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1. 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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2. 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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3. 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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4. Exclusive π+ electroproduction off the proton from low to high -t

Author: R. J. Holt, S. Basnet, L. G. Tang, X. Zheng, MathML\\'> F, V. Tadevosyan, H. Breuer, A. J. Sarty, Tanja Horn, Glen A. Warren, S. Jin, W. B. Li, A. Matsumura, V. A. Punjabi, D. G. Meekins, J. Volmer, G. M. Huber, P. M. King, Rolf Ent, Jin Liu, M. E. Christy, C. E. Keppel, C. C. Chang, C. F. Perdrisat, K. A. Aniol, E. J. Beise, I. Niculescu, Y. Okayasu, W. Kim, D. Gaskell, Geoffrey Smith, H. P. Blok, msub, D. J. Margaziotis, G. J. Lolos, Pete Markowitz, S. A. Wood, C. Xu, W.U. Boeglin, J. Reinhold, E. F. Gibson, D. J. Mack, H. Mkrtchyan, W. F. Vulcan, E. J. Brash, M. K. Jones, V. Kovaltchouk, Lubomir Pentchev, J. Arrington, V. Tvaskis, mrow> π, P. E. Reimer, J. Roche, Toshinobu Miyoshi, D. H. Potterveld, and Student Lab and Education
Subjects: SDG 16 - Peace, generalized parton distribution, Proton, accelerator, Hadron, Degrees of freedom (physics and chemistry), interference, Regge, Parton, nonperturbative, 01 natural sciences, 7. Clean energy, energy [beam], High Energy Physics - Experiment, Nuclear physics, Cross section (physics), 0103 physical sciences, ddc:530, structure, 010306 general physics, Nuclear Experiment, production [meson], Quantum chromodynamics, Physics, Range (particle radiation), 010308 nuclear & particles physics, background, momentum transfer, SDG 16 - Peace, Justice and Strong Institutions, electroproduction, Justice and Strong Institutions, Amplitude, kinematics, High Energy Physics::Experiment, distribution function [parton], Jefferson Lab, photoproduction
Abstract: Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To study the transition between non-perturbative and perturbative Quantum Chromodyanmics as the square of four momentum transfer to the struck proton, -t, is increased. Method: Cross sections for the $^1$H(e,e'$\pi^+$)n reaction were measured over the -t range of 0.272 to 2.127 GeV$^2$ with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q$^2$ of 2.4 GeV$^2$ and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C. Results: The -t dependence of the measured $\pi^+$ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude based theoretical model, but show poor agreement with a Generalized Parton Distribution (GPD) based model. Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t-slopes between the low and high -t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime., Comment: 9 pages, 5 figures Physical Review C, in press
Published: 2019
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5. 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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6. Measurements of the separated longitudinal structure function FL from hydrogen and deuterium targets at low Q2

Author: Bogdan Wojtsekhowski, E. McGrath, T. Angelescu, D. H. Potterveld, B. L. Berman, B. Zihlmann, P. E. Reimer, E. R. Kinney, G. Chang, T. Horn, V. V. Frolov, C. Yan, J. Arrington, Y. Liang, G. M. Huber, A. Lung, G. S. Adams, Rolf Ent, James J. Kelly, J. Telfeyan, D. G. Meekins, T. Dodario, Curtis Smith, E. Segbefia, T. Ostapenko, H. E. Jackson, H. Mkrtchyan, Glen A. Warren, K. Hafidi, Donal Day, A. Uzzle, W. F. Vulcan, W. U. Boeglin, V. Tvaskis, E. J. Brash, N. S. Chant, M. E. Christy, G. Mbianda, I. Niculescu, P. Stoler, Joerg Reinhold, M. Ungaro, X. Jiang, O. K. Baker, Z. Papandreou, G. R. Smith, H. C. Fenker, M. M. Dalton, H. P. Blok, H. Breuer, A. Tvaskis, V. P. Kubarovsky, Cynthia Keppel, A. S. Biselli, J. Kuhn, Paul Gueye, S. A. Wood, A. Ahmidouch, J. A. Dunne, D. Abbott, Simon Henry Connell, S. Vidakovic, V. Tadevosyan, D. J. Mack, K. Garrow, R. J. Holt, Avraham Klein, Jim Napolitano, Stephen Avery, N. Benmouna, S. Danagoulian, S. E. Rock, N. El Khayari, E. Schulte, G. Niculescu, S. Malace, P. Bosted, F. R. Wesselmann, G. J. Lolos, J. Roche, M. Nozar, L. Todor, A. N. Villano, D. Mckee, T. Navasardyan, M. K. Jones, Dipanwita Dutta, R. Asaturyan, Pete Markowitz, D. Gaskell, W. Hinton, Ronald Gilman, Andrei Afanasev, K. Joo, and L. G. Tang
Subjects: Physics, Proton, 010308 nuclear & particles physics, Scattering, Momentum transfer, Parton, Deep inelastic scattering, 01 natural sciences, Molecular physics, Nuclear physics, Deuterium, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the partonic dynamics within the nucleon. However, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available in particular for the longitudinal structure function. Here, we present separated structure functions for hydrogen and deuterium at low four-momentum transfer squared, Q2
Published: 2018
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7. Separated Kaon Electroproduction Cross Section and the Kaon Form Factor from 6 GeV JLab Data

Author: L. G. Tang, S. Jin, W. Kim, H. Breuer, Tanja Horn, H. P. Blok, C. E. Keppel, E. F. Gibson, Glen A. Warren, A. Vargas, A. Matsumura, D. J. Margaziotis, W. F. Vulcan, H. C. Fenker, C. Xu, P. E. Reimer, Jin Liu, R. J. Holt, M. E. Christy, S. A. Wood, C. C. Chang, S. Vidakovic, V. Tadevosyan, W.U. Boeglin, I. Niculescu, V. Tvaskis, D. J. Mack, V. Kovaltchouk, Jlab Fpi, Lubomir Pentchev, G. J. Lolos, J. Reinhold, A. J. Sarty, Rolf Ent, G. Niculescu, J. Volmer, J. Roche, Toshinobu Miyoshi, G. M. Huber, V. A. Punjabi, D. G. Meekins, E. J. Brash, E. J. Beise, M. Carmignotto, D. H. Potterveld, J. Arrington, K. A. Aniol, Richard Trotta, Y. Okayasu, Ian L. Pegg, P. M. King, Pete Markowitz, M. K. Jones, Brynle Barrett, C. F. Perdrisat, A. Dittmann, Geoffrey Smith, H. Mkrtchyan, D. Gaskell, X. Zheng, Shaikh Faruque Ali, and Student Lab and Education
Subjects: perturbation theory [quantum chromodynamics], Particle physics, Meson, interference, Regge, FOS: Physical sciences, Parton, nucl-ex, Atomic, 01 natural sciences, Cross section (physics), momentum transfer [form factor], Particle and Plasma Physics, Pion, Factorization, 0103 physical sciences, ddc:530, Nuclear, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, form factor [K], Quantum chromodynamics, Physics, distribution amplitude [parton], +electron+K%2B+Lambda%22">electron p --> electron K+ Lambda, model, factorization [quantum chromodynamics], 010308 nuclear & particles physics, Form factor (quantum field theory), Molecular, Perturbative QCD, Nuclear & Particles Physics, transverse [cross section], electroproduction [K], High Energy Physics::Experiment, longitudinal [cross section], distribution function [parton], experimental results, Jefferson Lab
Abstract: The H1(e,e′K+)Λ reaction was studied as a function of the Mandelstam variable -t using data from the E01-004 (FPI-2) and E93-018 experiments that were carried out in Hall C at the 6 GeV Jefferson Laboratory. The cross section was fully separated into longitudinal and transverse components, and two interference terms at four-momentum transfers Q2 of 1.00, 1.36, and 2.07GeV2. The kaon form factor was extracted from the longitudinal cross section using the Regge model by Vanderhaeghen et al. [Phys. Rev. C 57, 1454 (1998)PRVCAN0556-281310.1103/PhysRevC.57.1454]. The results establish the method, previously used successfully for pion analyses, for extracting the kaon form factor. Data from 12 GeV Jefferson Laboratory experiments are expected to have sufficient precision to distinguish between theoretical predictions, for example, recent perturbative QCD calculations with modern parton distribution amplitudes. The leading-twist behavior for light mesons is predicted to set in for values of Q2 between 5 and 10GeV2, which makes data in the few-GeV regime particularly interesting. The Q2 dependence at fixed x and -t of the longitudinal cross section that we extracted seems consistent with the QCD factorization prediction within the experimental uncertainty.
Published: 2018
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8. Construction and Performance of the Barrel Electromagnetic Calorimeter for the GlueX Experiment

Author: A. Toro, G. J. Lolos, Z. Papandreou, E. G. Anassontzis, Sergey Kuleshov, M.J. Staib, H. Hakobyan, C. A. Meyer, E. S. Smith, E. Chudakov, M. Shepherd, E.L. Plummer, William Brooks, Stephen Taylor, I. Vega, C. L. Henschel, Yujie Qiang, A. Yu. Semenov, A. M. Foda, O. Soto, M. M. Dalton, S.T. Krueger, C.P. Romero, W. McGinley, N. Sandoval, Christine Kourkoumelis, I. A. Semenova, Rimsky Alejandro Rojas, D. Lawrence, J. R. Stevens, T. Whitlatch, F. Barbosa, G. Vasileiadis, G. Voulgaris, C. Stanislav, S. Katsaganis, B. Zihlmann, W. Levine, and T. D. Beattie
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), Physics - Instrumentation and Detectors, GlueX, Spectrometer, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Detector, Monte Carlo method, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, 7. Clean energy, Calorimeter, Nuclear physics, Silicon photomultiplier, 0103 physical sciences, Calibration, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation
Abstract: The barrel calorimeter is part of the new spectrometer installed in Hall D at Jefferson Lab for the GlueX experiment. The calorimeter was installed in 2013, commissioned in 2014 and has been operating routinely since early 2015. The detector configuration, associated Monte Carlo simulations, calibration and operational performance are described herein. The calorimeter records the time and energy deposited by charged and neutral particles created by a multi-GeV photon beam. It is constructed as a lead and scintillating-fiber calorimeter and read out with 3840 large-area silicon photomultiplier arrays. Particles impinge on the detector over a wide range of angles, from normal incidence at 90 degrees down to 11.5 degrees, which defines a geometry that is fairly unique among calorimeters. The response of the calorimeter has been measured during a running experiment and performs as expected for electromagnetic showers below 2.5 GeV. We characterize the performance of the BCAL using the energy resolution integrated over typical angular distributions for $\pi^0$ and $\eta$ production of $\sigma_E/E$=5.2\%/$\sqrt{E(\rm{GeV})} \oplus$ 3.6\% and a timing resolution of $\sigma$\,=\,150\,ps at 1\,GeV., Comment: 46 pages, 33 figures
Published: 2018
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9. Measurement of the beam asymmetry Σ for π0 and η photoproduction on the proton at Eγ=9 GeV

Author: E. Chudakov, J. Nys, V. Kakoyan, D. Lawrence, V. Lyubovitskij, F. Nerling, V. E. Tarasov, P. Eugenio, Z. Zhang, R. Dzhygadlo, H. Al Ghoul, F. Barbosa, N. K. Walford, V. Crede, Sean A Dobbs, J. Hardin, Dmitri Romanov, J. Schwiening, A. Barnes, S. Somov, A. Somov, B. Zihlmann, I. Vega, M. Lara, Kamal K. Seth, G. Nigmatkulov, Mark Richard James Williams, M. M. Dalton, Sergey Kuleshov, D. W. Bennett, C. Salgado, A. Yu. Semenov, L. Gan, L. Robison, V. A. Matveev, D. J. Mack, Ting Xiao, William Brooks, T. D. Beattie, N. Gevorgyan, M. R. Shepherd, A. Teymurazyan, Lubomir Pentchev, C. Kourkoumeli, A. M. Foda, S. Furletov, A. Subedi, Z. Papandreou, J.R. Stevens, W. J. Briscoe, R. A. Schumacher, Friedrich Klein, S. Taylor, I. A. Semenova, F. Mokaya, K. Goetzen, N. S. Jarvis, Ashot Gasparian, T. Whitlatch, C. Fanelli, G. Vasileiadis, Hovanes Egiyan, M. Kamel, Joerg Reinhold, A. Toro, D. I. Sober, Michael Dugger, J. Frye, Vincent Mathieu, D. Werthmüller, Justin I. McIntyre, Igor Strakovsky, M. Patsyuk, A. Tsaris, I. Kuznetsov, W. I. Levine, J. Zarling, A. Deur, R. E. Mitchell, R. T. Jones, A. Gerasimov, H. Hakobyan, M. E. McCracken, A. Dolgolenko, M. J. Staib, V. V. Berdnikov, N. Ochoa, L. Guo, B. Pratt, M. M. Ito, O. Chernyshov, R. Mendez, K. Livingston, V. S. Goryachev, K. Moriya, Krisztian Peters, Amiran Tomaradze, Michael R. Pennington, A. Henderson, Cornelius Schwarz, E. Pooser, G. M. Huber, P. Mattione, R. Kliemt, N. Sparks, W. U. Boeglin, B. E. Cannon, A. I. Ostrovidov, D. G. Ireland, A. Austregesilo, R.S. Pedroni, W. McGinley, G. J. Lolos, E. G. Anassontzis, C. A. Meyer, Barry Ritchie, Elton Smith, O. Soto, Ilya Larin, M. McCaughan, T. C. Black, Yujie Qiang, R. Miskimen, I. Tolstukhin, and E. Wolin
Subjects: Physics, Particle physics, GlueX, Proton, 010308 nuclear & particles physics, Linear polarization, media_common.quotation_subject, Momentum transfer, 01 natural sciences, 7. Clean energy, Asymmetry, Nuclear physics, 0103 physical sciences, Quasiparticle, Nuclear Experiment, 010306 general physics, Liquid hydrogen, Beam (structure), media_common
Abstract: We report measurements of the photon beam asymmetry Σ for the reactions γ - p→pπ0 and γ - p→pη from the GlueX experiment using a 9 GeV linearly polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous π0 measurements and are the first η measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasiparticle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models.
Published: 2017
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10. Light yield of Kuraray SCSF-78MJ scintillating fibers for the Gluex barrel calorimeter

Author: T. D. Beattie, L. A. Teigrob, G. J. Lolos, A.P. Fischer, Elton Smith, I. A. Semenova, Z. Papandreou, E.L. Plummer, L.M. Sichello, S.T. Krueger, and A. Yu. Semenov
Subjects: Physics, Nuclear and High Energy Physics, Photomultiplier, GlueX, Yield (engineering), Calorimeter (particle physics), business.industry, Barrel (horology), Photodetector, Photoelectric effect, Optics, Optoelectronics, business, Instrumentation
Abstract: Over three quarters of a million 1-mm-diameter 4-m-long Kuraray double-clad SCSF-78MJ (blue-green) scintillating fibers have been used in the construction of the GlueX electromagnetic barrel calorimeter for the Hall D experimental program at Jefferson Lab. The quality of a random sample of 4750 of these fibers was evaluated by exciting the fibers at their mid point using a 90Sr source in order to determine the light yield using a calibrated vacuum photomultiplier as the photosensor. A novel methodology was developed to extract the number of photoelectrons detected for measurements where individual photoelectron peaks are not discernible. The average number of photoelectrons from this sample of fibers was 9.17±0.6 at a source distance of 200 cm from the PMT.
Published: 2014
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11. Relative gain monitoring of the GlueX calorimeters

Author: E. G. Anassontzis, G. Vasileiadis, J. Frye, Pavlos Ioannou, G. J. Lolos, Elton Smith, S.T. Krueger, M. Shepherd, T. Bogart, D. Lawrence, John P. Leckey, G. Voulgaris, Z. Papandreou, A. Yu. Semenov, Christine Kourkoumelis, T. D. Beattie, and E. Kappos
Subjects: Physics, Nuclear and High Energy Physics, Optical fiber, GlueX, business.industry, Controller (computing), Detector, Electrical engineering, Barrel (horology), Photodetector, Modular design, law.invention, Power (physics), law, business, Instrumentation
Abstract: The relative gain of the photodetectors for the GlueX Barrel and Forward calorimeters will be monitored using modular LED driver systems. The BCAL system consists of a global controller that feeds power, bias voltage and trigger signals to 96 local controllers situated at the ends of the 48 BCAL modules, which drive 40 LEDs associated with the 40 light guides at the end of each module. The FCAL system consists also of a global controller, a local controller for each acrylic quadrant covering the face of the FCAL, and ten 4-LED pulser boards per local controller connected in a star configuration along the edges of the acrylic panes. The respective systems are currently being installed on the detectors and their tested performance is presented herein.
Published: 2014
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12. Attenuation length and spectral response of Kuraray SCSF-78MJ scintillating fibres

Author: L. A. Teigrob, D. Kolybaba, S.T. Krueger, B.P. Giesbrecht, Blake Leverington, H. Qian, Y. Sun, A.E. Baulin, M.D. Sauder, Z. Papandreou, A. Yu. Semenov, M.J. Litzenberger, A.K. Heinrichs, E.L. Plummer, T. Li, K. Vuthitanachot, Y. Yongzhe, L.M. Sichello, S. Katsaganis, Y. Cao, I. A. Semenova, J. Chan, A.M. Watson, and G. J. Lolos
Subjects: Physics, Nuclear and High Energy Physics, GlueX, business.industry, Attenuation length, Spectral response, Standard deviation, Calorimeter, Photodiode, law.invention, Wavelength, Optics, Quality (physics), law, Optoelectronics, business, Instrumentation
Abstract: Over three quarters of a million, 4-m long Kuraray double-clad SCSF-78MJ (blue–green) scintillating fibres have been used in the construction of the GlueX electromagnetic barrel calorimeter, as part of the Hall D experimental program at Jefferson Lab. The response and quality of a random sample of 4750 of these fibres have been evaluated by employing a 373-nm UV LED to stimulate the fibres along their length and reading out the light using a spectrophotometer and a photodiode in order to extract the spectral response and the attenuation length, respectively. Single exponential fits to the spectral response in the 100–280 cm distance from the light source yielded an average bulk attenuation length and standard deviation of (387±26) cm. Double-exponential fits to the spectral response over the entire 4-m length also allowed the extraction of long and short wavelength components at (486±54) cm and (75±22) cm, respectively. Finally, diameter uniformity measurements were carried out. The quality assurance results confirmed that the fibres were of high quality and complied with GlueX specifications.
Published: 2013
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13. Spectral response of scintillating fibers

Author: G. J. Lolos, Blake Leverington, and Z. Papandreou
Subjects: Physics, Nuclear and High Energy Physics, Photomultiplier, business.industry, Attenuation length, Spectral response, Spectral line, Wavelength, Optics, Silicon photomultiplier, Zero-dispersion wavelength, Optoelectronics, Fiber, business, Instrumentation
Abstract: The spectral response of PHT-0044 (blue) and BCF-20 (green) scintillating fibers was measured as a function of wavelength using a UV LED. It was observed that significant spectral strength from the PHT-0044 fibers was missing compared to manufacturer's specifications at the origin of the source, shifting the peak value of the spectrum to significantly higher values in wavelength. In contrast, the corresponding shift for the BCF-20 fibers was minimal. The mechanisms responsible for the observed behavior are discussed herein. Moreover, the attenuation length for each fiber type was extracted and studied as a function of wavelength. Finally, the measured fiber spectra were convolved with the wavelength response from a typical bi-alkali photomultiplier as well as a green-sensitive silicon photomultiplier and compared.
Published: 2008
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14. Comparison of a silicon photomultiplier to a traditional vacuum photomultiplier

Author: K. Wolbaum, V. Kovaltchouk, Z. Papandreou, and G. J. Lolos
Subjects: Physics, Nuclear and High Energy Physics, Photomultiplier, GlueX, Calorimeter (particle physics), Physics::Instrumentation and Detectors, business.industry, Detector, Silicon photomultiplier, Optics, High Energy Physics::Experiment, business, Instrumentation, Electronic circuit
Abstract: Silicon photomultiplier devices (SiPM) were investigated as a possible front-end detector system for the electromagnetic barrel calorimeter of the GlueX Project at Jefferson Laboratory, USA, and compared against a traditional 2 in vacuum photomultiplier tube. The SiPM has gain and timing resolution comparable to that of a PMT, requires a simple electronic circuit and is not sensitive to magnetic fields. These attributes allow us to conclude that it is feasible to use the SiPM as a front-end detector for this calorimeter.
Published: 2005
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15. Relative branching ratio of the η→π0γγ decay channel

Author: R. Manweiler, S. P. Kruglov, N. Knecht, G. M. Huber, T. D. S. Stanislaus, S. McDonald, A. Shafi, D. M. Manley, D. D. Koetke, J. Olmsted, Z. Papandreou, G. J. Lolos, S. Li, V.S. Bekrenev, N. G. Kozlenko, K. Benslama, D. Grosnick, D. Isenhower, and W. J. Briscoe
Subjects: Physics, Rare eta decay, Nuclear and High Energy Physics, Chiral perturbation theory, Meson, 010308 nuclear & particles physics, Branching fraction, Hadron, Branching ratio, 01 natural sciences, Nuclear physics, Particle decay, Pion, 0103 physical sciences, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, 010306 general physics, Crystal Ball, Dimensionless quantity
Abstract: The η → π 0 γγ rare decay was measured at the AGS with the Crystal Ball photon spectrometer and its relative branching ratio was extracted to be B 1 =(8.3±2.8±1.4)×10 −4 , based on the analysis of 3×10 7 detected η mesons. This leads to a lower partial width for this eta channel than past measurements and is in line with chiral perturbation theory calculations.
Published: 2004
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16. Does the Σ(1580)32− resonance exist?

Author: N. G. Kozlenko, S. McDonald, I. I. Strakovsky, A. Starostin, A. F. Ramirez, I. Supek, Z. Papandreou, S. P. Kruglov, W. J. Briscoe, M. Clajus, C. E. Allgower, H. M. Spinka, D. Grosnick, D. Isenhower, A.A. Kulbardis, D. M. Manley, J. Olmsted, G. J. Lolos, J. R. Comfort, I. V. Lopatin, A. Shafi, W. B. Tippens, N. Phaisangittisakul, S. N. Prakhov, K. Craig, B. M. K. Nefkens, A. Marušić, V.S. Bekrenev, D. D. Koetke, H. M. Staudenmaier, J. W. Price, N. Knecht, R. Manweiler, D. Peaslee, M. E. Sadler, and T. D. S. Stanislaus
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), 010308 nuclear & particles physics, Partial wave analysis, Hyperon, State (functional analysis), Quantum number, 01 natural sciences, Resonance (particle physics), Exotic baryon, Quantum mechanics, 0103 physical sciences, Atomic physics, 010306 general physics, Low Mass
Abstract: Precise new data for the reaction K−p→π0Λ are presented in the c.m. energy range 1565 to 1600 MeV. Our analysis of these data sheds new light on claims for the Σ(1580) 3 2 − resonance, which (if it exists with the specified quantum numbers) must be an exotic baryon because of its very low mass. Our results show no evidence for this state.
Published: 2004
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17. The (π+,pd) and (π+,dd) reactions on light nuclei at 100 and 165 MeV incident pion energies

Author: G. A. C. Jones, P. L. Walden, D. F. Ottewell, G. M. Huber, G. J. Lolos, S. I. H. Naqvi, Z. Papandreou, X. Aslanoglou, and J. Hovdebo
Subjects: Physics, Nuclear reactions6Li12Cπ+,&#xa0, Nuclear and High Energy Physics, pd)(π+,&#xa0, 010308 nuclear & particles physics, Nuclear Theory, Kinetic energy, 01 natural sciences, 7. Clean energy, Nuclear physics, Cross section (physics), deduced reaction mechanism features, Pion, Deuterium, measuredparticle spectracoincidencesσ(θ)total σ, Yield (chemistry), 0103 physical sciences, 2d)E=100, 165 MeV, Physics::Accelerator Physics, Neutron, Nuclear Experiment, 010306 general physics, Absorption (electromagnetic radiation), Comparison with model predictions, Beam (structure)
Abstract: The (π+,pd), and (π+,dd) reactions on 6Li and 12C targets were investigated with pions of 100 and 165 MeV kinetic energy. The experimental apparatus employed for this work is characterized by good energy resolution (
Published: 2002
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18. Operational performance of the Hall A mirror aerogel Cherenkov counter

Author: Z. Papandreou, G. J. Lolos, R. L.J. van der Meer, E. J. Brash, J. Hovdebo, and G. M. Huber
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, Spectrometer, Physics::Instrumentation and Detectors, business.industry, Cherenkov detector, Detector, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Particle detector, law.invention, Optics, law, Calibration, Measuring instrument, Nuclear Experiment, business, Instrumentation, Cherenkov radiation
Abstract: We report the results of an operational test of the efficiency and position sensitivity of a silica-aerogel Cherenkov detector installed in the HRS-E spectrometer in Hall A at Jefferson Lab. The calibration was performed with data from elastic electron scattering from polarized 3 He . The response of the photo-multiplier tubes was linearized with a quadratic correction, allowing a unique number of photo-electrons (PEs) to be extracted. The result obtained (∼7.3 PEs) is consistent with the performance of the prototype detector tested earlier under ideal conditions.
Published: 2002
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19. Helicity signatures in subthreshold ρ0 production on nuclei

Author: G. J. Lolos, A. Shinozaki, Kazushige Maeda, M. Iurescu, H. Yamashita, K. Hossain, E. J. Brash, G. Garino, Toshio Suda, K. Maruyama, G. M. Huber, A. Toyofuku, D. Nordin, Z. Papandreou, and A. Sasaki
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Subthreshold conduction, Nuclear Theory, 0103 physical sciences, 010306 general physics, Polarization (waves), 01 natural sciences, Helicity
Abstract: We report a helicity analysis of subthreshold rho production on 2H and 12C nuclei at low photoproduction energies and large |t|. The results are indicative of a large longitudinal rho polarization (l=1, m=0) and are consistent with a strong helicity-flip mechanism of rho production. The analysis is model-independent and supports the large mass shift reported from the earlier 3He experiments.
Published: 2002
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20. Dynamics of the16O(e,e′p)Reaction at High Missing Energies

Author: C. Cavata, A. Soldi, A. J. Sarty, Y. Roblin, Paul Souder, T. Pussieux, K. Wijesooriya, Ronald Ransome, S. Malov, Shalev Gilad, E. Burtin, M. Liang, C. W. de Jager, K. A. Aniol, M. Holtrop, E. A.J.M. Offermann, Wolfgang Korsch, B. Doyle, G. Quéméner, P. Djawotho, T. Terasawa, Vincent Breton, A. Gasparian, A. V. Glamazdin, K. Joo, D. Rowntree, R. Holmes, C. R. Howell, D. M. Manley, J. R. Calarco, R. W. Lourie, O. Ravel, J. W. Watson, Justin I. McIntyre, J. Gao, E. J. Brash, W. U. Boeglin, B. D. Anderson, G. J. Lolos, M. B. Epstein, G. M. Urciuoli, J. A. Templon, W. Kahl, C. E. Hyde-Wright, S. Kerhoas, A. Serdarevic-Offermann, N. d'Hose, F. T. Baker, C. F. Perdrisat, S. Platchkov, Kazushige Maeda, A. Deur, G. M. Huber, T. Saito, J. Martino, L. Auerbach, Bogdan Wojtsekhowski, J. Domingo, J. Berthot, J. Y. Mougey, R. I. Pomatsalyuk, A. Saha, L. Bimbot, H. Ueno, Kevin Fissum, Z. Papandreou, T. P. Smith, Jian-Ping Chen, L. Todor, A. Leone, James J. Kelly, Seigo Kato, P.Y. Bertin, Nilanga Liyanage, G. Rutledge, Hiroaki Tsubota, Z. L. Zhou, Richard Wilson, Branislav Vlahovic, H. Fonvieille, Gordon D. Cates, Mauro Iodice, Larry Weinstein, G. Laveissière, R. Suleiman, E. Cisbani, William Bertozzi, S. Nanda, G. Kumbartzki, Jing Zhao, R. Madey, D. G. Zainea, Ronald Gilman, R. Roche, D. S. Dale, K. McCormick, R. Michaels, L. Cardman, P. E. Ulmer, V. Zeps, S. van Verst, Pete Markowitz, J. M. Finn, S. Jaminion, H. Breuer, J. Gomez, J.E. Ducret, M. Khandaker, R. A. Lindgren, J. J. LeRose, M. Khayat, H. Voskanyan, C. Jutier, D. Neyret, V. Gorbenko, Roberto Perrino, R. De Leo, F. W. Hersman, L. A. Ewell, B. Diederich, Laird Kramer, M. K. Jones, G. G. Petratos, J. S. McCarthy, T. P. Gorringe, Z. E. Meziani, P. M. Rutt, Leonid Levchuk, David L. Prout, F. Garibaldi, V. A. Punjabi, S. Frullani, P. Vernin, R. L.J. van der Meer, D. J. Margaziotis, C. C. Chang, K. S. Kumar, Pavel Sorokin, K. Kino, B. Frois, and Charles Glashausser
Subjects: Physics, Proton, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, Nuclear physics, Cross section (geometry), Pion, 0103 physical sciences, Isobar, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract: We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25
Published: 2001
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21. Measurement of neutron detection efficiencies in NaI using the Crystal Ball detector

Author: I. Lopatin, R. Manweiler, S. McDonald, R. J. Peterson, M. Clajus, A. Koulbardis, D. Grosnick, N. Knecht, T. E. Kasprzyk, T. D. S. Stanislaus, D. Peaslee, G. M. Huber, A. Starostin, N. Phaisangittisakul, A. Shafi, K. Craig, J. R. Comfort, A. Marušić, E. Berger, S. Kruglov, M. E. Sadler, Z. Papandreou, C. E. Allgower, K Benslama, N. Kozlenko, G. J. Lolos, W. J. Briscoe, H. M. Staudenmaier, H. M. Spinka, I. Supek, V. Bekrenev, W. B. Tippens, Ivo Šlaus, T. F. Kycia, David Manley, D. Isenhower, J. Thoms, D. D. Koetke, A. Gibson, J. Olmsted, B. M. K. Nefkens, A. F. Ramirez, and M. Pulver
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Condensed Matter::Superconductivity, Detector, Physics::Optics, Neutron detection, Nuclear Experiment, Instrumentation, Crystal Ball
Abstract: We report on a measurement ofthe neutron detection efficiency in NaI crystals in the Crystal Ball (CB)
Published: 2001
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22. Measurement ofπ0π0Production in the Nuclear Medium byπ−Interactions at0.408GeV/c

Author: N. Phaisangittisakul, K. Craig, T. F. Kycia, H. M. Spinka, I. Supek, M. Pulver, A. Koulbardis, B. Manweiler, S. N. Prakhov, A. Shafi, D. M. Manley, M. E. Sadler, D. Grosnick, A. Starostin, D. Isenhower, G. J. Lolos, S. McDonald, N. Knecht, R. J. Peterson, W. B. Tippens, V. Bekrenev, M. Clajus, A. Marušić, D. Peaslee, Z. Papandreou, W. J. Briscoe, I. V. Lopatin, S. Stanislaus, E. Berger, I. Slaus, N. Kozlenko, D. D. Koetke, C. E. Allgower, J. Olmsted, H. M. Staudenmaier, J. R. Comfort, S. Kruglov, B. M. K. Nefkens, and A. F. Ramirez
Subjects: Physics, Crystallography, Mass distribution, Pi, General Physics and Astronomy, Production (computer science), Invariant mass, Pi interaction
Abstract: We report on an investigation of the ({pi}{sup -}, {pi}{sup 0}{pi}{sup 0}) reaction by means of the {pi}{sup 0}{pi}{sup 0} invariant mass distributions from {pi}{sup -} interactions on H, D, C, Al, and Cu targets at {rho}{sub {pi}{sup -}} = 0.408 GeV/c. The sharp, strong peak in the {pi}{sup +}{pi}{sup -} invariant mass near 2m{sub {pi}} reported by the CHAOS Collaboration is not seen in our {pi}{sup 0}{pi}{sup 0} data. However, we do observe a change in the shape of the {pi}{sup 0}{pi}{sup 0} invariant mass spectrum for the different targets, indicating that the {pi}{sup 0}{pi}{sup 0} interaction diminishes in the nuclear medium as represented by nuclei D, C, Al, and Cu, compared to hydrogen.
Published: 2000
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23. Search for theCPForbidden Decayη→4π0

Author: S. McDonald, T. F. Kycia, G. M. Huber, M. Clajus, S. Prakhov, H. M. Spinka, N. Kozlenko, C. E. Allgower, I. Supek, I. Slaus, A. Starostin, A. Marusic, D. M. Manley, W. B. Tippens, G. J. Peterson, N. Knecht, E. Berger, W. J. Briscoe, J. Olmsted, N. Phaisangittisakul, D. Grosnick, V. Bekrenev, K. Craig, A. Shafi, D. Isenhower, Z. Papandreou, M. E. Sadler, G. J. Lolos, S. Stanislaus, A. Koulbardis, I. V. Lopatin, Chee Wei Wong, R. Manweiler, D. Peaslee, D. D. Koetke, H. M. Staudenmaier, M. Pulver, B. M. K. Nefkens, A. F. Ramirez, J. R. Comfort, and S. Kruglov
Subjects: Physics, Particle physics, General Physics and Astronomy, Neutrino, Minimal Supersymmetric Standard Model
Published: 2000
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24. Dynamical Relativistic Effects in Quasielastic1p-Shell Proton Knockout fromO16

Author: C. E. Hyde-Wright, D. J. Margaziotis, J. Martino, Nilanga Liyanage, C. R. Howell, K. Kino, M. Liang, Richard Wilson, J. R. Calarco, G. Quéméner, T. P. Smith, A. V. Glamazdin, Kazushige Maeda, Branislav Vlahovic, R. Suleiman, E. Cisbani, G. M. Urciuoli, K. Joo, S. Frullani, R. W. Lourie, R. Roche, S. Platchkov, D. Rowntree, Paul Souder, Y. Roblin, T. Terasawa, Vincent Breton, Bogdan Wojtsekhowski, W. Kahl, P. Vernin, T. Pussieux, J. M. Finn, J. Gao, J. Gomez, C. F. Perdrisat, B. Frois, Jian-Ping Chen, K. Wijesooriya, W. Korsh, O. Ravel, Hiroaki Tsubota, Ronald Ransome, Seigo Kato, R. L.J. van der Meer, S. Malov, E. Burtin, J. A. Templon, S. Kerhoas, J. W. Watson, M. Holtrop, B. Doyle, S. van Verst, R. Holmes, Z. Papandreou, R. A. Lindgren, J. J. LeRose, H. Voskanyan, C. Jutier, P. M. Rutt, A. Gasparian, G. Rutledge, F. T. Baker, G. M. Huber, David L. Prout, V. Gorbenko, M. Khayat, Charles Glashausser, B. D. Anderson, G. J. Lolos, M. B. Epstein, Mauro Iodice, L. Auerbach, A. Saha, H. Ueno, L. Todor, A. Leone, J. Berthot, Larry Weinstein, William Bertozzi, D. S. Dale, L. Cardman, S. Jaminion, Pete Markowitz, L. Bimbot, G. G. Petratos, Z. E. Meziani, M. Khandaker, V. Zeps, W. U. Boeglin, Leonid Levchuk, Roberto Perrino, R. De Leo, D. Neyret, V. A. Punjabi, B. Diederich, D. G. Zainea, C. C. Chang, K. S. Kumar, T. Saito, Pavel Sorokin, H. Fonvieille, G. Kumbartzki, J. Y. Mougey, F. Garibaldi, T. P. Gorringe, P. E. Ulmer, Z. L. Zhou, G. Laveissière, J. S. McCarthy, P. Djawotho, P.Y. Bertin, J.E. Ducret, Ronald Gilman, K. McCormick, M. K. Jones, A. Serdarevic-Offermann, A. Deur, H. Breuer, F. W. Hersman, L. A. Ewell, James J. Kelly, R. I. Pomatsalyuk, S. Nanda, Shalev Gilad, D. M. Manley, C. W. de Jager, K. A. Aniol, E. A.J.M. Offermann, J. Domingo, K. A. Griffioen, C. Cavata, A. Soldi, A. J. Sarty, Gordon D. Cates, Laird Kramer, R. Madey, E. J. Brash, Kevin Fissum, Jing Zhao, R. Michaels, Justin I. McIntyre, and N. d'Hose
Subjects: Physics, Nuclear reaction, Proton, 010308 nuclear & particles physics, Hadron, General Physics and Astronomy, Elementary particle, 01 natural sciences, Omega, Baryon, 0103 physical sciences, Atomic physics, 010306 general physics, Nucleon, Relativistic quantum chemistry
Abstract: We have measured the cross section for quasielastic 1p -shell proton knockout in the {sup 16}O( e, e{sup '}p) reaction at {omega}=0.439 GeV and Q{sup 2}=0.8 (GeV/c){sup 2} for missing momentum P{sub miss}{
Published: 2000
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25. GEp/GMpRatio by Polarization Transfer ine→p→ep→

Author: M. K. Jones, K. A. Aniol, F. T. Baker, J. Berthot, P. Y. Bertin, W. Bertozzi, A. Besson, L. Bimbot, W. U. Boeglin, E. J. Brash, D. Brown, J. R. Calarco, L. S. Cardman, C.-C. Chang, J.-P. Chen, E. Chudakov, S. Churchwell, E. Cisbani, D. S. Dale, R. De Leo, A. Deur, B. Diederich, J. J. Domingo, M. B. Epstein, L. A. Ewell, K. G. Fissum, A. Fleck, H. Fonvieille, S. Frullani, J. Gao, F. Garibaldi, A. Gasparian, G. Gerstner, S. Gilad, R. Gilman, A. Glamazdin, C. Glashausser, J. Gomez, V. Gorbenko, A. Green, J.-O. Hansen, C. R. Howell, G. M. Huber, M. Iodice, C. W. de Jager, S. Jaminion, X. Jiang, W. Kahl, J. J. Kelly, M. Khayat, L. H. Kramer, G. Kumbartzki, M. Kuss, E. Lakuriki, G. Lavessière, J. J. LeRose, M. Liang, R. A. Lindgren, N. Liyanage, G. J. Lolos, R. Macri, R. Madey, S. Malov, D. J. Margaziotis, P. Markowitz, K. McCormick, J. I. McIntyre, R. L. J. van der Meer, R. Michaels, B. D. Milbrath, J. Y. Mougey, S. K. Nanda, E. A. J. M. Offermann, Z. Papandreou, C. F. Perdrisat, G. G. Petratos, N. M. Piskunov, R. I. Pomatsalyuk, D. L. Prout, V. Punjabi, G. Quéméner, R. D. Ransome, B. A. Raue, Y. Roblin, R. Roche, G. Rutledge, P. M. Rutt, A. Saha, T. Saito, A. J. Sarty, T. P. Smith, P. Sorokin, S. Strauch, R. Suleiman, K. Takahashi, J. A. Templon, L. Todor, P. E. Ulmer, G. M. Urciuoli, P. Vernin, B. Vlahovic, H. Voskanyan, K. Wijesooriya, B. B. Wojtsekhowski, R. J. Woo, F. Xiong, G. D. Zainea, and Z.-L. Zhou
Subjects: Elastic scattering, Physics, Proton, 010308 nuclear & particles physics, Proton magnetic moment, General Physics and Astronomy, Electron, Polarization (waves), 01 natural sciences, Charged particle, Nuclear physics, Magnetization, 0103 physical sciences, Magnetic form factor, Physics::Accelerator Physics, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract: The ratio of the proton's elastic electromagnetic form factors was obtained by measuring the transverse and longitudinal polarizations of recoiling protons from the elastic scattering of polarized electrons with unpolarized protons. The ratio of the electric to magnetic form factor is proportional to the ratio of the transverse to longitudinal recoil polarizations. The ratio was measured over a range of four-momentum transfer squared between 0.5 and 3.5 GeV-squared. Simultaneous measurement of transverse and longitudinal polarizations in a polarimeter provides good control of the systematic uncertainty. The results for the ratio of the proton's electric to magnetic form factors show a systematic decrease with increasing four momentum squared, indicating for the first time a marked difference in the spatial distribution of charge and magnetization currents in the proton.
Published: 2000
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26. Investigation of the ExclusiveH3e(e,e′pp)nReaction

Author: D. L. Groep, M. F. van Batenburg, Th. S. Bauer, H. P. Blok, D. J. Boersma, E. Cisbani, R. De Leo, S. Frullani, F. Garibaldi, W. Glöckle, J. Golak, P. Heimberg, W. H. A. Hesselink, M. Iodice, D. G. Ireland, E. Jans, H. Kamada, L. Lapikás, G. J. Lolos, R. Perrino, A. Scott, R. Starink, M. F. M. Steenbakkers, G. M. Urciuoli, H. de Vries, L. B. Weinstein, and H. Witała
Subjects: General Physics and Astronomy
Published: 1999
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27. Evidence for a deep scalar field fromρ0mass modification in3He

Author: G. M. Huber, Z. Papandreou, E. J. Brash, G. J. Lolos, and Byron K. Jennings
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Nuclear Theory, Bound state, Vector meson, Nuclear Experiment, Scalar field, Scaling, Excitation
Abstract: Recent photoproduction measurements of the ${\ensuremath{\rho}}^{0}$ vector meson in the nuclear medium have revealed a substantial reduction in its mass from the vacuum value. The decay of the ${\ensuremath{\rho}}^{0}$ within the strong nucleonic field at low relative ${\ensuremath{\rho}}^{0}$-$N$ momenta, and the collective ${N}^{*}{(1520)N}^{\ensuremath{-}1}$ excitation, have both been presented previously as plausible explanations. In this Rapid Communication we show that the reduction can be explained through a bound ${\ensuremath{\rho}}^{0}$-nucleus state. The depth of the potential required to produce the bound state is consistent with that extracted from Dirac phenomenology using Brown-Rho scaling.
Published: 1999
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28. Measurements of the Deuteron Elastic Structure FunctionA(Q2)for0.7≤Q2≤6.0(GeV/c)2at Jefferson Laboratory

Author: Paul Souder, Z. L. Zhou, E. Burtin, R. I. Pomatsalyuk, D. S. Dale, N. d'Hose, Ch. Hyde-Wright, J. O. Hansen, T. Saito, H. Breuer, K. Arundell, Seigo Kato, W. M. Zhang, C. R. Howell, J. R. Calarco, S. Nanda, L. Auerbach, K. Wijesooriya, Kevin Fissum, G. M. Huber, G. Rutledge, R. W. Lourie, J. Domingo, Y. Roblin, H. Fonvieille, L. Bimbot, T. P. Smith, S. Frullani, E. Chudakov, P. E. Ulmer, L. A. Ewell, Nilanga Liyanage, Pierre Bertin, Mauro Iodice, S. Mehrabyan, G. W. Miller, S. Malov, P. Vernin, Bogdan Wojtsekhowski, Larry Weinstein, L. C. Alexa, R. Madey, W. Kahl, R. A. Lindgren, Richard Wilson, H. Voskanyan, Branislav Vlahovic, Charles Glashausser, C. Jutier, J. J. LeRose, M. Holtrop, A. Saha, D. Neyret, A. Gasparian, R. L.J. van der Meer, T. Terasawa, Vincent Breton, R. Suleiman, E. Cisbani, V. Gorbenko, G. M. Urciuoli, M. Liang, G. Quéméner, S. Platchkov, L. Cardman, D. J. Margaziotis, David L. Prout, C. Cavata, K. Soldi, A. Serdarevic, K. Kino, Z. Papandreou, A. Leone, S. Jaminion, F. T. Baker, P. M. Rutt, A. J. Sarty, J. Gomez, D. Rowntree, William Bertozzi, Jing Zhao, Ronald Ransome, James J. Kelly, J. Jardillier, J. M. Finn, T. Pussieux, Pete Markowitz, R. Michaels, J. Gao, D. M. Manley, H. Ueno, Jian-Ping Chen, A. Ketikyan, G. Lavessiere, D. G. Zainea, V. A. Punjabi, E. J. Brash, J. W. Watson, A. T. Katramatou, Roberto Perrino, C. C. Chang, R. De Leo, S. Kerhoas, K. S. Kumar, A. V. Glamazdin, B. Diederich, Shalev Gilad, M. Khayat, L. Van Hoorebeke, O. Ravel, Justin I. McIntyre, Pavel Sorokin, L. Todor, J. A. Templon, R. Holmes, C. W. de Jager, W. U. Boeglin, K. A. Aniol, G. G. Petratos, Z. E. Meziani, B. D. Anderson, G. J. Lolos, M. B. Epstein, J. Berthot, A. Deur, J. Martino, C. F. Perdrisat, E. A.J.M. Offermann, Kazushige Maeda, Haiyan Gao, J. Marroncle, Laird Kramer, J. Y. Mougey, C. J. Martoff, F. Garibaldi, G. Kumbartzki, Ronald Gilman, Hiroaki Tsubota, K. McCormick, B. Frois, N Degrande, M. K. Jones, and M. Kuss
Subjects: Quantum chromodynamics, Quark, Physics, Particle physics, 010308 nuclear & particles physics, Scattering, High Energy Physics::Lattice, Nuclear Theory, Quark model, General Physics and Astronomy, Elementary particle, 7. Clean energy, 01 natural sciences, Gluon, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Quantum field theory, Nuclear Experiment, 010306 general physics, Boson
Abstract: The deuteron elastic structure function A(Q2) has been extracted in the range 0.7≤Q2≤6.0(GeV/c)2 from cross section measurements of elastic electron-deuteron scattering in coincidence using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models, based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics.
Published: 1999
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29. Associated Λ production at Jefferson lab

Author: C. C. Chang, Christophe Furget, R. Perrino, H. Blok, J. Cha, J.-O. Hansen, N. S. Chant, T. Angelescu, Pat Welch, I. Niculescu, M. Finn, S. Kox, W. F. Vulcan, G. Savage, E. V. Hungerford, G. J. Lolos, O. K. Baker, B. Zeidman, D. G. Meekins, Ts A. Amatuni, L. Kramer, J. Volmer, L. G. Tang, Pete Markowitz, W. Kim, F. Garibaldi, T. Saito, H. Breuer, E. J. Beise, R. Sawafta, Laurent Eyraud, S. Majewski, R. Madey, Liliana Teodorescu, J. S. Real, J. Martoff, K. Gustafsson, John C. Mitchell, D. Koltenuk, T. Eden, Paul Gueye, G. Niculescu, M. Harvey, R. De Leo, J. Reinhold, D. F. Geesaman, Dipanwita Dutta, K. Bailey, E. Cisbani, V. Tadevosian, A. Ahmidouch, D. Gaskell, C. S. Armstrong, J. A. Dunne, M. Maeda, T. Leone, C. Jackson, S. Stepanyan, H. Mkrtchyan, V. Frolov, P. G. Roos, S. Beedoe, W. J. Cummings, A. F. Lung, R. D. Carlini, P. Stoler, A. Mihul, C. Yan, D. H. Potterveld, K. Kino, W. Hinton, Mauro Iodice, L. Ewell, Ketevi Assamagan, R. Williams, S. Danagoulian, Gabriel Niculescu, Rolf Ent, Brian Raue, J. W. Price, T. Fortune, T. Terasawa, Hiroaki Tsubota, D. Abbott, G. Collins, S. Mtingwa, S. Frullani, F. Duncan, P. Ambrozewicz, R. E. Segel, K. Beard, R. Mohring, S. A. Wood, D. J. Mack, Stephen Avery, C. E. Keppel, and G.M. Urcivoli
Subjects: Nuclear reaction, Physics, Nuclear physics, Nuclear and High Energy Physics, Meson, Hadron, Virtual particle, Elementary particle, Atomic physics, Strangeness, Lambda baryon, Sigma baryon
Abstract: The 1 H(e, e′K + )Λ and 1 H(e,e′K + )Σ 0 reactions were studied as a function of the squared four-momentum-transfer, Q 2 , and the virtual photon polarization, e, thus enabling the separation of the longitudinal and transverse parts of the cross section. The existence of a sizable longitudinal component for the 1 H(e,e′K + )Λ reaction seems to be indicated by these data.
Published: 1998
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30. Probing theρ0Mass Modification in the Subthreshold Region on3He

Author: Z. Papandreou, G. J. Lolos, and G. M. Huber
Subjects: Physics, Condensed matter physics, Subthreshold conduction, General Physics and Astronomy
Published: 1998
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31. Evidence forρ0Mass Modification in the3He(γ,ρ0)ppnReaction

Author: K. Maruyama, Z. Papandreou, H. Hirosawa, Takashi Maki, G. M. Huber, A. Weinerman, G. J. Lolos, F. Farzanpay, T. Terasawa, Y. Wada, K. Niwa, A. Sasaki, G. Garino, M. Iurescu, Kazushige Maeda, Koji Miyamoto, Roberto Perrino, Y. Sumi, A. Leone, Hirohito Yamazaki, Satoru Endo, H. Yamashita, Tsuneo Emura, and A. Shinozaki
Subjects: Physics, General Physics and Astronomy
Published: 1998
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32. Spin-transfer measurements of theπd→→p→preaction at energies spanning theΔresonance

Author: Rinaldo Rui, D.F. Ottewell, D. R. Gill, G. R. Smith, R. Olszewski, G.D. Wait, A. Feltham, M. E. Sevior, G. J. Lolos, P.L. Walden, E. L. Mathie, G. Jones, M. Pavan, R.P. Trelle, P. Weber, Z. Papandreou, V. Sossi, G. Sheffer, and D.C. Healey
Subjects: Scattering amplitude, Physics, Nuclear and High Energy Physics, Particle physics, Pi, Resonance, Spin transfer, Absorption (logic), Delta baryon, Mathematical physics, Spin-½
Abstract: The first spin-transfer experiment performed for the $\ensuremath{\pi}d\ensuremath{\rightarrow}\ensuremath{\rightarrow}p\ensuremath{\rightarrow}p$ reaction is described. Three spin-transfer parameters for this $\ensuremath{\pi}$-absorption process were determined, ${K}_{\mathrm{LS}}^{a}$, ${K}_{\mathrm{SS}}^{a}$, and ${K}_{\mathrm{NN}}^{a}$, which correspond to the \ensuremath{\pi}-production parameters, ${K}_{\mathrm{SL}}^{p}$, ${K}_{\mathrm{SS}}^{p}$, and ${K}_{\mathrm{NN}}^{p}$, of the time-reversed $p\ensuremath{\rightarrow}p\ensuremath{\rightarrow}d\ensuremath{\rightarrow}\ensuremath{\pi}$ process. Each observable was measured at a single angle for a number of energies spanning the $\ensuremath{\Delta}$ resonance of this system. The results are compared with the predictions of published partial wave amplitude fits which are primarily based on existing data for the time-reversed $\mathrm{pp}\ensuremath{\rightarrow}d\ensuremath{\pi}$ reaction, and also with the predictions of two current theories. The failure of these theories to describe the fundamental features of the data clearly demonstrates the need for further theoretical work in this area.
Published: 1997
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33. Role of quasideuteron absorption in theLi6(π+,pp) reaction atTπ+=100, 165 MeV

Author: S.I.H. Naqvi, P.L. Walden, E. L. Mathie, G. J. Lolos, J. L. Visschers, G. Jones, G. M. Huber, D.F. Ottewell, X. Aslanoglou, and Z. Papandreou
Subjects: Physics, Nuclear and High Energy Physics, Pion, Helium-4, Deuterium, Pi, Absorption (logic), Atomic physics, Nuclear environment
Abstract: Differential and total cross sections for ${\mathrm{\ensuremath{\pi}}}^{+}$ absorption on $^{6}\mathrm{Li}$, leading to the pp${+}^{4}$${\mathrm{He}}_{\mathrm{g}.\mathrm{s}.}$, pp${+}^{4}$${\mathrm{He}}^{\mathrm{*}}$, and pp+X final states, are presented at incident pion energies of 100 and 165 MeV. We conclude that most of the cross section is confined to the level of coplanarity expected from quasideuteron absorption in the nuclear environment and that the contributions of nonquasideuteron absorption mechanisms are small. \textcopyright{} 1996 The American Physical Society.
Published: 1996
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34. Analyzing power measurements in pion-deuteron breakup at intermediate energies

Author: D. M. Yeomans, G.D. Wait, E. L. Mathie, Humberto Garcilazo, G. J. Lolos, D.L. Humphrey, D.C. Healey, R.P. Trelle, G. T. Jones, S.I.H. Naqvi, V. Pafilis, Geoffrey Smith, M. E. Sevior, P. Weber, R. Tacik, G. M. Huber, and D.F. Ottewell
Subjects: Physics, Baryon, Nuclear reaction, Nuclear and High Energy Physics, Pion, Degree (graph theory), Proton, Hadron, Elementary particle, Atomic physics, Nucleon
Abstract: As part of an experimental study of the {pi}{ital NN} system, the pion-deuteron breakup reaction {pi}{sup +}{ital {rvec d}}{r_arrow}{ital pn}{pi}{sup +} was investigated at intermediate energies. Distributions of the vector analyzing power {ital iT}{sub 11} versus outgoing proton momentum {ital P}{sub {ital p}} are presented for 36 {pi}{ital p} angle pairs in the range of scattering angles 20{degree}{le}{theta}{sub {ital p}}{le}51{degree}, 62{degree}{le}{theta}{sub {pi}}{le}124{degree} at 228 and 134 MeV. These include 7 previously unmeasured angle pairs at 228 MeV and 20 new pairs at 134 MeV. In all regions of overlap with previous measurements, there is excellent agreement. There is generally excellent agreement with relativistic Faddeev predictions, except in the {ital np} final-state interaction region at 228 MeV. This is in contrast to the cross-section measurements, which are not well described by the theory.
Published: 1995
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35. Li6(π+,pp)4Heg.s.reaction at 100 and 165 MeV incident pion energies

Author: S.I.H. Naqvi, D.F. Ottewell, X. Aslanoglou, D.L. Humphrey, R.P. Trelle, E. L. Mathie, R. Tacik, P.L. Walden, Z. Papandreou, G. M. Huber, G. Jones, J.C. Cormier, and G. J. Lolos
Subjects: Physics, Nuclear physics, Baryon, Nuclear reaction, Nuclear and High Energy Physics, Pion, Helium-4, Hadron, Absorption (logic), Atomic physics, Nucleon, Isotopes of helium
Abstract: Differential and total cross sections for {pi}{sup +} absorption on {sup 6}Li leading to the {ital pp}+{sup 4}He{sub g.s} final state are presented at incident pion energies of 100 and 165 MeV. The narrow width of the {ital pp} angular correlation is observed and reported.
Published: 1995
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36. Virtual Compton scattering and the generalized polarizabilities of the proton atQ2=0.92and 1.76 GeV2

Author: L. B. Auerbach, C. Cavata, D. J. Margaziotis, K. Kino, A. J. Sarty, Seigo Kato, J. A. Templon, B. Frois, Ronald Ransome, D. Rowntree, R. W. Lourie, Christophe Furget, P. Grenier, M. K. Jones, D. S. Dale, G. W. Miller, H. Voskanyan, C. Jutier, S. Frullani, Z. L. Zhou, C. R. Howell, W. Kahl, M. Khayat, A. T. Katramatou, M. Kuss, J. W. Watson, K. Wijesooriya, W. M. Zhang, J. Jardillier, G.I. Smirnov, David L. Prout, G. Laveissière, A. Deur, G. E. Dodge, J. R. Calarco, G. Fournier, N. Degrande, R. A. Lindgren, J. J. LeRose, R. I. Pomatsalyuk, E. J. Brash, W. U. Boeglin, V. Gorbenko, R. Suleiman, F. T. Baker, S. Platchkov, G. M. Huber, F. Garibaldi, Ronald Gilman, K. McCormick, G. Rutledge, T. Saito, Richard Madey, G. G. Petratos, Z. E. Meziani, K. Arundell, Marc Vanderhaeghen, J. Martino, James J. Kelly, S. Kox, J. Marroncle, L. Cardman, C. E. Hyde, Raphael Noel Tieulent, Z. Papandreou, Pierre A.M. Guichon, F. Merchez, Bogdan Wojtsekhowski, D. Marchand, E. Tomasi-Gustaffson, M. Liang, P. M. Rutt, F. Renard, Shalev Gilad, S. Mehrabyan, G. Quéméner, V. A. Punjabi, D. M. Manley, C. W. de Jager, R. L.J. van der Meer, K. A. Aniol, Nilanga Liyanage, A. Gasparian, B. D. Anderson, G. J. Lolos, M. B. Epstein, Richard Wilson, Branislav Vlahovic, L. C. Alexa, A. Ketikyan, P. E. Ulmer, A. V. Glamazdin, E. A.J.M. Offermann, Jing Zhao, P. Y. Bertin, L. Van Hoorebeke, T. Pussieux, Mauro Iodice, Larry Weinstein, Laird Kramer, T. Terasawa, Vincent Breton, J. Gao, C. F. Perdrisat, C. Marchand, D. Neyret, William Bertozzi, R. Michaels, R. Holmes, H. Fonvieille, D. G. Zainea, Charles Glashausser, C. C. Chang, K. S. Kumar, J. Domingo, Pavel Sorokin, Haiyan Gao, Pete Markowitz, L. Bimbot, R. Di Salvo, J. M. Finn, J. S. Real, Justin I. McIntyre, S. Jaminion, G. Kumbartzki, E. Chudakov, Barbara Pasquini, Latifa Elouadrhiri, N. d'Hose, Roberto Perrino, R. De Leo, M. Baylac, J. O. Hansen, J. P. Chen, R. Van de Vyver, G. M. Urciuoli, J. Berthot, H. Breuer, Kevin Fissum, L. A. Ewell, G. Audit, Kazushige Maeda, J. Mougey, O. Ravel, S. Malov, E. Burtin, M. Holtrop, J. Gomez, Thomas E. Smith, Paul Souder, H. Ueno, S. K. Nanda, Hiroaki Tsubota, S. Kerhoas, L. Todor, A. Leone, A. Saha, E. Voutier, K. Soldi, A. Serdarevic, Sebastien Incerti, Y. Roblin, P. Vernin, and E. Cisbani
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Chiral perturbation theory, Proton, 010308 nuclear & particles physics, Structure function, Compton scattering, 01 natural sciences, Nuclear physics, Amplitude, Dispersion relation, 0103 physical sciences, Beta (velocity), 010306 general physics
Abstract: Virtual Compton Scattering (VCS) on the proton has been studied at Jefferson Lab using the exclusive photon electroproduction reaction (e p --> e p gamma). This paper gives a detailed account of the analysis which has led to the determination of the structure functions P{sub LL}-P{sub TT}/epsilon and P{sub LT}, and the electric and magnetic generalized polarizabilities (GPs) alpha{sub E}(Q{sup 2}) and beta{sub M}(Q{sup 2}) at values of the four-momentum transfer squared Q{sup 2} = 0.92 and 1.76 GeV{sup 2}. These data, together with the results of VCS experiments at lower momenta, help building a coherent picture of the electric and magnetic GPs of the proton over the full measured Q{sup 2}-range, and point to their non-trivial behavior.
Published: 2012
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37. Final analysis of proton form factor ratio data atQ2=4.0, 4.8, and 5.6 GeV2

Author: C. Cavata, T. Averett, J. R. Calarco, R. Endres, S. Kozlov, J. P. Chen, Kevin Fissum, C. C. Chang, I. Sitnik, Shalev Gilad, C. W. de Jager, A. V. Glamazdin, Z. Chai, K. A. Aniol, K. Wijesooriya, G. M. Urciuoli, E. Tomasi-Gustafsson, D. J. Margaziotis, X. Jiang, Douglas Higinbotham, M. K. Jones, N. M. Piskunov, Bogdan Wojtsekhowski, Fatiha Benmokhtar, R. Michaels, T. Chang, Charles Glashausser, Stephanie Escoffier, C. F. Perdrisat, L. Bimbot, C. Salgado, Mauro Iodice, L. Todor, R. A. Lindgren, J. J. LeRose, G. J. Lolos, M. B. Epstein, H. Voskanyan, K. Kramer, F. Marie, V. A. Punjabi, William Bertozzi, Brian Raue, Pete Markowitz, M. Rvachev, M. Khandaker, R. De Leo, D. Neyret, S. Frullani, Olivier Gayou, J. Gomez, Ronald Gilman, S. Strauch, E. Chudakov, J. O. Hansen, G. J. Kumbartzki, H. Fonvieille, B. D. Milbrath, E. J. Brash, K. McCormick, R. Roche, J. Gao, Simon Širca, G. M. Huber, F. Garibaldi, S. K. Nanda, Andrew Puckett, Sonja Dieterich, X. Zheng, D. Lhuillier, Nilanga Liyanage, L. Zhu, L. Pentchev, and Ronald Ransome
Subjects: Quark, Physics, Nuclear physics, Nuclear and High Energy Physics, Angular momentum, 010308 nuclear & particles physics, 0103 physical sciences, Momentum transfer, 010306 general physics, Nucleon, Polarization (waves), 01 natural sciences
Abstract: Precise measurements of the proton electromagnetic form factor ratio R = mu(p)G(E)(p)/G(M)(p) using the polarization transfer method at Jefferson Lab have revolutionized the understanding of nucleon structure by revealing the strong decrease of R with momentum transfer Q(2) for Q(2) greater than or similar to 1 GeV2, in strong disagreement with previous extractions of R from cross-section measurements. In particular, the polarization transfer results have exposed the limits of applicability of the one-photon-exchange approximation and highlighted the role of quark orbital angular momentum in the nucleon structure. The GEp-II experiment in Jefferson Lab's Hall A measured R at four Q(2) values in the range 3.5 GeV2
Published: 2012
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38. Exclusive pion production from few nucleon systems in the region of theΔ1232resonance

Author: R.D. Bent, P.L. Walden, E. Korkmaz, J.R. Campbell, H Guan, G. M. Huber, G. J. Lolos, F. A. Duncan, W. R. Falk, K. M. Furutani, S. Yen, A Celler, and A Trudel
Subjects: Physics, Nuclear physics, Nuclear reaction, Nuclear and High Energy Physics, Pion, Meson, Proton, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Hadron, Charge (physics), Atomic physics, Nucleon, Delta baryon
Abstract: Angular distributions of the differential cross sections and analyzing powers have been measured for the [sup 3]He([ital [rvec p]],[pi][sup +]) [sup 4]He and [sup 4]He([ital [rvec p]],[pi][sup +])[sup 5]He reactions at proton bombarding energies between 240 and 507 MeV. These new results provide a comprehensive set of data spanning the region of the [Delta][sub 1232] resonance and are compared with a phenomenological model that incorporates the amplitudes for the [ital pp][r arrow][ital d][pi][sup +] reaction, and with calculations from a microscopic ([ital p],[pi][sup +]) model. A [sup 5]He final state interaction calculation based upon the low energy [ital n]+[alpha] elastic phase shifts indicates that the [sup 4]He([ital p],[pi][sup +])[sup 5]He spectra are nearly independent of pion angle and proton energy. Comparisons made with the time reversed charge symmetric reaction [sup 3]H([ital n],[pi][sup [minus]])[sup 4]He reaction indicate substantial Coulomb effects are still present at 300 MeV.
Published: 1994
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39. Total Cross Section for Photon Absorption by Two Protons inHe3

Author: G. J. Lolos, Hirohito Yamazaki, G. M. Huber, T. Ogata, Chary Rangacharyulu, A. Sasaki, Y. Sumi, Y. Wada, Masahiro Koike, K. Maruyama, B. Lasiuk, T. Maki, K. Niki, Toshio Suda, H. Itoh, Kazushige Maeda, H. Miyamoto, Shigeaki Kato, Osamu Konno, R. Naridomi, Satoru Endo, and Tsuneo Emura
Subjects: Physics, Photon, Computer Science::Information Retrieval, Nuclear Theory, General Physics and Astronomy, Photon energy, Massless particle, Helium-3, Neutron, Atomic physics, Nuclear Experiment, Nucleon, Absorption (electromagnetic radiation), Isotopes of helium
Abstract: The [sup 3]He([gamma],[ital pp])[ital n] reaction was investigated in the photon energy range 200--500 MeV using the spectrometer TAGX, which has a solid angle for protons of [pi] sr. Two types of photon absorption, one by two protons and the other by three nucleons, were observed by looking at the undetected neutron momentum distributions. The total cross section for photon absorption by two protons shows that this process is consistent with the [ital E]2 transition.
Published: 1994
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40. Three-bodyHe3photodisintegration in the Δ region

Author: Masahiro Koike, T. Ogata, G. J. Lolos, H. Itoh, R. Naridomi, Hirohito Yamazaki, Kazushige Maeda, Satoru Endo, Chary Rangacharyulu, A. Sasaki, Osamu Konno, H. Miyamoto, G. M. Huber, Tsuneo Emura, Y. Wada, K. Maruyama, Y. Sumi, K. Niki, B. Lasiuk, Takashi Maki, Toshio Suda, and S. Kato
Subjects: Nuclear reaction, Baryon, Physics, Nuclear and High Energy Physics, Proton, Photodisintegration, Hadron, Elementary particle, Absorption (logic), Photon energy, Atomic physics
Abstract: Three-body $^{3}\mathrm{He}$ photodisintegration was measured in the photon energy range (${\mathit{E}}_{\ensuremath{\gamma}}$) of 145--425 MeV. The total cross section for photon absorption on the np pairs in $^{3}\mathrm{He}$, \ensuremath{\sigma}${(}^{3}$He(\ensuremath{\gamma},np)${\mathit{p}}_{\mathrm{sp}}$), where ${\mathit{p}}_{\mathrm{sp}}$ is a spectator proton, is reported here for the first time. The ${\mathit{E}}_{\ensuremath{\gamma}}$ dependence of the \ensuremath{\sigma} is found to scale to that of \ensuremath{\sigma}${(}^{2}$H(\ensuremath{\gamma},np)), and the ratio is determined to be \ensuremath{\sigma}${(}^{3}$He(\ensuremath{\gamma},np)${\mathit{p}}_{\mathrm{sp}}$)/\ensuremath{\sigma}${(}^{2}$H(\ensuremath{\gamma},np))=1.24\ifmmode\pm\else\textpm\fi{}0.,26.
Published: 1994
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41. Simultaneous measurement of He(γ, pπ) yields and model implications

Author: Toshio Suda, S. Kato, G. M. Huber, Y. Wada, Hiromichi Yamazaki, B. Lasiuk, H. Ito, G. J. Lolos, M. Koike, H. Miyamoto, A. Sasaki, K. Maruyama, K. Niki, Takashi Maki, Osamu Konno, Chary Rangacharyulu, Satoru Endo, Y. Sumi, Kazushige Maeda, and Tsuneo Emura
Subjects: Physics, Nuclear and High Energy Physics, Amplitude, Photon, Isovector, Component (thermodynamics), Isospin, Yield ratio, Atomic physics, Ground state
Abstract: 3 He(γ, pπ ± ) reactions are simultaneously measured for tagged photon energies of 380 ⩽ Eγ ⩽ 700 MeV. The yield ratio for the two channels, under the same kinematical and dynamical conditions, is found to be 0.90±0.07. Implications of this ratio in terms of the delta component in the ground state of 3He are examined. An alternate interpretation of this ratio as due to an admixture of isospin T = 1 2 and 3 2 transition amplitudes in a pure isovector interaction is also presented.
Published: 1993
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42. Measurement ofK−pradiative capture toγΛandγΣ0forpK−between 514 and 750 MeV/c

Author: N. Phaisangittisakul, A. Marusic, M. E. Sadler, D. Peaslee, A. Starostin, D. Isenhower, J. W. Price, N. S. Knecht, N. G. Kozlenko, S. McDonald, S. N. Prakhov, Pieter Vancraeyveld, V. Bekrenev, A. Shafi, Z. Papandreou, I. Supek, S. P. Kruglov, Jan Ryckebusch, T. Van Cauteren, W. J. Briscoe, I. V. Lopatin, G. J. Lolos, H. M. Staudenmaier, B. M. K. Nefkens, A. Koulbardis, I. I. Strakovsky, and L. De Cruz
Subjects: Physics, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Nuclear Theory, Hyperon, Alternating Gradient Synchrotron, 01 natural sciences, Resonance (particle physics), Nuclear physics, Excited state, 0103 physical sciences, Radiative transfer, Physics::Accelerator Physics, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Crystal Ball
Abstract: Differential cross sections for K{sup -} radiative capture in flight on the proton, leading to the gammaLAMBDA and gammaSIGMA{sup 0} final states, have been measured at eight K{sup -} momenta between 514 and 750 MeV/c. The data were obtained with the Crystal Ball multiphoton spectrometer installed at the separated K/pi beam line C6 of the BNL Alternating Gradient Synchrotron. The results substantially improve the existing experimental data available for studying radiative decays of excited hyperon states. An exploratory theoretical analysis is performed within the Regge-plus-resonance approach. According to this analysis, the gammaSIGMA{sup 0} final state is dominated by hyperon-resonance exchange and hints at an important role for a resonance in the mass region of 1700 MeV. In the gammaLAMBDA final state, in contrast, the resonant contributions account for only half the strength, and the data suggest the importance of a resonance in the mass region of 1550 MeV.
Published: 2010
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43. Differential cross sections of the charge-exchange reactionπ−p→π0nin the momentum range from103to178MeV/c

Author: I. I. Strakovsky, A. A. Kulbardis, N. Phaisangittisakul, K. Craig, A. Shafi, D. Mekterović, D. Grosnick, J. Olmsted, J. R. Comfort, S. P. Kruglov, D. Isenhover, C. Bircher, H. M. Spinka, J. W. Price, A. Starostin, V. V. Abaev, G. J. Lolos, I. V. Lopatin, M. Clajus, I. Supek, S. McDonald, S. Stanislaus, W. B. Tippens, V. Bekrenev, S. Watson, D. M. Manley, N. Knecht, Z. Papandreou, S. N. Prakhov, D. D. Koetke, H. M. Staudenmaier, J. Peterson, W. J. Briscoe, R. V. Cadman, M. Jerkins, M. E. Sadler, R. Manweiler, D. Peaslee, B. M. K. Nefkens, A. F. Ramirez, A. Marušić, M. Joy, and N. G. Kozlenko
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), 010308 nuclear & particles physics, Alternating Gradient Synchrotron, 01 natural sciences, Momentum, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, National laboratory, Differential (mathematics), Crystal Ball, Charge exchange
Abstract: Measured values of the differential cross sections for pion-nucleon charge exchange, ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}n$, are presented for ${\ensuremath{\pi}}^{\ensuremath{-}}$ momenta of $103,112,120,130,139,152$, and $178$ MeV/$c$. Complete angular distributions were obtained by using the Crystal Ball detector at the Alternating Gradient Synchrotron at Brookhaven National Laboratory. Statistical uncertainties of the differential cross sections vary from $3$ to $6%$ in the backward angle region and from $6$ to about $20%$ in the forward region with the exception of the two most forward angles. The systematic uncertainties are estimated to be about $3%$ for all momenta.
Published: 2009
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44. Publisher’s Note: Measurement ofπ0Λ,K¯0n, andπ0Σ0production inK−pinteractions forpK−between 514 and750 MeV/c[Phys. Rev. C80, 025204 (2009)]

Author: N. Phaisangittisakul, H. M. Staudenmaier, A. Starostin, A. Koulbardis, I. I. Strakovsky, D. Peaslee, A. Marusic, V. Bekrenev, N. S. Knecht, Z. Papandreou, J. W. Price, S. McDonald, B. M. K. Nefkens, G. J. Lolos, S. N. Prakhov, N. G. Kozlenko, A. Shafi, S. P. Kruglov, I. V. Lopatin, W. J. Briscoe, and I. Supek
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Pi, Sigma, Production (computer science), Lambda
Published: 2009
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45. Measurement ofπ0Λ,K¯0n, andπ0Σ0production inK−pinteractions forpK−between 514 and 750 MeV/c

Author: N. Phaisangittisakul, N. Knecht, D. Peaslee, J. W. Price, S. N. Prakhov, G. J. Lolos, S. McDonald, A. Koulbardis, W. J. Briscoe, I. I. Strakovsky, A. Marušić, B. M. K. Nefkens, A. Starostin, V. Bekrenev, Z. Papandreou, A. Shafi, S. P. Kruglov, I. V. Lopatin, H. M. Staudenmaier, N. G. Kozlenko, and I. Supek
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hyperon, Alternating Gradient Synchrotron, Lambda, 01 natural sciences, Excited state, 0103 physical sciences, Production (computer science), Atomic physics, 010306 general physics, Energy (signal processing), Crystal Ball
Abstract: Differential cross sections and hyperon polarizations have been measured for ${\overline{K}}^{0}n$, ${\ensuremath{\pi}}^{0}\ensuremath{\Lambda}$, and ${\ensuremath{\pi}}^{0}{\ensuremath{\Sigma}}^{0}$ production in ${K}^{\ensuremath{-}}p$ interactions at eight ${K}^{\ensuremath{-}}$ momenta between 514 and 750 MeV/$c$. The experiment detected the multiphoton final states with the Crystal Ball spectrometer using a ${K}^{\ensuremath{-}}$ beam from the BNL Alternating Gradient Synchrotron. The results provide significantly greater precision than the existing data, allowing a detailed reexamination of the excited hyperon states in our energy range.
Published: 2009
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46. Measurement of the total cross section of the reactionK−p→Σ0γbetween 514 and 750 MeV/c

Author: D. P. Grosnick, D. D. Koetke, S. P. Kruglov, N. Phaisangittisakul, I. V. Lopatin, H. M. Staudenmaier, A. Shafi, N. Knecht, M. E. Sadler, T. D. S. Stanislaus, J. W. Price, J. Alyea, D. Peaslee, D. Allen, I. I. Strakovsky, A. F. Ramirez, I. Supek, R. Greene, M. A. Bates, D. M. Manley, G. J. Lolos, J. Thoms, A. A. Kulbardis, J. R. Comfort, C. E. Allgower, R. W. Manweiler, A. Gibson, J. Olmsted, V. Bekrenev, Z. Papandreou, T.E. Kasprzyk, R. V. Cadman, V. V. Abaev, S. Schlobohm, K. Craig, S. McDonald, S. Wolf, R. Corliss, N. G. Kozlenko, W. J. Briscoe, A. Marusic, D. Isenhower, and H. M. Spinka
Subjects: Physics, Nuclear and High Energy Physics, Photon, Physics::Instrumentation and Detectors, Hyperon, Alternating Gradient Synchrotron, Scintillator, Charged particle, Nuclear physics, High Energy Physics::Experiment, Neutron, Atomic physics, Nuclear Experiment, Crystal Ball, Beam (structure)
Abstract: We report the first measurements of the total cross section of the reaction K{sup -}p{yields}{sigma}{sup 0}{gamma} at eight beam momenta from 514 to 750 MeV/c. The data were obtained at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory using the Crystal Ball detector consisting of 672 NaI crystals. All charged particles were vetoed by a barrel of plastic scintillators, resulting in a study of only the neutral decays of the {sigma}{sup 0}. The prompt photon and the photons from the decay products of {sigma}{sup 0} were detected for each reconstructed event; the neutron was also detected in a small fraction of the events.
Published: 2009
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47. Virtual Compton Scattering and Neutral Pion Electroproduction in the Resonance Region up to the Deep Inelastic Region at Backward Angles

Author: Seigo Kato, H. Ueno, K. Wijesooriya, R. Di Salvo, L. C. Alexa, G. W. Miller, H. Voskanyan, C. Jutier, J. Jardillier, E. Voutier, J. A. Templon, G. Rutledge, B. Frois, D. G. Zainea, C. C. Chang, E. Chudakov, David L. Prout, G. Laveissière, T. Terasawa, Vincent Breton, Mauro Iodice, Bogdan Wojtsekhowski, K. S. Kumar, Latifa Elouadrhiri, J. O. Hansen, A. Gasparian, K. Arundell, Pavel Sorokin, Sebastien Incerti, Larry Weinstein, P. Grenier, R. W. Lourie, W. Kahl, J. Berthot, G. Audit, L. B. Auerbach, T. Pussieux, G. Fournier, William Bertozzi, A. Deur, P. Vernin, Pierre A.M. Guichon, Ronald Ransome, Kazushige Maeda, K. Kino, N. Degrande, Pete Markowitz, D. Rowntree, Z. Papandreou, R. L.J. van der Meer, A. T. Katramatou, T. Saito, Richard Madey, Paul Souder, P. M. Rutt, S. K. Nanda, Roberto Perrino, R. De Leo, D. S. Dale, S. Mehrabyan, S. Kerhoas, J. M. Finn, W. U. Boeglin, D. J. Margaziotis, R. I. Pomatsalyuk, A. Ketikyan, L. Todor, A. Leone, M. Baylac, S. Jaminion, Nilanga Liyanage, S. Malov, E. Burtin, M. Holtrop, Thomas E. Smith, Richard Wilson, G. E. Dodge, R. Holmes, J. Marroncle, D. Marchand, E. Tomasi-Gustaffson, S. Platchkov, J. S. Real, J. Martino, Raphael Noel Tieulent, G.I. Smirnov, J. P. Chen, R. Van de Vyver, G. M. Urciuoli, Branislav Vlahovic, R. A. Lindgren, J. J. LeRose, C. R. Howell, Justin I. McIntyre, J. R. Calarco, L. Tiator, L. Bimbot, Arijit Saha, K. Soldi, O. Ravel, Hiroaki Tsubota, A. Serdarevic, C. E. Hyde, Y. Roblin, J. Y. Mougey, G. M. Huber, F. Garibaldi, E. Cisbani, J. Gomez, V. Gorbenko, J. W. Watson, F. Renard, L. Cardman, B. D. Anderson, G. J. Lolos, M. B. Epstein, F. T. Baker, F. Merchez, P. Y. Bertin, Haiyan Gao, M. Liang, G. Quéméner, D. Neyret, N. d'Hose, S. Frullani, Charles Glashausser, M. Khayat, H. Breuer, D. M. Manley, J. Gao, L. Van Hoorebeke, G. G. Petratos, Z. E. Meziani, V. A. Punjabi, L. A. Ewell, Ronald Gilman, K. McCormick, H. Fonvieille, Z. L. Zhou, A. V. Glamazdin, S. Kox, Jing Zhao, C. F. Perdrisat, R. Michaels, C. Marchand, M. K. Jones, C. Furget, P. E. Ulmer, Kevin Fissum, M. Kuss, James J. Kelly, E. J. Brash, Laird Kramer, Shalev Gilad, C. W. de Jager, K. A. Aniol, E. A.J.M. Offermann, C. Cavata, S.S. Kamalov, G. J. Kumbartzki, A. J. Sarty, W. M. Zhang, R. Suleiman, J. Domingo, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), HALL A, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Scattering, Compton scattering, Resonance, FOS: Physical sciences, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Deep inelastic scattering, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Pion, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment
Abstract: We have made the first measurements of the virtual Compton scattering (VCS) process via the H$(e,e'p)\gamma$ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the $W$-dependence at fixed $Q^2=1$ GeV$^2$, and for the $Q^2$-dependence at fixed $W$ near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed $Q^2$-dependence is smooth. The measured ratio of H$(e,e'p)\gamma$ to H$(e,e'p)\pi^0$ cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared to Real Compton Scattering (RCS) at high energy and large angles, our VCS data at the highest $W$ (1.8-1.9 GeV) show a striking $Q^2$- independence, which may suggest a transition to a perturbative scattering mechanism at the quark level., Comment: 20 pages, 8 figures. To appear in Phys.Rev.C
Published: 2009
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48. Analyzing powers for theHe3(p→,π+)4He reaction in the region of theΔ1232resonance

Author: G. M. Huber, E. Korkmaz, G. J. Lolos, W. R. Falk, P.L. Walden, K. M. Furutani, S. Yen, F. A. Duncan, and R.D. Bent
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Helium-4, Proton, Meson, Hadron, Elementary particle, Atomic physics, Nuclear Experiment, Isotopes of helium, Delta baryon
Abstract: Angular distributions of the analyzing powers have been measured for the $^{3}\mathrm{He}$(p\ensuremath{\rightarrow},${\mathrm{\ensuremath{\pi}}}^{+}$${)}^{4}$He reaction at proton bombarding energies of 300, 416, and 507 MeV. These results, together with existing measurements at 178, 198, and 800 MeV, provide a comprehensive set of data spanning the region of the ${\mathrm{\ensuremath{\Delta}}}_{1232}$ resonance. The results are compared with a phenomenological model that incorporates the amplitudes for the pp\ensuremath{\rightarrow}d${\mathrm{\ensuremath{\pi}}}^{+}$ reaction and calculations from a microscopic (p,${\mathrm{\ensuremath{\pi}}}^{+}$) model.
Published: 1991
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49. Spin-transfer measurements of the πd→→p→preaction spanning the Δ resonance

Author: G. A. C. Jones, P.L. Walden, R.P. Trelle, M. Pavan, G. J. Lolos, R. Olszewski, Vesna Sossi, D.F. Ottewell, D. R. Gill, G.D. Wait, P. Weber, D.C. Healey, Rinaldo Rui, Z. Papandreou, E. L. Mathie, M. E. Sevior, Geoffrey Smith, and A. Feltham
Subjects: Physics, Nuclear reaction, Amplitude, Proton, Scattering, Computer Science::Information Retrieval, Pi, General Physics and Astronomy, Spin transfer, Resonance, Inelastic scattering, Atomic physics
Abstract: The first spin-transfer observables for the {pi}{bold d}{r arrow}{bold p}{ital p} reaction have been measured at a number of energies spanning the {Delta} resonance in this system. These parameters correspond to {ital K}{sub {ital S}{ital L}} and {ital K}{sub {ital S}{ital S}} of the {ital p}{bold p}{r arrow}{bold d}{pi} reaction for incident proton energies ranging from 600 to 800 MeV. Such data can provide an important constraint on the determination of the partial-wave amplitudes describing this fundamental reaction. The discrepancies between our data, theoretical predictions, and values calculated from published partial-wave amplitudes demonstrate the need for further work in this area.
Published: 1991
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50. Charged pion form factor betweenQ2=0.60and2.45 GeV2. II. Determination of, and results for, the pion form factor

Author: C. E. Keppel, D. J. Margaziotis, L. M. Qin, S. Vidakovic, John C. Mitchell, B. Zihlmann, T. Eden, V. Tadevosyan, Y. Okayasu, J. Arrington, D. H. Potterveld, J. Roche, Toshinobu Miyoshi, D. van Westrum, B. Mueller, K. A. Aniol, G. Niculescu, E. J. Brash, S. A. Wood, Ketevi Assamagan, K. Vansyoc, P. H. Kim, W. Zhao, D. McKee, H. C. Fenker, W.U. Boeglin, C. S. Armstrong, D. J. Mack, A. Matsumura, Stephen Avery, E. J. Beise, H. E. Jackson, D. Pitz, C. Xu, G. J. Lolos, A. J. Sarty, C. Yan, Andreas Klein, Jin Liu, M. E. Christy, P. E. Reimer, X. Zheng, I. K. Shin, J. Reinhold, E. F. Gibson, W. F. Vulcan, W. Hinton, S. Stepanyan, P. G. Roos, Ronald Gilman, C. C. Chang, R. van der Meer, D. Abbott, D. Gaskell, M. K. Jones, I. Niculescu, C. F. Perdrisat, Brynle Barrett, V. Kovaltchouk, H. Mkrtchyan, V. Tvaskis, A. F. Lung, Lubomir Pentchev, H. Anklin, Oliver Keith Baker, Geoffrey Smith, Pete Markowitz, Rolf Ent, Glen A. Warren, K. Gustafsson, M. Liang, C. Bochna, J. Volmer, G. M. Huber, P. M. King, D. Koltenuk, H. P. Blok, J. A. Dunne, L. G. Tang, V. A. Punjabi, D. G. Meekins, S. Jin, W. Kim, N. S. Chant, H. Breuer, Tanja Horn, and R. J. Holt
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Bethe–Salpeter equation, 010308 nuclear & particles physics, Hadron, Lattice field theory, Magnetic monopole, Form factor (quantum field theory), Sigma, Particle accelerator, 7. Clean energy, 01 natural sciences, Charged particle, law.invention, Nuclear physics, Pion, law, Charge radius, 0103 physical sciences, Neutron, Invariant mass, Nucleon, 010306 general physics
Abstract: Cross sections for the reaction {sup 1}H(e,e'{Pi}{sup +})n were measured in Hall C at Thomas Jefferson National Accelerator Facility (JLab) using the high-intensity Continuous Electron Beam Accelerator Facility (CEBAF) to determine the charged pion form factor. Data were taken for central four-momentum transfers ranging from Q{sup 2} = 0.60 to 2.45 GeV{sup 2} at an invariant mass of the virtual photon-nucleon system of W = 1.95 and 2.22 GeV. The measured cross sections were separated into the four structure functions {sigma}{sub L},{sigma}{sub T}, {sigma}{sub LT}, and {sigma}{sub TT}. The various parts of the experimental setup and the analysis steps are described in detail, including the calibrations and systematic studies, which were needed to obtain high-precision results. The different types of systematic uncertainties are also discussed. The results for the separated cross sections as a function of the Mandelstam variable t at the different values of Q{sup 2} are presented. Some global features of the data are discussed, and the data are compared with the results of some model calculations for the reaction {sup 1}H(e,e'{Pi}{sup +})n.
Published: 2008
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