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19 results on '"C. Bochna"'

1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

7. Measurements of electron-proton elastic cross sections for0.4<Q2<5.5(GeV∕c)2

Author

R. Asaturyan, B. Mueller, L. Cole, D. Gaskell, A. Lung, Pete Markowitz, B. D. Fox, Rolf Ent, D. Meekins, D. S. Brown, A. Gasparian, A. Cochran, J. A. Dunne, H. Breuer, Ronald Ransome, A. J. Sarty, Ross Milner, John Arrington, C. E. Keppel, L. Gan, J. W. Martin, K. Garrow, R. D. Carlini, M. Harvey, A. Bruell, G. Niculescu, E. Schulte, H. P. Blok, R. J. Holt, Paul Gueye, W. U. Boeglin, D. F. Geesaman, N. S. Chant, S. A. Wood, Wolfgang Lorenzon, J. Reinhold, S. Strauch, Curtis Smith, Raphael Noel Tieulent, S. Stepanyan, P. G. Roos, X. Jiang, M. Bouwhuis, S. F. Pate, H. Mkrtchyan, C. Bochna, L. Yuan, M. A. Miller, Thomas O'Neill, A. Uzzle, Stephen Avery, M. Zeier, V. Tadevosyan, C. S. Armstrong, E. Rollinde, V. Papavassiliou, Dipanwita Dutta, O. K. Baker, P. Bosted, Haiyan Gao, I. Niculescu, Alan M. Nathan, E. R. Kinney, L. G. Tang, M. E. Christy, V. Ziskin, B. Zihlmann, R. Sawafta, F. Xiong, Douglas H Beck, Y. Liang, A. Ahmidouch, E. Segbefia, H. C. Fenker, K. McIlhany, J. H. Mitchell, D. H. Potterveld, W. F. Vulcan, R. B. Piercey, S. Danagoulian, D. McKee, and Donal Day

Subjects
Systematic error, Physics, Nuclear and High Energy Physics, Range (particle radiation), Proton, 010308 nuclear & particles physics, Scattering, Momentum transfer, Electron, Polarization (waves), 01 natural sciences, Nuclear physics, Cross section (physics), 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

We report on precision measurements of the elastic cross section for electron-proton scattering performed in Hall C at Jefferson Lab. The measurements were made at 28 distinct kinematic settings covering a range in momentum transfer of 0.4

Published
2004

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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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15. Proton propagation through nuclei and the quasi-free reaction mechanism studied with

Author

Eppo E. W. Bruins, Sheldon Kaufman, V. Tadevosyan, Thomas O'Neill, Wooyoung Kim, John Arrington, Juerg Reinhold, C. Cothran, Kenneth McFarlane, J.-O. Hansen, Carlos Salgado, E. R. Kinney, Richard Madey, C. Yan, Beni Zihlmann, W. Zhao, W. J. Cummings, Shelton Beedoe, H. Mkrtchyan, Ketevi Assamagan, Dave Potterveld, Richard Milner, Donal Day, B. Terburg, Andi Klein, J. Fedchak, Tom Eden, Ralph Segel, Mike Miller, Pete Markowitz, H. T. Fortune, Rolf Ent, Joseph Mitchell, F. Duncan, D. G. Meekins, L. G. Tang, J. A. Dunne, R. D. Carlini, D. van Westrum, E. J. Beise, Jeffrey Martin, C. Bochna, S. Danagoulian, Cathleen Jones, Gabriel Niculescu, D. Beatty, Wolfgang Lorenzon, L. H. Kramer, J. W. Price, David Mack, P. Stoler, D. Abbott, V. V. Frolov, Ben Zeidman, Stephen Barrow, Claude Williamson, Paul Gueye, Mahbub Khandaker, D. F. Geesaman, Jean-Eric Ducret, J. Yu, I. Niculescu, J. P. Schiffer, Oliver K. Baker, James J. Kelly, N. S. Chant, K. Beard, C. Jackson, R. Mohring, R. J. Holt, A. Ahmidouch, C. E. Keppel, E. Belz, Ts A. Amatuni, A. F. Lung, Hal Jackson, W. Hinton, H. Breuer, Riad Suleiman, S. A. Wood, Haiyan Gao, Ronald Gilman, Doug Koltenuk, William Turchinetz, Arthur Mateos, D. DeSchepper, J. C. Yang, Pat Welch, J. Cha, Dipangkar Dutta, and C. S. Armstrong

Subjects
Nuclear reaction, Nuclear physics, Physics, Proton, Momentum transfer, Hadron, Elementary particle, Atomic physics, Nuclear Experiment, Nucleon, Energy (signal processing), Charged particle
Abstract

Jefferson Lab experiment E91-013 measured the energy dependence of proton propagation in nuclei, using the quasi-free (e, e{prime}p) reaction. The ratios of the experimental (e, e{prime}p) cross-sections integrated over the quasi-free region to PWIA calculations are presented as a function of momentum transfer, (0.6 < Q{sup 2} < 3.3 GeV{sup 2}) and target nucleus (C, Fe and Au). As a first step towards a longitudinal and transverse separation of the quasi-free cross-section, a super ratio of the measured to the calculated cross-sections at forward and backward angles is presented.

Published
1997

16. Results from CEBAF experiment E89-012: Measurements of deuteron photo-disintegration up to 4 GeV

Author

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

Subjects
Nuclear reaction, Physics, Particle physics, Proton, Meson, Hadron, Particle accelerator, law.invention, Baryon, Nuclear physics, law, Center of mass, Nuclear Experiment, Nucleon
Abstract

The first measurements of differential cross sections for deuteron photo-disintegration at photon energies up to 4 GeV were performed at the Thomas Jefferson National Accelerator Facility early in 1996. Cross section results for D(γ,p)n at proton center of mass angle of 35°, 53° and 90° will be presented. These results are in good agreement with previous measurements at low energy and extend to higher energies where data were previously unavailable. The 90° degree data show behavior consistent with the constituent counting rules up to 4 GeV and are also in fair agreement with the asymptotic meson exchange model. The 37° and 53° data do not show clear signs of counting rule behavior, although a threshold in transverse momentum for the onset of scaling cannot be excluded.

17. Measurement of the high energy two-body deuteron photodisintegration differential cross section

Author

S. A. Wood, H. C. Fenker, Pete Markowitz, K. McIlhany, Thomas O'Neill, D. J. Mack, Raphael Noel Tieulent, R. J. Holt, X. Jiang, Stephen Avery, D. F. Geesaman, H. P. Blok, Paul Gueye, Alan M. Nathan, E. R. Kinney, V. Ziskin, Dipanwita Dutta, L. Cole, Wolfgang Lorenzon, F. Xiong, C. E. Keppel, Haiyan Gao, B. D. Fox, J. Reinhold, S. Stepanyan, G. Niculescu, P. G. Roos, M. Harvey, A. Bruell, Douglas H Beck, H. Breuer, Arijit Saha, M. A. Miller, L. G. Tang, R. Sawafta, R. V. Cadman, M. Bouwhuis, B. Mueller, S. F. Pate, H. Mkrtchyan, D. Potterveld, A. Ahmidouch, Y. Liang, I. Niculescu, John Arrington, S. Strauch, Ronald Gilman, M. Zeier, E. Rollinde, V. Papavassiliou, L. Yuan, W. F. Vulcan, N. S. Chant, A. Uzzle, Ronald Ransome, J. H. Mitchell, E. Segbefia, L. Gan, Charles Glashausser, J. W. Martin, R. B. Piercey, D. Meekins, H. E. Jackson, W. U. Boeglin, V. Tadevosyan, A. J. Sarty, Ross Milner, M. Sutter, J. A. Dunne, P. Bosted, K. Garrow, A. Lung, Rolf Ent, B. Zihlmann, T. Shin, D. S. Brown, A. Gasparian, A. Cochran, C. Bochna, C. S. Armstrong, D. McKee, O. K. Baker, Donal Day, S. Danagoulian, R. D. Carlini, E. Schulte, David Gaskell, R. Asaturyan, and (Astro)-Particles Physics

Subjects
Physics, Nuclear reaction, Particle physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, General Physics and Astronomy, Particle accelerator, Elementary particle, law.invention, Baryon, Nuclear physics, law, Photodisintegration, Neutron, Nuclear Experiment, Nucleon
Abstract

The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at straight theta(cm) = 37 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 1.5 GeV.

18. 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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19. 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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