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29 results on '"T. Navasardyan"'

1. Measurements of the separated longitudinal structure function FL from hydrogen and deuterium targets at low Q2

Author

Bogdan Wojtsekhowski, E. McGrath, T. Angelescu, D. H. Potterveld, B. L. Berman, B. Zihlmann, P. E. Reimer, E. R. Kinney, G. Chang, T. Horn, V. V. Frolov, C. Yan, J. Arrington, Y. Liang, G. M. Huber, A. Lung, G. S. Adams, Rolf Ent, James J. Kelly, J. Telfeyan, D. G. Meekins, T. Dodario, Curtis Smith, E. Segbefia, T. Ostapenko, H. E. Jackson, H. Mkrtchyan, Glen A. Warren, K. Hafidi, Donal Day, A. Uzzle, W. F. Vulcan, W. U. Boeglin, V. Tvaskis, E. J. Brash, N. S. Chant, M. E. Christy, G. Mbianda, I. Niculescu, P. Stoler, Joerg Reinhold, M. Ungaro, X. Jiang, O. K. Baker, Z. Papandreou, G. R. Smith, H. C. Fenker, M. M. Dalton, H. P. Blok, H. Breuer, A. Tvaskis, V. P. Kubarovsky, Cynthia Keppel, A. S. Biselli, J. Kuhn, Paul Gueye, S. A. Wood, A. Ahmidouch, J. A. Dunne, D. Abbott, Simon Henry Connell, S. Vidakovic, V. Tadevosyan, D. J. Mack, K. Garrow, R. J. Holt, Avraham Klein, Jim Napolitano, Stephen Avery, N. Benmouna, S. Danagoulian, S. E. Rock, N. El Khayari, E. Schulte, G. Niculescu, S. Malace, P. Bosted, F. R. Wesselmann, G. J. Lolos, J. Roche, M. Nozar, L. Todor, A. N. Villano, D. Mckee, T. Navasardyan, M. K. Jones, Dipanwita Dutta, R. Asaturyan, Pete Markowitz, D. Gaskell, W. Hinton, Ronald Gilman, Andrei Afanasev, K. Joo, and L. G. Tang

Subjects
Physics, Proton, 010308 nuclear & particles physics, Scattering, Momentum transfer, Parton, Deep inelastic scattering, 01 natural sciences, Molecular physics, Nuclear physics, Deuterium, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the partonic dynamics within the nucleon. However, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available in particular for the longitudinal structure function. Here, we present separated structure functions for hydrogen and deuterium at low four-momentum transfer squared, Q2

Published
2018

2. Observation of theHeΛ7Hypernucleus by the (e,e′K+) Reaction

Author

N. Kalantarians, L. Yuan, D. Kawama, S. Danagoulian, N. Maruyama, G. Marikyan, T. Horn, Y. Fujii, Amur Margaryan, Hiroki Kanda, T. Navasardyan, H. C. Fenker, C. Yan, K. Johnston, G. Niculescu, R. D. Carlini, M. K. Jones, C. Jayalath, V. Tvaskis, Y. Song, E. Segbefia, M. I. Niculescu, K. S. Egiyan, A. Ahmidouch, Tomofumi Maruta, A. Mkrtchyan, Osamu Hashimoto, L. Cole, D. Honda, Hiroshi Nomura, S. N. Nakamura, Pavlo Baturin, K. Nonaka, L. Gan, S. Wells, W. F. Vulcan, O. K. Baker, Seigo Kato, S. Randeniya, A. Ohtani, Yoichi Sato, T. Miyoshi, V. M. Rodriguez, A. Daniel, Sho Nagao, B. S. Hu, M. Elaasar, M. Sumihama, S. Malace, Neven Simicevic, Joerg Reinhold, N. Perez, Ashot Gasparian, Kyo Tsukada, Emiko Hiyama, E. F. Gibson, Masayuki Oyamada, Darko Androić, A. Matsumura, Masashi Kaneta, V. Dharmawardane, P. Gueye, Fatiha Benmokhtar, Toshiyuki Gogami, A. Acha, S. Zhamkochyan, M. E. Christy, K. J. Lan, P. Bosted, Kazushige Maeda, V. Tadevosyan, Tomislav Petković, W. Luo, A. Asaturyan, L. G. Tang, H. Mkrtchyan, Ed V. Hungerford, T. Seva, G. R. Smith, R. Asaturyan, Pete Markowitz, Miroslav Furić, Chunhui Chen, F. Kato, Y. Okayasu, T. Takahashi, C. E. Keppel, Y. Han, J. Roche, S. A. Wood, D. J. Mack, D. Gaskell, and R. Ent

Subjects
Physics, Electron spectrometer, Spectrometer, 010308 nuclear & particles physics, Nuclear Theory, Binding energy, General Physics and Astronomy, Hypernucleus, 7. Clean energy, 01 natural sciences, Nuclear physics, 0103 physical sciences, Mass spectrum, Symmetry breaking, Nuclear Experiment, 010306 general physics, Spectroscopy, Ground state
Abstract

An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, (Λ)(7)He, was observed for the first time with the (e, e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The (Λ)(7)He binding energy supplies the last missing information of the A = 7, T = 1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.

Published
2013

3. New Measurements of High-Momentum Nucleons and Short-Range Structures in Nuclei

Author

M. K. Jones, G. Niculescu, A. Lung, S. Tajima, Colin Hill, P. E. Reimer, B. W. Filippone, Simon Henry Connell, C. Wasko, George Davey Smith, E. Chudakov, R. Asaturyan, J. Wright, Xin Qian, D. G. Meekins, V. Tvaskis, J. Roche, L. El Fassi, W. U. Boeglin, S. A. Wood, A. Bruell, P. Markowitz, O. Rondon, M. E. Christy, Cynthia Keppel, Fatiha Benmokhtar, C. F. Perdrisat, G. Testa, V. A. Punjabi, K. Garrow, R. A. Lindgren, S. Malace, Rolf Ent, T. Navasardyan, V. M. Rodriguez, L. G. Tang, M. Kotulla, Patricia Solvignon, Masroor H. S. Bukhari, F.R. Wesselmann, V. Tadevosyan, T. Horn, D. Kiselev, Nadia Fomin, A. K. Opper, R. Trojer, H. Mkrtchyan, W. F. Vulcan, X. Zheng, E. Segbefia, N. Kalantarians, M. M. Dalton, D. H. Potterveld, Donal Day, Karl Slifer, E. Schulte, Dipangkar Dutta, J. Arrington, P. Bosted, Benjamin Clasie, P. McKee, H. Fenker, A. Daniel, R. J. Holt, J. Seely, D. Gaskell, and J. Jourdan

Subjects
Physics, Light nucleus, Range (particle radiation), Scattering, Nuclear Theory, General Physics and Astronomy, FOS: Physical sciences, Electron, Kinematics, Nuclear physics, Nuclear Experiment (nucl-ex), Nucleon, Cluster analysis, Nuclear Experiment, Electron scattering
Abstract

We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate., 5 pages, 3 figures. Results from JLab E02-019

Published
2012

4. Semi-Inclusive Charged-Pion Electroproduction off Protons and Deuterons: Cross Sections, Ratios and Access to the Quark-Parton Model at Low Energies

Author

N. Kalantarians, C. Xu, L. Yuan, T. Horn, A. Ahmidouch, Y. Cui, Dipangkar Dutta, P. E. Reimer, G. S. Adams, E. Schulte, W. Hinton, R. J. Holt, T. Navasardyan, R. Ent, S. A. Wood, Curtis Smith, Y. Liang, S. Danagoulian, M. Wang, H. Mkrtchyan, Simon Henry Connell, K. Hafidi, P. Bosted, Y. Li, E. Segbefia, S. E. Rock, A. N. Villano, A. Asaturyan, Bogdan Wojtsekhowski, John Arrington, S. Vidakovic, V. Tadevosyan, Glen A. Warren, C. Bertoncini, M. M. Dalton, James J. Kelly, I. Niculescu, M. E. Christy, O. K. Baker, P. McKee, X. Zheng, T. Angelescu, G. Niculescu, N. Benmouna, D. J. Mack, L. Gan, J. Roche, J. A. Dunne, X. Jiang, D. G. Meekins, A. Mkrtchyan, V. P. Kubarovsky, J. Reinhold, S. Malace, H. Breuer, W. U. Boeglin, Donal Day, E. V. Hungerford, A. K. Opper, E. McGrath, C. E. Keppel, F. R. Wesselmann, Geoffrey Smith, R. Asaturyan, N. El Khayari, Pete Markowitz, V. V. Frolov, G. M. Huber, M. Ungaro, P. Stoler, B. Moziak, H. P. Blok, K. Joo, A. Uzzle, H. C. Fenker, L. G. Tang, T. Ostapenko, W. F. Vulcan, M. K. Jones, and D. Gaskell

Subjects
Physics, Quark, Nuclear and High Energy Physics, Particle physics, Proton, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, Parton, Deep inelastic scattering, 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, Invariant mass, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment
Abstract

A large set of cross sections for semi-inclusive electroproduction of charged pions ($��^\pm$) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared $W^2$ > 4 GeV$^2$ and range in four-momentum transfer squared $2 < Q^2 < 4$ (GeV/c)$^2$, and cover a range in the Bjorken scaling variable 0.2 < x < 0.6. The fractional energy of the pions spans a range 0.3 < z < 1, with small transverse momenta with respect to the virtual-photon direction, $P_t^2 < 0.2$ (GeV/c)$^2$. The invariant mass that goes undetected, $M_x$ or W', is in the nucleon resonance region, W' < 2 GeV. The new data conclusively show the onset of quark-hadron duality in this process, and the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark --> pion production mechanisms. The x, z and $P_t^2$ dependences of several ratios (the ratios of favored-unfavored fragmentation functions, charged pion ratios, deuteron-hydrogen and aluminum-deuteron ratios for $��^+$ and $��^-$) have been studied. The ratios are found to be in good agreement with expectations based upon a high-energy quark-parton model description. We find the azimuthal dependences to be small, as compared to exclusive pion electroproduction, and consistent with theoretical expectations based on tree-level factorization in terms of transverse-momentum-dependent parton distribution and fragmentation functions. In the context of a simple model, the initial transverse momenta of $d$ quarks are found to be slightly smaller than for $u$ quarks, while the transverse momentum width of the favored fragmentation function is about the same as for the unfavored one, and both fragmentation widths are larger than the quark widths.

Published
2011

5. Binding Energy of 7He-Lambda and Test of Charge Symmetry Breaking in the Lambda-Nucleon nteraction Potential

Author

O. Hashimoto, Y. Fujii, D. Honda, M. Kaneta, F. Kato, D. Kawama, N. Maruyama, A. Matsumura, S. N. Nakamura, H. Nomura, K. Nonaka, A. Ohtani, Y. Okayasu, M. Osaka, M. Oyamada, M. Sumihama, H. Tamura, O. K. Baker, L. Cole, M. Christy, P. Gueye, C. Keppel, L. Tang, L. Yuan, A. Acha, P. Baturin, W. Boeglin, L. Kramer, P. Markowitz, P. Pamela, N. Perez, B. Raue, J. Reinhold, R. Rivera, S. Kato, Y. Sato, T. Takahashi, A. Daniel, Ed V. Hungerford, M. Ispiryan, N. Kalantarians, K. J. Lan, Y. Li, T. Miyoshi, S. Randeniya, V. M. Rodriguez, P. Bosted, R. Carlini, R. Ent, H. Fenker, D. Gaskell, M Jones, D. Mack, J. Roche, G. Smith, V. Tvaskis, W. Vulcan, S. Wood, C. Yan, A Asaturyan, R. Asaturyan, K. Egiyan, A. Mkrtchyan, H. Mkrtchyan, A. Margaryan8, G. Marikyan, T. Navasardyan, V. Tadevosyan, S. Zamkochian, B. Hu, Y. Song, W. Luo, Darko Androic, Furić, Miroslav, Petković, Tomislav, Ševa, Tomislav, A. Ahmidouch, S. Danagoulian, A. Gasparian, R. Halkyard, K. Johnston, N. Šimičević, S. Wells, G. Niculescu, M.-I. Niculescu, L. Gan, F. Benmokhtar, T. Horn, M. Elaasar, and E. F. Gibson, Dilling, J., and Thomson, J.

Subjects
Nuclear Theory, Nuclear Experiment, hypernuclear spectroscopy, high resoution, electro-production reaction, iso-triplet hypernuclei, charge symmetry breaking
Abstract

The binding energy of 7He-Lambda has been obtained for the first time with reaction spectroscopy using the (e, e'K+) reaction at Jefferson Lab's Hall C. A comparison among the binding energies of the A=7 T=l iso-triplet hypernuclei, 7He-Lambda, 7Li*-Lambda and 7Be-Lambda, is made and possible charge symmetry breaking (CSB) in the Lambda-Nucleon potential is discussed. For 7He-Lambda and 7Be-Lamnda, the shifts in binding energies are opposite to those predicted by a recent cluster model calculation, which assumes that the unexplained part of the binding energy difference between 4H-Lambda and 4He-Lambda, is due to the CSB of the Lambda-Nucleon potential. Further examination of CSB in light hypernuclear systems is required both experimentally and theoretically.

Published
2011

6. Spectroscopic investigation of Lambda hypernuclei in the wide mass region using the (e, e'K+) reaction

Author

S. N. Nakamura, P. Achenbach, A. Ahmidouch, I. Albayrak, Darko, Androic, A. Asaturyan, R. Asaturyan, O. Ates, R. Badui, P. Baturin, W. Boeglin, J. Bono, P. Bosted, E. Brash, P. Carter, C. Chen, A. Chiba, M. Christy, M. Dalton, S. Danagoulian, R. De Leo, D. Doi, K. Egiyan, M. Elaasar, R. Ent, H. Fenker, Y. Fujii, Miroslav Furic, M. Gabrielyan, L. Gan, F. Garibaldi, D. Gaskell, A. Gasparian, T. Gogami, O. Hashimoto, T. Horn, B. Hu, M. Jones, H. Kanda, M. Kaneta, S. Kato, M. Kawai, D. Kawama, H. Khanal, M. Kohl, A. Liyanage, W. Luo, D. Mack, K. Maeda, A. Margaryan, G. Marikyan, P. Markowitz, T. Maruta, A. Matsumura, V. Maxwell, A. Mkrtchyan, H. Mkrtchyan, S. Nagao, A. Narayan, T. Navasardyan, C. Neville, G. Niculescu, M.I. Niculescu, A. Nunez, Y. Okayasu, Tomislav Petković, J. Pochodzalla, X. Qiu, J. Reinhold, C. Rodriguez, V. Samanta, B. Sawatzky, D. Schott, Tomislav Ševa, A. Shichijo, G. Smith, V. Tadevosyan, H. Tamura, L. Tang, N. Taniya, V. Tvaskis, M. Veilleux, W. Vulcan, F.R. Wesselmann, S.A. Wood, T. Yamamoto, L. Ya, Z. Ye, K. Yokota, L. Yuan, S. Zhamkochyan, L. Zhu, Dilling, J., and Thomson, J.

Subjects
hypernuclei, electro-production, high resolution, hyperon-nucleon interaction, Physics::Instrumentation and Detectors, Nuclear Theory, Nuclear Experiment
Abstract

The third generation spectroscopic study of Lambda hypernuclei using (e, e'K+) reaction (JLab E05-115) was performed at JLab Hall-C in 2009. The experiment introduced the newly developed high-resolution electron spectrometer (HES) with the existing high-resolution kaon spectrometer (HKS). Experimental configuration, conditions, spectrometer designs and current status of analysis are presented.

Published
2011

7. Scaling of theF2Structure Function in Nuclei and Quark Distributions atx>1

Author

M. Kotulla, P. Solvignon, S. A. Wood, J. Jourdan, M. K. Jones, A. Daniel, P. E. Reimer, H. Mkrtchyan, L. G. Tang, Simon Henry Connell, W.U. Boeglin, Xin Qian, R. Trojer, C. Wasko, Masroor H. S. Bukhari, R. Asaturyan, V. Tvaskis, Colin Hill, Pete Markowitz, E. Chudakov, G. Niculescu, A. F. Lung, J. Seely, H. C. Fenker, C. E. Keppel, L. El Fassi, A. Bruell, K. Garrow, N. Kalantarians, O. Rondon, Donal Day, S. Malace, Rolf Ent, X. Zheng, B. Boillat, F. R. Wesselmann, M. M. Dalton, Geoffrey Smith, V. Tadevosyan, R. A. Lindgren, Tanja Horn, Y. Okayasu, G. Testa, Dipanwita Dutta, D. Kiselev, W. F. Vulcan, J. Arrington, E. Segbefia, J. Wright, N. Fomin, S. Tajima, B. W. Filippone, Karl Slifer, D. Gaskell, P. E. Bosted, F. Benmokhtar, A. K. Opper, C. F. Perdrisat, T. Navasardyan, V. M. Rodriguez, R. J. Holt, V. A. Punjabi, D. G. Meekins, M. E. Christy, E. Schulte, D. H. Potterveld, Benjamin Clasie, P. McKee, J. Roche, and Toshinobu Miyoshi

Subjects
Quark, Physics, Muon, 010308 nuclear & particles physics, Scattering, Nuclear Theory, General Physics and Astronomy, Elementary particle, Fermion, Inelastic scattering, Deep inelastic scattering, 01 natural sciences, Nuclear physics, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Lepton
Abstract

We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x > 1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the “superfast” quarks probed at x > 1. The falloff at x > 1 is noticeably stronger in ^2H and ^3He, but nearly identical for all heavier nuclei.

Published
2010

8. Experimental study of theA(e,e′π+) reaction onH1,H2,C12,Al27,Cu63, andAu197

Author

A. N. Villano, T. Horn, M. Sumihama, S. A. Wood, E. Segbefia, M. K. Jones, A. W. Rauf, N. Fomin, F. R. Wesselmann, A. Matsumura, Y. Li, M. M. Dalton, Geoffrey Smith, R. Asaturyan, K. Garrow, Xin Qian, J. Ferrer, I. Niculescu, Pete Markowitz, Fatiha Benmokhtar, G. Niculescu, V. M. Rodriquez, A. Lung, Y. Okayasu, V. Tadevosyan, Donal Day, D. G. Meekins, M. E. Christy, P. Bosted, Rolf Ent, T. Mertens, X. Zheng, A. Daniel, W. F. Vulcan, A. Bruell, T. Miyoshi, Dipangkar Dutta, C. E. Keppel, A. K. Opper, R. Monson, H. C. Fenker, C. Gray, S. Malace, L. El Fassi, J. Arrington, W. U. Boeglin, V. A. Punjabi, J. Seely, E. Chudakov, Haiyan Gao, Benjamin Clasie, Daniela Rohe, H. Mkrtchyan, D. Gaskell, G. M. Huber, K. Kramer, C. F. Perdrisat, T. Navasardyan, N. Kalantarians, L. Yuan, L. G. Tang, and Y. Liang

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Meson, 010308 nuclear & particles physics, Hadron, Elementary particle, 01 natural sciences, Baryon, Crystallography, Pion, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, 0103 physical sciences, Atomic physics, 010306 general physics, Nucleon, Energy (signal processing)
Abstract

Cross sections for the {sup 1}H(e,e'{pi}{sup +})n process on {sup 1}H, {sup 2}H, {sup 12}C, {sup 27}Al, {sup 63}Cu, and {sup 197}Au targets were measured at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) to extract nuclear transparencies. Data were taken from Q{sup 2}=1.1-4.7 GeV{sup 2} for a fixed center-of-mass energy of W=2.14 GeV. The ratio of {sigma}{sub L} and {sigma}{sub T} was extracted from the measured cross sections for {sup 1}H, {sup 2}H, {sup 12}C, and {sup 63}Cu targets at Q{sup 2}=2.15 and 4.0 GeV{sup 2}, allowing for additional studies of the reaction mechanism. In this article, we present the experimental setup and the analysis of the data in detail, including systematic uncertainty studies. Differential cross sections and nuclear transparencies as a function of the pion momentum at different values of Q{sup 2} are presented. Our results are consistent with the predicted early onset of color transparency in mesons. Global features of the data are discussed and the data are compared with model calculations for the {sup 1}H(e,e'{pi}{sup +})n reaction from nuclear targets.

Published
2010

9. Kaon, Pion, and Proton Associated Photofission of Bi Nuclei

Author

M. Ispiryan, N. Kalantarians, Miroslav Furić, T. Seva, R. Halkyard, L. Yuan, R. Asaturyan, S. Wells, F. Kato, R. D. Carlini, L. Cole, A. Acha, Pavlo Baturin, M. K. Jones, Paul Gueye, Seigo Kato, Hirokazu Tamura, Ashot Gasparian, C. Yan, H. C. Fenker, S. Danagoulian, Y. Okayasu, L. G. Tang, T. Miyoshi, Rolf Ent, M. I. Niculescu, Y. Song, Y. Sato, P. Pamela, Darko Androić, A. Matsumura, A. Ahmidouch, R. Rivera, D. Honda, K. Nonaka, V. M. Rodriguez, Osamu Hashimoto, T. Horn, Masashi Kaneta, A. Mkrtchyan, J. Roche, S. Randeniya, Satoshi Nakamura, G. Marikyan, M. E. Christy, B. Hu, S. Knyazyan, Y. Fujii, A. Ohtani, Amur Margaryan, A. Asaturyan, H. Vardanyan, N. Grigoryan, D. Gaskell, K. S. Egiyan, Y. Li, L. Gan, V. Tadevosyan, W. F. Vulcan, M. Sumihama, E. F. Gibson, D. Kawama, N. Maruyama, X. Chen, Ed V. Hungerford, Neven Simicevic, N. Perez, G. R. Smith, O. K. Baker, J. Reinhold, Tomislav Petković, W. Luo, G. Niculescu, L. Parlakyan, Fatiha Benmokhtar, K. Johnston, V. Dharmawardane, M. Elaasar, C. E. Keppel, Hiroshi Nomura, V. Tvaskis, T. Takahashi, B. Wang, T. Navasardyan, S. A. Wood, D. J. Mack, S. Hu, H. Mkrtchyan, and A. Daniel

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Cluster decay, Meson, Proton, Fission, Hadron, Nuclear Theory, Photofission, associated fission experiment of Bi, experimental setup at JLab, fission probability with kao, pion, and proton, Atomic and Molecular Physics, and Optics, Nuclear physics, Pion, High Energy Physics::Experiment, Nuclear Experiment
Abstract

The first measurement of proton, pion, and kaon associated fission of Bi nuclei has been performed in a photon energy range 1. 45 < E γ < 1. 55 GeV. The fission probabilities are compared with an inclusive fission probabilities obtained with photons, protons and pions. The fission probability of Bi nuclei in coincidence with kaons is 0. 18 ± 0. 06 which is ∼3 times larger than the proton and pion associated fission probabilities and ∼2 times larger than inclusive ones. The kaon associated excess fission events are explained in terms of bound Λ residual states and their weak nonmesonic decays.

Published
2010

10. New Measurements of the European Muon Collaboration Effect in Very Light Nuclei

Author

L. Yuan, M. Kotulla, P. E. Reimer, Karl Slifer, R. Asaturyan, M. E. Christy, L. G. Tang, I. Niculescu, Y. Okayasu, Masroor H. S. Bukhari, V. M. Rodriguez, H. Nomura, V. Tadevosyan, John Arrington, N. Kalantarians, D. H. Potterveld, C. Lee, A. Bruell, G. R. Smith, A. Lung, E. Schulte, Fatiha Benmokhtar, Dipangkar Dutta, V. Tvaskis, Cynthia Keppel, S. Malace, Colin Hill, T. Navasardyan, A. Daniel, J. A. Dunne, R. J. Holt, E. Segbefia, P. Bosted, O. Rondon, Rolf Ent, V. A. Punjabi, S. Tajima, B. Boillat, Donal Day, Haiyan Gao, P. Solvignon, J. Seely, M. M. Dalton, Benjamin Clasie, H. Fenker, C. F. Perdrisat, J. Roche, F.R. Wesselmann, S. A. Wood, B. W. Filippone, Xin Qian, T. Mertens, D. G. Meekins, D. Gaskell, J. Jourdan, M. K. Jones, L. El Fassi, W. U. Boeglin, G. Testa, G. Niculescu, Simon Henry Connell, T. Horn, R. Trojer, W. F. Vulcan, H. Mkrtchyan, X. Zheng, D. Kiselev, Nadia Fomin, E. V. Hungerford, A. K. Opper, and J. Wright

Subjects
Physics, Nuclear physics, Particle physics, Helium-4, Helium-3, EMC effect, Carbon-12, General Physics and Astronomy, Nucleon, Isotopes of beryllium, Isotopes of helium, European Muon Collaboration
Abstract

New Jefferson Lab data are presented on the nuclear dependence of the inclusive cross section from {sup 2}H, {sup 3}He, {sup 4}He, {sup 9}Be and {sup 12}C for 0.3 < x < 0.9, Q{sup 2} {approx} 3-6 GeV{sup 2}. These data represent the first measurement of the EMC effect for {sup 3}He at large x and a significant improvement for {sup 4}He. The data do not support previous A-dependent or density-dependent fits to the EMC effect and suggest that the nuclear dependence of the quark distributions may depend on the local nuclear environment.

Published
2009

11. Applications of quark-hadron duality in theF2structure function

Author

Y. Li, John Arrington, N. Kalantarians, O. K. Baker, G. Niculescu, L. Yuan, I. Niculescu, G. S. Adams, T. Navasardyan, E. R. Kinney, P. E. Reimer, G. M. Huber, E. Segbefia, Y. Liang, J. A. Dunne, S. Vidakovic, Donal Day, V. Tadevosyan, Y. Cui, X. Zheng, F. R. Wesselmann, S. Danagoulian, H. C. Fenker, Geoffrey Smith, E. V. Hungerford, E. McGrath, P. McKee, A. N. Villano, M. E. Christy, P. Bosted, E. Schulte, A. Uzzle, L. Gan, J. Roche, A. Ahmidouch, M. Ungaro, H. P. Blok, K. Joo, J. Reinhold, R. Asaturyan, L. G. Tang, S. P. Malace, Bogdan Wojtsekhowski, Pete Markowitz, H. Mkrtchyan, T. Angelescu, T. Horn, Dipangkar Dutta, M. M. Dalton, N. Benmouna, W. F. Vulcan, D. G. Meekins, W. U. Boeglin, C. E. Keppel, S. A. Wood, X. Jiang, V. P. Kubarovsky, Curtis Smith, K. Hafidi, M. K. Jones, D. Gaskell, W. Hinton, James J. Kelly, R. J. Holt, R. Ent, H. Breuer, and (Astro)-Particles Physics

Subjects
Quantum chromodynamics, Physics, Quark, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Hadron, Duality (optimization), Parton, Inelastic scattering, 01 natural sciences, Resonance (particle physics), High Energy Physics - Experiment, Nuclear physics, Distribution function, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract

Inclusive electron-proton and electron-deuteron inelastic cross sections have been measured at Jefferson Lab (JLab) in the resonance region, at large Bjorken x, up to 0.92, and four-momentum transfer squared Q2 up to 7.5 GeV2 in the experiment E00-116. These measurements are used to extend to larger x and Q2 precision, quantitative, studies of the phenomenon of quark-hadron duality. Our analysis confirms, both globally and locally, the apparent violation of quark-hadron duality previously observed at a Q2 of 3.5 GeV2 when resonance data are compared to structure function data created from CTEQ6M and MRST2004 parton distribution functions (PDFs). More importantly, our new data show that this discrepancy saturates by Q2 ~ 4 Gev2, becoming Q2 independent. This suggests only small violations of Q2 evolution by contributions from the higher-twist terms in the resonance region which is confirmed by our comparisons to ALEKHIN and ALLM97.We conclude that the unconstrained strength of the CTEQ6M and MRST2004 PDFs at large x is the major source of the disagreement between data and these parameterizations in the kinematic regime we study and that, in view of quark-hadron duality, properly averaged resonance region data could be used in global QCD fits to reduce PDF uncertainties at large x., Comment: 35 pages

Published
2009

12. Electroproduction ofηmesons in theS11(1535)resonance region at high momentum transfer

Author

R. J. Holt, H. Mkrtchyan, N. El Khayari, E. Schulte, S. A. Wood, Simon Henry Connell, M. K. Jones, S. E. Rock, Y. Li, M. E. Christy, P. Bosted, Bogdan Wojtsekhowski, N. Kalantarians, L. Gan, P. E. Reimer, C. Xu, E. V. Hungerford, T. Horn, A. N. Villano, C. Bertoncini, L. Yuan, H. Breuer, M. M. Dalton, V. V. Frolov, T. Navasardyan, A. K. Opper, F. R. Wesselmann, A. Uzzle, G. M. Huber, Y. Liang, M. Wang, R. Asaturyan, D. Gaskell, Pete Markowitz, P. Stoler, N. Benmouna, D. G. Meekins, Curtis Smith, Y. Cui, G. S. Adams, A. Ahmidouch, O. K. Baker, Rolf Ent, K. Hafidi, V. Tvaskis, B. Moziak, W. U. Boeglin, S. Vidakovic, V. Tadevosyan, James J. Kelly, T. Dodario, G. Niculescu, W. Hinton, X. Jiang, T. Ostapenko, X. Zheng, W. F. Vulcan, Glen A. Warren, V. P. Kubarovsky, H. C. Fenker, E. Segbefia, Joerg Reinhold, P. McKee, Hongbo Zhu, Cynthia Keppel, J. A. Dunne, S. Danagoulian, Donal Day, M. Ungaro, G. R. Smith, Dipangkar Dutta, K. Joo, S. Malace, I. Niculescu, J. Arrington, T. Angelescu, L. Tang, and J. Roche

Subjects
Nuclear physics, Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle decay, Particle physics, Amplitude, Meson, Momentum transfer, Perturbative QCD, Resonance (particle physics), Helicity
Abstract

The differential cross-section for the exclusive process p(e, e0p) has been measured at Q2 5.7 and 7.0 (GeV/c)2, which represents the highest momentum transfer measurement of this to date, significantly higher than the previous highest at Q2 3.6 (GeV/c)2. Data was taken for centre-of-mass energies from threshold to 1.8 GeV, encompassing the S11(1535) resonance, which dominates the pη channel. The total cross section is obtained, from which is extracted the helicity-conserving transition amplitude A1/2, for the production of the S11(1535) resonance. This quantity appears to begin scaling as Q-3, a predicted signal of the dominance of perturbative QCD, within the Q2 range of this measurement. No currently available theoretical predictions can account for the behaviour of this quantity over the full measured range of Q2.

Published
2009

13. Scaling study of the pion electroproduction cross sections

Author

T. Navasardyan, M. M. Dalton, F. Benmokthar, G. Niculescu, Y. Liang, Y. Li, N. Kalantarians, John Arrington, A. Bruell, L. Yuan, C. E. Keppel, S. A. Wood, A. Matsumura, S. Malace, N. Fomin, H. Mkrtchyan, H. C. Fenker, K. Kramer, K. Garrow, A. N. Villano, Y. Okayasu, V. A. Punjabi, Xin Qian, D. G. Meekins, T. Mertens, X. Zheng, M. E. Christy, P. Bosted, J. Ferrer, V. M. Rodriguez, A. K. Opper, A. W. Rauf, Dipangkar Dutta, M. Sumihama, G. R. Smith, C. F. Perdrisat, L. El Fassi, W. U. Boeglin, F. R. Wesselmann, T. Horn, V. Tadevosyan, E. Chudakov, R. Monson, W. F. Vulcan, A. Lung, L. G. Tang, T. Miyoshi, I. Niculescu, Rolf Ent, R. Asaturyan, E. Segbefia, Pete Markowitz, G. M. Huber, Daniela Rohe, C. Gray, A. Daniel, J. Seely, Donal Day, Haiyan Gao, Benjamin Clasie, M. K. Jones, D. Gaskell, and V. Tvaskis

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Cross section.transverse, Particle physics, 010308 nuclear & particles physics, Resonance, 01 natural sciences, symbols.namesake, Pion, Factorization, 0103 physical sciences, Weierstrass factorization theorem, symbols, Invariant mass, 010306 general physics, Scaling
Abstract

The ${}^{1}\mathrm{H}(e, {e}^{'}{\ensuremath{\pi}}^{+})n$ cross section was measured for arange of four-momentum transfer up to ${Q}^{2}=3.91 {\mathrm{GeV}}^{2}$ at values of the invariant mass $W$ above the resonance region. The ${Q}^{2}$ dependence of the longitudinal component was found to be consistent with the ${Q}^{2}$-scaling prediction for hard exclusive processes. This suggests that the QCD factorization theorem is applicable at rather low values of ${Q}^{2}$. The transverse term falls off slower than the naive ${Q}^{\ensuremath{-}8}$ expectation and remains appreciable even at ${Q}^{2}=3.91 {\mathrm{GeV}}^{2}$.

Published
2008

14. Search for Sub-threshold Photoproduction of J/Psi Mesons

Author

V. M. Rodriguez, John Arrington, G. Testa, M. E. Christy, J. Roche, P. Bosted, D. Gaskell, Rolf Ent, Benjamin Clasie, D. G. Meekins, T. Horn, Simon Henry Connell, Dipangkar Dutta, Fatiha Benmokhtar, S. Tajima, A. Daniel, J. A. Dunne, D. Kiselev, M. M. Dalton, H. Mkrtchyan, R. Asaturyan, E. Chudakov, Mark Strikman, J. Seely, Roman Trojer, T. Navasardyan, N. Kalantarians, X. Zheng, Claire Alexandra Lee, Donal Day, N. Fomin, Karl Slifer, P. Junnarkar, F. R. Wesselmann, C. E. Keppel, and S. A. Wood

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson production, Meson, Bremsstrahlung, FOS: Physical sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Photon beams, Sub threshold, Nuclear Experiment (nucl-ex), Nuclear Experiment, Beam (structure), Bremsstrahlung photon, Energy (signal processing)
Abstract

A search was made for sub-threshold $J/\psi$ production from a carbon target using a mixed real and quasi-real Bremsstrahlung photon beam with an endpoint energy of 5.76 GeV. No events were observed, which is consistent with predictions assuming quasi-free production. The results place limits on exotic mechanisms that strongly enhance quasi-free production., Comment: 19 pages, 7 figures, to be submitted to Phys. Rev. C

Published
2008
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15. Hypernuclear spectroscopy program at JLab Hall C

Author

M. Sumihama, D. Kawama, Y. Li, R. Asaturyan, N. Maruyama, T. Miyoshi, V. Dharmawardane, Seigo Kato, K. Johnston, Paul Gueye, Hirokazu Tamura, Ashot Gasparian, E. F. Gibson, C. E. Keppel, L. G. Tang, L. Cole, Pavlo Baturin, Y. Okayasu, G. Niculescu, D. Gaskell, T. Navasardyan, Osamu Hashimoto, L. Gan, Ed V. Hungerford, S. Randeniya, T. Seva, R. Halkyard, Y. Song, H. Mkrtchyan, A. Daniel, Darko Androić, A. Matsumura, G. R. Smith, S. A. Wood, Miroslav Furić, Fatiha Benmokhtar, Tomislav Petković, W. Luo, Hiroshi Nomura, D. J. Mack, J. Reinhold, S. Wells, S. Hu, M. Ispiryan, M. K. Jones, M. E. Christy, V. Tvaskis, P. Bosted, A. Mkrtchyan, P. Pamela, N. Kalantarians, F. Kato, R. D. Carlini, B. Wang, Neven Simicevic, L. Yuan, N. Perez, M. I. Niculescu, S. Zamkochian, O. K. Baker, A. Ahmidouch, D. Honda, K. Nonaka, Rolf Ent, V. Tadevosyan, B. Hu, M. Elaasar, K. S. Egiyan, T. Horn, Masashi Kaneta, A. Acha, V. M. Rodriguez, T. Takahashi, W. F. Vulcan, C. Yan, A. Ohtani, H. C. Fenker, J. Roche, S. Danagoulian, G. Marikyan, Y. Fujii, Amur Margaryan, A. Asaturyan, Yoichi Sato, X. Chen, R. Rivera, and Satoshi Nakamura

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Tilt (optics), Spectrometer, SHELL model, Spectroscopy, Hypernucleus, hypernuclear production, hypernuclear spectroscopy, high-resolution kaon spectrometer
Abstract

Hypernuclear production by the ( e , e ′ K + ) reaction has unique advantages in hypernuclear spectroscopy of the S = − 1 regime. The second-generation spectroscopy experiment on 12C, 7Li and 28Si targets has been recently carried out at JLab Hall C with a new experimental configuration (Tilt method) and also using a new high-resolution kaon spectrometer (HKS). The experiment is described and preliminary results are presented together with the empasis of significance of the ( e , e ′ K + ) reaction for Λ hypernuclear spectroscopy and its future prospects.

Published
2008

16. Measurement of Nuclear Transparency for theA(e,e′π+)Reaction

Author

V. Tadevosyan, N. Kalantarians, G. R. Smith, M. Sumihama, L. Yuan, V. A. Punjabi, Mark Strikman, K. Kramer, S. A. Wood, H. C. Fenker, A. N. Villano, A. Matsumura, I. Niculescu, C. Gray, R. Monson, H. Mkrtchyan, Y. Li, John Arrington, W. Cosyn, A. W. Rauf, T. Navasardyan, J. Ferrer, Jan Ryckebusch, L. G. Tang, K. Garrow, Xin Qian, D. G. Meekins, V. Tvaskis, A. Bruell, A. Lung, V. M. Rodriquez, W. F. Vulcan, X. Zheng, S. Malace, C. E. Keppel, G. Niculescu, Rolf Ent, Haiyan Gao, Benjamin Clasie, Fatiha Benmokhtar, R. Asaturyan, L. El Fassi, W. U. Boeglin, Y. Okayasu, Pete Markowitz, Y. Liang, T. Mertens, M. E. Christy, P. Bosted, E. Segbefia, A. Larson, A. K. Opper, G. M. Huber, C. F. Perdrisat, F. R. Wesselmann, Dipangkar Dutta, T. Horn, E. Chudakov, M. M. Dalton, N. Fomin, Gerald A. Miller, Daniela Rohe, A. Daniel, M. K. Jones, J. Seely, Donal Day, D. Gaskell, and T. Miyoshi

Subjects
Physics, Elastic scattering, Particle physics, Meson, 010308 nuclear & particles physics, Nuclear Theory, Quark model, Hadron, General Physics and Astronomy, Elementary particle, 01 natural sciences, Nuclear transparency, 0103 physical sciences, Atomic number, Atomic physics, Nuclear Experiment, 010306 general physics, Boson
Abstract

We have measured the nuclear transparency of the $A(e,{e}^{\ensuremath{'}}{\ensuremath{\pi}}^{+})$ process in $^{2}\mathrm{H}$, $^{12}\mathrm{C}$, $^{27}\mathrm{Al}$, $^{63}\mathrm{Cu}$, and $^{197}\mathrm{Au}$ targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range ${Q}^{2}=1.1$ to $4.7\text{ }\text{ }(\mathrm{GeV}/c{)}^{2}$. The nuclear transparency was extracted as the super-ratio of (${\ensuremath{\sigma}}_{A}/{\ensuremath{\sigma}}_{H}$) from data to a model of pion-electroproduction from nuclei without $\ensuremath{\pi}\mathrm{\text{\ensuremath{-}}}N$ final-state interactions. The ${Q}^{2}$ and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

Published
2007

17. Transverse momentum dependence of semi-inclusive pion production

Author

G. Niculescu, E. Segbefia, A. N. Villano, V. V. Frolov, I. Niculescu, V. Tadevosyan, T. Horn, X. Zheng, Y. Cui, T. Angelescu, X. Jiang, S. Vidakovic, E. V. Hungerford, A. K. Opper, E. McGrath, Glen A. Warren, H. Breuer, Donal Day, S. A. Wood, V. P. Kubarovsky, P. Stoler, O. K. Baker, Pete Markowitz, N. Kalantarians, C. Xu, L. Yuan, R. J. Holt, H. Mkrtchyan, T. Dodario, C. Bertoncini, M. M. Dalton, L. G. Tang, T. Ostapenko, Y. Li, J. A. Dunne, Curtis Smith, K. Hafidi, B. Moziak, E. Schulte, W. F. Vulcan, John Arrington, S. E. Rock, A. Uzzle, A. Ahmidouch, Bogdan Wojtsekhowski, James J. Kelly, H. C. Fenker, N. Benmouna, Hongbo Zhu, M. K. Jones, C. E. Keppel, N. El Khayari, P. Bosted, G. S. Adams, F. R. Wesselmann, R. Asaturyan, K. Joo, Rolf Ent, Dipangkar Dutta, D. G. Meekins, P. McKee, S. Danagoulian, M. E. Christy, L. Gan, W. U. Boeglin, M. Ungaro, G. R. Smith, D. Gaskell, W. Hinton, H. P. Blok, G. M. Huber, J. Reinhold, S. Malace, T. Navasardyan, P. E. Reimer, Y. Liang, M. Wang, Simon Henry Connell, J. Roche, and (Astro)-Particles Physics

Subjects
Quark, Physics, Scattering cross-section, Nuclear and High Energy Physics, Particle physics, Proton, Physics::Instrumentation and Detectors, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, Nuclear physics, Transverse plane, High Energy Physics - Phenomenology, Pion, High Energy Physics - Phenomenology (hep-ph), Deuterium, Transverse momentum, Fragmentation function, High Energy Physics::Experiment, SDG 6 - Clean Water and Sanitation, Nuclear Experiment, Astrophysics::Galaxy Astrophysics
Abstract

Cross sections for semi-inclusive electroproduction of charged pions ($\pi^{\pm}$) from both proton and deuteron targets were measured for $0.2, Comment: 15 pages, 4 figures. Fit form changed to include Cahn effect Minor revisions. Added one new figure

Published
2007

18. Measurement of nuclear transparency for the A(e,e'pi+) reaction

Author

B, Clasie, X, Qian, J, Arrington, R, Asaturyan, F, Benmokhtar, W, Boeglin, P, Bosted, A, Bruell, M E, Christy, E, Chudakov, W, Cosyn, M M, Dalton, A, Daniel, D, Day, D, Dutta, L, El Fassi, R, Ent, H C, Fenker, J, Ferrer, N, Fomin, H, Gao, K, Garrow, D, Gaskell, C, Gray, T, Horn, G M, Huber, M K, Jones, N, Kalantarians, C E, Keppel, K, Kramer, A, Larson, Y, Li, Y, Liang, A F, Lung, S, Malace, P, Markowitz, A, Matsumura, D G, Meekins, T, Mertens, G A, Miller, T, Miyoshi, H, Mkrtchyan, R, Monson, T, Navasardyan, G, Niculescu, I, Niculescu, Y, Okayasu, A K, Opper, C, Perdrisat, V, Punjabi, A W, Rauf, V M, Rodriquez, D, Rohe, J, Ryckebusch, J, Seely, E, Segbefia, G R, Smith, M, Strikman, M, Sumihama, V, Tadevosyan, L, Tang, V, Tvaskis, A, Villano, W F, Vulcan, F R, Wesselmann, S A, Wood, L, Yuan, and X C, Zheng

Abstract

We have measured the nuclear transparency of the A(e,e'pi+) process in 2H, 12C, 27Al, 63Cu, and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q2=1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of (sigmaA/sigmaH) from data to a model of pion-electroproduction from nuclei without pi-N final-state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

Published
2007

19. Onset of Quark-Hadron Duality in Pion Electroproduction

Author

W. Hinton, S. E. Rock, Glen A. Warren, S. Danagoulian, Y. Cui, T. Angelescu, R. J. Holt, D. G. Meekins, P. Stoler, Hongbo Zhu, G. S. Adams, K. Joo, Rolf Ent, W. U. Boeglin, F. R. Wesselmann, G. Niculescu, M. K. Jones, P. E. Reimer, S. Vidakovic, V. Tadevosyan, B. Moziak, A. N. Villano, Geoffrey Smith, J. A. Dunne, X. Jiang, T. Horn, Y. Li, John Arrington, Donal Day, V. V. Frolov, Y. Liang, James J. Kelly, M. Wang, M. E. Christy, H. Mkrtchyan, O. K. Baker, T. Navasardyan, S. A. Wood, E. Segbefia, N. Kalantarians, A. Ahmidouch, N. El Khayari, H. Breuer, Curtis Smith, C. Bertoncini, M. M. Dalton, R. Asaturyan, K. Hafidi, Simon Henry Connell, D. Gaskell, Pete Markowitz, C. E. Keppel, A. Uzzle, N. Benmouna, C. Xu, I. Niculescu, L. Yuan, G. M. Huber, E. Schulte, H. C. Fenker, P. Bosted, P. McKee, L. Gan, J. Roche, T. Dodario, T. Ostapenko, W. F. Vulcan, L. G. Tang, M. Ungaro, H. P. Blok, J. Reinhold, S. Malace, Bogdan Wojtsekhowski, Dipangkar Dutta, X. Zheng, V. Kubarovski, E. V. Hungerford, A. K. Opper, E. McGrath, and (Astro)-Particles Physics

Subjects
Quark, Physics, Particle physics, 010308 nuclear & particles physics, Scattering, High Energy Physics::Lattice, Hadron, High Energy Physics::Phenomenology, Nuclear Theory, General Physics and Astronomy, FOS: Physical sciences, Electron, 01 natural sciences, Duality (electricity and magnetism), Nuclear physics, High Energy Physics - Phenomenology, Pion, High Energy Physics - Phenomenology (hep-ph), Factorization, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, Ansatz
Abstract

A large data set of charged-pion electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-to- pion production mechanisms., Comment: 11 pages, 3 figures, accepted in Phys. Rev. Lett. Tables added

Published
2007

20. The HKS experiment on Lambda-hypernuclear spectroscopy via electroproduction at JLab

Author

S. Randeniya, H. Mkrtchyan, T. Navasardyan, B. S. Hu, L. Cole, L. G. Tang, M. Ispiryan, T. Seva, Pavlo Baturin, N. Kalantarians, Oliver Keith Baker, P. Pamela, R. Halkyard, L. Yuan, Neven Simicevic, Joerg Reinhold, N. Perez, G. Marikyan, Ed V. Hungerford, M. Sumihama, B. Wang, R. D. Carlini, S. Wells, Fatiha Benmokhtar, A. Acha, A. Asaturyan, S. A. Wood, Hiroshi Nomura, Y. Fujii, Seigo Kato, Amur Margaryan, Y. Okayasu, L. Gan, J. Roche, D. J. Mack, D. Honda, K. Nonaka, S. Hu, S. Danagoulian, C. Yan, R. Asaturyan, A. Daniel, Toshinobu Miyoshi, Yoichi Sato, Osamu Hashimoto, S. Zamkochian, W. F. Vulcan, Gerald A. Smith, X. Chen, V. M. Rodriguez, P. Gueye, Darko Androić, A. Matsumura, V. Tadevosyan, D. Gaskell, H. C. Fenker, Masashi Kaneta, Rolf Ent, D. Kawama, R. Rivera, M. Elaasar, A. Ohtani, C. Kepple, G. Niculescu, Tomislav Petković, W. Luo, N. Maruyama, Hirokazu Tamura, M. E. Christy, Ashot Gasparian, P. Bosted, Y. Li, Miroslav Furić, V. Tvaskis, T. Takahashi, Y. Song, A. Ahmidouch, M. K. Jones, V. Dharmawardane, F. Kato, A. Mkrtchyan, Ed. F. Gibson, M. I. Niculescu, T. Horn, K. S. Egiyan, K. Johnston, and S. N. Nakamura

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, spectroscopy, Λ -hypernuclei, (e, e'K+) reaction, hypernuclear spectra, Spectroscopy, Spectral line
Abstract

The HKS (Jlab E01-011) experiment on spectroscopy of Λ -hypernuclei using (e, e'K+) reaction was successfully carried out in 2005. This paper gives a brief description of the experiment and its technique and shows some of the preliminary spectra that are still under analysis.

Published
2007

21. Factorization studies in SIDIS at JLab

Author

D. Gaskell, T. Navasardyan, V. Tadevosyan, Rolf Ent, H. Mkrtchyan, and P. E. Bosted

Subjects
Nuclear physics, Physics, Particle physics, Pion, Meson production, Deuterium, Factorization, Hydrogen, chemistry, Quark model, chemistry.chemical_element
Abstract

Data for positive and negative pion electroproduction from both hydrogen and deuterium targets are found to satisfy factorization tests in the kinematic region Q2 > 2 GeV2, 0.2 2 GeV, Mx > 1.5 GeV, and 0.3 < z < 0.6.

Published
2006

22. Binding Energy of7ΛHe and Test of Charge Symmetry Breaking in the ΛN Interaction Potential

Author

V. Tvaskis, K. J. Lan, M. Elaasar, W. U. Boeglin, Neven Simicevic, Joerg Reinhold, Y. Li, N. Perez, L. Gan, M. Osaka, Hiroshi Nomura, A. Daniel, T. Miyoshi, S. N. Nakamura, L. Cole, Yoichi Sato, V Tadevosyan, T. Takahashi, A Ahmidouch, Masayuki Oyamada, A Mkrtchyan, Rolf Ent, A Gasparian, Y. Song, S. Randeniya, Miroslav Furić, Pavlo Baturin, T. Horn, B. S. Hu, Brian Raue, Osamu Hashimoto, Seigo Kato, W. F. Vulcan, P. Pamela, S. Wells, Darko Androić, A. Matsumura, Y. Fujii, K. Johnston, M. E. Christy, O. K. Baker, P. Bosted, V. M. Rodriguez, R. D. Carlini, H. C. Fenker, Fatiha Benmokhtar, A. Acha, M I Niculescu, D. Kawama, F. Kato, N. Maruyama, J. Roche, R. Rivera, Laird Kramer, G. Niculescu, S Zamkochian, A Asaturyan, M. Sumihama, S. A. Wood, R Asaturyan, C. Yan, Tomislav Petković, W. Luo, K Egiyan, T. Seva, Y. Okayasu, R. Halkyard, D. J. Mack, Pete Markowitz, C. E. Keppel, S Danagoulian, H Mkrtchyan, L. G. Tang, M. Ispiryan, N. Kalantarians, T Navasardyan, A Margaryan, D. Gaskell, G Marikyan, M. K. Jones, Ed V. Hungerford, L. Yuan, G. R. Smith, Paul Gueye, D. Honda, K. Nonaka, Hirokazu Tamura, E. F. Gibson, A. Ohtani, and Masashi Kaneta

Subjects
Physics, hypernuclear, electroproduction, kaon spectrometer, electron spectrometer, charge symmetry, History, Binding energy, Charge (physics), Lambda, Potential energy, Computer Science Applications, Education, Interaction potential, Cluster (physics), Symmetry breaking, Atomic physics, Spectroscopy
Abstract

The binding energy of 7ΛHe has been obtained for the first time with reaction spectroscopy using the (e, e'K+) reaction at Jefferson Lab's Hall C. A comparison among the binding energies of the A = 7 T = l iso-triplet hypernuclei, 7ΛHe, 7ΛLi*and 7ΛBe, is made and possible charge symmetry breaking (CSB) in the ΛN potential is discussed. For 7ΛHe and 7ΛBe, the shifts in binding energies are opposite to those predicted by a recent cluster model calculation, which assumes that the unexplained part of the binding energy difference between 4ΛH and 4ΛHe, is due to the CSB of the ΛN potential. Further examination of CSB in light hypernuclear systems is required both experimentally and theoretically.

Published
2011

23. Recovery of valuable metals from polymetallic mine tailings by natural microbial consortium.

Author

Vardanyan N, Sevoyan G, Navasardyan T, and Vardanyan A

Subjects
Copper, Iron, Zinc, Metals, Microbial Consortia
Abstract

Possibilities for the recovery of non-ferrous and precious metals from Kapan polymetallic mine tailings (Armenia) were studied. The aim of this paper was to study the possibilities of bioleaching of samples of concentrated tailings by the natural microbial consortium of drainage water. The extent of extraction of metals from the samples of concentrated tailings by natural microbial consortium reached 41-55% and 53-73% for copper and zinc, respectively. Metal leaching efficiencies of pure culture Leptospirillum ferrooxidans Teg were higher, namely 47-93% and 73-81% for copper and zinc, respectively. The content of gold in solid phase of tailings increased about 7-16% and 2-9% after bio-oxidation process by L. ferrooxidans Teg and natural microbial consortium, respectively. It was shown that bioleaching of the samples of tailings could be performed using the natural consortium of drainage water. However, to increase the intensity of the recovery of valuable metals, natural consortium of drainage water combined with iron-oxidizing L. ferrooxidans Teg has been proposed.

Published
2019
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24. Observation of the (Λ)(7)He hypernucleus by the (e, e'K+) reaction.

Author

Nakamura SN, Matsumura A, Okayasu Y, Seva T, Rodriguez VM, Baturin P, Yuan L, Acha A, Ahmidouch A, Androic D, Asaturyan A, Asaturyan R, Baker OK, Benmokhtar F, Bosted P, Carlini R, Chen C, Christy M, Cole L, Danagoulian S, Daniel A, Dharmawardane V, Egiyan K, Elaasar M, Ent R, Fenker H, Fujii Y, Furic M, Gan L, Gaskell D, Gasparian A, Gibson EF, Gogami T, Gueye P, Han Y, Hashimoto O, Hiyama E, Honda D, Horn T, Hu B, Hungerford EV, Jayalath C, Jones M, Johnston K, Kalantarians N, Kanda H, Kaneta M, Kato F, Kato S, Kawama D, Keppel C, Lan KJ, Luo W, Mack D, Maeda K, Malace S, Margaryan A, Marikyan G, Markowitz P, Maruta T, Maruyama N, Miyoshi T, Mkrtchyan A, Mkrtchyan H, Nagao S, Navasardyan T, Niculescu G, Niculescu MI, Nomura H, Nonaka K, Ohtani A, Oyamada M, Perez N, Petkovic T, Randeniya S, Reinhold J, Roche J, Sato Y, Segbefia EK, Simicevic N, Smith G, Song Y, Sumihama M, Tadevosyan V, Takahashi T, Tang L, Tsukada K, Tvaskis V, Vulcan W, Wells S, Wood SA, Yan C, and Zhamkochyan S

Abstract

An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, (Λ)(7)He, was observed for the first time with the (e, e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The (Λ)(7)He binding energy supplies the last missing information of the A = 7, T = 1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.

Published
2013
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25. New measurements of high-momentum nucleons and short-range structures in nuclei.

Author

Fomin N, Arrington J, Asaturyan R, Benmokhtar F, Boeglin W, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Daniel A, Day DB, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Gaskell D, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Mkrtchyan H, Navasardyan T, Niculescu G, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Seely J, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X

Abstract

We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.

Published
2012
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26. Scaling of the F2 structure function in nuclei and quark distributions at x>1.

Author

Fomin N, Arrington J, Day DB, Gaskell D, Daniel A, Seely J, Asaturyan R, Benmokhtar F, Boeglin W, Boillat B, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Miyoshi T, Mkrtchyan H, Navasardyan T, Niculescu G, Okayasu Y, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X

Abstract

We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.

Published
2010
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27. New measurements of the European Muon Collaboration effect in very light nuclei.

Author

Seely J, Daniel A, Gaskell D, Arrington J, Fomin N, Solvignon P, Asaturyan R, Benmokhtar F, Boeglin W, Boillat B, Bosted P, Bruell A, Bukhari MH, Christy ME, Clasie B, Connell S, Dalton MM, Day D, Dunne J, Dutta D, El Fassi L, Ent R, Fenker H, Filippone BW, Gao H, Hill C, Holt RJ, Horn T, Hungerford E, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lee C, Lung AF, Malace S, Meekins DG, Mertens T, Mkrtchyan H, Navasardyan T, Niculescu G, Niculescu I, Nomura H, Okayasu Y, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Segbefia E, Slifer K, Smith GR, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wesselmann FR, Wood SA, Wright J, Yuan L, and Zheng X

Abstract

New Jefferson Lab data are presented on the nuclear dependence of the inclusive cross section from (2)H, (3)He, (4)He, (9)Be and (12)C for 0.3 < x < 0.9, Q(2) approximately 3-6 GeV(2). These data represent the first measurement of the EMC effect for (3)He at large x and a significant improvement for (4)He. The data do not support previous A-dependent or density-dependent fits to the EMC effect and suggest that the nuclear dependence of the quark distributions may depend on the local nuclear environment.

Published
2009
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28. Measurement of nuclear transparency for the A(e,e'pi+) reaction.

Author

Clasie B, Qian X, Arrington J, Asaturyan R, Benmokhtar F, Boeglin W, Bosted P, Bruell A, Christy ME, Chudakov E, Cosyn W, Dalton MM, Daniel A, Day D, Dutta D, El Fassi L, Ent R, Fenker HC, Ferrer J, Fomin N, Gao H, Garrow K, Gaskell D, Gray C, Horn T, Huber GM, Jones MK, Kalantarians N, Keppel CE, Kramer K, Larson A, Li Y, Liang Y, Lung AF, Malace S, Markowitz P, Matsumura A, Meekins DG, Mertens T, Miller GA, Miyoshi T, Mkrtchyan H, Monson R, Navasardyan T, Niculescu G, Niculescu I, Okayasu Y, Opper AK, Perdrisat C, Punjabi V, Rauf AW, Rodriquez VM, Rohe D, Ryckebusch J, Seely J, Segbefia E, Smith GR, Strikman M, Sumihama M, Tadevosyan V, Tang L, Tvaskis V, Villano A, Vulcan WF, Wesselmann FR, Wood SA, Yuan L, and Zheng XC

Abstract

We have measured the nuclear transparency of the A(e,e'pi+) process in 2H, 12C, 27Al, 63Cu, and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q2=1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of (sigmaA/sigmaH) from data to a model of pion-electroproduction from nuclei without pi-N final-state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

Published
2007
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29. Onset of quark-hadron duality in pion electroproduction.

Author

Navasardyan T, Adams GS, Ahmidouch A, Angelescu T, Arrington J, Asaturyan R, Baker OK, Benmouna N, Bertoncini C, Blok HP, Boeglin WU, Bosted PE, Breuer H, Christy ME, Connell SH, Cui Y, Dalton MM, Danagoulian S, Day D, Dodario T, Dunne JA, Dutta D, El Khayari N, Ent R, Fenker HC, Frolov VV, Gan L, Gaskell D, Hafidi K, Hinton W, Holt RJ, Horn T, Huber GM, Hungerford E, Jiang X, Jones M, Joo K, Kalantarians N, Kelly JJ, Keppel CE, Kubarovski V, Li Y, Liang Y, Malace S, Markowitz P, McGrath E, McKee P, Meekins DG, Mkrtchyan H, Moziak B, Niculescu G, Niculescu I, Opper AK, Ostapenko T, Reimer P, Reinhold J, Roche J, Rock SE, Schulte E, Segbefia E, Smith C, Smith GR, Stoler P, Tadevosyan V, Tang L, Ungaro M, Uzzle A, Vidakovic S, Villano A, Vulcan WF, Wang M, Warren G, Wesselmann F, Wojtsekhowski B, Wood SA, Xu C, Yuan L, Zheng X, and Zhu H

Abstract

A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms.

Published
2007
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