,e}^{\ensuremath{'}}p){}^{11}\mathrm{B}$ reaction at quasielastic kinematics and central momentum transfer of $|\stackrel{\ensuremath{\rightarrow}}{q}|=400\mathrm{M}\mathrm{e}\mathrm{V}/\mathrm{c}.$ The measurement was at an opening angle of ${\ensuremath{\theta}}_{\mathrm{pq}}=11\ifmmode^\circ\else\textdegree\fi{},$ covering a range in missing energy of ${E}_{m}=0$ to 65 MeV. The ${R}_{\mathrm{LT}}$ structure function is found to be consistent with zero for ${E}_{m}g50\mathrm{MeV},$ confirming an earlier study which indicated that ${R}_{L}$ vanishes in this region. The integrated strengths of the $p$- and $s$-shell are compared with a distorted wave impulse approximation (DWIA) calculation. The $s$-shell strength and shape are also compared with a Hartree Fock--random phase approximation (HF-RPA) calculation. The DWIA calculation does not succeed in giving a consistent description of both the cross section data and the extracted ${R}_{\mathrm{LT}}$ response for either shell. The HF-RPA calculation describes the data more consistently, which may be due to the inclusion of 2-body currents in this calculation.
Published: 1998
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29. The region one drift chamber for the CLAS spectrometer

Author: R. Magahiz, S. Dytman, R. A. Schumacher, M. D. Mestayer, G.R. Wilkin, Daniel S. Carman, D. J. Tedeschi, R. A. Thompson, James Mueller, and R. A. Miskimen
Subjects: Physics, Nuclear and High Energy Physics, Toroid, Spectrometer, Physics::Instrumentation and Detectors, business.industry, Detector, Mechanical components, Particle detector, Magnetic field, Nuclear magnetic resonance, Optics, Magnet, Measuring instrument, business, Instrumentation
Abstract: The Region One detector is the innermost of three nested drift chamber packages of the CLAS spectrometer at Jefferson Laboratory. This detector, with 7776 drift cells, was optimized for the CLAS toroidal magnet geometry, and consists of six wedge-shaped sectors integrated into a single unit. Each sector has thin and relatively weak aluminum endplates which support the large mechanical loads from the wire tensions and associated readout hardware. The unusual feature of the detector is its self-supporting design, wherein the wire tensions of neighboring sectors balance each other without the use of massive structural support. We discuss the design criteria, mechanical components, and assembly procedures.
Published: 1998
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30. Induced proton polarization forπ0electroproduction atQ2=0.126 GeV2/c2around theΔ(1232)resonance

Author: S. E. Williamson, X. Jiang, B. Asavapibhop, G. W. Dodson, Glen A. Warren, Larry Weinstein, A. J. Sarty, S. B. Soong, K. Joo, D. J. Margaziotis, S. Kowalski, James J. Kelly, Shalev Gilad, C. Vellidis, K. A. Dow, C. S. Armstrong, L. M. Qin, P. Markowitz, Jiunn-Wei Chen, A. Young, R. W. Gothe, D. S. Dale, Justin I. McIntyre, Volker D. Burkert, P. M. Rutt, Ricardo Alarcon, J. P. Chen, M. B. Epstein, D. Liu, R. J. Woo, C. Tschalaer, V. A. Punjabi, D. H. Barkhuff, M. K. Jones, William Bertozzi, D. R. Tieger, J. M. Finn, A. Karabarbounis, J. R. Comfort, M. Farkhondeh, S. Van Verst, B. D. Milbrath, Richard Madey, R. A. Miskimen, S. Mukhopadhyay, S. Dolfini, C. Kunz, C. F. Perdrisat, J. Shaw, Costas N. Papanicolas, P. E. Ulmer, R.W. Lourie, W. Turchinetz, John C. Mitchell, and C. Mertz
Subjects: Physics, Baryon, Nuclear and High Energy Physics, Particle physics, Pion, Proton, Meson, Hadron, Elementary particle, Nucleon, Delta baryon
Abstract: We present a measurement of the induced proton polarization ${P}_{n}$ in ${\ensuremath{\pi}}^{0}$ electroproduction on the proton around the $\ensuremath{\Delta}$ resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of $W=1231 \mathrm{MeV}$ and ${Q}^{2}=0.126 {\mathrm{GeV}}^{2}{/c}^{2},$ respectively. We measured a large induced polarization, ${P}_{n}=\ensuremath{-}0.397\ifmmode\pm\else\textpm\fi{}0.055\ifmmode\pm\else\textpm\fi{}0.009.$ The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model.
Published: 1998
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31. Investigation of the10B(γ,p)reaction using tagged photons

Author: P. J. Woods, D. Van Neck, A. C. Shotter, Lennart Isaksson, R. A. Miskimen, Javad Rahighi, D. Branford, T. Davinson, Robert Page, Bent Schröder, I. Bobeldijk, G. van der Steenhoven, K. Wang, J.-O. Adler, R. S. Hicks, K. Livingston, D. G. Ireland, G. A. Peterson, B.-E. Andersson, R. van der Meer, H. Ruijter, and L.J. de Bever
Subjects: Momentum, Physics, Nuclear and High Energy Physics, Angular distribution, Photon, Meson, Excited state, Model parameters, Atomic physics, Ground state
Abstract: The reaction ${}^{10}\mathrm{B}(\ensuremath{\gamma},p)$ has been studied using tagged photons of mean energies ${E}_{\ensuremath{\gamma}}=57.6$ and 72.9 MeV. Angular distributions and derived single-particle momentum distributions for protons leading to the ground state of ${}^{9}\mathrm{Be}$ and higher excited states are compared to various calculations made using model parameters constrained by ${}^{10}\mathrm{B}{(e,e}^{\ensuremath{'}}{p)}^{9}\mathrm{Be}$ and ${}^{9}\mathrm{Be}{(p,p}^{\ensuremath{'}}{)}^{9}\mathrm{Be}$ measurements. The effects of varying final-state interactions (including channel couplings) and meson exchange currents are considered. A sizable discrepancy between direct-knockout calculations and the experimental results is observed. If meson exchange currents are included in an approximate fashion, a good description of the ${}^{10}\mathrm{B}(\ensuremath{\gamma}{,p}_{0}{)}^{9}\mathrm{Be}$ data is found.
Published: 1998
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32. Radial dependence of the nucleon effective mass in 10B

Author: L.J. de Bever, G. van der Steenhoven, R. S. Hicks, Nasser Kalantar-Nayestanaki, de H Vries, H. P. Blok, James J. Kelly, G. A. Peterson, D. Van Neck, R. A. Miskimen, L. Lapikás, C. W. de Jager, and (Astro)-Particles Physics
Subjects: Physics, Proton, 010308 nuclear & particles physics, Nuclear Theory, SHELL model, General Physics and Astronomy, Inelastic scattering, 01 natural sciences, Nuclear physics, Effective mass (solid-state physics), 0103 physical sciences, Atomic nucleus, Nuclear Experiment, 010306 general physics, Nucleon, Wave function, Electron scattering
Abstract: The dynamic properties of the atomic nucleus depend strongly on correlations between the nucleons. We present a combined analysis of inelastic electron-scattering data and electron-induced proton knockout measurements in an effort to obtain phenomenological information on nucleon-nucleon correlations. Our results indicate that the ratio of radial wave functions extracted from precise B-10(e, e') and B-10(e, e'p) measurements evolve from an interior depression for small E-m, characteristic of short-range correlations, to a surface-peaked enhancement for larger E-m, characteristic of long-range correlations. This observation can be interpreted in terms of the nucleon effective mass.
Published: 1998
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33. Measurement of the Longitudinal, Transverse, and Longitudinal-Transverse Structure Functions in theH2(e,e′p)nReaction

Author: R. A. Miskimen, William Bertozzi, D. J. Margaziotis, W. Kim, S. Dolfini, M. Epstein, S. Penn, W.W. Sapp, J. Görgen, R. Beck, Shalev Gilad, K. Joo, W. Turchinetz, K. A. Dow, Ricardo Alarcon, A. J. Sarty, Larry Weinstein, D. Martinez, C. Tschalaer, Jiahao Chen, D. S. Dale, D. Jordan, R. M. Laszewski, J. Kelsey, Glen A. Warren, M. Holtrop, J. Dzengeleski, Joseph B. Mandeville, R.W. Lourie, W. Boeglin, M. Farkhondeh, S. E. Williamson, G. W. Dodson, Costas N. Papanicolas, D. R. Tieger, V. Bhushan, and T. McIlvain
Subjects: Physics, Transverse plane, Meson, Condensed matter physics, Structure function, Isobar, General Physics and Astronomy, Atomic physics, Omega
Abstract: We have separated the longitudinal ({ital f}{sub 00}), transverse ({ital f}{sub 11}), and longitudinal-transverse interference ({ital f}{sub 01}) structure functions in the {sup 2}H({ital e},{ital e}{prime}{ital p}){ital n} reaction at {ital q}{searrow}{parallel}{approx_equal} 400 MeV/{ital c} and {omega}{approx_equal}110 MeV. A nonrelativistic calculation which includes effects due to final state interactions, meson exchange currents, and isobar configurations agrees with the measured {ital f}{sub 11} and {ital f}{sub 01} but overpredicts {ital f}{sub 00} by 25{percent} (2{sigma}). The data are also compared to the results of previous structure function measurements. {copyright} {ital 1996 The American Physical Society.}
Published: 1996
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34. Construction update and drift velocity calibration for the CLAS drift chamber system

Author: R. A. Miskimen, R. Magahiz, S. Dytman, Ch. Hyde-Wright, Gerard Gilfoyle, J.E. O'Meara, L. M. Qin, T.D. Pyron, E. Burtin, S. Christo, A. Yegneswaran, F. Barbosa, R. A. Schumacher, L. Y. Murphy, P. Bonneau, Avraham Klein, Larry Weinstein, G. Doolittle, B. A. Raue, W. Tuzel, S. E. Kuhn, M. D. Mestayer, and M.V. Kossov
Subjects: Physics, Nuclear and High Energy Physics, Drift velocity, Physics::Instrumentation and Detectors, business.industry, Detector, Chamber geometry, Mechanics, Function (mathematics), Key features, Cathode, Anode, law.invention, Optics, law, Calibration, business, Instrumentation
Abstract: We briefly describe the drift chamber system for the CLAS detector at CEBAF, concentrating on the method which will be used to calibrate the drift velocity function. We identify key features of the function which should apply to any small-cell drift chamber geometry in which the cathode and anode surfaces are wires. Using these ideas, we describe a simple method to compensate for variations in the drift velocity function due to environmental changes.
Published: 1995
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35. Measurements of the (e,e’pπ−) reaction on nuclei in the nucleon resonance region

Author: P. V. Degtyarenko, F. S. Dietrich, S. O. Melnikoff, R. A. Miskimen, S.M. Shuvalov, G. A. Peterson, V. Gavrilov, K. van Bibber, L. Elouadrhiri, K. Wang, J. D. Molitoris, and J. Button-Shafer
Subjects: Nuclear reaction, Physics, Nuclear physics, Baryon, Nuclear and High Energy Physics, Meson, Hadron, Resonance, Atomic physics, Inelastic scattering, Nucleon, Delta baryon
Published: 1994
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36. Multiple hadron production by 14.5 GeV electron and positron scattering from nuclear targets

Author: S. O. Melnikoff, R. A. Miskimen, Bibber Kv, M. V. Kossov, V. Gavrilov, F. S. Dietrich, J. Button-Shafer, G.A. Leksin, S.M. Shuvalov, J. D. Molitoris, G. A. Peterson, K. Wang, Degtyarenko Pv, and L. Elouadrhiri
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Proton, Nuclear Theory, Hadron, Charged particle, Baryon, Nuclear physics, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment, Nucleon
Abstract: Multiple proton and pion electroproduction from nuclei are studied. Final states including at least two protons produced by the interaction of 14.5 GeV electrons and positrons with light nuclei (mainly $^{12}\mathrm{C}$ and $^{16}\mathrm{O}$) have been measured, and compared with analogous data from $^{40}\mathrm{Ar}$. Scattered electrons and positrons were detected in the energy transfer range from 0.2 to 12.5 GeV, and four-momentum transfer squared range from 0.1 to 5.0 ${\mathrm{GeV}}^{2}$/${\mathit{c}}^{2}$. Phenomenological characteristics of the secondary hadron production cross sections such as temperature and velocity of the effective source of hadrons were found to be dependent on energy transfer to the nucleus and independent on the four-momentum transfer squared at energy transfers greater than 2 GeV.
Published: 1994
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37. Measurement of the partial cross sectionsσTT,σLT, and(σT+ɛσL)of the1H(e,e′π+)nreaction in theΔ(1232)resonance

Author: P. Bourgeois, Z. L. Zhou, G. Tsentalivich, A. Hotta, S. Stave, Tancredi Botto, A. J. Sarty, Ross Milner, S. Širca, I. Nakagawa, William Bertozzi, W. Turchinetz, Efstathios Stiliaris, M. Farkondeh, C. Tschalaer, S. Georgakopoulos, J. R. Calarco, J. Kirkpatrick, R. S. Hicks, A. Karabarbounis, F. Casagrande, Ricardo Alarcon, Yukinori Sato, Shalev Gilad, A. Holtrop, R. A. Miskimen, J. Shaw, K. A. Dow, S. Kowalski, Nikos Sparveris, Tadaaki Tamae, E. Six, T. Zwart, M. O. Distler, Costas N. Papanicolas, Aron M. Bernstein, and X. Jiang
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Pion, Meson, Hadron, Resonance, Sigma, Elementary particle, Atomic physics, Nucleon
Abstract: We report precision {sup 1}H(e, e{sup '{pi}+})n measurements in the {Delta}(1232) resonance at Q{sup 2}=0.127(GeV/c){sup 2} obtained at the MIT-Bates out-of-plane scattering facility. These are the lowest, but nonzero, Q{sup 2} measurements in the {pi}{sup +} channel. The data offer tests of the theoretical calculations, particularly of the background amplitude contributions. The chiral effective field theory and Sato-Lee model calculations are not in agreement with this experiment.
Published: 2011
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38. Transverse form factors ofSn117

Author: R. A. Miskimen, Toshio Suzuki, R. S. Hicks, H. Baghaei, S. H. Rokni, M. Frodyma, J. Dubach, G. A. Peterson, and A. Hotta
Subjects: Nuclear reaction, Elastic scattering, Physics, Nuclear and High Energy Physics, Scattering, Momentum transfer, Atomic physics, Inelastic scattering, Nucleon, Electron scattering, Omega
Abstract: Transverse elastic and inelastic form factors for low-lying levels in $^{117}\mathrm{Sn}$ have been measured by 180\ifmmode^\circ\else\textdegree\fi{} electron scattering in the momentum transfer range ${\mathit{q}}_{\mathrm{eff}}$=1.1\char21{}2.4 ${\mathrm{fm}}^{\mathrm{\ensuremath{-}}1}$. The simple independent-particle model fails to account for these data, predicting form factors that are much too large. In better quantitative agreement with the data are the results of more detailed calculations that allow for configuration mixing of valence nucleons, as well as first-order core polarization. As in the similar case of $^{205}\mathrm{Tl}$, these calculations successfully predict the presence of a deep diffraction minimum observed in the intermediate q region of the elastic M1 form factor. Nevertheless, the overall description of the data by the detailed calculations remains quantitatively unsatisfactory. A more complete understanding of these data may rely upon the consideration of multiparticle-multihole configurations outside the 0\ensuremath{\Elzxh}\ensuremath{\omega} basis space.
Published: 1993
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39. Ground-state magnetization density ofY89

Author: E. E. Saperstein, R. A. Miskimen, A. P. Platonov, J. R. Calarco, Jochen Heisenberg, G. A. Peterson, R. S. Hicks, F. W. Hersman, W. Kim, S. A. Fayans, J. P. Connelly, J. E. Wise, R.P. Singhal, and Tom Milliman
Subjects: Physics, Elastic scattering, Nuclear reaction, Nuclear and High Energy Physics, Magnetization, Scattering, Elastic electron, Atomic physics, Ground state, Polarization (waves), Fermi Gamma-ray Space Telescope
Abstract: Elastic electron scattering cross sections have been measured for [sup 89]Y at 180[degree] for 0.72[lt][ital q][lt]2.67 fm[sup [minus]1]. The [ital M]1 form factor has been extracted and a Fourier-Bessel analysis performed to obtain the ground-state magnetization density. Calculations including effects of core polarization have been performed within the framework of the finite Fermi system theory. These show a weakening of the strong repulsion in the spin-isospin channel and are in overall agreement with the data.
Published: 1993
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40. Measurements of the electric and magnetic form factors of the neutron fromQ2=1.75 to 4.00 (GeV/c)2

Author: A. Lung, L. M. Stuart, P. E. Bosted, L. Andivahis, J. Alster, R. G. Arnold, C. C. Chang, F. S. Dietrich, W. R. Dodge, R. Gearhart, J. Gomez, K. A. Griffioen, R. S. Hicks, C. E. Hyde-Wright, C. Keppel, S. E. Kuhn, J. Lichtenstadt, R. A. Miskimen, G. A. Peterson, G. G. Petratos, S. E. Rock, S. H. Rokni, W. K. Sakumoto, M. Spengos, K. Swartz, Z. Szalata, and L. H. Tao
Subjects: General Physics and Astronomy
Published: 1993
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41. New Measurement of the π0 radiative decay width

Author: A. Kolarkar, M. Khandaker, A. V. Glamazdin, M. Gabrielyan, D. Kashy, R. A. Miskimen, G. Dzyubenko, I. Larin, M. A. Kubantsev, L. Jiang, T. E. Rodrigues, V. Vishnyakov, M. Payen, X. Li, A. Evdokimov, D. McNulty, G. Davidenko, W. A. Stephens, M. Konchatnyi, I. Nakagawa, S. Danagoulian, E. Pasyuk, J. He, S. Mtingwa, P. Ambrozewicz, L. Gan, A. Dolgolenko, J. Feng, S. Kowalski, P. Kingsberry, J. Underwood, R. C. Minehart, P. Collins, L. Benton, A. Deur, P. L. Cole, D. Lawrence, V. Gyurjyan, M. Wood, V. P. Kubarovsky, A. Ahmidouch, B. A. Mecking, Wolfgang Korsch, S. Gevorkyan, P. P. Martel, Aron M. Bernstein, Ashot Gasparian, V. Goryachev, M. M. Ito, V. V. Mochalov, A. Sitnikov, Y. Prok, Barry Ritchie, E. Clinton, D. S. Dale, V. Matveev, K. Baker, A. Teymurazyan, C. Salgado, S. Overby, Andrey Vasiliev, K. Hardy, Brian D. Milbrath, Rolf Ent, R.S. Pedroni, R. Demirchyan, A. Korchin, A. Shahinyan, A. Asratyan, S. Zhou, Volker D. Burkert, S. Stepanyan, and D. I. Sober
Subjects: Physics, Meson, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Carbon-12, General Physics and Astronomy, Particle Data Group, Elementary particle, 01 natural sciences, 7. Clean energy, Massless particle, Nuclear physics, Particle decay, Pion, 0103 physical sciences, High Energy Physics::Experiment, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract: High precision measurements of the differential cross sections for $\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\pi^0 \to \gamma\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The ${\pi^0 \to \gamma\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\Gamma{(\pi^0 \to \gamma\gamma)} = 7.82 \pm 0.14 ~({\rm stat.}) \pm 0.17 ~({\rm syst.}) ~{\rm eV}$. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions., Comment: 4 pages, 5 figures
Published: 2010

42. Measurements of the electric and magnetic form factors of the proton fromQ2=1.75 to 8.83 (GeV/c)2

Author: P. E. Bosted, Sayed Rokni, J. Alster, M. Spengos, L. M. Stuart, K. A. Griffioen, L. Andivahis, R. G. Arnold, L. H. Tao, C. E. Hyde-Wright, Sakumoto Wk, W. R. Dodge, J. Lichtenstadt, A. Lung, Z. M. Szalata, F. S. Dietrich, S. E. Rock, J. Gomez, G. G. Petratos, R. S. Hicks, R. A. Gearhart, G. A. Peterson, C. C. Chang, K. Swartz, S. E. Kuhn, R. A. Miskimen, and C. E. Keppel
Subjects: Scattering cross-section, Physics, Particle physics, Particle properties, Proton, Particle model, Quark model, Hadron, Form factor (quantum field theory), General Physics and Astronomy, Elementary particle, Vector meson dominance, Baryon, Combinatorics, Crystallography, Neutron, Nucleon
Abstract: The proton elastic form factors ${\mathit{G}}_{\mathit{E}\mathit{p}}$(${\mathit{Q}}^{2}$) and ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$) have been extracted for ${\mathit{Q}}^{2}$=1.75 to 8.83 (GeV/c${)}^{2}$ via a Rosenbluth separation to ep elastic cross section measurements in the angular range 13\ifmmode^\circ\else\textdegree\fi{}\ensuremath{\le}\ensuremath{\theta}\ensuremath{\le}90\ifmmode^\circ\else\textdegree\fi{}. The ${\mathit{Q}}^{2}$ range covered more than doubles that of the existing data. For ${\mathit{Q}}^{2}$4 (GeV/c${)}^{2}$, where the data overlap with previous measurements, the total uncertainties have been reduced to 14% in ${\mathit{G}}_{\mathit{E}\mathit{p}}$ and 1.5% in ${\mathit{G}}_{\mathit{M}\mathit{p}}$. Results for ${\mathit{G}}_{\mathit{E}\mathit{p}}$(${\mathit{Q}}^{2}$) are consistent with the dipole fit ${\mathit{G}}_{\mathit{D}}$(${\mathit{Q}}^{2}$)=(1+${\mathit{Q}}^{2}$/0.71${)}^{\mathrm{\ensuremath{-}}2}$, while those for ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$)/${\mathrm{\ensuremath{\mu}}}_{\mathit{p}}$${\mathit{G}}_{\mathit{D}}$(${\mathit{Q}}^{2}$) decrease smoothly from 1.05 to 0.92. Deviations from form factor scaling are observed up to 20%. The ratio ${\mathit{Q}}^{2}$${\mathit{F}}_{2}$/${\mathit{F}}_{1}$ is observed to approach a constant value for ${\mathit{Q}}^{2}$g3 (GeV/c${)}^{2}$. Comparisons are made to vector meson dominance, dimensional scaling, QCD sum rule, diquark, and constituent quark models, none of which fully characterize all the new data.
Published: 1992
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43. Precise Measurement of the Neutron Magnetic Form FactorGMnin the Few-GeV2Region

Author: R. J. Feuerbach, J. P. Cummings, L. C. Smith, E. Munevar, R. De Masi, D. Keller, M. Kossov, B. S. Ishkhanov, I. Popa, K. S. Egiyan, G. Ricco, K. Mikhailov, L. Cheng, M. Khandaker, M. Garçon, J. Shaw, Michael Wood, P. Nadel-Turonski, Nikolay Shvedunov, M. R. Niroula, K. Hafidi, R. Nasseripour, S. McAleer, Friedrich Klein, B. P. Quinn, Brian Raue, V. S. Serov, L. Casey, F. X. Girod, Susan Taylor, Marco A. Huertas, M. Lowry, V. Sapunenko, D. P. Watts, L. C. Dennis, B. E. Bonner, Hartmuth Arenhövel, Dinko Pocanic, H. Egiyan, R. G. Fersch, H. Avakian, D. Doughty, B. B. Niczyporuk, G. S. Adams, S. Park, D. Sharov, N. Kalantarians, P. L. Cole, Sylvain Bouchigny, Sabine Jeschonnek, R. C. Minehart, Kei Moriya, D. Heddle, P. Rossi, J. Lachniet, H. G. Juengst, C. A. Meyer, N. Pivnyuk, K. Joo, W. J. Briscoe, B. L. Berman, A. Tkabladze, G. V. Fedotov, E. Pasyuk, D. Rowntree, A. Coleman, L. M. Qin, M. Y. Gabrielyan, S. E. Kuhn, S. A. Dytman, V. Crede, Y. Ilieva, J. R. Calarco, T. Mineeva, J. W. Price, M. J. Amaryan, C. Paterson, S. Strauch, M. MacCormick, A.V. Stavinsky, M. Klusman, I. Hleiqawi, V. P. Kubarovsky, K. P. Adhikari, S. L. Careccia, A. Empl, L. El Fassi, O. Pogorelko, B. Moreno, D. P. Weygand, J. Salamanca, R. Suleiman, M. E. McCracken, Elton Smith, K. L. Giovanetti, B. Asavapibhop, G. V. O'Rielly, Tsutomu Mibe, Larry Weinstein, Z. W. Zhao, J. W C McNabb, D. J. Tedeschi, D. Protopopescu, D. G. Jenkins, Barry Ritchie, M. Anghinolfi, James Mueller, S. Malace, S. A. Morrow, P. Rubin, I. Bedlinskiy, G. S. Mutchler, Konstantin Stopani, S. Pozdniakov, V. Gyurjyan, M. M. Ito, C. Djalali, Y. G. Sharabian, G. Rosner, T. Kageya, K. Livingston, D. S. Dale, X. Wei, R. Dickson, V. Kuznetsov, C. E. Hyde-Wright, H. Denizli, N. Guler, N. A. Baltzell, P. Mattione, K. A. Griffioen, M. S. Saini, A. V. Skabelin, P. Dragovitsch, J. Zhang, S. Barrow, E. De Sanctis, S. Niccolai, J. T. Goetz, E. Polli, H. Bagdasaryan, R. A. Miskimen, J. D. Kellie, B. McKinnon, Sergey Kuleshov, M. Bektasoglu, J. Hardie, M. Nozar, W. Kim, Laird Kramer, G. Niculescu, D. I. Sober, D. Branford, M. Guidal, R. A. Schumacher, H. Hakobyan, M. Mirazita, P. Khetarpal, C. Hanretty, J. M. Laget, M. Holtrop, Victor Mokeev, L. Graham, J. R. Johnstone, N. Gevorgyan, L. Guo, M. Ungaro, M. Osipenko, F. Sabatié, A. Daniel, K. Beard, Kalvir S. Dhuga, S. Bültmann, A. I. Ostrovidov, J. Yun, D. Cords, V. Batourine, T. A. Forest, A. Yegneswaran, A. C S Lima, A. Sandorfi, K. Park, R. Fatemi, S. Stepanyan, A. V. Vlassov, D. G. Ireland, Volker D. Burkert, A. S. Biselli, J. Pierce, Avraham Klein, B. Zhao, J. Langheinrich, R. De Vita, A. Fradi, S. S. Stepanyan, S. A. Philips, William Brooks, N. Markov, P. Konczykowski, B. E. Stokes, J. J. Manak, S. Anefalos Pereira, G. E. Dodge, H. Y. Lu, N. Dashyan, Maryam Moteabbed, P. V. Degtyarenko, K. V. Dharmawardane, I. Niculescu, D. Lawrence, D. Schott, F. W. Hersman, M. Battaglieri, N. Baillie, P. Stoler, K. Hicks, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. Corvisiero, R. Bradford, B. A. Mecking, K. Lukashin, E. Wolin, Gerard Gilfoyle, M. Guillo, D. Sokhan, W. Gohn, N. Hassall, M. Bellis, E. Golovatch, J. P. Ball, J. Hu, Y. Prok, D. S. Carman, S. Dhamija, M. D. Mestayer, L. Elouadrhiri, I. I. Strakovsky, E. L. Isupov, R. W. Gothe, G. Gavalian, S. Tkachenko, A. Deur, Michael L. Williams, J. Kuhn, N. Benmouna, J. P. Santoro, Andrei Afanasev, M. Ripani, D. G. Crabb, K. Y. Kim, Roy Thompson, Cynthia Marie Hadjidakis, S. Boiarinov, Michael Dugger, B. M. Preedom, Douglas Higinbotham, M. Yurov, Lorenzo Zana, H. S. Jo, C. Bookwalter, C. Salgado, Kwangsoo Kim, G. Riccardi, P. Eugenio, A. Starostin, M. Taiuti, Michael Vineyard, and P. Collins
Subjects: Physics, 010308 nuclear & particles physics, Scattering, Nuclear Theory, General Physics and Astronomy, Scintillator, 7. Clean energy, 01 natural sciences, Nuclear physics, Dipole, Deuterium, 0103 physical sciences, Magnetic form factor, Neutron detection, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, Electron scattering
Abstract: The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.
Published: 2009
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44. Measurement of Directf0(980)Photoproduction on the Proton

Author: S. Park, Sylvain Bouchigny, V. Crede, J. R. Calarco, E. Wolin, C. E. Hyde, R. A. Schumacher, V. Sapunenko, Dinko Pocanic, P. Nadel-Turonski, L. Casey, V. Mokeev, D. Lawrence, J. P. Cummings, H. G. Juengst, B. E. Stokes, Cynthia Marie Hadjidakis, J. P. Ball, D. S. Carman, A. Fradi, A. V. Vlassov, P. Konczykowski, M. J. Amaryan, S. Dhamija, Michael Dugger, K. Livingston, D. S. Dale, T. Lee, Maryam Moteabbed, M. Kossov, S. E. Kuhn, L. Graham, Ashot Gasparian, B. B. Niczyporuk, C. I O Gordon, M. MacCormick, R. W. Gothe, Z. W. Zhao, R. Dickson, N. Gevorgyan, T. Kageya, H. Avakian, I. Hleiqawi, K. V. Dharmawardane, A.V. Stavinsky, J. Donnelly, G. Asryan, N. Pivnyuk, D. G. Crabb, J. Kuhn, M. E. McCracken, R. De Vita, S. Strauch, E. Clinton, S. Bültmann, S. L. Careccia, D. G. Jenkins, O. P. Dzyubak, D. P. Watts, H. Egiyan, Gerard Gilfoyle, G. Ricco, Lorenzo Zana, J. P. Santoro, C. Tur, L. Gan, Tsutomu Mibe, W. Gohn, T. A. Forest, D. J. Tedeschi, N. Markov, D. Sokhan, D. Sharov, W. Kim, S. Anefalos Pereira, S. Stepanyan, G. Niculescu, M. Yurov, J. Goett, R. A. Miskimen, I. Bedlinskiy, B. McKinnon, M. Y. Gabrielyan, J. Pierce, K. L. Giovanetti, F. X. Girod, Sergey Kuleshov, Avraham Klein, Shifeng Chen, N. Guler, E. Golovatch, Friedrich Klein, Larry Weinstein, N. A. Baltzell, G. E. Dodge, P. Khetarpal, K. A. Stopani, Brian Raue, D. Keller, H. Y. Lu, M. Nozar, D. Branford, J. Salamanca, H. S. Jo, C. Bookwalter, E. De Sanctis, L. Lesniak, G. Riccardi, J. M. Laget, V. V. Mochalov, P. Mattione, K. A. Griffioen, M. Aghasyan, X. Wei, V. Kuznetsov, M. S. Saini, P. V. Degtyarenko, A. I. Ostrovidov, D. I. Sober, A. Sandorfi, K. Park, P. Eugenio, Adam P. Szczepaniak, V. Batourine, C. Hanretty, A. Starostin, M. Guidal, N. Dashyan, M. Taiuti, W. J. Briscoe, E. Pasyuk, H. Hakobyan, S. A. Morrow, G. Rosner, J. T. Goetz, M. Mirazita, C. Djalali, Paolo Rossi, M. Khandaker, L. Bibrzycki, I. Niculescu, J. Lachniet, A. Tkabladze, Y. Ilieva, J. W. Price, M. Holtrop, R. A. Niyazov, Elton Smith, D. G. Ireland, A. Daniel, A. Teymurazyan, I. I. Strakovsky, G. Gavalian, N. Hassall, M. Bellis, P. Ambrozewicz, P. Collins, B. Zhao, R. De Masi, S. Tkachenko, D. Schott, M. Ripani, D. Doughty, P. Stoler, J. J. Melone, S. Niccolai, Z. Krahn, Volker D. Burkert, A. S. Biselli, M. Anghinolfi, C. Salgado, N. Benmouna, J. Langheinrich, S. S. Stepanyan, D. Heddle, J. D. Kellie, A. Deur, N. Baillie, T. Mineeva, S. Malace, Mark W. Paris, J. R. Johnstone, Hall Crannell, M. Osipenko, V. P. Kubarovsky, Y. G. Sharabian, Laird Kramer, L. Cheng, W. K. Brooks, J. Hardie, F. W. Hersman, R. S. Hakobyan, L. Guo, M. Ungaro, B. Moreno, O. Pogorelko, G. S. Mutchler, K. Hicks, Nikolay Shvedunov, D. Protopopescu, B. L. Berman, K. S. Egiyan, L. El Fassi, S. Pozdniakov, M. Garçon, Michael Wood, K. Mikhailov, K. Hafidi, V. S. Serov, M. Battaglieri, N. Kalantarians, R. Bradford, B. A. Mecking, R. Nasseripour, K. Joo, A. Yegneswaran, Michael Vineyard, V. Gyurjyan, J. Zhang, H. Bagdasaryan, L. Todor, R. G. Fersch, C. Paterson, Ji Li, P. L. Cole, M. D. Mestayer, E. L. Isupov, Michael L. Williams, M. M. Ito, S. Boiarinov, F. Sabatié, L. C. Smith, E. Munevar, B. S. Ishkhanov, M. R. Niroula, M. Lowry, Latifa Elouadrhiri, R. C. Minehart, Kei Moriya, C. A. Meyer, G. V. Fedotov, K. P. Adhikari, D. P. Weygand, O. Glamazdin, Alexei V. Klimenko, Y. Prok, Barry Ritchie, and I. Nakagawa
Subjects: Physics, Particle physics, Proton, Meson, 010308 nuclear & particles physics, Partial wave analysis, Hadron, General Physics and Astronomy, Resonance, 01 natural sciences, 7. Clean energy, Nuclear physics, Particle decay, Pion, 0103 physical sciences, 010306 general physics, Nucleon
Abstract: We report on the results of the first measurement of exclusive f{sub 0}(980) meson photoproduction on protons for E{sub {gamma}}=3.0-3.8 GeV and -t=0.4-1.0 GeV{sup 2}. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the {pi}{sup +}{pi}{sup -} channel by performing a partial wave analysis of the reaction {gamma}p{yields}p{pi}{sup +}{pi}{sup -}. Clear evidence of the f{sub 0}(980) meson was found in the interference between P and S waves at M{sub {pi}{sup +}}{sub {pi}{sup -}}{approx}1 GeV. The S-wave differential cross section integrated in the mass range of the f{sub 0}(980) was found to be a factor of about 50 smaller than the cross section for the {rho} meson. This is the first time the f{sub 0}(980) meson has been measured in a photoproduction experiment.
Published: 2009
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45. Elastic magnetic electron scattering fromC13atQ2=1GeV2/c2

Author: R. A. Miskimen, M. Frodyma, W. Turchinetz, K. S. Lee, J. Martino, K. A. Dow, S. H. Rokni, R. S. Hicks, S. E. Rock, R.L. Huffman, G. A. Peterson, P. E. Bosted, A. Hotta, B. Frois, S.K. Platchkov, J. D. Zumbro, and H. Baghaei
Subjects: Physics, Elastic scattering, Nuclear reaction, Nuclear and High Energy Physics, Scattering, Momentum transfer, Form factor (quantum field theory), Atomic physics, Ground state, Electron scattering, Omega
Abstract: Electron scattering from {sup 13}C was measured at a momentum transfer of 5.08 fm{sup {minus}1}. No electron events were observed in the vicinity of the elastic peak, giving an upper limit for the elastic cross section of 1.2{times}10{sup {minus}39} cm{sup 2}/sr with a confidence level of 90%. At this momentum transfer, the square of the elastic {ital M}1 form factor apparently continues to fall exponentially with {ital q}. Comparison of the data with shell-model calculations indicates that admixtures of 2{h bar}{omega} configurations in the {sup 13}C ground state cannot entirely explain the high-{ital q} enhancement of the {ital M}1 form factor relative to 1{ital p}-shell calculations.
Published: 1991
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46. Use of the (e,e’n) reaction to study the giant multipole resonances inSn116

Author: S. Dolfini, Bolme Go, E. A. Ammons, P. L. Cole, A. J. Linzey, L. S. Cardman, Costas N. Papanicolas, Joseph B. Mandeville, A. Serdarevi, R. A. Miskimen, S. E. Williamson, J. R. Deininger, P. E. Mueller, B. L. Miller, and J. D. T. Arruda-Neto
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Computer Science::Information Retrieval, Giant resonance, Hadron, Resonance, Inelastic scattering, Atomic physics, Nucleon, Multipole expansion, Random phase approximation
Abstract: The giant multipole resonances in {sup 116}Sn have been studied using the ({ital e},{ital e}{prime}{ital n}) reaction. Data were taken at effective momentum transfers of 0.37, 0.45, and 0.55 fm{sup {minus}1} and a multipole analysis of the data was performed. The inferred multipole strength functions identify the {ital E}2 and {ital E}0 resonances as distinct peaks at 12.2 and 17.9 MeV, respectively. The energy-weighted sum-rule strengths for the {ital E}2 and {ital E}0 resonances, obtained using a Lorentzian fit to the data, are 34{plus minus}13% and 93{plus minus}37%. When compared with results from alpha scattering and pion scattering the sum-rule strengths exhibit approximate agreement, but the {ital E}0 strength identified in this measurement lies at higher excitation energy, consistent with the trend observed in heavier nuclei. The ({ital e},{ital e}{prime}{ital n}) data are compared with a continuum random phase approximation (RPA) calculation of the {ital E}2 and {ital E}0 strengths, and with an open-shell RPA calculation of the {ital E}2 strength. Both calculations disagree with the data in the region of the {ital E}2 resonance.
Published: 1991
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47. Nuclear Targets for a Precision Measurement of the Neutral Pion Radiative Width

Author: A. Kolarkar, V. Gyurjyan, D. Lawrence, S. Overby, P. L. Cole, M. Wood, R.S. Pedroni, I. Nakagawa, D. S. Dale, V. Matveev, O. Glamazdin, A. Sitnikov, Brian D. Milbrath, V. Goryachev, E. Clinton, K. Baker, A. Deur, A. Evdokimov, Sekazi K. Mtingwa, K. Hardy, G. Dzyubenko, I. Larin, Y. Prok, Barry Ritchie, Aron M. Bernstein, M. A. Kubantsev, P. P. Martel, P. Collins, L. Gan, W. A. Stephens, A. Teymurazyan, M. Khandaker, S. Danagoulian, G. Davidenko, J. Feng, D. McNulty, M. Gabrielyan, Ashot Gasparian, A. Dolgolenko, P. Ambrozewicz, J. Underwood, R. C. Minehart, S. Kowalski, M. Konchatnyi, Wolfgang Korsch, L. Benton, R. S. McWilliams, V. Vishnyakov, M. Payen, D. I. Sober, M. M. Ito, R. Demirchyan, C. Salgado, A. Asratyan, V. V. Mochalov, A. Ahmidouch, Andrey Vasiliev, O. Korchin, R. A. Miskimen, V. Verebryusov, E. Pasyuk, P. Kingsberry, and V. P. Kubarovsky
Subjects: Physics, Nuclear and High Energy Physics, Meson, Attenuation, FOS: Physical sciences, Particle accelerator, Radiation length, Linear particle accelerator, law.invention, Nuclear physics, Pion, law, Radiative transfer, Area density, Nuclear Experiment (nucl-ex), Instrumentation, Nuclear Experiment
Abstract: A technique is presented for precision measurements of the area densities, ρT , of approximately 5% radiation length carbon and 208 Pb targets used in an experiment at Jefferson Laboratory to measure the neutral pion radiative width. The precision obtained in the area density for the carbon target is ±0.050%, and that obtained for the lead target through an X-ray attenuation technique is ±0.43%.
Published: 2008

48. Electroexcitation of the Roper resonance for1.7<Q2<4.5GeV2ine→p→enπ+

Author: B. Zhao, F. W. Hersman, Marco Ripani, S. Dhamija, R. W. Gothe, K. Y. Kim, J. Kuhn, J. P. Santoro, E. De Sanctis, Latifa Elouadrhiri, B. M. Preedom, P. Eugenio, R. C. Minehart, Kei Moriya, D. I. Sober, M. Taiuti, G. Rosner, C. A. Meyer, M. Battaglieri, G. V. Fedotov, P. Collins, J. J. Melone, Lorenzo Zana, R. Bradford, K. Lukashin, J. Shaw, V. Batourine, D. P. Weygand, H. Hakobyan, Friedrich Klein, H. S. Jo, Michael Wood, K. Hafidi, Brian Raue, Gerald Feldman, Elton Smith, R. Fatemi, V. S. Serov, A. V. Vlassov, T. Lee, M. Anghinolfi, P. Coltharp, James Mueller, I. I. Strakovsky, N. A. Baltzell, R. De Vita, P. D. Rubin, A. Cazes, Maryam Moteabbed, C. Salgado, Bernhard Mecking, Y. G. Sharabian, A. Deur, K. A. Griffioen, K. S. Egiyan, K. V. Dharmawardane, Baile Zhang, Alexei V. Klimenko, S. Anefalos Pereira, Z. Krahn, W. K. Brooks, Shifeng Chen, J. D. Kellie, Y. Prok, N. Hassall, M. Bellis, J. Langheinrich, Barry Ritchie, N. Baillie, P. Mattione, M. S. Saini, L. C. Dennis, B. E. Bonner, S. S. Stepanyan, S. A. Philips, R. A. Miskimen, B. McKinnon, H. Avakian, J. T. Goetz, E. Polli, B. L. Berman, D. Sharov, M. Mirazita, D. Branford, K. Livingston, D. S. Dale, Ji Li, L. M. Qin, J. M. Laget, H. Denizli, N. Gevorgyan, C. Paterson, G. Gavalian, W. J. Briscoe, E. Pasyuk, S. Tkachenko, M. D. Mestayer, S. A. Dytman, J. Donnelly, G. Asryan, A. V. Skabelin, N. Benmouna, Gerard Gilfoyle, O. P. Dzyubak, R. A. Niyazov, E. L. Isupov, A. Fradi, D. Sokhan, M. Guillo, V. Crede, Michael L. Williams, W. Gohn, N. Markov, V. Sapunenko, Dinko Pocanic, J. R. Calarco, P. Corvisiero, E. Golovatch, S. Boiarinov, S. E. Kuhn, Charles Hyde, V. P. Kubarovsky, O. Pogorelko, C. Tur, M. J. Amaryan, M. MacCormick, I. Hleiqawi, R. Nasseripour, S. L. Careccia, S. McAleer, F. X. Girod, Laird Kramer, B. E. Stokes, G. S. Adams, J. P. Cummings, Cynthia Marie Hadjidakis, G. E. Dodge, H. Y. Lu, K. L. Giovanetti, L. Blaszczyk, P. V. Degtyarenko, M. Kossov, V. Gyurjyan, K. Joo, I. Popa, Sergey Kuleshov, M. Bektasoglu, Michael Dugger, D. Heddle, M. Nozar, P. Stoler, I. Niculescu, D. Lawrence, J. Zhang, R. De Masi, D. Schott, S. A. Morrow, C. Djalali, R. A. Schumacher, M. Guidal, Larry Weinstein, K. Hicks, M. Holtrop, L. Graham, H. Bagdasaryan, C. I O Gordon, P. Ambrozewicz, S. Bültmann, L. Morand, T. A. Forest, S. Stepanyan, J. Pierce, Avraham Klein, K. Mikhailov, L. Cheng, Nikolay Shvedunov, A. I. Ostrovidov, L. Casey, A. C S Lima, K. Park, N. Kalantarians, B. B. Niczyporuk, D. G. Ireland, Michael Vineyard, N. Pivnyuk, Giovanni Ricco, Atilla Gonenc, E. Wolin, Volker D. Burkert, A. S. Biselli, J. P. Ball, D. S. Carman, D. G. Crabb, J. Salamanca, J. W C McNabb, M. Yurov, J. W. Price, S. Mehrabyan, C. Bookwalter, G. Riccardi, H. Funsten, P. Nadel-Turonski, C. Butuceanu, Tsutomu Mibe, N. Dashyan, K. Hafnaoui, C. Hanretty, G. V. O'Rielly, J. R. Johnstone, Z. W. Zhao, D. Keller, Paolo Rossi, D. G. Jenkins, J. Lachniet, A. Tkabladze, S. Park, Sylvain Bouchigny, D. Rowntree, M. M. Ito, R. S. Hakobyan, L. El Fassi, M. Khandaker, H. G. Juengst, A.V. Stavinsky, D. J. Tedeschi, V. Mokeev, I. Bedlinskiy, L. C. Smith, E. Munevar, B. S. Ishkhanov, M. R. Niroula, V. Kuznetsov, S. Strauch, R. Suleiman, L. Guo, G. S. Mutchler, M. Ungaro, S. Niccolai, J. Hardie, D. Doughty, W. Kim, D. P. Watts, G. Niculescu, J. Yun, D. Cords, H. Egiyan, T. Takeuchi, A. Yegneswaran, M. Osipenko, F. Sabatié, Kalvir S. Dhuga, M. Y. Gabrielyan, R. Dickson, R. J. Feuerbach, N. Guler, Inna Aznauryan, P. L. Cole, S. Barrow, L. Todor, D. Protopopescu, S. Pozdniakov, M. Garçon, Y. Ilieva, and B. Moreno
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Roper resonance, Meson production, 010308 nuclear & particles physics, State (functional analysis), 01 natural sciences, Helicity, Baryon, 0103 physical sciences, Pi, Isobar, 010306 general physics, Ground state
Abstract: The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for $1.7l{Q}^{2}l4.5\phantom{\rule{0.3em}{0ex}}{\mathrm{GeV}}^{2}$ from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for ${\ensuremath{\pi}}^{+}$ electroproduction on protons at $W=1.15\ensuremath{-}1.69$ GeV. The analysis is made using two approaches, dispersion relations and a unitary isobar model, which give consistent ${Q}^{2}$ behavior of the helicity amplitudes for the ${\ensuremath{\gamma}}^{*}p\ensuremath{\rightarrow}$N(1440)P${}_{11}$ transition. It is found that the transverse helicity amplitude ${A}_{1/2}$, which is large and negative at ${Q}^{2}=0$, becomes large and positive at ${Q}^{2}\ensuremath{\simeq}2\phantom{\rule{0.3em}{0ex}}{\mathrm{GeV}}^{2}$, and then drops slowly with ${Q}^{2}$. The longitudinal helicity amplitude ${S}_{1/2}$, which was previously found from CLAS $\stackrel{\ensuremath{\rightarrow}}{e}p\ensuremath{\rightarrow}\mathit{ep}{\ensuremath{\pi}}^{0},\mathit{en}{\ensuremath{\pi}}^{+}$ data to be large and positive at ${Q}^{2}=0.4,0.65\phantom{\rule{0.3em}{0ex}}{\mathrm{GeV}}^{2}$, drops with ${Q}^{2}$. Available model predictions for ${\ensuremath{\gamma}}^{*}p\ensuremath{\rightarrow}$N(1440)P${}_{11}$ allow us to conclude that these results provide strong evidence in favor of N(1440)P${}_{11}$ as a first radial excitation of the $3q$ ground state. The results of the present paper also confirm the conclusion of our previous analysis for ${Q}^{2}l1$ GeV${}^{2}$ that the presentation of N(1440)P${}_{11}$ as a q$^{3}\mathrm{G}$ hybrid state is ruled out.
Published: 2008
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49. Electroproduction ofϕ(1020)mesons at1.4⩽Q2⩽3.8GeV2measured with the CLAS spectrometer

Author: M. Guidal, R. Nasseripour, M. Holtrop, I. I. Strakovsky, R. J. Feuerbach, G. V. O'Rielly, Cynthia Marie Hadjidakis, B. Zhao, Z. W. Zhao, D. G. Jenkins, Alexei V. Klimenko, R. De Masi, A. Deur, Michael Dugger, H. O. Funsten, Michael Wood, K. Hafidi, N. Dashyan, B. E. Stokes, G. S. Adams, Barry Ritchie, P. L. Cole, B. M. Preedom, V. S. Serov, C. E. Hyde-Wright, S. McAleer, J. Langheinrich, S. S. Stepanyan, S. A. Philips, L. Blaszczyk, G. Ricco, J. Ball, F. W. Hersman, Sergey Kuleshov, Lorenzo Zana, J. P. Santoro, M. Bektasoglu, M. Nozar, M. Garçon, Elton Smith, M. Battaglieri, J. Salamanca, J. Lachniet, A. Tkabladze, Latifa Elouadrhiri, P. Coltharp, H. Hakobyan, F. Sabatié, H. S. Jo, K. Livingston, D. S. Dale, J. W C McNabb, J. R. Ficenec, N. A. Baltzell, V. Kuznetsov, R. Bradford, R. C. Minehart, Kei Moriya, C. A. Meyer, J. W. Price, M. M. Ito, S. Strauch, V. Mokeev, C. Salgado, L. Cheng, B. L. Berman, L. M. Qin, D. P. Watts, H. Egiyan, K. A. Griffioen, J. P. Cummings, V. Gyurjyan, G. V. Fedotov, S. A. Morrow, M. Anghinolfi, E. De Sanctis, V. P. Kubarovsky, D. Keller, Nikolay Shvedunov, Friedrich Klein, R. Dickson, James Mueller, C. Paterson, D. I. Sober, O. Pogorelko, C. Djalali, E. Munevar, D. P. Weygand, L. C. Smith, M. Kossov, L. C. Dennis, J. Zhang, B. E. Bonner, H. Avakian, Ji Li, M. Guillo, Brian Raue, S. Niccolai, I. Popa, S. Dhamija, N. Hassall, M. Bellis, H. Bagdasaryan, F. X. Girod, B. S. Ishkhanov, S. Park, R. Fatemi, N. Kalantarians, W. Gohn, A. V. Vlassov, J. R. Johnstone, D. Sharov, M. D. Mestayer, Y. G. Sharabian, Sylvain Bouchigny, J. Hardie, H. G. Juengst, J. Kuhn, L. El Fassi, C. Marchand, G. Audit, E. Wolin, H. Denizli, E. L. Isupov, R. De Vita, J. D. Kellie, L. Morand, Michael L. Williams, P. Rossi, N. Guler, William Brooks, Christian Weiss, A.V. Stavinsky, M. R. Niroula, R. W. Gothe, S. Boiarinov, W. Kim, M. Mirazita, W. J. Briscoe, L. Casey, G. Gavalian, C. Hanretty, S. Tkachenko, S. Anefalos Pereira, G. Niculescu, P. Nadel-Turonski, N. Benmouna, J. P. Ball, Tsutomu Mibe, Y. Prok, D. S. Carman, A. V. Skabelin, A. Cazes, Maryam Moteabbed, Hall Crannell, Bernhard Mecking, D. J. Tedeschi, M. Ripani, E. Pasyuk, V. Crede, Shifeng Chen, G. Rosner, K. V. Dharmawardane, J. R. Calarco, S. A. Dytman, I. Bedlinskiy, B. B. Niczyporuk, L. Guo, M. Ungaro, N. Pivnyuk, D. G. Crabb, R. A. Schumacher, M. Khandaker, S. Barrow, P. Mattione, M. S. Saini, P. Eugenio, M. Taiuti, K. Joo, G. S. Mutchler, Michael Vineyard, D. Cords, L. Graham, C. I O Gordon, A. Yegneswaran, M. Yurov, J. T. Goetz, S. Mehrabyan, S. Bültmann, V. Sapunenko, P. Collins, Dinko Pocanic, J. J. Melone, M. Osipenko, S. Procureur, T. A. Forest, C. Bookwalter, G. Riccardi, S. Stepanyan, S. E. Kuhn, Kalvir S. Dhuga, C. Butuceanu, J. Pierce, Avraham Klein, C. Tur, G. E. Dodge, L. Todor, H. Y. Lu, P. V. Degtyarenko, M. J. Amaryan, D. Protopopescu, M. MacCormick, I. Hleiqawi, S. Pozdniakov, I. Niculescu, D. Lawrence, S. L. Careccia, D. Schott, K. L. Giovanetti, Larry Weinstein, D. Doughty, D. Heddle, Y. Ilieva, B. Moreno, R. A. Miskimen, B. McKinnon, D. Branford, J. M. Laget, N. Gevorgyan, A. I. Ostrovidov, K. Park, D. G. Ireland, Volker D. Burkert, A. S. Biselli, Z. Krahn, N. Baillie, Laird Kramer, Gerard Gilfoyle, D. Sokhan, A. Fradi, N. Markov, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. Corvisiero, K. S. Egiyan, K. Mikhailov, P. Stoler, and K. Hicks
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Vector meson dominance, 01 natural sciences, Helicity, Gluon, 0103 physical sciences, Exponent, Vector meson, 010306 general physics, Nucleon, Exchange model
Abstract: Electroproduction of exclusive \ensuremath{\phi} vector mesons has been studied with the CLAS detector in the kinematic range $1.4\ensuremath{\leqslant}{Q}^{2}\ensuremath{\leqslant}3.8$ GeV${}^{2},0.0\ensuremath{\leqslant}{t}^{'}\ensuremath{\leqslant}3.6$ GeV${}^{2}$, and $2.0\ensuremath{\leqslant}W\ensuremath{\leqslant}3.0$ GeV. The scaling exponent for the total cross section as $1/({Q}^{2}+{M}_{\ensuremath{\phi}}^{2}){}^{n}$ was determined to be $n=2.49\ifmmode\pm\else\textpm\fi{}0.33$. The slope of the four-momentum transfer ${t}^{'}$ distribution is ${b}_{\ensuremath{\phi}}=0.98\ifmmode\pm\else\textpm\fi{}0.17$ GeV${}^{\ensuremath{-}2}$. Under the assumption of $s$-channel helicity conservation, we determine the ratio of longitudinal to transverse cross sections to be $R=0.86\ifmmode\pm\else\textpm\fi{}0.24$. A two-gluon exchange model is able to reproduce the main features of the data.
Published: 2008
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50. Ratios ofN15/C12andHe4/C12inclusive electroproduction cross sections in the nucleon resonance region

Author: K. S. Egiyan, L. Guo, K. Mikhailov, Calarco, P. Stoler, K. Hicks, Susan Taylor, M. Ungaro, C. D. Keith, J. Donnelly, G. Asryan, O. P. Dzyubak, R. A. Niyazov, H. Egiyan, P. Corvisiero, C. E. Hyde-Wright, Y. Ilieva, R. A. Miskimen, G. Ricco, M. Amarian, E. Wolin, B. Zhao, B. McKinnon, R. Fatemi, S. Strauch, Laird Kramer, K. Park, B. B. Niczyporuk, P. Dragovitsch, Nikolay Shvedunov, J. P. Ball, Y. Prok, D. S. Carman, K. Joo, L. M. Qin, R. Suleiman, D. Branford, N. Pivnyuk, Shifeng Chen, A. V. Vlassov, Sergey Kuleshov, J. Yun, D. Cords, M. Mirazita, D. G. Crabb, J. M. Laget, M. Bektasoglu, G. S. Mutchler, S. Niccolai, A. Yegneswaran, M. Battaglieri, Niroula, A. Fradi, M. Nozar, N. A. Baltzell, J. Hardie, P. Eugenio, H. G. Juengst, S. A. Morrow, R. De Vita, O. Pogorelko, C. Djalali, Kubarovsky, C. Paterson, Friedrich Klein, K. A. Griffioen, R. J. Feuerbach, N. Markov, K. Livingston, M. Klusman, M. Taiuti, A.V. Stavinsky, N. Kalantarians, Brian Raue, F. W. Hersman, R. Bradford, K. Lukashin, Marco A. Huertas, D. J. Tedeschi, J. Langheinrich, A. I. Ostrovidov, A. C S Lima, J. T. Goetz, J. Shaw, E. Polli, S. S. Stepanyan, Crede, S. A. Philips, P. Collins, D. G. Ireland, Michael Wood, K. Hafidi, I. Bedlinskiy, Batourine, Elton Smith, Gerard Gilfoyle, Mestayer, Volker D. Burkert, V. S. Serov, L. C. Dennis, A. S. Biselli, N. Guler, B. E. Bonner, H. Avakian, B. Carnahan, G. Gavalian, S. Tkachenko, M. Anghinolfi, N. Benmouna, M. Ripani, Kwangsoo Kim, J. Kuhn, J. Zhang, S Anefalos, R. W. Gothe, G. Riccardi, A. Cazes, James Mueller, J. W C McNabb, Maryam Moteabbed, Bernhard Mecking, J. D. Kellie, S. Barrow, C. Butuceanu, K. V. Dharmawardane, E. Pasyuk, H. Bagdasaryan, Mokeev, Cynthia Marie Hadjidakis, E. De Sanctis, P. D. Rubin, K. Y. Kim, Y. G. Sharabian, M. Guidal, S. A. Dytman, R. G. Fersch, Michael Dugger, H. O. Funsten, L. Todor, N. Baillie, D. I. Sober, D. Protopopescu, M. Holtrop, S. Pozdniakov, M. Garçon, Hong Lu, Sbr Ultmann, Dinko Pocanic, Sylvain Bouchigny, P. L. Cole, P. Rossi, S. E. Kuhn, M. Bellis, J. Lachniet, H. Denizli, A. Tkabladze, D. Rowntree, Sapunenko, R. S. Hakobyan, A. V. Skabelin, P. Nadel-Turonski, Tsutomu Mibe, R. C. Minehart, C. A. Meyer, G. V. Fedotov, B. E. Stokes, G. S. Adams, D. P. Weygand, U. Thoma, M. Khandaker, L. C. Smith, B. S. Ishkhanov, D. Doughty, D. Heddle, Gyurjyan, W. Kim, S. Stepanyan, G. Niculescu, M. MacCormick, I. Hleiqawi, G. Rosner, R. Nasseripour, P. Bosted, S. L. Careccia, K. L. Giovanetti, Larry Weinstein, P. Coltharp, M. M. Ito, M. Osipenko, F. Sabatié, M. Guillo, K. Beard, L. Elouadrhiri, A. Deur, W. K. Brooks, R. A. Schumacher, G. V. O'Rielly, E. Golovatch, L. Morand, T. A. Forest, J. Pierce, Avraham Klein, Z. W. Zhao, J. P. Cummings, Hall Crannell, M. Kossov, D. G. Jenkins, G. E. Dodge, P. V. Degtyarenko, S. McAleer, F. X. Girod, I. Niculescu, D. Lawrence, J. W. Price, R. De Masi, Ji Li, E. L. Isupov, Michael L. Williams, S. Boiarinov, Michael Vineyard, B. M. Preedom, Lorenzo Zana, J. P. Santoro, H. S. Jo, and C. Salgado
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, Hadron, Carbon-12, Deep inelastic scattering, 01 natural sciences, Nuclear physics, Baryon, Helium-4, 0103 physical sciences, Phenomenological model, Atomic physics, 010306 general physics, Nucleon
Abstract: The (W,Q{sup 2}) dependence of the ratio of inclusive electron scattering cross sections for {sup 15}N/{sup 12}C was determined in the kinematic ranges 0.8
Published: 2008
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