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32 results on '"D. Koltenuk"'

1. Electroproduction of kaons on light nuclei

Author

R. Sawafta, J. H. Liu, John C. Mitchell, T. Eden, C. Yan, D. G. Meekins, E. Christy, F. Dohrmann, P. Ambrozewicz, L. Cole, M. Sarsour, A. Ahmidouch, Y. Sato, P. E. Reimer, S. Tajima, J. A. Dunne, J. Roche, S. Danagoulian, Kevin Bailey, B. Mueller, J. W. Price, W. Hinton, N. S. Chant, H. Mkrtchyan, J. Crowder, H. Juengst, Haiyan Gao, John Arrington, G. Savage, C. Cothran, J. P. Schiffer, B. Zihlmann, M. Zeier, H. C. Fenker, J.-O. Hansen, Paul Gueye, Rolf Ent, R. D. Carlini, Brian Raue, R. Asaturyan, L. Gan, W. J. Cummings, A. Semenov, D. F. Geesaman, J. Cha, D. S. Brown, M. Elaasar, A. Cochran, H. Breuer, Dipangkar Dutta, Pete Markowitz, L. Yuan, J. Reinhold, H. Bitao, A. Uzzle, K. Gustafsson, B. Terburg, F. Duncan, S. Stepanyan, P. G. Roos, Ketevi Assamagan, Avraham Klein, G. Collins, Thomas O'Neill, D. Potterveld, V. Tadevosian, K. Garrow, H. E. Jackson, D. Koltenuk, C. S. Armstrong, Y. Liang, O. K. Baker, I. Niculescu, B. Zeidman, A. F. Lung, G. Niculescu, Toshinobu Miyoshi, H. Yamaguchi, R. Madey, D. Abbott, L. Ewell, H. T. Fortune, Y. Fujii, K. Hafidi, R. E. Segel, S. Beedoe, S. Mtingwa, C. J. Martoff, R. Mohring, C. E. Keppel, S. A. Wood, D. J. Mack, Stephen Avery, and L. G. Tang

Subjects
Physics, Nuclear and High Energy Physics, Meson, Proton, Helium-3, Hadron, Production (computer science), Elementary particle, Atomic physics, Nuclear Experiment, Lambda, Isotopes of helium
Abstract

The A(e,e{prime}K{sup +})YX reaction on H, D, {sup 3}He, and {sup 4}He was investigated in Hall C at CEBAF. Data were obtained for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at 3.245 GeV. The missing mass spectra for both H and D are fitted with Monte-Carlo simulations incorporating peaks corresponding to {Lambda} production on the proton and {Sigma} production on both the proton and neutron. For D, the cross section ratio {Sigma}{sup 0}/{Sigma}{sup {minus}} {approx} 2, and excess yield close to the thresholds for {Lambda} and {Sigma} production can be attributed to final-state interactions that are compared to the data. The analysis of the data for the He targets is in a more preliminary state with broader quasi-free peaks resulting from the higher Fermi momenta. Evidence for bound {Lambda}-hypernuclear states is seen and other structure may be present.

Published
2001

2. Electroproduction of kaons and light hypernuclei

Author

John C. Mitchell, Y. Liang, T. Eden, Thomas O'Neill, D. F. Geesaman, R. E. Segel, L. Ewell, J. Cha, H. Bitao, E. Christy, Ketevi Assamagan, M. Sarsour, J. Crowder, L. Cole, J. W. Price, S. Danagoulian, Dipangkar Dutta, H. Juengst, H. Yamaguchi, H.T. Fortune, D. Koltenuk, N. Chant, J. H. Liu, D. Abbott, R. Asaturyan, D. G. Meekins, W. Hinton, T. Miyoshi, J. Roche, Brian Raue, Paul Gueye, W. U. Boeglin, J. Reinhold, Pete Markowitz, J.-O. Hansen, L. G. Tang, R. Mohring, R. Sawafta, K. Garrow, J. P. Schiffer, C. E. Keppel, C. J. Martoff, C. Cothran, John Arrington, Kevin Bailey, C. Yan, B. Zihlmann, H. C. Fenker, B. Terburg, C. S. Armstrong, P. Roos, Y. Sato, Rolf Ent, S. Tajima, B. Mueller, P. Ambrozewicz, G. Savage, S. Stepanyan, D. S. Brown, A. Uzzle, O. K. Baker, Avraham Klein, A. Cochran, H. Mkrtchyan, A. Semenov, L. Gan, W. J. Cummings, G. Collins, F. Duncan, K. Gustafsson, F. Dohrmann, Y. Fujii, R. Madey, M. Zeier, J. A. Dunne, A. Ahmidouch, R. D. Carlini, S. A. Wood, A. F. Lung, D. J. Mack, L. Yuan, S. Beedoe, M. Elaasar, Stephen Avery, G. Niculescu, I. Niculescu, D. Potterveld, V. Tadevosian, S. Mtingwa, H. Breuer, K. Hafidi, Haiyan Gao, H. E. Jackson, P. E. Reimer, B. Zeidman, and (Astro)-Particles Physics

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Deuterium, Production (computer science), Electron, Nucleon, Fundamental interaction
Abstract

A detailed investigation of the basic hyperon-nucleon interactions in nuclei is one of the aims of Experiment 91-016, approved with high priority at CEBAF, to study the electroproduction of kaons on targets of deuterium, {sup 3}He, and {sup 4}He. Inasmuch as both the electron and K{sup +} are particles that interact relatively weakly with nucleons, electroproduction of light hypernuclei provides a low-distortion method for investigating the fundamental interactions between nucleons, {Alpha}`s, and {Epsilon}`s in few-body systems. In particular, the (e,e`K{sup +}) reactions on cryogenic targets of D, {sup 3}He, and {sup 4}He will be studied at incident electron energies near 3 GeV with coincident detection of the emergent e and K{sup +} in the HMS and SOS magnetic spectrometers in Hall C. Construction of the He target, operating at {approximately}10 atm, {approximately}50 K and capable of dissipating {approximately}30 W, is expected to be complete prior to commencement of production runs in Hall C. The first data runs for E91-016, expected to begin late in FY 1995, will also be the basis for a doctoral thesis at Hampton University. In addition to providing new information on the phases of hyperon-nucleon interactions, measurements of cross sections for hypernuclear formation, and interference phenomena,more » the data may provide evidence for the presence of bound {Epsilon}`s and strange di-baryonic states that are the subject of considerable theoretical discussion.« less

Published
2001

3. Evidence for Valencelike Quark-Hadron Duality

Author

W. F. Vulcan, C. Yan, I. Niculescu, S. A. Wood, J. H. Mitchell, Paul Gueye, John Arrington, D. J. Mack, P. Stoler, J. W. Price, H. E. Jackson, Donal Day, C. E. Keppel, B. Terburg, J. Reinhold, V. Frolov, D. G. Meekins, L. G. Tang, Rolf Ent, D. Koltenuk, C. S. Armstrong, J. Cha, Dipangkar Dutta, C. Bochna, R. E. Segel, R. D. Carlini, D. van Westrum, D. Potterveld, R. Mohring, G. Niculescu, C. Cothran, W. Hinton, R. J. Holt, D. F. Geesaman, Ketevi Assamagan, O. K. Baker, M. A. Miller, J. A. Dunne, Douglas H Beck, B. Zeidman, and Haiyan Gao

Subjects
Quantum chromodynamics, Quark, Physics, Particle physics, Scattering, Nuclear Theory, Hadron, General Physics and Astronomy, Elementary particle, Resonance (particle physics), Nuclear physics, Nuclear Experiment, Nucleon, Scaling
Abstract

A newly obtained data sample of inclusive electron-nucleon scattering from both hydrogen and deuterium targets is analyzed. These JLab data span the nucleon resonance region up to four-momentum transfers of 5 (GeV/c){sup 2} . The data are found to follow an average scaling curve. The inclusion of low-momentum transfer data yields a scaling curve resembling deep inelastic neutrino-nucleus scattering data, suggesting a sensitivity to valencelike structure only. (c) 2000 The American Physical Society.

Published
2000

4. Electroproduction of theΔ(1232)Resonance at High Momentum Transfer

Author

V. Frolov, D. Koltenuk, P. E. Bosted, L. G. Tang, N. C. Mukhopadhyay, Oliver Keith Baker, Volker D. Burkert, P. Stoler, D. G. Meekins, R. C. Minehart, C. S. Armstrong, C. E. Keppel, Ketevi Assamagan, V. Tadevosian, M. Witkowski, John C. Mitchell, G. Niculescu, J. W. Price, J. Napolitano, S. A. Wood, D. J. Mack, Stephen Avery, W. Hinton, Richard Madey, W. Kim, D. Gaskell, J. A. Dunne, R. M. Davidson, H. Mkrtchyan, T. Eden, A. Ahmidouch, Paul Gueye, M. Nozar, M. Klusman, G. S. Adams, Rolf Ent, R. Carlini, and I. Niculescu

Subjects
Baryon, Physics, Pion, Meson, Hadron, Quark model, General Physics and Astronomy, Resonance, Elementary particle, Atomic physics, Delta baryon
Abstract

Jefferson Lab experiment E94-014 measured the excitation of the Delta (1232) resonance via the reaction p(e,e{prime}p){pi}{sup 0} at Q{sup 2} near 2.8 and 4 Gev{sup 2}. This is the highest Q{sup 2} for which exclusive resonance electroproduction has ever been observed. Decay distributions of the Delta (1232) resonance into the ppi{sup 0} final state were measured over a wide range of barycentric decay angles and energies. The goal of this experiment is to assess the transition in Q{sup 2} from the constituent quark model (CQM) to the regime where hard processes become important. At Q{sup 2} {approx} few GeV{sup 2}/c{sup 2} the ratio E{sub 1+}/M{sub 1+} depends dramatically on the theoretical description, varying from a few 10{sup -2} in the CQM limit, to about 1 in the pQCD limit. Preliminary analysis of the data shows that the ratio E{sub 1+}/M{sub 1+} remains small at Q{sup 2} up to 4 Gev{sup 2}/c{sup 2}. After first pass analysis we obtain E{sub 1+}/M{sub 1+} = -4.1 {+-} 1.2 at Q{sup 2} = 2.8 Gev{sup 2}/c{sup 2} and E{sub 1+}/M{sub 1+} = -7.9 {+-} 0.8 at Q{sup 2} = 4 Gev{sup 2}/c{sup 2} (statistical errors only).

Published
1999

5. Measurements of Deuteron Photodisintegration up to 4.0 GeV

Author

D. Beatty, Pete Markowitz, L. Cardman, J. A. Dunne, D. van Westrum, J. Cha, David Mack, H. T. Fortune, K. Gustafsson, R. D. Carlini, C. Bochna, G. J. Kumbartzki, B. R. Owen, J.-O. Hansen, S. Danagoulian, Gabriel Niculescu, Dipangkar Dutta, B. Zeidman, S. Barrow, G. Collins, A. Ahmidouch, Thomas O'Neill, J. W. Price, John Arrington, G. Savage, I. Niculescu, C. Yan, R. J. Holt, H. Mkrtchyan, P. M. Rutt, P. Stoler, Haiyan Gao, D. H. Potterveld, H. E. Jackson, B. W. Filippone, O. K. Baker, Z. E. Meziani, H. Breuer, M. Khandaker, J. Napolitano, B. Terburg, C. S. Armstrong, M. A. Miller, D. Koltenuk, F. Duncan, R. Suleiman, E. J. Brash, K. McFarlane, Rolf Ent, N. Simicevic, D. Abbott, Paul Gueye, R. Madey, W. F. Vulcan, D. F. Geesaman, V. Frolov, T. A. Forest, S. F. Pate, J. E. Belz, M. Harvey, P. E. Bosted, Avraham Klein, T. Eden, J. H. Mitchell, W. J. Cummings, G. Rakness, A. F. Lung, C. Salgado, N. S. Chant, W. Hinton, M. Witkowski, Ronald Gilman, S. Beedoe, R. E. Segel, R. Mohring, S. A. Wood, C. E. Keppel, S. E. Williamson, Alan M. Nathan, E. R. Kinney, Douglas H Beck, R. D. McKeown, J. Reinhold, L. G. Tang, R. V. Cadman, Ketevi Assamagan, Ronald Ransome, D. G. Meekins, E. J. Beise, and C. Cothran

Subjects
Physics, Quantum chromodynamics, Nuclear reaction, Particle physics, Proton, Hadron, FOS: Physical sciences, General Physics and Astronomy, Particle accelerator, Photon energy, law.invention, Nuclear physics, law, Photodisintegration, Physics::Accelerator Physics, Nuclear Experiment (nucl-ex), Nuclear Experiment, Nucleon
Abstract

The first measurements of the differential cross section for the d(gamma,p)n reaction up to 4.0 GeV were performed at Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. We report the cross sections at the proton center-of-mass angles of 36, 52, 69 and 89 degrees. These results are in reasonable agreement with previous measurements at lower energy. The 89 and 69 degree data show constituent-counting-rule behavior up to 4.0 GeV photon energy. The 36 and 52 degree data disagree with the counting rule behavior. The quantum chromodynamics (QCD) model of nuclear reactions involving reduced amplitudes disagrees with the present data., Comment: 5 pages (REVTeX), 1 figure (postscript)

Published
1998

6. Longitudinal and Transverse Cross Sections in the1H(e,e′K+)ΛReaction

Author

G. Niculescu, R. M. Mohring, P. Gueye, D. Abbott, A. Ahmidouch, Ts. A. Amatuni, P. Ambrozewicz, T. Angelescu, C. S. Armstrong, K. Assamagan, S. Avery, K. Bailey, O. K. Baker, K. Beard, S. Beedoe, E. Beise, H. Breuer, R. Carlini, J. Cha, C. C. Chang, N. Chant, E. Cisbani, G. Collins, W. Cummings, S. Danagoulian, R. De Leo, F. Duncan, J. Dunne, D. Dutta, T. Eden, R. Ent, L. Eyraud, L. Ewell, M. Finn, T. Fortune, V. Frolov, S. Frullani, C. Furget, F. Garibaldi, D. Gaskell, D. F. Geesaman, K. K. Gustafsson, J.-O. Hansen, M. Harvey, W. Hinton, E. Hungerford, M. Iodice, C. Jackson, C. Keppel, W. Kim, K. Kino, D. Koltenuk, S. Kox, L. Kramer, T. Leone, G. Lolos, A. Lung, D. Mack, R. Madey, M. Maeda, S. Majewski, P. Markowitz, C. J. Martoff, D. Meekins, A. Mihul, J. Mitchell, H. Mkrtchyan, S. Mtingwa, I. Niculescu, R. Perrino, D. Potterveld, J. W. Price, B. A. Raue, J.-S. Real, J. Reinhold, P. Roos, T. Saito, G. Savage, R. Sawafta, R. Segel, S. Stepanyan, P. Stoler, V. Tadevosian, L. Tang, L. Teodorescu, T. Terasawa, H. Tsubota, G. M. Urciuoli, J. Volmer, W. Vulcan, P. Welch, R. Williams, S. Wood, C. Yan, and B. Zeidman

Subjects
Nuclear physics, Physics, Transverse plane, Science and engineering, General Physics and Astronomy, Lambda
Abstract

U.S. Department of Energy, National Science Foundation, Stichting voor Fundamenteel Onderzoek der Materie (Netherlands), Korean Science and Engineering Foundation

Published
1998

7. 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

8. Quasifree(e,e′p)Reactions and Proton Propagation in Nuclei

Author

Alan M. Nathan, E. R. Kinney, A.O. Mateos, O. K. Baker, W. J. Cummings, Wolfgang Lorenzon, J. Reinhold, S. Barrow, D. H. Potterveld, V. Frolov, A. Ahmidouch, H. Mkrtchyan, R. E. Segel, Donal Day, B. Terburg, Ketevi Assamagan, L. G. Tang, C. Yan, K. Beard, R. Mohring, D. van Westrum, E. E. W. Bruins, J.-E. Ducret, J. Cha, Dipangkar Dutta, C. E. Keppel, P. Stoler, B. Zeidman, R. Suleiman, E. Belz, V. Tadevosyan, Kevin Bailey, R. D. Carlini, J.-O. Hansen, S. Danagoulian, Gabriel Niculescu, C. S. Armstrong, D. Abbott, C. Salgado, C. E. Jones, H. T. Fortune, D. Koltenuk, John C. Mitchell, Haiyan Gao, S. A. Wood, T. Eden, J. Arrington, W. Hinton, J. C. Yang, Thomas O'Neill, Ross Milner, J. W. Martin, H. E. Jackson, L. H. Kramer, J. Yu, J. A. Dunne, D. Beatty, S. Beedoe, R. J. Holt, C. Cothran, Ronald Gilman, J. W. Price, C. R. Jackson, Pete Markowitz, I. Niculescu, B. Zihlmann, M. Khandaker, Pat Welch, M. A. Miller, F. Duncan, David Mack, J. P. Schiffer, D. G. Meekins, Rolf Ent, Paul Gueye, E. J. Beise, D. F. Geesaman, C. Bochna, D. DeSchepper, Avraham Klein, K. McFarlane, R. Madey, W. Kim, C. F. Williamson, W. Zhao, Ts A. Amatuni, H. Breuer, S. B. Kaufman, James J. Kelly, and N. S. Chant

Subjects
Nuclear physics, Physics, Missing energy, Proton, Nuclear transparency, Scattering, Attenuation, Momentum transfer, Plane wave, General Physics and Astronomy, Atomic physics, Impulse (physics), Nuclear Experiment
Abstract

The (e,e'p) reaction was studies on targets of C, Fe, and Au at momentum transfers squared Q{sup 2} of 0.6, 1.3, 1.8 and 3.3 GeV{sup 2} in a region of kinematics dominated by quasifree electron-proton scattering. Missing energy and missing momentum distributions are reasonably well described by plane wave impulse approximation calculations with Q{sup 2} and A dependent corrections that measure the attenuation of the final state protons.

Published
1998

9. 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

10. Determination of the pion charge form factor forQ2=0.60–1.60 GeV2

Author

D. van Westrum, Ketevi Assamagan, R. van der Meer, J. Reinhold, V. Tadevosyan, C. S. Armstrong, P. H. Kim, W. Zhao, I. Niculescu, K. Vansyoc, D. Gaskell, W. Hinton, H. E. Jackson, B. Zihlmann, Andreas Klein, J. A. Dunne, D. McKee, Ronald Gilman, C. Yan, W. F. Vulcan, Rolf Ent, H. Mkrtchyan, D. Abbott, D. G. Meekins, J. Arrington, M. K. Jones, W. Kim, G. J. Lolos, H. Anklin, Oliver Keith Baker, John C. Mitchell, T. Eden, S. Stepanyan, A. F. Lung, C. Bochna, D. H. Potterveld, L. M. Qin, K. Gustafsson, G. Niculescu, I. K. Shin, C. E. Keppel, H. Breuer, S. A. Wood, D. J. Mack, Stephen Avery, N. S. Chant, B. Mueller, M. Liang, E. J. Brash, J. Volmer, G. M. Huber, D. Koltenuk, D. Pitz, H. P. Blok, and L. G. Tang

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Cross section.transverse, Pion, 010308 nuclear & particles physics, Hydrogen-1, 0103 physical sciences, Form factor (quantum field theory), Charge (physics), 010306 general physics, 01 natural sciences
Abstract

The data analysis for the reaction {sup 1}H(e,e{sup '}{pi}{sup +})n, which was used to determine values for the charged pion form factor F{sub {pi}} for values of Q{sup 2}= 0.6-1.6 GeV{sup 2}, has been repeated with careful inspection of all steps and special attention to systematic uncertainties. Also the method used to extract F{sub {pi}} from the measured longitudinal cross section was critically reconsidered. Final values for the separated longitudinal and transverse cross sections and the extracted values of F{sub {pi}} are presented.

Published
2007

11. Separated response functions in exclusive, forward pi(+/-) electroproduction on deuterium

Author

L. Pentchev, L. G. Tang, S. Jin, D. van Westrum, D. G. Meekins, C. C. Chang, John C. Mitchell, C. Yan, H. C. Fenker, E. J. Beise, P. E. Reimer, G. M. Huber, John Arrington, W. U. Boeglin, P. M. King, G. R. Smith, D. Koltenuk, X. Zheng, D. J. Margaziotis, V. Kovaltchouk, H. P. Blok, B. Mueller, S. A. Wood, T. Eden, W. Hinton, M. Liang, Ketevi Assamagan, D. McKee, Joerg Reinhold, A. J. Sarty, V. Tvaskis, S. Vidakovic, V. Tadevosyan, R. J. Holt, W. F. Vulcan, D. J. Mack, L. M. Qin, C. S. Armstrong, Stephen Avery, Ronald Gilman, I. K. Shin, D. Abbott, K. A. Aniol, B. Zihlmann, C. E. Keppel, P. H. Kim, W. Zhao, J. Volmer, Y. Okayasu, D. H. Potterveld, H. E. Jackson, M. K. Jones, E. J. Brash, G. J. Lolos, J. Roche, H. Breuer, Tanja Horn, R. L.J. van der Meer, K. Vansyoc, C. Butuceanu, H. Anklin, C. Xu, D. Gaskell, N. S. Chant, D. Pitz, C. Bochna, I. Niculescu, Glen A. Warren, K. Gustafsson, E. F. Gibson, S. Stepanyan, H. Mkrtchyan, P. G. Roos, Avraham Klein, A. Matsumura, O. K. Baker, A. Lung, T. Miyoshi, C. F. Perdrisat, Rolf Ent, Jin Liu, M. E. Christy, W. Kim, G. Niculescu, Pete Markowitz, J. A. Dunne, B. Barrett, V. A. Punjabi, and Student Lab and Education

Subjects
Quantum chromodynamics, Quark, Physics, Nuclear and High Energy Physics, Particle physics, SDG 16 - Peace, Meson, Isoscalar, SDG 16 - Peace, Justice and Strong Institutions, Form factor (quantum field theory), Virtual particle, Parton, Justice and Strong Institutions, Nuclear physics, Pion, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Background: Measurements of forward exclusive meson production at different squared four-momenta of the exchanged virtual photon, $Q^2$, and at different four-momentum transfer, t, can be used to probe QCD's transition from meson-nucleon degrees of freedom at long distances to quark-gluon degrees of freedom at short scales. Ratios of separated response functions in $\pi^-$ and $\pi^+$ electroproduction are particularly informative. The ratio for transverse photons may allow this transition to be more easily observed, while the ratio for longitudinal photons provides a crucial verification of the assumed pole dominance, needed for reliable extraction of the pion form factor from electroproduction data. Method: Data were acquired with 2.6-5.2 GeV electron beams and the HMS+SOS spectrometers in Jefferson Lab Hall C, at central $Q^2$ values of 0.6, 1.0, 1.6 GeV$^2$ at W=1.95 GeV, and $Q^2$=2.45 GeV$^2$ at W=2.22 GeV. There was significant coverage in $\phi$ and $\epsilon$, which allowed separation of $\sigma_{L,T,LT,TT}$. Results: $\sigma_L$ shows a clear signature of the pion pole, with a sharp rise at small -t. In contrast, $\sigma_T$ is much flatter versus t. The longitudinal/transverse ratios evolve with $Q^2$ and t, and at the highest $Q^2$=2.45 GeV$^2$ show a slight enhancement for $\pi^-$ production compared to $\pi^+$. The $\pi^-/\pi^+$ ratio for transverse photons exhibits only a small $Q^2$-dependence, following a nearly universal curve with t, with a steep transition to a value of about 0.25, consistent with s-channel quark knockout. The $\sigma_{TT}/\sigma_T$ ratio also drops rapidly with $Q^2$, qualitatively consistent with s-channel helicity conservation. The $\pi^-/\pi^+$ ratio for longitudinal photons indicates a small isoscalar contamination at W=1.95 GeV, consistent with what was observed in our earlier determination of the pion form factor at these kinematics., Comment: 25 pages, 16 figures, 6 tables

Published
2015

12. Electroproduction of strangeness on [sub Λ][sup 3,4]H bound states on Helium

Author

A. Lung, L. Cole, Rolf Ent, A. Yu. Semenov, D. S. Brown, A. Cochran, H. E. Jackson, John C. Mitchell, R. Asaturyan, K. Gustafsson, Joerg Reinhold, H. C. Fenker, K. Garrow, J. Roche, T. Eden, J. Crowder, P. E. Reimer, G. Collins, Pete Markowitz, Thomas O'Neill, S. A. Wood, H. Breuer, W. Hinton, J.-O. Hansen, Brian Raue, J. A. Dunne, L. A. Ewell, F. Dohrmann, A. Uzzle, P. Ambrozewicz, C. J. Martoff, I. Niculescu, J. W. Price, D. J. Mack, H. Bitao, C. Yan, M. Sarsour, E. Christy, D. H. Potterveld, M. Elaasar, Paul Gueye, A. Ahmidouch, S. Beedoe, L. G. Tang, D. F. Geesaman, Stephen Avery, F. Duncan, H. Mkrtchyan, C. Cothran, R. Sawafta, Y. Liang, L. Yuan, S. Stepanyan, B. Zihlmann, P. G. Roos, Avraham Klein, S. Mtingwa, R. E. Segel, M. Zeier, Kevin Bailey, J. H. Liu, V. Tadevosian, J. Cha, B. Terburg, S. Tajima, R. Mohring, D. G. Meekins, R. Madey, Dipangkar Dutta, N. S. Chant, S. Danagoulian, H. Juengst, G. Savage, C. E. Keppel, G. Niculescu, Ketevi Assamagan, R. D. Carlini, B. Mueller, L. Gan, W. J. Cummings, H. Yamaguchi, J. Arrington, C. S. Armstrong, D. Abbott, D. Koltenuk, Y. Fujii, Haiyan Gao, B. Zeidman, Toshinobu Miyoshi, Yoichi Sato, H. T. Fortune, and K. Hafidi

Subjects
Physics, Particle physics, chemistry.chemical_element, Particle accelerator, Strangeness, Lambda baryon, Lambda, law.invention, Nuclear physics, Helium-4, chemistry, law, Helium-3, Bound state, Helium
Abstract

The A(e,e'K+)X reaction has been investigated at Jefferson Laboratory. Data were taken for Q2 {approx_equal} 0.35 GeV2 at a beam energy of 3.245 GeV for 1H,3He and 4He targets. Evidence for {lambda}-hypernuclear bound states is seen for 3,4He targets. This is the first time that the electroproduction of these hypernuclei has been observed.

Published
2005

13. Near threshold electroproduction of theωmeson atQ2≈0.5GeV2

Author

L. Ewell, J. Arrington, D. Abbott, S. Danagoulian, J. A. Dunne, John C. Mitchell, D. G. Meekins, Brian Raue, T. Eden, J.-O. Hansen, J. Reinhold, H. Mkrtchyan, H. T. Fortune, Dipanwita Dutta, L. G. Tang, V. Tadevosyan, Oliver Keith Baker, R. Sawafta, G. Niculescu, C. Cothran, Richard Madey, B. Zihlmann, D. H. Potterveld, Kevin Bailey, B. Zeidman, Ketevi Assamagan, R. D. Carlini, Andreas Klein, Donal Day, B. Terburg, J. W. Price, Pete Markowitz, J. Cha, C. Yan, C. S. Armstrong, W. J. Cummings, D. Koltenuk, A. Ahmidouch, K. Gustafsson, F. Duncan, G. Collins, Thomas O'Neill, I. Niculescu, Rolf Ent, G. Savage, Haiyan Gao, W. Hinton, Paul Gueye, D. F. Geesaman, S. A. Wood, S. Stepanyan, P. G. Roos, H. Breuer, D. J. Mack, C. E. Keppel, R. E. Segel, R. Mohring, S. Beedoe, S. Mtingwa, P. Ambrozewicz, and C. J. Martoff

Subjects
Physics, Nuclear and High Energy Physics, Angular range, Particle physics, Photon, Meson production, Meson, 010308 nuclear & particles physics, Parity (physics), 01 natural sciences, Omega, Nuclear physics, Near threshold, Angular distribution, 0103 physical sciences, Nuclear Experiment, 010306 general physics
Abstract

Electroproduction of the {omega} meson was investigated in the {sup 1}H(e,e{sup '}p){omega} reaction. The measurement was performed at a four-momentum transfer Q{sup 2}{approx_equal}0.5 GeV{sup 2}. Angular distributions of the virtual photon-proton center-of-momentum cross sections have been extracted over the full angular range. These distributions exhibit a strong enhancement over t-channel parity exchange processes in the backward direction. According to a newly developed electroproduction model, this enhancement provides significant evidence of resonance formation in the {gamma}*p{yields}{omega}p reaction channel.

Published
2004

14. Electroproduction of Strangeness on Light Nuclei

Author

F. DOHRMANN, D. ABBOTT, A. AHMIDOUCH, P. AMBROZEWICZ, C.S. ARMSTRONG, J. ARRINGTON, R. ASATURYAN, K. ASSAMAGAN, S. AVERY, K. BAILEY, O.K. BAKER, S. BEEDOE, H. BITAO, H. BREUER, D.S. BROWN, R. CARLINI, J. CHA, N. CHANT, E. CHRISTY, A. COCHRAN, L. COLE, G. COLLINS, C. COTHRAN, J. CROWDER, W.J. CUMMINGS, S. DANAGOULIAN, F. DUNCAN, J. DUNNE, D. DUTTA, T. EDEN, M. ELAASAR, R. ENT, L. EWELL, H. FENKER, H.T. FORTUNE, Y. FUJII, L. GAN, H. GAO, K. GARROW, D.F. GEESAMAN, P. GUEYE, K. GUSTAFSSON, K. HAFIDI, J.O. HANSEN, W. HINTON, H.E. JACKSON, H. JUENGST, C. KEPPEL, A. KLEIN, D. KOLTENUK, Y. LIANG, J.H. LIU, A. LUNG, D. MACK, R. MADEY, P. MARKOWITZ, C.J. MARTOFF, D. MEEKINS, J. MITCHELL, T. MIYOSHI, H. MKRTCHYAN, R. MOHRING, S.K. MTINGWA, B. MUELLER, T.G. O’NEILL, G. NICULESCU, I. NICULESCU, D. POTTERVELD, J.W. PRICE, B.A. RAUE, P.E. REIMER, J. REINHOLD, J. ROCHE, P. ROOS, M. SARSOUR, Y. SATO, G. SAVAGE, R. SAWAFTA, R.E. SEGEL, A.YU. SEMENOV, S. STEPANYAN, V. TADEVOSIAN, S. TAJIMA, L. TANG, B. TERBURG, A. UZZLE, S. WOOD, H. YAMAGUCHI, C. YAN, L. YUAN, M. ZEIER, B. ZEIDMAN, and B. ZIHLMANN

Subjects
Physics, Light nucleus, Electroproduction, Nuclear Theory, Strangeness, Hyperons, Spectral function, Nuclear physics, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Nuclear Experiment, Hypernuclear boundstates, Electroproduction of strangeness, Nuclear targets
Abstract

The A(e,e'K+)YX reaction has been investigated in Hall C at Jefferson Laboratory for 6 different targets. Data were taken for Q2)approx 0.35 and 0.5 GeV2) at a beam energy of 3.245GeV for 1)H, 2)H, 3)He, 4)He, C and Al targets. The missing mass spectra are fitted with Monte Carlo simulations taking into account the production of Lambda and Sigma0) hyperon production off the proton, and Sigma-) off the neutron. Models for quasifree production are compared to the data, excess yields close to threshold are attributed to FSI. Evidence for Lambda-hypernuclear bound states is seen for 3,4)He targets.

Published
2004

15. Quasielastic(e,e′p)reaction onC12,Fe56, andAu197

Author

D. Dutta, D. van Westrum, D. Abbott, A. Ahmidouch, Ts. A. Amatuoni, C. Armstrong, J. Arrington, K. A. Assamagan, K. Bailey, O. K. Baker, S. Barrow, K. Beard, D. Beatty, S. Beedoe, E. Beise, E. Belz, C. Bochna, P. E. Bosted, H. Breuer, E. E. W. Bruins, R. Carlini, J. Cha, N. Chant, C. Cothran, W. J. Cummings, S. Danagoulian, D. Day, D. DeSchepper, J.-E. Ducret, F. Duncan, J. Dunne, T. Eden, R. Ent, H. T. Fortune, V. Frolov, D. F. Geesaman, H. Gao, R. Gilman, P. Guèye, J. O. Hansen, W. Hinton, R. J. Holt, C. Jackson, H. E. Jackson, C. Jones, S. Kaufman, J. J. Kelly, C. Keppel, M. Khandaker, W. Kim, E. Kinney, A. Klein, D. Koltenuk, L. Kramer, W. Lorenzon, A. Lung, K. McFarlane, D. J. Mack, R. Madey, P. Markowitz, J. Martin, A. Mateos, D. Meekins, M. A. Miller, R. Milner, J. Mitchell, R. Mohring, H. Mkrtchyan, A. M. Nathan, G. Niculescu, I. Niculescu, T. G. O’Neill, D. Potterveld, J. W. Price, J. Reinhold, C. Salgado, J. P. Schiffer, R. E. Segel, P. Stoler, R. Suleiman, V. Tadevosyan, L. Tang, B. Terburg, T. P. Welch, C. Williamson, S. Wood, C. Yan, J.-C. Yang, J. Yu, B. Zeidman, W. Zhao, and B. Zihlmann

Subjects
Physics, Nuclear and High Energy Physics, Mathematical physics
Published
2003

16. Separation of the longitudinal and transverse cross sections in the1H(e,e′K+)Λand1H(e,e′K+)Σ0reactions

Author

A. Ahmidouch, M. Harvey, S. Beedoe, T. P. Welch, John C. Mitchell, T. Eden, M. Maeda, S. Frullani, F. Duncan, A. F. Lung, K. Gustafsson, K. Kino, S. A. Wood, Paul Gueye, D. F. Geesaman, M. Finn, W. F. Vulcan, Brian Raue, Ts A. Amatuni, Guido Urciuoli, S. Mtingwa, J. A. Dunne, Christophe Furget, D. J. Mack, P. Ambrozewicz, F. Garibaldi, P. Stoler, V. Tadevosian, Kevin Bailey, H. Breuer, Stephen Avery, V. Frolov, H. Mkrtchyan, Terry Mart, T. Saito, D. Abbott, C. Yan, D. Koltenuk, C. C. Chang, S. Stepanyan, P. G. Roos, C. E. Keppel, W. Hinton, S. Danagoulian, W. Kim, J. Cha, Dipangkar Dutta, D. H. Potterveld, Rolf Ent, A. Mihul, G. Collins, D. G. Meekins, J. Arrington, E. V. Hungerford, C. S. Armstrong, E. Cisbani, L. Eyraud, R. Perrino, W. J. Cummings, Laird Kramer, J. Volmer, Hiroaki Tsubota, L. A. Ewell, E. J. Beise, S. Majewski, T. Angelescu, S. Kox, R. E. Segel, C. J. Martoff, B. Zeidman, G. Savage, Mauro Iodice, T. Terasawa, K. Beard, D. Gaskell, R. Mohring, L. Teodorescu, C. Jackson, R. Williams, J.-O. Hansen, I. Niculescu, Pete Markowitz, J. S. Real, R. De Leo, R. Madey, R. D. Carlini, J. W. Price, L. G. Tang, R. Sawafta, N. S. Chant, Ketevi Assamagan, J. Reinhold, T. Leone, and T. Fortune

Subjects
Physics, Nuclear and High Energy Physics, Meson production, 010308 nuclear & particles physics, Hyperon, Virtual particle, Lambda, 01 natural sciences, Transverse plane, 0103 physical sciences, Invariant mass, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

We report measurements of cross sections for the reaction ${}^{1}\mathrm{H}{(e,e}^{\ensuremath{'}}{K}^{+})Y,$ for both the \ensuremath{\Lambda} and ${\ensuremath{\Sigma}}^{0}$ hyperon states, at an invariant mass of $W=1.84\mathrm{GeV}$ and four-momentum transfers $0.5l{Q}^{2}l2(\mathrm{GeV}{/c)}^{2}.$ Data were taken for three values of virtual photon polarization $\ensuremath{\epsilon},$ allowing the decomposition of the cross sections into longitudinal and transverse components. The \ensuremath{\Lambda} data are a revised analysis of prior work, whereas the ${\ensuremath{\Sigma}}^{0}$ results have not been previously reported.

Published
2003

17. ELECTROPRODUCTION OF STRANGENESS ON LIGHT NUCLEI

Author

R. Carlini, M. Elaasar, F. Dohrmann, I. Niculescu, H. E. Jackson, G. Savage, H. Yamaguchi, J. Roche, H. G. Juengst, S. A. Wood, S. Danagoulian, D. Abbott, Paul Gueye, T. Eden, G. Niculescu, M. Zeier, M. Sarsour, C. J. Martoff, L. Cole, Stephen Avery, R. E. Segel, J. Crowder, Y. Liang, B. Terburg, P. G. Roos, Avraham Klein, H. Mkrtchyan, Rolf Ent, Ketevi Assamagan, S. Beedoe, Cynthia Keppel, P. E. Reimer, J. W. Price, Y. Fujii, B. Zeidman, R. Mohring, O. K. Baker, D. Koltenuk, J. H. Liu, R. Asaturyan, J. H. Mitchell, H. Bitao, P. Ambrozewicz, N. Chant, A. Ahmidouch, W. Hinton, B. Zihlmann, D. G. Meekins, D. F. Geesaman, S. Mtingwa, A. Uzzle, T. Miyoshi, V. Tadevosian, K. Gustafsson, S. S. Stepanyan, David Mack, L. G. Tang, R. Sawafta, Kevin Bailey, C. S. Armstrong, Chenyu Yan, L. Yuan, D. H. Potterveld, E. Christy, C. Cothran, P. Markowitz, L. Gan, A. Yu. Semenov, W. J. Cummings, G. Collins, F. Duncan, Thomas O'Neill, Joerg Reinhold, K. Garrow, A. Lung, J. Cha, Dipangkar Dutta, R. Madey, D. S. Brown, A. Cochran, J. Arrington, J. O. Hansen, Haiyan Gao, James Dunne, H. Fenker, B. Mueller, Yoichi Sato, H. Breuer, H. T. Fortune, B. A. Raue, K. Hafidi, S. Tajima, and L. A. Ewell

Subjects
Nuclear physics, Physics, Light nucleus, Strangeness
Published
2003

18. Measurement of longitudinal and transverse cross sections in the3He(e,e′π+)3Hreaction atW=1.6 GeV

Author

J. Cha, Dipangkar Dutta, I. Niculescu, D. McKee, V. Tadevosyan, B. Mueller, Kevin Bailey, J. Arrington, B. Beise, P. Ambrozewicz, B. Zihlmann, D. Schepper, S. A. Wood, H. Breuer, J. A. Dunne, Toshiyuki Takahashi, H. Mkrtchyan, B. Terburg, R. D. Carlini, L. Gan, D. J. Mack, Paul Gueye, L. G. Tang, D. H. Potterveld, D. F. Geesaman, Ketevi Assamagan, Stephen Avery, R. Sawafta, R. E. Segel, N. S. Chant, John C. Mitchell, T. P. Welch, S. Stepanyan, P. G. Roos, D. Gaskell, V. Papavassiliou, C. Jackson, G. Hofman, B. Zeidman, Thomas O'Neill, C. E. Keppel, C. Glashausser, A. Lung, M. Harvey, J. Reinhold, Rolf Ent, D. Koltenuk, D. S. Brown, S. Beedoe, A. Gasparian, J. Volmer, A. A. Cowley, Osamu Hashimoto, H. E. Jackson, O. K. Baker, H. Anklin, A. Ahmidouch, L. Yuan, E. R. Kinney, D. van Westrum, S. Danagoulian, G. Niculescu, W. Hinton, and Ronald Gilman

Subjects
Physics, Nuclear and High Energy Physics, Meson production, Photon, Nuclear Theory, Virtual particle, Polarization (waves), Nuclear physics, Transverse plane, Pion, Pi, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Nucleon
Abstract

The coherent 3He(e,e{pi}+)3H reaction was measured at Q2 = 0.4 (GeV/c)2 and W = 1.6 GeV for two values of the virtual photon polarization, {epsilon}, allowing the separation of longitudinal and transverse cross sections. The results from the coherent process on 3He were compared to H(e,e{pi}+)n data taken at the same kinematics. This marks the first direct comparison of these processes. At these kinematics (p{pi} = 1.1 GeV/c), pion rescattering from the spectator nucleons in the 3He(e,e{pi}+)3H process is expected to be small, simplifying the comparison to {pi}+ production from the free proton.

Published
2001

19. Longitudinal Electroproduction of Charged Pions fromH1,H2, andH3e

Author

A. Cowley, P. Ambrozewicz, Ronald Gilman, P. Roos, D. Van Westrum, R. Carlini, B. Beise, B. Zeidman, D. McKee, P. Gueye, H. Anklin, C. Jackson, D. Dutta, D. S. Brown, O. Hashimoto, J. Cha, R. Segel, M. Harvey, A. Lung, R. Ent, J. Mitchell, A. Gasparian, T. Takahashi, L. Yuan, L. Gan, T. G. O'Neill, D. Potterveld, I. Niculescu, T. P. Welch, Stephen Avery, B. Zihlmann, H. E. Jackson, J. Reinhold, D. F. Geesaman, H. Breuer, V. Papavassiliou, G. Kyle, S. Stepanyan, W. Hinton, G. Niculescu, N. Chant, J. Volmer, J. Arrington, D. Mack, K. Bailey, D. Koltenuk, V. Tadevosyan, D. De Schepper, C. Glashausser, E. Kinney, B. Mueller, O. K. Baker, B. Terburg, K. Assamagan, A. Ahmidouch, R. Sawafta, D. Gaskell, James Dunne, L. Tang, S. Danagoulian, G. Hofman, C. Keppel, H. Mkrtchyan, S. Beedoe, and S. Wood

Subjects
Physics, Particle physics, Meson, Nuclear Theory, Hadron, General Physics and Astronomy, Fermi surface, Elementary particle, Nuclear physics, Pion, Recoil, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment, Boson
Abstract

Separated longitudinal and transverse cross sections for charged pion electroproduction from (1)H, (2)H, and (3)He were measured at Q(2) = 0.4 (GeV/c)(2) for two values of the invariant mass, W = 1.15 GeV and W = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in (3)He at W = 1.60 GeV. The W = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.

Published
2001

20. xandξscaling of the nuclear structure function at largex

Author

J. Zhao, D. Koltenuk, Ingo Sick, C. E. Keppel, W. F. Vulcan, B. Zihlmann, D. G. Crabb, A. Honegger, Curtis Smith, B. Bray, J. Jourdan, G. Niculescu, B. W. Filippone, Dipangkar Dutta, Donal Day, J. H. Mitchell, B. Terburg, C. S. Armstrong, J. Arrington, T. Averett, James McCarthy, G. Collins, J. Jensen, R. A. Lindgren, A. Lung, R. D. Carlini, O. Rondon, I. Niculescu, S. A. Wood, W.U. Boeglin, C. Cothran, D. J. Mack, T. Petitjean, R. D. McKeown, C. Yan, H. Mkrtchyan, Oliver Keith Baker, L.J. de Bever, J. A. Dunne, D. G. Meekins, C. Bochna, E. W. Hughes, and Rolf Ent

Subjects
Physics, Momentum, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Scattering, Momentum transfer, Nuclear structure, Inelastic scattering, Nuclear Experiment, Nucleon, Electron scattering, Scaling
Abstract

Inclusive electron scattering data are presented for ^2H, C, Fe, and Au targets at an incident electron energy of 4.045 GeV for a range of momentum transfers from Q^2=1 to 7 (GeV/c)^2. Data were taken at Jefferson Laboratory for low values of energy loss, corresponding to values of Bjorken x ≳ 1. The structure functions do not show scaling in x in this range, where inelastic scattering is not expected to dominate the cross section. The data do show scaling, however, in the Nachtmann variable ξ. This scaling appears to be the result of Bloom- Gilman duality in the nucleon structure function combined with the Fermi motion of the nucleons in the nucleus. The resulting extension of scaling to larger values of ξ opens up the possibility of accessing nuclear structure functions in the high-x region at lower values of Q^2 than previously believed.

Published
2001

21. Measurement of the Charged Pion Electromagnetic Form Factor

Author

J. Volmer, D. Abbott, H. Anklin, C. Armstrong, J. Arrington, K. Assamagan, S. Avery, O. K. Baker, H. P. Blok, C. Bochna, E. J. Brash, H. Breuer, N. Chant, J. Dunne, T. Eden, R. Ent, D. Gaskell, R. Gilman, K. Gustafsson, W. Hinton, G. M. Huber, H. Jackson, M. K. Jones, C. Keppel, P. H. Kim, W. Kim, A. Klein, D. Koltenuk, M. Liang, G. J. Lolos, A. Lung, D. J. Mack, D. McKee, D. Meekins, J. Mitchell, H. Mkrtchyan, B. Mueller, G. Niculescu, I. Niculescu, D. Pitz, D. Potterveld, L. M. Qin, J. Reinhold, I. K. Shin, S. Stepanyan, V. Tadevosyan, L. G. Tang, R. L. J. van der Meer, K. Vansyoc, D. Van Westrum, W. Vulcan, S. Wood, C. Yan, W.-X. Zhao, B. Zihlmann, and (Astro)-Particles Physics

Subjects
Physics, Particle physics, 010308 nuclear & particles physics, Momentum transfer, Form factor (quantum field theory), Magnetic monopole, FOS: Physical sciences, General Physics and Astronomy, Charge (physics), 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Transverse plane, Cross section (physics), Pion, 0103 physical sciences, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics
Abstract

Separated longitudinal and transverse structure functions for the reaction 1H(e,eprime pi+)n were measured in the momentum transfer region Q2=0.6-1.6 (GeV/c)**2 at a value of the invariant mass W=1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parameterization fitted to very low Q2 elastic data., Comment: 5 pages, 3 figures

Published
2001

22. Experimental Verification of Quark-Hadron Duality

Author

S. A. Wood, D. Koltenuk, C. S. Armstrong, R. J. Holt, D. van Westrum, B. W. Filippone, D. J. Mack, J. Reinhold, B. Zeidman, Paul Gueye, John Arrington, J. A. Dunne, C. E. Keppel, C. Cothran, G. Niculescu, L. G. Tang, R. E. Segel, R. D. Carlini, Douglas H Beck, Rolf Ent, W. F. Vulcan, Donal Day, R. Mohring, B. Terburg, Haiyan Gao, W. Hinton, C. Bochna, P. Stoler, D. G. Meekins, J. H. Mitchell, J. W. Price, J. Cha, Dipangkar Dutta, D. F. Geesaman, D. Potterveld, I. Niculescu, O. K. Baker, Ketevi Assamagan, H. E. Jackson, V. Frolov, M. A. Miller, and C. Yan

Subjects
Quark, Physics, Particle physics, Hadron, Nuclear Theory, General Physics and Astronomy, Duality (optimization), Elementary particle, Resonance (particle physics), Nuclear physics, Magnetic form factor, Twist, Nucleon, Nuclear Experiment, Caltech Library Services
Abstract

A newly-obtained sample of inclusive electron-nucleon scattering data has been analyzed for precision tests of quark-hadron duality. The data are in the nucleon resonance region, and span the range 0.3 < Q{sup 2} < 5.0 (GeV/c){sup 2}. Duality is observed both in limited and extended regions around the prominent resonance enhancements. Higher twist contributions to the F{sub 2} structure function are found to be minimal on average, even in the low Q{sub 2} regime of approximately 0.5 (GeV/c){sup 2}. The proton magnetic form factor, extracted from purely inelastic data assuming duality, is in good agreement with the direct measurements. In all cases, duality appears to be a non-trivial property of the nucleon structure function.

Published
2000

23. Separated spectral functions for the quasifree12C(e,e′p)reaction

Author

R. E. Segel, W. Kim, K. Beard, R. Mohring, A.O. Mateos, D. van Westrum, S. A. Wood, J. C. Yang, S. Barrow, P. Stoler, C. E. Keppel, M. A. Khandaker, John C. Mitchell, C. Jackson, L. G. Tang, S. Danagoulian, T. Eden, Gabriel Niculescu, R. J. Sutter, D. Abbott, R. Sawafta, H. T. Fortune, C. Bochna, Alan M. Nathan, J. Yu, P. E. Bosted, I. Niculescu, O. K. Baker, Ketevi Assamagan, J. W. Martin, Donal Day, B. Terburg, T. P. Welch, E. R. Kinney, J. Reinhold, A. Ahmidouch, V. Tadevosyan, D. Beatty, Kevin Bailey, Ross Milner, E. Meier, C. Cothran, Ts A. Amatuni, E. Belz, Paul Gueye, R. E. Chrien, B. Zihlmann, D. F. Geesaman, Avraham Klein, C. Salgado, H. Breuer, Wolfgang Lorenzon, J. Arrington, D. DeSchepper, J.-E. Ducret, J. A. Dunne, J.-O. Hansen, D. G. Meekins, J. P. Schiffer, W. Hinton, R. Suleiman, E. J. Beise, S. B. Kaufman, Rolf Ent, H. E. Jackson, C. Yan, R. Madey, C. F. Williamson, V. Frolov, H. Mkrtchyan, R. D. Carlini, R. J. Holt, D. H. Potterveld, J. W. Price, W. Zhao, J. Cha, James J. Kelly, Ronald Gilman, Dipangkar Dutta, N. S. Chant, C. S. Armstrong, Pete Markowitz, E. E.W. Bruins, K. McFarlane, David Mack, S. Beedoe, C. E. Jones, L. H. Kramer, Thomas O'Neill, M. A. Miller, F. Duncan, Haiyan Gao, W. J. Cummings, D. Koltenuk, and B. Zeidman

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Missing energy, Proton, Nuclear Theory, Momentum transfer, Nuclear physics, Momentum, Parallel kinematics, Transverse plane, Physics::Accelerator Physics, Atomic physics, Nuclear Experiment, Nucleon
Abstract

A separation of the longitudinal and transverse 12 C(e, e8p) cross sections in the quasifree region has been performed in parallel kinematics at Q 2 of 0.64 and 1.8 GeV 2 for initial proton momentum ,80 MeV. The separated transverse and longitudinal spectral functions at Q 2 50.64 GeV 2 show significant differences for missing energy between 25 and 60 MeV indicating a breakdown in the single nucleon knockout picture. The transverse spectral functions exhibit definite momentum transfer dependence.

Published
2000

24. Coherentπ0photoproduction on the deuteron up to 4 GeV

Author

M. Witkowski, R. E. Segel, D. H. Potterveld, H. Breuer, C. Bochna, B. Zeidman, Ronald Ransome, D. G. Meekins, J. Cha, G. Collins, S. Barrow, R. Mohring, Thomas O'Neill, P. Stoler, Dipangkar Dutta, V. Frolov, S. F. Pate, H. Mkrtchyan, H. T. Fortune, E. J. Beise, D. Abbott, S. A. Wood, P. M. Rutt, J.-O. Hansen, N. Simicevic, C. S. Armstrong, Alan M. Nathan, R. Madey, Pete Markowitz, E. R. Kinney, R. Suleiman, David Mack, D. Beatty, C. Cothran, L. G. Tang, C. E. Keppel, W. Hinton, P. E. Bosted, I. Niculescu, S. E. Williamson, Haiyan Gao, R. V. Cadman, B. W. Filippone, J. Reinhold, O. K. Baker, W. F. Vulcan, Douglas H Beck, L. Cardman, Ronald Gilman, G. J. Kumbartzki, J. A. Dunne, R. D. McKeown, T. Eden, R. D. Carlini, A. Ahmidouch, M. Harvey, K. McFarlane, J. H. Mitchell, R. J. Holt, M. Khandaker, Ketevi Assamagan, Paul Gueye, A. F. Lung, C. Salgado, M. A. Miller, D. F. Geesaman, F. Duncan, G. Rakness, G. Savage, J. W. Price, J. Napolitano, B. Terburg, D. van Westrum, H. E. Jackson, B. R. Owen, S. Danagoulian, Gabriel Niculescu, Rolf Ent, C. Yan, Z. E. Meziani, J. Arrington, K. Gustafsson, E. J. Brash, D. Koltenuk, J. E. Belz, S. Beedoe, W. J. Cummings, T. A. Forest, N. S. Chant, and Avraham Klein

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Amplitude, Pion, Photon, Meson, Scattering, Hadron, Elementary particle, Photon energy, Nuclear Experiment
Abstract

The differential cross section for ^2H(γ,d)π^0 has been measured at deuteron center-of-mass angles of 90° and 136°. This work reports the first data for this reaction above a photon energy of 1 GeV, and permits a test of the apparent constituent counting rule and reduced nuclear amplitude behavior as observed in elastic ed scattering. Measurements were performed up to a photon energy of 4.0 GeV, and are in good agreement with previous lower energy measurements. Overall, the data are inconsistent with both constituent-counting rule and reduced nuclear amplitude predictions.

Published
1999

25. Electroproduction of theS11(1535)resonance at high momentum transfer

Author

C. S. Armstrong, P. Stoler, G. S. Adams, A. Ahmidouch, K. Assamagan, S. Avery, O. K. Baker, P. Bosted, V. Burkert, R. Carlini, J. Dunne, T. Eden, R. Ent, V. V. Frolov, D. Gaskell, P. Guèye, W. Hinton, C. Keppel, W. Kim, M. Klusman, D. Koltenuk, D. Mack, R. Madey, D. Meekins, R. Minehart, J. Mitchell, H. Mkrtchyan, J. Napolitano, G. Niculescu, I. Niculescu, M. Nozar, J. W. Price, V. Tadevosyan, L. Tang, M. Witkowski, and S. Wood

Subjects
Baryon, Physics, Nuclear physics, Nuclear and High Energy Physics, Meson, Branching fraction, Hadron, Resonance, Elementary particle, Atomic physics, Helicity, Boson
Abstract

The differential cross section for the process p(e, e{prime}p){eta} has been measured at Q{sup 2}=2.4 and 3.6 (GeV/c){sup 2} at center-of-mass energies encompassing the S{sub 11}(1535) resonance. The latter point is the highest-Q{sup 2} exclusive measurement of this process to date. The resonance width and the helicity-1/2 transition amplitude are extracted from the data, and evidence for the possible onset of scaling in this reaction is shown. A lower bound of approximately 0.45 is placed on the S{sub 11}(1535) {r_arrow} p{eta} branching fraction.

Published
1999

26. Inclusive Electron-Nucleus Scattering at Large Momentum Transfer

Author

R. A. Lindgren, C. Bochna, I. Niculescu, D. G. Meekins, W. U. Boeglin, T. Petitjean, T. Averett, S. A. Wood, D. J. Mack, Dipangkar Dutta, C. Cothran, O. Rondon, G. Niculescu, C. E. Keppel, J. Jourdan, C. S. Armstrong, B. Zihlmann, D. G. Crabb, Ingo Sick, Rolf Ent, H. Mkrtchyan, A. Honegger, J. A. Dunne, R. D. Carlini, Oliver Keith Baker, L.J. de Bever, G. Collins, Curtis Smith, J. Zhao, C. Yan, D. Koltenuk, B. W. Filippone, R. D. McKeown, J. Arrington, B. Bray, E. W. Hughes, Donal Day, B. Terburg, J. Jensen, James McCarthy, A. Lung, W. F. Vulcan, and J. H. Mitchell

Subjects
Physics, Series (mathematics), Scattering, Astrophysics::High Energy Astrophysical Phenomena, Momentum transfer, General Physics and Astronomy, FOS: Physical sciences, Electron, Nuclear matter, Nuclear physics, medicine.anatomical_structure, medicine, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment (nucl-ex), Nucleon, Nuclear Experiment, Scaling, Nucleus
Abstract

Inclusive electron scattering is measured with 4.045 GeV incident beam energy from C, Fe and Au targets. The measured energy transfers and angles correspond to a kinematic range for Bjorken $x > 1$ and momentum transfers from $Q^2 = 1 - 7 (GeV/c)^2$. When analyzed in terms of the y-scaling function the data show for the first time an approach to scaling for values of the initial nucleon momenta significantly greater than the nuclear matter Fermi-momentum (i.e. $> 0.3$ GeV/c)., 5 pages TEX, 5 Postscript figures also available at http://www.krl.caltech.edu/preprints/OAP.html

Published
1998
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27. Configuration off18O}(7.12 MeV,4+)

Author

D. Koltenuk and Fortune Ht

Subjects
Physics, Nuclear and High Energy Physics, Oxygen-18, Light nucleus, Helium ions, SHELL model, Alpha particle, State (functional analysis), Atomic physics, Charged particle, Ion
Abstract

Alpha-particle widths calculated in a potential model demonstrate that the 7.12-MeV, 4[sub 2][sup +] state of [sup 18]O has about the right alpha width for the dominant four-particle--two-hole 4[sup +] state.

Published
1995

28. Separated response function ratios in exclusive, forward π(±) electroproduction.

Author

Huber GM, Blok HP, Butuceanu C, Gaskell D, Horn T, Mack DJ, Abbott D, Aniol K, Anklin H, Armstrong C, Arrington J, Assamagan K, Avery S, Baker OK, Barrett B, Beise EJ, Bochna C, Boeglin W, Brash EJ, Breuer H, Chang CC, Chant N, Christy ME, Dunne J, Eden T, Ent R, Fenker H, Gibson EF, Gilman R, Gustafsson K, Hinton W, Holt RJ, Jackson H, Jin S, Jones MK, Keppel CE, Kim PH, Kim W, King PM, Klein A, Koltenuk D, Kovaltchouk V, Liang M, Liu J, Lolos GJ, Lung A, Margaziotis DJ, Markowitz P, Matsumura A, McKee D, Meekins D, Mitchell J, Miyoshi T, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Pitz D, Potterveld D, Punjabi V, Qin LM, Reimer PE, Reinhold J, Roche J, Roos PG, Sarty A, Shin IK, Smith GR, Stepanyan S, Tang LG, Tadevosyan V, Tvaskis V, van der Meer RL, Vansyoc K, Van Westrum D, Vidakovic S, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, Yan C, Zhao WX, Zheng X, and Zihlmann B

Abstract

The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=σT(π-)/σT(π+) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive π(±) electroproduction on the deuteron at central Q(2) values of 0.6, 1.0, 1.6  GeV(2) at W=1.95  GeV, and Q(2)=2.45  GeV(2) at W=2.22  GeV. Here, we present the L and T cross sections, with emphasis on RL and RT, and compare them with theoretical calculations. Results for the separated ratio RL indicate dominance of the pion-pole diagram at low -t, while results for RT are consistent with a transition between pion knockout and quark knockout mechanisms.

Published
2014
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29. Longitudinal electroproduction of charged pions from (1)H, (2)H, and (3)He.

Author

Gaskell D, Ahmidouch A, Ambrozewicz P, Anklin H, Arrington J, Assamagan K, Avery S, Bailey K, Baker OK, Beedoe S, Beise B, Breuer H, Brown DS, Carlini R, Cha J, Chant N, Cowley A, Danagoulian S, De Schepper D, Dunne J, Dutta D, Ent R, Gan L, Gasparian A, Geesaman DF, Gilman R, Glashausser C, Gueye P, Harvey M, Hashimoto O, Hinton W, Hofman G, Jackson C, Jackson HE, Keppel C, Kinney E, Koltenuk D, Kyle G, Lung A, Mack D, McKee D, Mitchell J, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, O'Neill TG, Papavassiliou V, Potterveld D, Reinhold J, Roos P, Sawafta R, Segel R, Stepanyan S, Tadevosyan V, Takahashi T, Tang L, Terburg B, Van Westrum D, Volmer J, Welch TP, Wood S, Yuan L, Zeidman B, and Zihlmann B

Abstract

Separated longitudinal and transverse cross sections for charged pion electroproduction from (1)H, (2)H, and (3)He were measured at Q(2) = 0.4 (GeV/c)(2) for two values of the invariant mass, W = 1.15 GeV and W = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in (3)He at W = 1.60 GeV. The W = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.

Published
2001
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30. Measurement of the charged pion electromagnetic form factor.

Author

Volmer J, Abbott D, Anklin H, Armstrong C, Arrington J, Assamagan K, Avery S, Baker OK, Blok HP, Bochna C, Brash EJ, Breuer H, Chant N, Dunne J, Eden T, Ent R, Gaskell D, Gilman R, Gustafsson K, Hinton W, Huber GM, Jackson H, Jones MK, Keppel C, Kim PH, Kim W, Klein A, Koltenuk D, Liang M, Lolos GJ, Lung A, Mack DJ, McKee D, Meekins D, Mitchell J, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, Pitz D, Potterveld D, Qin LM, Reinhold J, Shin IK, Stepanyan S, Tadevosyan V, Tang LG, van der Meer RL, Vansyoc K, Van Westrum D, Vulcan W, Wood S, Yan C, Zhao WX, and Zihlmann B

Abstract

Separated longitudinal and transverse structure functions for the reaction 1H(e,e(')pi(+))n were measured in the momentum transfer region Q2 = 0.6--1.6 (GeV/c)(2) at a value of the invariant mass W = 1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parametrization fitted to very low Q2 elastic data.

Published
2001
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