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2. Time scales from two-neutron intensity interferometry for the reaction40Ar+165HoatE/A=25MeV

Author

C. K. Gelbke, P. D. Zecher, Ferenc Deák, M. B. Tsang, Aaron Galonsky, A. Kiss, Ákos Horváth, Roy Crawford Lemmon, T. Glasmacher, Z. Seres, Kazuo Ieki, Yoshiyuki Iwata, J. Wang, Jon J. Kruse, M. J. Huang, W. G. Lynch, S. J. Gaff, and G. J. Kunde

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Interferometry, Correlation function (statistical mechanics), Neutron emission, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Neutron, Neutron scattering, Nuclear Experiment, Intensity (heat transfer)
Abstract

As a test for the time scale of neutron emission, two-neutron intensity interferometry was applied to the reaction Ar1Ho at E/A525 MeV. After appropriate corrections for neutron scattering, the correlation function showed a lifetime that was about a factor of two shorter than the lifetime predicted for the statistical decay of an equilibrated nucleus. Preequilibrium emission may explain some of this difference. @S0556-2813~98!00210-6#

Published
1998

3. Measurement of the8Li(n,γ)9Li cross section at astrophysical energies by reverse kinematics

Author

Ferenc Deák, S. J. Gaff, Aaron Galonsky, J. von Schwarzenberg, R. E. Warner, Ákos Horváth, J. Wang, J. J. Kolata, Yoshiyuki Iwata, Erik Tryggestad, Jon J. Kruse, Z. Seres, G. J. Kunde, P. D. Zecher, Hugo R. Schelin, A. Kiss, Kazuo Ieki, and D. J. Morrissey

Subjects
Physics, Nuclear and High Energy Physics, Big Bang nucleosynthesis, Radiative capture, Coulomb, r-process, Inverse, Neutron, Atomic physics, Radioactive beam
Abstract

We have made the first attempt at determining the ${}^{8}$Li$(n,\ensuremath{\gamma})$${}^{9}$Li cross section at astrophysical energies. This reaction competes with the ${}^{8}$Li$(\ensuremath{\alpha}{,n)}^{11}$B reaction in the inhomogeneous big bang model and with ${}^{8}$Li $\ensuremath{\beta}$ decay in the $r$ process. It may affect the primordial abundance and the stellar production of Ag12 nuclei. Using a radioactive beam of ${}^{9}$Li and the Coulomb dissociation method we attempted to measure the cross section of the inverse reaction ${}^{9}$Li$(\ensuremath{\gamma}{,n)}^{8}$Li. We report only an upper limit because we were unable to determine and subtract the nuclear dissociation. Through the detailed balance theorem, this lead to an upper limit for the cross section of interest, ${}^{8}$Li$(n,\ensuremath{\gamma})$${}^{9}$Li. The limit is 19$\ifmmode\pm\else\textpm\fi{}$8 b for ${E}_{n}$ = 0--500 keV or, when expressed as a reaction rate, 7200 cm${}^{3}$ s${}^{\ensuremath{-}1}$ mole${}^{\ensuremath{-}1}$.

Published
1998

4. Temperature Measurements for CentralAu+AuCollisions at35AMeV

Author

J. D. Dinius, Rinaldo Rui, F. Petruzzelli, M. J. Huang, M. D'Agostino, F. Gramegna, W. G. Lynch, L. Martin, A. Moroni, G. Tagliente, M. B. Tsang, T. Glasmacher, Evan Scannapieco, P. F. Mastinu, I. Iori, Hongfei Xi, G. J. Kunde, C. K. Gelbke, M. L. Fiandri, Nicola Colonna, P. M. Milazzo, S. J. Gaff, M. Azzano, C. P. Montoya, M. Bruno, A. Ferrero, Giacomo Vito Margagliotti, L. Celano, and G. Vannini

Subjects
Physics, Yield (engineering), Excited state, Extrapolation, Zero (complex analysis), General Physics and Astronomy, Atomic physics, Impact parameter, Nuclear Experiment, Temperature measurement
Abstract

The breakup temperatures for central $\mathrm{Au}+\mathrm{Au}$ collisions at $35A\mathrm{MeV}$ have been determined from the relative populations of excited states of ${}^{5}\mathrm{Li}$, ${}^{4}\mathrm{He}$, and ${}^{10}\mathrm{B}$ fragments and nine double ratios involving the yields of elements with $1\ensuremath{\le}Z\ensuremath{\le}6$. Unlike results reported at significantly higher energies, all thermometers yield temperatures that are consistent within the experimental uncertainties. Extrapolation of the data to zero impact parameter yields ${T}_{\mathrm{em}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4.6\ifmmode\pm\else\textpm\fi{}0.4\mathrm{MeV}$, somewhat lower than the temperature assumed in statistical multifragmentation model calculations which describe most of the other features of this reaction.

Published
1997

5. Isospin dependence of intermediate mass fragment production in heavy-ion collisions atE/A=55 MeV

Author

T. Glasmacher, W. Skulski, M. J. Huang, W. G. Lynch, W. A. Friedman, J. Dempsey, L. G. Sobotka, Jan Toke, L. Martin, Dileep Agnihotri, W. U. Schröder, R. Lemmon, L. Manduci, M. B. Tsang, G. J. Kunde, C. K. Gelbke, B. Djerroud, S. J. Gaff, and R. J. Charity

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Projectile, Nuclear Theory, Charged particle, Baryon, Nuclear physics, Isotopes of tin, Neutron, Atomic physics, Nuclear Experiment, Nucleon, Ternary fission
Abstract

The production of intermediate mass fragments (IMF's) from the four reactions 55A MeV $^{124,136}\mathrm{Xe}$ + $^{112,124}\mathrm{Sn}$ is studied with an experimental apparatus which is highly efficient for the detection of both charged particles and neutrons. The IMF's are more localized in the midvelocity region than are the light charged particles, and the detected multiplicity of IMF's depends linearly on the charge lost from the projectile and increases with the neutron excess of the system. Remnants of the projectile, with very little velocity reduction, are found for most of the reaction cross section. Isotopic and isobaric fragment yields in the projectile-velocity region indicate that charge-to-mass ratio neutralization is generally not achieved but is approached when little remains of the projectile. For all systems, the fragments found in the midvelocity region are substantially more neutron rich than those found in the velocity region dominated by the emission from the projectile. This observation can be accounted for if the midvelocity source (or sources) is either more neutron rich or smaller, with the same neutron-to-proton ratio, than the source with the velocity of the projectile. Taken together, the observations of this work suggest that the intermediate mass fragments are, to a large extent, formed by multiple neck rupture of the overlap material, a process which might enhance the neutron-to-proton ratio of the primary source material and/or limit the size of the sources. This scenario is reminiscent of low-energy ternary fission and one predicted by Boltzmann-Uehling-Uhlenbeck calculations. However, these calculations predict too much velocity damping of the projectile remnant. The calculations improve, in this regard, when the in-medium nucleon-nucleon cross sections and the cost of creating low density material are reduced. \textcopyright{} 1996 The American Physical Society.

Published
1996

6. Multifragment Production in Reactions ofS112n+S112nandS124n+S124natE/A=40MeV

Author

M. J. Huang, R. J. Charity, W. Skulski, M. B. Tsang, J. Dempsey, L. G. Sobotka, L. Martin, W. A. Friedman, L. Manduci, Dileep Agnihotri, C. K. Gelbke, R. Lemmon, S. J. Gaff, W. G. Lynch, Jan Toke, W. U. Schröder, B. Djerroud, G. J. Kunde, T. Glasmacher, and K. Wyrozebski

Subjects
Physics, Proton, Astrophysics::High Energy Astrophysical Phenomena, General Physics and Astronomy, Neutron, Multiplicity (mathematics), Atomic physics, Nuclear Experiment, Charged particle
Abstract

Multiplicities of intermediate-mass fragments (IMFs), neutrons, and charged particles were measured for ${}^{112}\mathrm{Sn}{+}^{112}\mathrm{Sn}$ and ${}^{124}\mathrm{Sn}{+}^{124}\mathrm{Sn}$ at $E/A\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}40\mathrm{MeV}$. Significantly different scalings of the mean IMF multiplicities with neutron and charged-particle multiplicities are observed for the two reactions. These differences can be qualitatively understood in terms of fragment emission from an expanding evaporating source for which the initial rates of cooling by neutron and light-charged-particle emission depend on the neutron and proton numbers of the source according to statistical expectations.

Published
1996

7. Q2dependence of theS11(1535)photocoupling and evidence for aP-wave resonance in η electroproduction

Author

S. A. Morrow, Laird Kramer, P. Dragovitsch, P. Stoler, Barry Ritchie, J. Hardie, S. O. Nelson, K. Hicks, H. G. Juengst, M. L. Leber, Federico Ronchetti, K. Livingston, A.V. Stavinsky, D. J. Tedeschi, J. Kuhn, N. A. Baltzell, R. C. Minehart, C. A. Meyer, G. V. Fedotov, R. Dickson, L. Elouadrhiri, H. Denizli, J. P. Santoro, Roy Thompson, D. P. Weygand, I. Bedlinskiy, K. A. Griffioen, G. Ricco, N. Markov, J. Langheinrich, S. S. Stepanyan, N. Dashyan, S. A. Philips, I. I. Strakovsky, N. Guler, M. Bellis, G. A. Peterson, K. S. Egiyan, Nikolay Shvedunov, A. Deur, V. Frolov, M. J. Amaryan, K. Mikhailov, Shifeng Chen, R. J. Feuerbach, A. I. Ostrovidov, P. Eugenio, R. Fatemi, B. B. Niczyporuk, S. Barrow, W. K. Brooks, M. Taiuti, V. Batourine, I. Hleiqawi, Friedrich Klein, Y. Ilieva, C. Cetina, A. V. Vlassov, S. L. Careccia, N. Kalantarians, J. Hu, J. D. Kellie, J. P. Cummings, S. Simionatto, C. E. Hyde-Wright, Brian Raue, N. Pivnyuk, J. Napolitano, Michael Vineyard, L. Farhi, D. Rowntree, Sergey Kuleshov, N. Baillie, J. T. Goetz, E. Polli, M. Bektasoglu, M. Nozar, V. Gyurjyan, G. V. O'Rielly, P. Collins, Maryam Moteabbed, K. L. Giovanetti, B. Asavapibhop, M. Kossov, M. MacCormick, Valeria Muccifora, Bernhard Mecking, V. Sapunenko, Dinko Pocanic, R. De Vita, J. Zhang, M. Guidal, Z. W. Zhao, G. Gavalian, S. Tkachenko, R. A. Schumacher, Susan Taylor, N. Benmouna, P. L. Cole, M. Spraker, Larry Weinstein, D. Doughty, G. Rosner, L. C. Smith, S. J. Gaff, H. Bagdasaryan, R. Nasseripour, M. Holtrop, D. G. Jenkins, C. Djalali, M. D. Mestayer, E. L. Isupov, M. Ripani, L. Guo, S. Strauch, Gerard Gilfoyle, K. Sabourov, D. Heddle, Nicola Bianchi, D. P. Watts, H. Egiyan, S. Bültmann, M. Ungaro, Michael L. Williams, B. S. Ishkhanov, Sylvain Bouchigny, S. E. Kuhn, T. A. Forest, D. Sokhan, S. Stepanyan, P. Nadel-Turonski, B. E. Stokes, J. W. Price, J. Pierce, Avraham Klein, G. S. Adams, Tsutomu Mibe, G. E. Dodge, J. J. Manak, S. Boiarinov, Michael Dugger, S. McAleer, B. M. Preedom, H. Y. Lu, P. Rossi, H. O. Funsten, F. X. Girod, P. V. Degtyarenko, D. Protopopescu, R. A. Miskimen, B. McKinnon, J. H. Kelley, K. Joo, G. S. Mutchler, S. Pozdniakov, M. Garçon, L. M. Qin, J. Yun, D. Cords, C. Tur, Lorenzo Zana, D. G. Ireland, A. Shafi, A. Yegneswaran, I. Niculescu, M. Battaglieri, V. Crede, D. Lawrence, D. Branford, P. Ambrozewicz, H. Hakobyan, Kwangsoo Kim, G. Riccardi, Gerald Feldman, K. Moriya, U. Thoma, J. R. Calarco, A. Tkabladze, M. Mirazita, J. M. Laget, C. Paterson, Elton Smith, K. Wang, C. Salgado, Atilla Gonenc, M. R. Niroula, M. Klusman, R. Bradford, K. Lukashin, C. Butuceanu, M. Guillo, E. De Sanctis, M. Khandaker, M. Anghinolfi, E. Wolin, H. S. Jo, R. S. Hakobyan, James Mueller, L. El Fassi, P. D. Rubin, J. P. Ball, Y. Prok, Y. G. Sharabian, D. S. Carman, J. Lachniet, D. I. Sober, S. Niccolai, D. G. Crabb, J. Salamanca, J. W C McNabb, A. Coleman, H. R. Weller, Volker D. Burkert, A. S. Biselli, J. Donnelly, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. Corvisiero, J. Miles, P. Coltharp, M. Osipenko, F. Sabatié, M. M. Ito, K. Beard, R. W. Gothe, Kalvir S. Dhuga, K. Y. Kim, W. Kim, A. V. Skabelin, G. Niculescu, B. Zhao, R. D. Levine, V. Mokeev, F. W. Hersman, L. C. Dennis, B. E. Bonner, H. Avakian, W. J. Briscoe, E. Pasyuk, S. A. Dytman, Patrick Girard, J. Shaw, Michael Wood, K. Hafidi, V. S. Serov, K. Park, V. P. Kubarovsky, A. Empl, and O. Pogorelko

Subjects
Baryon, Scattering cross-section, Physics, Nuclear and High Energy Physics, Cross section.transverse, Particle physics, Amplitude, Photon, Angular distribution, Momentum transfer, Resonance, High Energy Physics::Experiment
Abstract

New cross sections for the reaction $\mathit{ep}\ensuremath{\rightarrow}{e}^{'}\ensuremath{\eta}p$ are reported for total center-of-mass energy $W=1.5\text{\ensuremath{-}}2.3$ GeV and invariant squared momentum transfer ${Q}^{2}=0.13\text{\ensuremath{-}}3.3$ GeV${}^{2}$. This large kinematic range allows the extraction of new information about response functions, photocouplings, and $\ensuremath{\eta}N$ coupling strengths of baryon resonances. A sharp structure is seen at $W~1.7$ GeV. The shape of the differential cross section is indicative of the presence of a $P$-wave resonance that persists to high ${Q}^{2}$. Improved values are derived for the photocoupling amplitude for the ${S}_{11}$(1535) resonance. The new data greatly expand the ${Q}^{2}$ range covered, and an interpretation of all data with a consistent parametrization is provided.

Published
2007

8. Singleπ+electroproduction on the proton in the first and second resonance regions at0.25GeV2<Q2<0.65GeV2

Author

J. Kuhn, Shifeng Chen, R. J. Feuerbach, Roy Thompson, R. W. Gothe, K. Y. Kim, C. Cetina, Y. Kuang, V. Gyurjyan, J. Zhang, E. Anciant, Michael Vineyard, M. Guidal, G. E. Dodge, H. Bagdasaryan, E. Polli, F. W. Hersman, G. Gavalian, K. S. Egiyan, G. Niculescu, Daijin Kim, Min Suk Kim, S. Stepanyan, P. V. Degtyarenko, L. M. Qin, Sylvain Bouchigny, N. Benmouna, M. Ripani, M. Khandaker, K. A. Griffioen, G. Ricco, K. Mikhailov, P. Rossi, M. Holtrop, H. Denizli, Elton Smith, P. Eugenio, M. Taiuti, Philip L. Cole, Ji Li, F. Ronchetti, K. Livingston, E. DeSanctis, G. V. O'Rielly, M. Klusman, M. Anghinolfi, James Mueller, I. Niculescu, Moshe Gai, A. V. Skabelin, E. Wolin, I. G. Aznauryan, I. Hleiqawi, P. D. Rubin, Y. G. Sharabian, J. P. Cummings, D. G. Jenkins, Friedrich Klein, Victor Mokeev, D. Lawrence, S. L. Careccia, S. Simionatto, M. D. Mestayer, Alexei V. Klimenko, K. Sabourov, M. Osipenko, J. Langheinrich, R. DeVita, J. D. Kellie, J. W C McNabb, R. S. Hicks, Brian Raue, J. Lachniet, P. Stoler, J. R. Calarco, L. C. Smith, S. J. Gaff, B. S. Ishkhanov, S. A. Philips, Barry Ritchie, K. Beard, P. Dragovitsch, Dinko Pocanic, M. Kossov, G. T. Goetz, D. Rowntree, Rakhsha Nasseripour, S. McAleer, S. O. Nelson, K. L. Giovanetti, B. Asavapibhop, M. Spraker, Larry Weinstein, L. Guo, M. Ungaro, J. J. Melone, Bernhard Mecking, K. Hicks, S. E. Kuhn, B. Carnahan, F. Sabatié, Latifa Elouadrhiri, W. Kim, K. V. Dharmawardane, D. Doughty, D. Heddle, J. P. Ball, Y. Prok, R. C. Minehart, Cynthia Marie Hadjidakis, C. A. Meyer, B. B. Niczyporuk, J. H. Kelley, S. Niccolai, G. V. Fedotov, C. Tur, Shalev Gilad, Thierry Auger, Michael Dugger, N. Guler, S. Boiarinov, B. M. Preedom, A. Tkabladze, R. S. Hakobyan, O. P. Dzyubak, Daniel S. Carman, Susan Taylor, S. Strauch, G. A. Peterson, H. O. Funsten, M. Eckhause, D. P. Weygand, J. W. Price, J. Hardie, N. Pivnyuk, J. Napolitano, A. Longhi, G. Audit, K. Joo, C. E. Hyde-Wright, R. A. Niyazov, J. Yun, D. Cords, H. Egiyan, A. Yegneswaran, J. P. Santoro, P. Corvisiero, M. Sargsyan, A.V. Stavinsky, N. Baltzel, Hall Crannell, S. A. Morrow, S. Barrow, L. C. Dennis, B. E. Bonner, C. S. Whisnant, C. Djalali, D. J. Tedeschi, C. Marchand, Gerald Feldman, R. A. Schumacher, H. Avakian, J. Hu, M. Nozar, A. Coleman, L. Todor, M. Battaglieri, H. R. Weller, P. Ambrozewicz, K. Wang, C. Salgado, D. Protopopescu, S. Pozdniakov, C. I O Gordon, R. Bradford, K. Lukashin, D. G. Crabb, G. S. Mutchler, Z. L. Zhou, G. Rosner, J. Donnely, A. Shafi, L. Morand, T. A. Forest, W. J. Briscoe, E. Pasyuk, Avraham Klein, S. A. Dytman, G. S. Adams, Y. Ilieva, M. Bellis, K. Park, M. M. Ito, R. Fatemi, A. V. Vlassov, V. P. Kubarovsky, A. Empl, O. Pogorelko, J. J. Manak, Patrick Girard, J. Shaw, Michael Wood, V. S. Serov, Nicola Bianchi, D. I. Sober, L. Y. Murphy, S. Mehrabyan, Kwangsoo Kim, G. Riccardi, C. Butuceanu, Laird Kramer, M. Bektasoglu, D. G. Ireland, Volker D. Burkert, Jing Zhao, A. S. Biselli, R. A. Miskimen, B. McKinnon, H. G. Juengst, D. Branford, M. Mirazita, J. M. Laget, V. Sapunenko, Valeria Muccifora, Gerard Gilfoyle, U. Thoma, M. Guillo, I. I. Strakovsky, and W. K. Brooks

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, 010308 nuclear & particles physics, Hadron, Resonance, Sigma, 01 natural sciences, 7. Clean energy, Helicity, Particle identification, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The ep {yields} e'pi{sup +}n reaction was studied in the first and second nucleon resonance regions in the 0.25 GeV{sup 2} < Q{sup 2} < 0.65 GeV{sup 2} range using the CLAS detector at Thomas Jefferson National Accelerator Facility. For the first time the absolute cross sections were measured covering nearly the full angular range in the hadronic center-of-mass frame. The structure functions {sigma}{sub TL}, {sigma}{sub TT} and the linear combination {sigma}{sub T} + {epsilon}{sigma}{sub L} were extracted by fitting the {phi}-dependence of the measured cross sections, and were compared to the MAID and Sato-Lee models.

Published
2006

9. Measurement of the polarized structure functionσLT'for pion electroproduction in the Roper-resonance region

Author

H. Avakian, L. Elouadrhiri, V. Gyurjyan, J. Zhang, H. Bagdasaryan, A.V. Stavinsky, M. Osipenko, V. Batourine, E. Anciant, L. Guo, M. Ungaro, P. Stoler, R. Fatemi, D. J. Tedeschi, I. I. Strakovsky, A. Deur, A. V. Vlassov, K. Joo, N. A. Baltzell, R. A. Niyazov, J. Yun, D. Cords, A. Yegneswaran, M. Bektasoglu, R. A. Schumacher, B. Carnahan, F. Sabatié, W. J. Briscoe, E. Pasyuk, Thierry Auger, K. Beard, S. A. Dytman, I. Bedlinskiy, T. Lee, J. P. Cummings, W. K. Brooks, E. Wolin, K. A. Griffioen, S. Strauch, S. O. Nelson, K. Hicks, M. Kossov, Susan Taylor, R. A. Miskimen, B. McKinnon, H. G. Juengst, J. J. Manak, G. Gavalian, M. Khandaker, J. Lachniet, S. Bueltmann, J. Kuhn, Kalvir S. Dhuga, V. Mokeev, Shifeng Chen, T. A. Forest, J. P. Ball, M. Bellis, Patrick Girard, L. C. Maximon, J. Donnelly, G. Asryan, O. P. Dzyubak, N. Benmouna, M. Ripani, D. Rowntree, H. Egiyan, S. Stepanyan, J. Pierce, Avraham Klein, P. Coltharp, J. Shaw, Michael Wood, J. D. Kellie, M. Guillo, D. Doughty, P. Dragovitsch, Sylvain Bouchigny, Roy Thompson, P. Corvisiero, E. De Sanctis, P. Rossi, J. T. Goetz, D. Protopopescu, G. E. Dodge, E. Polli, D. I. Sober, D. Heddle, R. DeVita, S. Niccolai, Federico Ronchetti, D. G. Ireland, J. Hardie, V. Sapunenko, Dinko Pocanic, K. S. Egiyan, D. Branford, D. G. Crabb, S. Pozdniakov, M. Garçon, J. W C McNabb, W. Kim, M. M. Ito, P. V. Degtyarenko, K. Kim, R. S. Hakobyan, K. Mikhailov, V. S. Serov, G. Niculescu, J. R. Calarco, J. Hu, S. E. Kuhn, M. Mirazita, G. Ricco, S. A. Morrow, J. M. Laget, J. H. Kelley, C. Tur, A. Shafi, L. Farhi, G. S. Mutchler, I. Niculescu, C. Djalali, D. Lawrence, Elton Smith, V. Frolov, M. Battaglieri, K. Park, P. Nadel-Turonski, M. Anghinolfi, P. Eugenio, I. Hleiqawi, James Mueller, R. J. Feuerbach, S. L. Careccia, M. Taiuti, R. Bradford, K. Lukashin, A. Coleman, A. I. Ostrovidov, Friedrich Klein, P. D. Rubin, Y. G. Sharabian, P. Ambrozewicz, S. Simionatto, H. R. Weller, Brian Raue, K. Livingston, Michael Dugger, H. O. Funsten, V. P. Kubarovsky, K. L. Giovanetti, B. Asavapibhop, A. Empl, O. Pogorelko, M. Spraker, Larry Weinstein, G. Rosner, R. Nasseripour, C. Marchand, Volker D. Burkert, A. S. Biselli, Alexei V. Klimenko, M. D. Mestayer, L. C. Smith, S. J. Gaff, Bernhard Mecking, B. S. Ishkhanov, Michael L. Williams, K. V. Dharmawardane, Inna Aznauryan, B. E. Stokes, Y. Prok, B. B. Niczyporuk, G. S. Adams, Laird Kramer, Barry Ritchie, S. Boiarinov, N. Pivnyuk, J. Napolitano, G. Riccardi, N. Guler, N. Baillie, C. Butuceanu, G. A. Peterson, Valeria Muccifora, Gerard Gilfoyle, P. L. Cole, J. Langheinrich, C. Cetina, Michael Vineyard, A. V. Skabelin, S. S. Stepanyan, S. A. Philips, B. M. Preedom, S. Barrow, R. C. Minehart, C. A. Meyer, G. V. Fedotov, Lorenzo Zana, J. P. Santoro, B. L. Berman, M. Guidal, L. M. Qin, A. Tkabladze, Y. Ilieva, D. P. Weygand, H. S. Jo, Gerald Feldman, M. Holtrop, M. Klusman, K. Wang, C. Salgado, Daniel S. Carman, G. Audit, C. E. Hyde-Wright, M. Nozar, Nicola Bianchi, R. W. Gothe, K. Y. Kim, U. Thoma, F. W. Hersman, S. McAleer, F. X. Girod, J. W. Price, G. V. O'Rielly, D. G. Jenkins, K. Sabourov, L. C. Dennis, and B. E. Bonner

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Roper resonance, 010308 nuclear & particles physics, Structure function, Sigma, Electron, Polarization (waves), 01 natural sciences, Pion, Amplitude, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Beam energy
Abstract

The polarized longitudinal-transverse structure function {sigma}{sub LT{sup '}} measures the interference between real and imaginary amplitudes in pion electroproduction and can be used to probe the coupling between resonant and nonresonant processes. We report new measurements of {sigma}{sub LT{sup '}} in the N(1440)(1/2){sup +} (Roper) resonance region at Q{sup 2}=0.40 and 0.65GeV{sup 2} for both the {pi}{sup 0}p and {pi}{sup +}n channels. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) using longitudinally polarized electrons at a beam energy of 1.515 GeV. Complete angular distributions were obtained and are compared to recent phenomenological models. The {sigma}{sub LT{sup '}}({pi}{sup +}n) channel shows a large sensitivity to the Roper-resonance multipoles M{sub 1-} and S{sub 1-} and provides new constraints on models of resonance formation.

Published
2005

10. Measurement of the polarized structure functionσLT′forp(e⃗,e′π+)nin theΔ(1232)resonance region

Author

K. Joo, L. C. Smith, I. G. Aznauryan, V. D. Burkert, R. Minehart, G. Adams, P. Ambrozewicz, E. Anciant, M. Anghinolfi, B. Asavapibhop, G. Asryan, G. Audit, T. Auger, H. Avakian, H. Bagdasaryan, J. P. Ball, S. Barrow, V. Batourine, M. Battaglieri, K. Beard, M. Bektasoglu, N. Benmouna, N. Bianchi, A. S. Biselli, S. Boiarinov, B. E. Bonner, S. Bouchigny, R. Bradford, D. Branford, W. J. Briscoe, W. K. Brooks, S. Bültmann, C. Butuceanu, J. R. Calarco, D. S. Carman, B. Carnahan, C. Cetina, S. Chen, L. Ciciani, P. L. Cole, D. Cords, P. Corvisiero, D. Crabb, H. Crannell, J. P. Cummings, E. De Sanctis, R. DeVita, P. V. Degtyarenko, L. Dennis, A. Deur, K. V. Dharmawardane, K. S. Dhuga, C. Djalali, G. E. Dodge, D. Doughty, P. Dragovitsch, M. Dugger, S. Dytman, O. P. Dzyubak, H. Egiyan, K. S. Egiyan, L. Elouadrhiri, A. Empl, P. Eugenio, R. Fersch, R. J. Feuerbach, T. A. Forest, H. Funsten, S. J. Gaff, M. Garçon, G. Gavalian, S. Gilad, G. P. Gilfoyle, K. L. Giovanetti, R. W. Gothe, K. A. Griffioen, M. Guidal, M. Guillo, N. Guler, L. Guo, V. Gyurjyan, C. Hadjidakis, R. S. Hakobyan, J. Hardie, D. Heddle, F. W. Hersman, K. Hicks, I. Hleiqawi, M. Holtrop, J. Hu, C. E. Hyde-Wright, Y. Ilieva, D. Ireland, M. M. Ito, D. Jenkins, H. G. Juengst, J. D. Kellie, J. H. Kelley, M. Khandaker, K. Y. Kim, K. Kim, W. Kim, A. Klein, F. J. Klein, A. V. Klimenko, M. Klusman, M. Kossov, V. Koubarovski, L. H. Kramer, S. E. Kuhn, J. Kuhn, J. Lachniet, J. M. Laget, J. Langheinrich, D. Lawrence, T. Lee, K. Livingston, K. Lukashin, J. J. Manak, C. Marchand, S. McAleer, J. W. C. McNabb, B. A. Mecking, M. D. Mestayer, C. A. Meyer, K. Mikhailov, M. Mirazita, R. Miskimen, V. Mokeev, L. Morand, S. A. Morrow, V. Muccifora, J. Mueller, G. S. Mutchler, J. Napolitano, R. Nasseripour, S. O. Nelson, S. Niccolai, G. Niculescu, I. Niculescu, B. B. Niczyporuk, R. A. Niyazov, M. Nozar, G. V. O’Rielly, M. Osipenko, A. I. Ostrovidov, K. Park, E. Pasyuk, G. Peterson, S. A. Philips, N. Pivnyuk, D. Pocanic, O. Pogorelko, E. Polli, S. Pozdniakov, B. M. Preedom, J. W. Price, Y. Prok, D. Protopopescu, L. M. Qin, B. A. Raue, G. Riccardi, G. Ricco, M. Ripani, B. G. Ritchie, F. Ronchetti, G. Rosner, P. Rossi, D. Rowntree, P. D. Rubin, F. Sabatié, K. Sabourov, C. Salgado, J. P. Santoro, V. Sapunenko, R. A. Schumacher, V. S. Serov, Y. G. Sharabian, J. Shaw, S. Simionatto, A. V. Skabelin, E. S. Smith, D. I. Sober, M. Spraker, A. Stavinsky, S. Stepanyan, S. S. Stepanyan, B. E. Stokes, P. Stoler, I. I. Strakovsky, S. Strauch, M. Taiuti, S. Taylor, D. J. Tedeschi, U. Thoma, R. Thompson, A. Tkabladze, L. Todor, C. Tur, M. Ungaro, M. F. Vineyard, A. V. Vlassov, K. Wang, L. B. Weinstein, H. Weller, D. P. Weygand, M. Williams, E. Wolin, M. H. Wood, A. Yegneswaran, J. Yun, and L. Zana

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Hadron, Elementary particle, 01 natural sciences, Delta baryon, Baryon, Pion, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The polarized longitudinal-transverse structure function {sigma}{sub LT{sup '}} has been measured using the p(e-vector,e{sup '}{pi}{sup +})n reaction in the {delta}(1232) resonance region at Q{sup 2}=0.40 and 0.65 GeV{sup 2}. No previous {sigma}{sub LT{sup '}} data exist for this reaction channel. The kinematically complete experiment was performed at the Jefferson Lab with the CEBAF large acceptance spectrometer using longitudinally polarized electrons at an energy of 1.515 GeV. A partial-wave analysis of the data shows generally better agreement with recent phenomenological models of pion electroproduction compared to the previously measured {pi}{sup 0}p channel. A fit to both {pi}{sup 0}p and {pi}{sup +}n channels using a unitary isobar model suggests the unitarized Born terms provide a consistent description of the nonresonant background. The t-channel pion pole term is important in the {pi}{sup 0}p channel through a rescattering correction, which could be model dependent.

Published
2004

11. Tensor polarization of theϕmeson photoproduced at hight

Author

J. P. Cummings, M. Kossov, J. Langheinrich, M. Bektasoglu, Rakhsha Nasseripour, S. A. Philips, P. Dragovitsch, Jing Zhao, Daniel S. Carman, P. Stoler, M. Osipenko, K. Beard, G. Audit, C. E. Hyde-Wright, J. Lachniet, Dinko Pocanic, S. Niccolai, S. E. Kuhn, L. C. Dennis, S. O. Nelson, K. Hicks, J. H. Kelley, C. Tur, D. Rowntree, B. E. Bonner, Hall Crannell, Susan Taylor, S. McAleer, J. Hardie, G. Gavalian, M. Guillo, J. Kuhn, H. Egiyan, H. Avakian, B. M. Preedom, W. Major, R. S. Hakobyan, O. P. Dzyubak, R. A. Niyazov, C. Marchand, M. Guidal, G. Niculescu, Roy Thompson, R. A. Schumacher, R. A. Miskimen, M. Holtrop, H. G. Juengst, P. Corvisiero, E. Anciant, C. S. Whisnant, J. P. Santoro, C. I O Gordon, G. A. Peterson, D. J. Tedeschi, W. Kim, K. S. Egiyan, F. W. Hersman, E. Pasyuk, S. Barrow, L. Morand, T. A. Forest, M. Mirazita, J. M. Laget, P. Eugenio, M. Taiuti, S. A. Dytman, B. Carnahan, F. Sabatié, M. Khandaker, R. J. Feuerbach, K. Wang, T. Smith, C. Salgado, L. Farhi, Thierry Auger, Volker D. Burkert, A. S. Biselli, U. Thoma, Avraham Klein, G. S. Adams, D. Hancock, G. Ricco, K. Joo, G. E. Dodge, Patrick Girard, B. L. Berman, J. Shaw, V. Gyurjyan, D. Doughty, Nicola Bianchi, Michael Wood, V. Sapunenko, L. M. Qin, Valeria Muccifora, Philip L. Cole, P. V. Degtyarenko, V. S. Serov, Laird Kramer, A. Coleman, D. Heddle, H. R. Weller, C. Cetina, Gerard Gilfoyle, L. Todor, Moshe Gai, M. Klusman, Michael Vineyard, M. Bellis, K. Park, D. Protopopescu, M. Garçon, J. W. Price, I. Niculescu, Z. L. Zhou, H. Bagdasaryan, J. J. Melone, D. Lawrence, Friedrich Klein, R. S. Hicks, Brian Raue, A. Shafi, Ji Li, L. Guo, M. Ungaro, M. D. Mestayer, O. Pogorelko, W. K. Brooks, F. Ronchetti, V. Frolov, S. Boiarinov, J. Yun, D. Cords, K. L. Giovanetti, B. Asavapibhop, M. Spraker, Larry Weinstein, A. Yegneswaran, L. C. Smith, S. J. Gaff, D. G. Jenkins, K. Sabourov, Cynthia Marie Hadjidakis, Michael Dugger, M. Nozar, E. De Sanctis, H. O. Funsten, M. M. Ito, D. I. Sober, A. V. Vlassov, J. J. Manak, S. Mehrabyan, Elton Smith, J. R. Ficenec, M. Anghinolfi, James Mueller, K. McCormick, P. D. Rubin, Y. G. Sharabian, C. Butuceanu, Shifeng Chen, E. Wolin, Y. Kuang, E. Polli, J. P. Ball, Y. Prok, M. Eckhause, M. Sargsyan, Latifa Elouadrhiri, D. G. Crabb, R. C. Minehart, C. A. Meyer, D. P. Weygand, N. Benmouna, M. Ripani, H. Denizli, J. Connelly, A. V. Skabelin, Alexei V. Klimenko, Barry Ritchie, M. Battaglieri, R. Bradford, K. Lukashin, S. Strauch, J. R. Calarco, M. Witkowski, Bernhard Mecking, K. V. Dharmawardane, G. S. Mutchler, K. A. Griffioen, S. Stepanyan, Sylvain Bouchigny, P. Rossi, G. Riccardi, R. DeVita, J. W C McNabb, S. A. Morrow, C. Djalali, Shalev Gilad, P. Ambrozewicz, M. Sanzone-Arenhovel, B. B. Niczyporuk, N. Pivnyuk, and J. Napolitano

Subjects
Physics, Coupling constant, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Momentum transfer, Hadron, Quarkonium, Phi meson, 01 natural sciences, Helicity, Nuclear physics, Particle decay, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics
Abstract

As part of a measurement [E. Anciant et al., Phys. Rev. Lett. 85, 4682 (2000)] of the cross section of phi meson photoproduction to high momentum transfer, we measured the polar angular decay distribution of the outgoing K+ in the channel K+K- in the phi center-of-mass frame (the helicity frame). We find that phi s-channel helicity conservation (SCHC) holds in the kinematical range where t-channel exchange dominates (up to -t {approx}2.5 GeV2 for E = 3.6 GeV). Above this momentum, phi u-channel production of a meson dominates and induces a violation of SCHC. The deduced value of the phi NN coupling constant lies in the upper range of previously reported values.

Published
2004

12. Publisher’s Note: Observation of an Exotic Baryon withS=+1in Photoproduction from the Proton [Phys. Rev. Lett.PRLTAO0031-900792, 032001 (2004)]

Author

K. Park, Clarisse Tur, Volker D. Burkert, A. K. Opper, Shifeng Chen, A. S. Biselli, M. Osipenko, U. Thoma, L. C. Smith, K. Beard, S. J. Gaff, R. W. Major, B. Carnahan, F. Sabatié, E. Polli, G. V. O'Rielly, B. M. Preedom, J. Lachniet, D. Rowntree, L. Elouadrhiri, V. Gyurjyan, J. P. Santoro, L. Ciciani, K. A. Griffioen, S. Simionatto, D. G. Jenkins, Roy Thompson, K. Sabourov, Thierry Auger, K. L. Giovanetti, B. Asavapibhop, Larry Weinstein, Dinko Pocanic, I. I. Strakovsky, G. Gavalian, V. Mokeev, R. S. Hakobyan, Brian Raue, S. E. Kuhn, K. Wang, R. C. Minehart, R. A. Miskimen, C. A. Meyer, J. Langheinrich, E. De Sanctis, V. V. Frolov, J. H. Kelley, Stephen Taylor, H. Bagdasaryan, S. A. Philips, G. S. Adams, F. W. Hersman, S. McAleer, G. A. Peterson, J. P. Cummings, O. P. Dzyubak, R. A. Niyazov, D. Branford, M. Mirazita, J. W. Price, L. Guo, M. Ungaro, S. Barrow, B. L. Berman, John T. O'Brien, W. Kim, M. Kossov, D. I. Sober, P. L. Cole, P. Dragovitsch, J. M. Laget, L. M. Qin, Laird Kramer, H. Egiyan, D. P. Weygand, P. Corvisiero, Alexei V. Klimenko, R. Fatemi, J. R. Ficenec, Rakhsha Nasseripour, L. Todor, D. Protopopescu, William Brooks, A. V. Vlassov, P. Eugenio, M. Taiuti, M. Anghinolfi, S. Strauch, S. Niccolai, Hall Crannell, S. Pozdniakov, M. Garçon, C. S. Whisnant, Federico Ronchetti, James Mueller, M. Spraker, C. Cetina, Frank Klein, G. S. Mutchler, Barry Ritchie, J. Hardie, Michael Vineyard, A. Longhi, J. R. Calarco, R. DeVita, J. W C McNabb, Y. G. Sharabian, R. W. Gothe, M. Guidal, M. Klusman, M. Guillo, N. Benmouna, A.V. Stavinsky, J. J. Melone, A. Weisberg, P. Stoler, J. Hu, K. Joo, C. Marchand, Ji Li, M. Ripani, G. Niculescu, Carlos A. Salgado, S. A. Morrow, P. Rubin, J. Yun, D. Cords, A. Shafi, M. D. Mestayer, P. Heimberg, C. Djalali, D. J. Tedeschi, A. Yegneswaran, Patrick Girard, J. J. Manak, J. Shaw, S. O. Nelson, K. Hicks, Michael Wood, S. Boiarinov, M. Holtrop, Thomas E. Smith, R. A. Schumacher, E. S. Smith, K. S. Egiyan, P. Ambrozewicz, V. S. Serov, K. Mikhailov, Cynthia Marie Hadjidakis, H. Denizli, Sylvain Bouchigny, H. Juengst, Michael Dugger, H. O. Funsten, C. I O Gordon, P. Rossi, L. Farhi, M. Nozar, M. Bellis, M. U. Mozer, L. Morand, T. A. Forest, S. Stepanyan, G. Audit, V. Sapunenko, G. E. Dodge, J. Connelly, A. V. Skabelin, K. V. Dharmawardane, R. J. Feuerbach, P. V. Degtyarenko, K. Kim, V. P. Kubarovsky, Valeria Muccifora, I. Niculescu, D. Lawrence, M. Bektasoglu, A. Empl, B. B. Niczyporuk, O. Pogorelko, D. Hancock, N. Pivnyuk, K. Lukashin, J. Napolitano, L. C. Dennis, Gerard Gilfoyle, Jens H. Kuhn, Nicola Bianchi, H. Avakian, M. M. Ito, W. J. Briscoe, M. Battaglieri, E. Pasyuk, S. A. Dytman, R. Bradford, B. A. Mecking, E. Anciant, M. Khandaker, D. Doughty, D. Heddle, Yordanka Ilieva, S. Mehrabyan, Kwangsoo Kim, G. Riccardi, C. Butuceanu, E. Wolin, J. P. Ball, Y. Prok, D. S. Carman, M. Sargsyan, and D. G. Crabb

Subjects
Nuclear physics, Physics, Particle physics, Proton, Exotic baryon, Hyperon, General Physics and Astronomy
Published
2004

13. Two-proton correlations forO16+Au197collisions atE/A=200 MeV

Author

Eugene Gualtieri, R. Lacey, M. J. Huang, C. P. Montoya, S. Hannuschke, F. Daffin, Kevin Haglin, M. B. Tsang, R. Pak, T. Glasmacher, C. K. Gelbke, L. Martin, W. G. Lynch, G. J. Kunde, G. D. Westfall, N. T. B. Stone, S. J. Gaff, Scott Pratt, J. Yee, D. O. Handzy, Wolfgang Bauer, and A. M. Vander Molen

Subjects
Baryon, Nuclear reaction, Momentum, Physics, Nuclear and High Energy Physics, Correlation function, Proton, Nuclear Theory, Hadron, Elementary particle, Atomic physics, Nuclear Experiment, Nucleon
Abstract

Two-proton correlation functions are measured for inclusive collisions of $^{16}\mathrm{O}$ + $^{197}\mathrm{Au}$ at E/A=200 MeV. Calculations with the Boltzmann-Uehling-Uhlenbeck transport theory overpredict the dependence of the correlation function on the total momentum of the coincident proton pair, but correctly reproduce the energy-integrated correlation function.

Published
1995

14. Measurement of the Proton Spin Structure Functiong1(x,Q2)forQ2from 0.15 to1.6 GeV2with CLAS

Author

S. J. Gaff, D. Doughty, M. Seely, G. Ricco, D. Heddle, R. J. Feuerbach, Philip L. Cole, C. S. Whisnant, L. Farhi, Bernhard Mecking, V. Sapunenko, Dinko Pocanic, Valeria Muccifora, K. V. Dharmawardane, C. D. Keith, P. Eugenio, Shalev Gilad, M. Taiuti, M. Guillo, Gerard Gilfoyle, S. E. Kuhn, R. A. Niyazov, John T. O'Brien, S. Strauch, Friedrich Klein, L. C. Dennis, B. E. Bonner, B. Carnahan, F. Sabatié, W. K. Brooks, L. M. Qin, P. Corvisiero, J. H. Kelley, R. S. Hicks, Brian Raue, Jing Zhao, William Bertozzi, C. Tur, S. Mehrabyan, D. Protopopescu, J. P. Cummings, H. R. Weller, Volker D. Burkert, C. Cetina, A. S. Biselli, S. Pozdniakov, M. Garçon, Thierry Auger, J. R. Calarco, F. W. Hersman, K. S. Egiyan, V. Koubarovski, K. Mikhailov, E. Anciant, Michael Vineyard, Baile Zhang, E. Pasyuk, B. M. Preedom, G. V. O'Rielly, L. Elouadrhiri, Z. L. Zhou, C. Butuceanu, M. Kossov, W. Kim, E. Wolin, R. A. Miskimen, S. A. Dytman, M. Ripani, J. P. Santoro, C. E. Hyde-Wright, J. Hu, D. Branford, Rakhsha Nasseripour, M. Khandaker, A. V. Skabelin, G. S. Mutchler, D. G. Jenkins, Susan Taylor, H. Egiyan, K. Sabourov, J. P. Ball, Y. Prok, M. Eckhause, M. Sargsyan, D. G. Crabb, M. Spraker, Y. Ilieva, Patrick Girard, J. Shaw, Michael Wood, M. Mirazita, J. M. Laget, K. Wang, C. Salgado, P. E. Bosted, A. P. Freyberger, Harut Avakian, Y. Kuang, K. Y. Kim, C. Marchand, Laird Kramer, V. S. Serov, S. McAleer, E. Polli, M. Battaglieri, M. Bellis, K. Park, Federico Ronchetti, K. A. Griffioen, Roy Thompson, V. Frolov, Elton Smith, M. Guidal, R. Bradford, M. M. Ito, J. Ficenec, G. Niculescu, L. Ciciani, A. Longhi, M. Klusman, Ji Li, L. Todor, R. Clark, P. Heimberg, Jens H. Kuhn, M. Holtrop, Thomas E. Smith, M. Anghinolfi, M. D. Mestayer, A. Empl, O. Pogorelko, S. Simionatto, J. D. Kellie, S. Stepanyan, Nicola Bianchi, K. Lukashin, Sylvain Bouchigny, K. Livingston, James Mueller, H. Funsten, Cynthia Marie Hadjidakis, K. L. Giovanetti, B. Asavapibhop, P. Rossi, S. Boiarinov, P. D. Rubin, J. W. Price, Michael Dugger, Larry Weinstein, M. Osipenko, Y. G. Sharabian, H. Denizli, Daniel S. Carman, G. Audit, K. Beard, G. A. Peterson, J. Connelly, Kalvir S. Dhuga, Alexei V. Klimenko, S. Barrow, M. Bektasoglu, G. Gavalian, Barry Ritchie, M. Nozar, R. C. Minehart, C. A. Meyer, P. Stoler, S. O. Nelson, K. Hicks, R. Fatemi, A. V. Vlassov, R. De Vita, J. J. Manak, E. De Sanctis, D. I. Sober, A.V. Stavinsky, L. Sorrel, D. J. Tedeschi, V. Gyurjyan, H. Bagdasaryan, D. Hancock, L. Guo, M. Ungaro, P. Dragovitsch, S. Niccolai, K. Joo, J. Yun, J. Hardie, D. Cords, A. Yegneswaran, G. E. Dodge, P. V. Degtyarenko, K. Kim, I. Niculescu, D. Lawrence, R. A. Schumacher, J. Lachniet, D. Rowntree, C. I O Gordon, L. Morand, T. A. Forest, A. Coleman, B. B. Niczyporuk, N. Pivnyuk, S. E. Rock, Avraham Klein, J. Napolitano, W. Major, G. S. Adams, Hall Crannell, G. Riccardi, J. W C McNabb, S. A. Morrow, C. Djalali, U. Thoma, D. P. Weygand, and L. C. Smith

Subjects
Physics, Nuclear physics, Particle physics, Scattering, Proton spin crisis, General Physics and Astronomy, Electron, Nucleon, Parametrization, Resonance (particle physics), Scaling, Sign (mathematics)
Abstract

Double-polarization asymmetries for inclusive $ep$ scattering were measured at Jefferson Lab using 2.6 and 4.3 GeV longitudinally polarized electrons incident on a longitudinally polarized NH$_3$ target in the CLAS detector. The polarized structure function $g_1(x,Q^2)$ was extracted throughout the nucleon resonance region and into the deep inelastic regime, for $Q^2 = 0.15 -1.64 $GeV$^2$. The contributions to the first moment $\Gamma_1(Q^2) = \int g_1(x,Q^2)dx$ were determined up to $Q^2=1.2$ GeV$^2$. Using a parametrization for $g_1$ in the unmeasured low $x$ regions, the complete first moment was estimated over this $Q^2$ region. A rapid change in $\Gamma_1$ is observed for $Q^2 < 1 $GeV$^2$, with a sign change near $Q^2 = 0.3 $GeV$^2$, indicating dominant contributions from the resonance region. At $Q^2=1.2$ GeV$^2$ our data are below the pQCD evolved scaling value.

Published
2003

15. Measurement of the polarized structure functionσLT′forp(e→,e′p)π0in theΔ(1232)resonance region

Author

Susan Taylor, W. Kim, J. Kuhn, C. S. Whisnant, D. I. Sober, Laird Kramer, Roy Thompson, Daniel S. Carman, H. Denizli, R. J. Feuerbach, G. Audit, C. E. Hyde-Wright, P. Eugenio, M. Taiuti, S. Strauch, J. Hu, S. McAleer, G. A. Peterson, Cynthia Marie Hadjidakis, L. C. Dennis, M. Nozar, Dinko Pocanic, H. Avakian, Michael Dugger, L. Guo, S. Barrow, M. Guidal, Alexei V. Klimenko, H. O. Funsten, R. Fatemi, M. Ungaro, S. E. Kuhn, G. Niculescu, E. Anciant, A. V. Vlassov, M. Osipenko, A. C S Lima, L. M. Qin, W. J. Briscoe, E. Pasyuk, M. Holtrop, J. H. Kelley, C. Tur, L. Y. Murphy, K. Beard, S. A. Dytman, G. Ricco, Barry Ritchie, Kalvir S. Dhuga, P. Dragovitsch, Volker D. Burkert, A. S. Biselli, J. P. Cummings, L. Todor, Jing Zhao, G. Gavalian, M. Klusman, M. Bektasoglu, J. W. Price, Philip L. Cole, D. Protopopescu, S. Niccolai, Elton Smith, E. Wolin, S. Pozdniakov, M. Kossov, M. Anghinolfi, S. A. Philips, J. Hardie, J. J. Melone, Friedrich Klein, Z. L. Zhou, Rakhsha Nasseripour, James Mueller, K. Y. Kim, M. Khandaker, R. S. Hicks, Brian Raue, P. D. Rubin, N. Benmouna, M. Guillo, M. Ripani, Y. G. Sharabian, J. P. Ball, Y. Prok, M. Eckhause, O. P. Dzyubak, R. A. Niyazov, A.V. Stavinsky, J. J. Manak, G. V. O'Rielly, A. K. Opper, Hovanes Egiyan, B. Carnahan, D. J. Tedeschi, F. Sabatié, Hall Crannell, D. G. Jenkins, A. V. Skabelin, Y. Kuang, M. Sargsyan, Y. Ilieva, K. Sabourov, Thierry Auger, G. S. Mutchler, J. Ficenec, E. Polli, L. Ciciani, F. W. Hersman, K. Joo, Federico Ronchetti, R. C. Minehart, C. A. Meyer, S. Simionatto, J. Yun, P. Corvisiero, D. Cords, D. G. Crabb, C. Cetina, L. Elouadrhiri, A. Yegneswaran, V. Sapunenko, Valeria Muccifora, Michael Vineyard, I. I. Strakovsky, K. L. Giovanetti, B. Asavapibhop, K. S. Egiyan, W. K. Brooks, M. Spraker, Larry Weinstein, E. DeSanctis, D. Doughty, Gerard Gilfoyle, K. Mikhailov, D. Heddle, V. Gyurjyan, S. Mehrabyan, H. Bagdasaryan, Nicola Bianchi, R. A. Miskimen, D. P. Weygand, Ji Li, Shalev Gilad, G. Riccardi, G. E. Dodge, P. Stoler, D. Branford, M. Mirazita, J. M. Laget, C. Butuceanu, S. O. Nelson, K. Hicks, M. D. Mestayer, P. V. Degtyarenko, K. Kim, S. Boiarinov, G. S. Adams, B. M. Preedom, R. DeVita, K. A. Griffioen, J. W C McNabb, U. Thoma, I. Niculescu, J. Lachniet, D. Rowntree, D. Lawrence, J. P. Santoro, P. Heimberg, R. S. Hakobyan, R. A. Schumacher, K. Wang, C. Salgado, C. I O Gordon, L. Morand, B. B. Niczyporuk, T. A. Forest, S. Stepanyan, N. Pivnyuk, K. Lukashin, J. Napolitano, Avraham Klein, S. A. Morrow, C. Djalali, P. Ambrozewicz, M. Battaglieri, R. Bradford, M. U. Mozer, Bernhard Mecking, K. V. Dharmawardane, M. M. Ito, A. Coleman, H. R. Weller, L. C. Smith, S. J. Gaff, C. Marchand, Patrick Girard, J. Shaw, Michael Wood, Sylvain Bouchigny, V. S. Serov, P. Rossi, M. Bellis, K. Park, J. R. Calarco, A. Empl, and O. Pogorelko

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Pion, Nuclear magnetic resonance, Structure function, Pole term, Isobar, Resonance, Electron, Nuclear Experiment, Energy (signal processing)
Abstract

The polarized longitudinal-transverse structure function ${\ensuremath{\sigma}}_{L{T}^{\ensuremath{'}}}$ has been measured using the $p(\stackrel{P\vec}{e},{e}^{\ensuremath{'}}{\ensuremath{\pi}}^{+})n$ reaction in the $\ensuremath{\Delta}(1232)$ resonance region at ${Q}^{2}=0.40$ and $0.65\phantom{\rule{0.3em}{0ex}}{\mathrm{GeV}}^{2}$. No previous ${\ensuremath{\sigma}}_{L{T}^{\ensuremath{'}}}$ data exist for this reaction channel. The kinematically complete experiment was performed at the Jefferson Lab with the CEBAF large acceptance spectrometer using longitudinally polarized electrons at an energy of $1.515\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}$. A partial-wave analysis of the data shows generally better agreement with recent phenomenological models of pion electroproduction compared to the previously measured ${\ensuremath{\pi}}^{0}p$ channel. A fit to both ${\ensuremath{\pi}}^{0}p$ and ${\ensuremath{\pi}}^{+}n$ channels using a unitary isobar model suggests the unitarized Born terms provide a consistent description of the nonresonant background. The $t$-channel pion pole term is important in the ${\ensuremath{\pi}}^{0}p$ channel through a rescattering correction, which could be model dependent.

Published
2003

16. ep→epπ0reaction studied in theΔ(1232)mass region using polarization asymmetries

Author

A. Biselli, G. S. Adams, M. J. Amaryan, E. Anciant, M. Anghinolfi, B. Asavapibhop, G. Asryan, G. Audit, T. Auger, H. Avakian, S. Barrow, M. Battaglieri, K. Beard, M. Bektasoglu, W. Bertozzi, N. Bianchi, S. Boiarinov, B. E. Bonner, P. Bosted, S. Bouchigny, R. Bradford, D. Branford, W. K. Brooks, S. Bueltmann, V. D. Burkert, J. R. Calarco, D. S. Carman, B. Carnahan, C. Cetina, L. Ciciani, P. L. Cole, A. Coleman, J. Connelly, D. Cords, P. Corvisiero, D. Crabb, H. Crannell, J. Cummings, E. De Sanctis, R. De Vita, P. V. Degtyarenko, R. A. Demirchyan, H. Denizli, L. C. Dennis, K. V. Dharmawardane, K. S. Dhuga, C. Djalali, G. E. Dodge, J. Domingo, D. Doughty, P. Dragovitsch, M. Dugger, S. Dytman, M. Eckhause, Y. V. Efremenko, H. Egiyan, K. S. Egiyan, L. Elouadrhiri, A. Empl, P. Eugenio, L. Farhi, R. Fatemi, R. J. Feuerbach, J. Ficenec, K. Fissum, T. A. Forest, A. Freyberger, V. Frolov, H. Funsten, S. J. Gaff, M. Gai, G. Gavalian, V. B. Gavrilov, S. Gilad, G. P. Gilfoyle, K. L. Giovanetti, P. Girard, E. Golovatch, K. A. Griffioen, M. Guidal, M. Guillo, L. Guo, V. Gyurjyan, D. Hanock, J. Hardie, D. Heddle, F. W. Hersman, K. Hicks, R. S. Hicks, M. Holtrop, J. Hu, C. E. Hyde-Wright, M. M. Ito, D. Jenkins, K. Joo, J. H. Kelley, M. Khandaker, K. Y. Kim, K. Kim, W. Kim, A. Klein, F. J. Klein, A. V. Klimenko, M. Klusman, M. Kossov, L. H. Kramer, Y. Kuang, J. Kuhn, S. E. Kuhn, J. Lachniet, J. M. Laget, D. Lawrence, G. A. Leksin, A. Longhi, K. Loukachine, R. W. Major, J. J. Manak, C. Marchand, S. K. Matthews, S. McAleer, J. W. C. McNabb, J. McCarthy, B. A. Mecking, M. D. Mestayer, C. A. Meyer, R. Minehart, M. Mirazita, R. Miskimen, V. Mokeev, V. Muccifora, J. Mueller, L. Y. Murphy, G. S. Mutchler, J. Napolitano, S. O. Nelson, G. Niculescu, B. Niczyporuk, R. A. Niyazov, M. Nozar, J. T. O’Brien, G. V. O’Rielly, M. S. Ohandjanyan, M. Osipenko, K. Park, Y. Patois, G. A. Peterson, S. Philips, N. Pivnyuk, D. Pocanic, O. Pogorelko, E. Polli, B. M. Preedom, J. W. Price, L. M. Qin, B. A. Raue, G. Riccardi, G. Ricco, M. Ripani, B. G. Ritchie, S. Rock, F. Ronchetti, P. Rossi, D. Rowntree, P. D. Rubin, K. Sabourov, C. W. Salgado, V. Sapunenko, M. Sargsyan, R. A. Schumacher, V. S. Serov, Y. G. Sharabian, J. Shaw, S. M. Shuvalov, S. Simionatto, A. Skabelin, E. S. Smith, L. C. Smith, T. Smith, D. I. Sober, L. Sorrell, M. Spraker, S. Stepanyan, P. Stoler, I. I. Strakovsky, M. Taiuti, S. Taylor, D. Tedeschi, U. Thoma, R. Thompson, L. Todor, T. Y. Tung, C. Tur, M. Ungaro, M. F. Vineyard, A. Vlassov, K. Wang, L. B. Weinstein, H. Weller, R. Welsh, D. P. Weygand, S. Whisnant, M. Witkowski, E. Wolin, A. Yegneswaran, J. Yun, B. Zhang, J. Zhao, and Z. Zhou

Subjects
Physics, Delta, Nuclear and High Energy Physics, Range (particle radiation), media_common.quotation_subject, Polarization (waves), Asymmetry, Nuclear physics, Effective lagrangian, Isobar, High Energy Physics::Experiment, Nuclear Experiment, Spin (physics), media_common
Abstract

Measurements of the angular distributions of target and double spin asymmetries for the Delta(1232) in the exclusive channel (polarized-p polarized-e,e-prime p)pi0 obtained at Jefferson Lab in the Q2 range from 0.5 to 1.5 gev2 are presented. Results of the asymmetries are compared with the unitary isobar model, dynamical models, and the effective Lagrangian theory. Sensitivity to the different models was observed, particularly in relation to the description of background terms on which the target asymmetry depends significantly.

Published
2003

17. Measurement ofep→e′pπ+π−and Baryon Resonance Analysis

Author

R. Fatemi, A. Cazes, M. U. Mozer, Bernhard Mecking, K. V. Dharmawardane, A. V. Vlassov, J. Hu, M. Battaglieri, R. Bradford, R. De Vita, E. Wolin, J. J. Manak, R. A. Niyazov, B. Carnahan, Jing Zhao, S. A. Philips, E. De Sanctis, Thierry Auger, D. I. Sober, Patrick Girard, J. Shaw, Michael Wood, P. Corvisiero, E. Golovach, J. P. Ball, Y. Prok, V. S. Serov, R. A. Schumacher, Daniel S. Carman, D. Protopopescu, S. Pozdniakov, M. Garçon, M. Eckhause, G. Ricco, G. Audit, Z. L. Zhou, A. Shafi, C. E. Hyde-Wright, Philip L. Cole, M. Taiuti, M. Ripani, Moshe Gai, Friedrich Klein, M. Bektasoglu, R. S. Hicks, Brian Raue, L. Morand, T. A. Forest, Roy Thompson, Avraham Klein, G. E. Dodge, S. A. Morrow, D. G. Crabb, I. I. Strakovsky, C. Djalali, P. V. Degtyarenko, K. Kim, G. S. Adams, B. M. Preedom, M. Spraker, M. Bellis, K. Park, B. L. Berman, I. Niculescu, K. Joo, D. Lawrence, J. P. Santoro, M. Klusman, E. Anciant, M. Guidal, G. Niculescu, W. K. Brooks, L. M. Qin, A. Empl, O. Pogorelko, K. Lukashin, B. E. Bonner, M. Holtrop, U. Thoma, H. Avakian, D. P. Weygand, Dinko Pocanic, Gerald Feldman, A. K. Opper, S. E. Kuhn, W. J. Briscoe, E. Pasyuk, K. Wang, F. W. Hersman, S. A. Dytman, R. A. Miskimen, J. H. Kelley, C. Salgado, M. Khandaker, M. Nozar, B. B. Niczyporuk, N. Pivnyuk, P. Stoler, D. Branford, J. Napolitano, Elton Smith, Ji Li, Cynthia Marie Hadjidakis, M. Mirazita, J. M. Laget, G. V. O'Rielly, Michael Dugger, S. O. Nelson, M. D. Mestayer, L. Elouadrhiri, K. Hicks, M. Anghinolfi, Laird Kramer, J. P. Cummings, James Mueller, S. Boiarinov, K. S. Egiyan, G. Riccardi, J. W C McNabb, V. Sapunenko, P. D. Rubin, F. Ronchetti, Y. G. Sharabian, Valeria Muccifora, K. Mikhailov, D. G. Jenkins, M. Kossov, K. Sabourov, Rakhsha Nasseripour, J. Ficenec, M. Guillo, Gerard Gilfoyle, L. Ciciani, Hall Crannell, W. Kim, Baile Zhang, R. C. Minehart, J. R. Calarco, C. A. Meyer, S. Simionatto, C. Cetina, Michael Vineyard, P. Dragovitsch, Volker D. Burkert, A. S. Biselli, G. V. Fedotov, Y. Kuang, L. Y. Murphy, E. Polli, K. Y. Kim, A. Longhi, S. Niccolai, S. McAleer, C. Marchand, K. L. Giovanetti, B. Asavapibhop, H. Funsten, S. Stepanyan, Sylvain Bouchigny, J. W. Price, P. Rossi, L.C. Dennis, M. M. Ito, L. Todor, J. Hardie, H. Denizli, Larry Weinstein, L. C. Smith, S. J. Gaff, B. S. Ishkhanov, B. P. Quinn, D. Doughty, H. R. Weller, Alexei V. Klimenko, Barry Ritchie, D. Heddle, M. Osipenko, F. Sabatié, K. Beard, A. V. Skabelin, G. Gavalian, V. Mokeev, G. S. Mutchler, K. A. Griffioen, P. Heimberg, J. D. Kellie, Shalev Gilad, R. J. Feuerbach, A.V. Stavinsky, D. J. Tedeschi, J. S. McCarthy, J. Lachniet, D. Rowntree, Jens H. Kuhn, L. Guo, M. Ungaro, Nicola Bianchi, A. Coleman, Susan Taylor, H. Egiyan, C. S. Whisnant, K. Livingston, G. A. Peterson, S. Barrow, J. Yun, D. Cords, A. Yegneswaran, V. Gyurjyan, and H. Bagdasaryan

Subjects
Baryon, Nuclear physics, Physics, Particle physics, Meson production, Resonance analysis, General Physics and Astronomy, Resonance (particle physics)
Abstract

The cross section for the reaction ep→e'ppi(+)pi(-) was measured in the resonance region for 1.4 lt W lt 2.1 GeV and 0.5 lt Q(2) lt 1.5 GeV2/c(2) using the CLAS detector at Jefferson Laboratory. The data show resonant structures not visible in previous experiments. The comparison of our data to a phenomenological prediction using available information on N* and Delta states shows an evident discrepancy. A better description of the data is obtained either by a sizable change of the properties of the P-13(1720) resonance or by introducing a new baryon state, not reported in published analyses.

Published
2003

18. Kinematically complete measurement of the proton structure functionF2in the resonance region and evaluation of its moments

Author

W. Kim, Ji Li, E. Wolin, Baile Zhang, A. K. Opper, M. D. Mestayer, R. Fatemi, P. Bosted, J. P. Ball, Y. Prok, A. V. Vlassov, M. Eckhause, M. Sargsyan, Y. Kuang, J. P. Cummings, R. De Vita, E. De Sanctis, S. Boiarinov, D. I. Sober, D. G. Crabb, E. Polli, S. A. Philips, J. W C McNabb, J. Lachniet, D. Rowntree, M. Kossov, Rakhsha Nasseripour, K. Paschke, S. Mehrabyan, B. M. Preedom, M. M. Ito, H. Denizli, Elton Smith, K. S. Egiyan, J. J. Manak, G. Riccardi, B. Carnahan, M. Osipenko, J. R. Ficenec, J. R. Calarco, Shalev Gilad, Roy Thompson, F. Sabatié, M. Anghinolfi, Marco Ripani, K. Beard, M. Battaglieri, R. A. Schumacher, J. P. Santoro, James Mueller, Susan Taylor, A. Coleman, P. D. Rubin, Daniel S. Carman, H. R. Weller, K. Mikhailov, Y. G. Sharabian, E. Anciant, Thierry Auger, G. Gavalian, G. Audit, R. Bradford, C. E. Hyde-Wright, K. Lukashin, H. Egiyan, V. Sapunenko, K. Wang, K. A. Griffioen, L. C. Dennis, L. C. Smith, C. I O Gordon, S. J. Gaff, Dinko Pocanic, B. S. Ishkhanov, M. Taiuti, Alexei V. Klimenko, B. B. Niczyporuk, S. E. Kuhn, C. Salgado, L. Morand, T. A. Forest, M. Khandaker, C. S. Whisnant, J. D. Kellie, L. Y. Murphy, J. H. Kelley, C. Tur, Philip L. Cole, Avraham Klein, G. V. O'Rielly, Silvano Simula, M. Bektasoglu, H. Avakian, N. Pivnyuk, A. Cazes, J. Napolitano, L. M. Qin, Bernhard Mecking, S. Stepanyan, G. E. Dodge, K. V. Dharmawardane, Barry Ritchie, R. J. Feuerbach, Moshe Gai, P. V. Degtyarenko, K. Kim, Cynthia Marie Hadjidakis, Sylvain Bouchigny, M. Klusman, D. G. Jenkins, K. Sabourov, P. Rossi, P. Stoler, Friedrich Klein, R. S. Hicks, Brian Raue, Michael Dugger, H. O. Funsten, A. V. Skabelin, I. Niculescu, Michael Vineyard, S. A. Morrow, S. McAleer, F. Ronchetti, C. Djalali, D. Lawrence, G. S. Mutchler, S. O. Nelson, M. Guidal, G. Niculescu, Daijin Kim, L. Ciciani, Giovanni Ricco, S. Simionatto, K. Hicks, J. Hu, Hall Crannell, J. W. Price, W. J. Briscoe, C. Marchand, K. L. Giovanetti, B. Asavapibhop, Latifa Elouadrhiri, R. C. Minehart, C. A. Meyer, E. Pasyuk, M. Spraker, Larry Weinstein, D. Doughty, R. A. Niyazov, D. Heddle, S. A. Dytman, M. Holtrop, G. V. Fedotov, P. Corvisiero, D. P. Weygand, Patrick Girard, J. Shaw, Michael Wood, V. S. Serov, G. S. Adams, K. Joo, K. Park, U. Thoma, R. Clark, A. Empl, O. Pogorelko, K. Y. Kim, M. Guillo, F. W. Hersman, M. Nozar, E. Golovatch, L. Todor, D. Protopopescu, S. Pozdniakov, Z. L. Zhou, K. Livingston, W. K. Brooks, G. A. Peterson, S. Barrow, C. Cetina, Jens H. Kuhn, Nicola Bianchi, Victor Mokeev, V. Gyurjyan, H. Bagdasaryan, Min Suk Kim, L. Guo, M. Ungaro, Jing Zhao, J. Yun, D. Cords, A. Yegneswaran, Valeria Muccifora, Gerard Gilfoyle, R. A. Miskimen, Volker D. Burkert, A. S. Biselli, D. Branford, M. Mirazita, J. M. Laget, Laird Kramer, A.V. Stavinsky, D. J. Tedeschi, J. S. McCarthy, J. Domingo, P. Dragovitsch, S. Niccolai, and J. Hardie

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Cross section (physics), Proton, Momentum transfer, Moment (physics), Bibliography, Twist, Nucleon, Resonance (particle physics)
Abstract

We measured the inclusive electron-proton cross section in the nucleon resonance region (W From these data we extracted the structure function F2 and, by including other world data, we studied the Q2 evolution of its moments, Mn(Q2), in order to estimate higher twist contributions. The small statistical and systematic uncertainties of the CLAS data allow a precise extraction of the higher twists and will require significant improvements in theoretical predictions if a meaningful comparison with these new experimental results is to be made.

Published
2003

19. First Measurement of Transferred Polarization in the Exclusivee→p→e′K+Λ→Reaction

Author

L. Guo, M. Ungaro, R. Fatemi, D. S. Armstrong, A. V. Vlassov, R. C. Minehart, C. A. Meyer, G. V. Fedotov, C. Bennhold, A. Coleman, H. R. Weller, V. Sapunenko, Valeria Muccifora, J. Yun, D. Cords, L. Elouadrhiri, D. P. Weygand, Baile Zhang, J. J. Manak, S. A. Morrow, A. Yegneswaran, Gerard Gilfoyle, M. Eckhause, C. Djalali, J. P. Cummings, Susan Taylor, A. K. Opper, P. Dragovitsch, H. Egiyan, H. Denizli, Laird Kramer, R. A. Miskimen, M. Kossov, P. Ambrozewicz, Rakhsha Nasseripour, R. A. Schumacher, S. Niccolai, A. V. Skabelin, Y. Kuang, D. Branford, L. Ciciani, G. S. Adams, K. S. Egiyan, M. Mirazita, J. M. Laget, S. Stepanyan, Sylvain Bouchigny, L. C. Smith, J. Hardie, S. J. Gaff, S. Simionatto, Alexei V. Klimenko, C. S. Whisnant, E. Polli, K. Joo, B. S. Ishkhanov, L. Todor, D. Protopopescu, K. Mikhailov, P. Rossi, Barry Ritchie, K. L. Giovanetti, B. Asavapibhop, S. Pozdniakov, M. Garçon, A. Cazes, M. U. Mozer, M. Guidal, C. Cetina, E. DeSanctis, W. K. Brooks, B. B. Niczyporuk, A.V. Stavinsky, Jing Zhao, M. Spraker, Larry Weinstein, Michael Vineyard, C. I O Gordon, Z. L. Zhou, G. Niculescu, K. V. Dharmawardane, D. J. Tedeschi, Dinko Pocanic, S. E. Kuhn, N. Pivnyuk, J. Napolitano, M. Holtrop, U. Thoma, E. Anciant, Ji Li, J. R. Calarco, L. Morand, K. A. Griffioen, J. H. Kelley, G. V. O'Rielly, T. A. Forest, C. Tur, O. P. Dzyubak, R. A. Niyazov, K. Livingston, M. Khandaker, J. Lachniet, D. G. Jenkins, K. Sabourov, M. D. Mestayer, K. Paschke, D. Rowntree, P. Corvisiero, V. Gyurjyan, Elton Smith, Daniel S. Carman, S. Mehrabyan, S. McAleer, D. Doughty, D. Heddle, S. Boiarinov, Terry Mart, D. I. Sober, Avraham Klein, R. J. Feuerbach, J. R. Ficenec, M. M. Ito, B. M. Preedom, G. Audit, C. E. Hyde-Wright, J. W C McNabb, G. E. Dodge, M. Anghinolfi, R. S. Hakobyan, P. Stoler, James Mueller, J. P. Santoro, J. W. Price, P. D. Rubin, H. Bagdasaryan, J. Hu, E. N. Golovach, G. A. Peterson, S. O. Nelson, P. V. Degtyarenko, K. Hicks, Y. G. Sharabian, M. Bektasoglu, K. Wang, C. Salgado, M. Battaglieri, M. Guillo, S. Barrow, I. Niculescu, D. Lawrence, R. Bradford, B. A. Mecking, Hall Crannell, C. Marchand, Kwangsoo Kim, M. Ripani, G. Riccardi, Cynthia Marie Hadjidakis, Jens H. Kuhn, C. Butuceanu, Michael Dugger, Nicola Bianchi, H. O. Funsten, W. Kim, M. Bellis, K. Park, J. S. McCarthy, K. Y. Kim, A. Longhi, R. Clark, L. Y. Murphy, A. Empl, O. Pogorelko, K. Lukashin, G. Ricco, Philip L. Cole, M. Osipenko, E. Wolin, F. Sabatié, Moshe Gai, F. W. Hersman, Friedrich Klein, K. Beard, M. Nozar, R. S. Hicks, Brian Raue, Kalvir S. Dhuga, Patrick Girard, J. Shaw, Michael Wood, Steven M. Grimes, G. Gavalian, V. Mokeev, J. P. Ball, Federico Ronchetti, Roy Thompson, Y. Prok, V. S. Serov, L. C. Dennis, B. E. Bonner, H. Avakian, W. J. Briscoe, E. Pasyuk, P. Eugenio, M. Taiuti, S. A. Dytman, J. J. Melone, D. G. Crabb, Volker D. Burkert, A. S. Biselli, G. S. Mutchler, L. M. Qin, R. DeVita, Shalev Gilad, M. Klusman, B. Carnahan, P. Heimberg, J. D. Kellie, and Thierry Auger

Subjects
Physics, Quark, Particle physics, Spectrometer, Spins, Nuclear Theory, Quark model, Hyperon, General Physics and Astronomy, Creation and annihilation operators, Particle accelerator, Polarization (waves), law.invention, Nuclear physics, law, High Energy Physics::Experiment, Nuclear Experiment
Abstract

The first measurements of the transferred polarization for the exclusive (e) over right arrow p --> e'K+(U) over right arrow reaction have been performed at Jefferson Laboratory using the CLAS spectrometer. A 2.567 GeV beam was used to measure the hyperon polarization over Q(2) from 0.3 to 1.5 (GeV/c)(2), W from 1.6 to 2.15 GeV, and over the full K+ center-of-mass angular range. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. A nonrelativistic quark-model interpretation of our data suggests that the s (s) over bar quark pair is produced with spins predominantly antialigned. Implications for the validity of the most widely used quark-pair creation operator are discussed.

Published
2003

20. Publisher’s Note:ηPhotoproduction on the Proton for Photon Energies from 0.75 to 1.95 GeV [Phys. Rev. Lett.89, 222002 (2002)]

Author

V. V. Frolov, D. Doughty, R. A. Niyazov, John T. O'Brien, D. Heddle, Barry Ritchie, S. A. Morrow, P. Rubin, M. Eckhause, C. Djalali, P. Dragovitsch, K. A. Griffioen, G. E. Dodge, M. Lucas, P. Corvisiero, D. Hancock, E. S. Smith, Sylvain Bouchigny, P. Rossi, P. V. Degtyarenko, S. Niccolai, Carlos A. Salgado, L. Elouadrhiri, G. Ricco, J. Hardie, K. S. Egiyan, Baile Zhang, R. C. Minehart, C. A. Meyer, G. S. Mutchler, V. Koubarovski, K. Mikhailov, G. Gavalian, A. K. Opper, I. Niculescu, M. M. Ito, I. I. Strakovsky, A.V. Stavinsky, D. Lawrence, M. Spraker, C. Cetina, H. Egiyan, G. V. O'Rielly, E. Wolin, Michael Vineyard, J. P. Cummings, D. P. Weygand, L. Farhi, Y. Kuang, D. J. Tedeschi, C. S. Whisnant, D. G. Jenkins, K. Sabourov, G. P. Capitani, E. Polli, William Brooks, G. S. Adams, R. DeVita, J. W C McNabb, Ji Li, H. Denizli, Hall Crannell, M. U. Mozer, P. Heimberg, M. Witkowski, K. V. Dharmawardane, A. Coleman, P. L. Cole, Cynthia Marie Hadjidakis, Andreas Klein, J. R. Ficenec, S. McAleer, J. D. Kellie, P. Stoler, J. Lachniet, H. R. Weller, M. Kossov, J. R. Calarco, C. Marchand, M. D. Mestayer, J. J. Manak, D. Rowntree, M. Anghinolfi, James Mueller, Michael Dugger, J. Connelly, A. V. Skabelin, K. S. Dhuga, D. Pogorelko, H. O. Funsten, S. O. Nelson, Y. G. Sharabian, Frank Klein, L. C. Smith, Rakhsha Nasseripour, S. J. Gaff, K. Hicks, M. Sanzone-Arenhovel, R. A. Schumacher, S. Boiarinov, B. B. Niczyporuk, B. M. Preedom, S. Strauch, S. A. Philips, W. Kim, N. Pivnyuk, C. I O Gordon, K. Lukashin, J. Napolitano, Moshe Gai, Dinko Pocanic, M. Battaglieri, Shalev Gilad, M. Nozar, S. E. Kuhn, L. Morand, T. A. Forest, B. Carnahan, F. Sabatié, K. L. Giovanetti, B. Asavapibhop, J. H. Kelley, Stephen Taylor, J. P. Ball, Y. Prok, Patrick Girard, R. Bradford, B. A. Mecking, Larry Weinstein, Gerald Feldman, J. Shaw, S. Stepanyan, D. S. Carman, Jens H. Kuhn, A. Longhi, E. Anciant, K. Wang, U. Thoma, Nicola Bianchi, Thierry Auger, Michael Wood, R. S. Hicks, Brian Raue, K. Livingston, V. S. Serov, L. C. Dennis, M. Khandaker, G. Audit, M. Ripani, M. Guillo, C. E. Hyde-Wright, B. L. Berman, L. M. Qin, H. Avakian, R. J. Feuerbach, K. Beard, M. Klusman, D. G. Crabb, G. A. Peterson, W. Major, M. Bektasoglu, S. Barrow, M. Guidal, G. Niculescu, W. J. Briscoe, E. Pasyuk, Federico Ronchetti, M. Holtrop, Thomas E. Smith, S. A. Dytman, L. Todor, J. S. McCarthy, M. Bellis, D. Protopopescu, L. Y. Murphy, S. Pozdniakov, S. Mehrabyan, Z. L. Zhou, R. Clark, A. Shafi, G. Riccardi, J. P. Santoro, Roy Thompson, Jing Zhao, M. Taiuti, V. Sapunenko, Valeria Muccifora, Gerard Gilfoyle, F. W. Hersman, R. A. Miskimen, D. Branford, M. Mirazita, J. M. Laget, Laird Kramer, R. Fatemi, A. V. Vlassov, K. Park, D. I. Sober, Volker D. Burkert, A. S. Biselli, L. Guo, M. Ungaro, K. Joo, J. Yun, D. Cords, A. Yegneswaran, E. DeSanctis, V. Gyurjyan, H. Bagdasaryan, and J. W. Price

Subjects
Physics, Nuclear physics, Photon, Proton, General Physics and Astronomy
Published
2002

21. Erratum: First Measurement of the Double Spin Asymmetry ine→p→→e′π+nin the Resonance Region [Phys. Rev. Lett. 88, 082001 (2002)]

Author

R. De Vita, M. Anghinolfi, V. D. Burkert, G. E. Dodge, R. Minehart, M. Taiuti, H. Weller, G. Adams, M. J. Amaryan, E. Anciant, D. S. Armstrong, B. Asavapibhop, G. Asryan, G. Audit, T. Auger, H. Avakian, H. Bagdasaryan, J. P. Ball, S. Barrow, M. Battaglieri, K. Beard, M. Bektasoglu, N. Bianchi, A. S. Biselli, S. Boiarinov, B. E. Bonner, P. Bosted, S. Bouchigny, D. Branford, W. K. Brooks, S. Bueltmann, J. R. Calarco, G. P. Capitani, D. S. Carman, B. Carnahan, A. Cazes, L. Ciciani, P. L. Cole, A. Coleman, J. Connelly, D. Cords, P. Corvisiero, D. Crabb, H. Crannell, J. P. Cummings, E. De Sanctis, P. V. Degtyarenko, R. Demirchyan, H. Denizli, L. Dennis, K. V. Dharmawardane, K. S. Dhuga, C. Djalali, D. Doughty, P. Dragovitsch, M. Dugger, S. Dytman, M. Eckhause, H. Egiyan, K. S. Egiyan, L. Elouadrhiri, A. Empl, L. Farhi, R. Fatemi, R. J. Feuerbach, J. Ficenec, T. A. Forest, V. Frolov, H. Funsten, S. J. Gaff, M. Gai, M. Garçon, G. Gavalian, S. Gilad, G. P. Gilfoyle, K. L. Giovanetti, P. Girard, E. Golovatch, K. Griffioen, M. Guidal, M. Guillo, V. Gyurjyan, C. Hadjidakis, D. Hancock, J. Hardie, D. Heddle, P. Heimberg, F. W. Hersman, K. Hicks, R. S. Hicks, M. Holtrop, J. Hu, C. E. Hyde-Wright, B. S. Ishkanov, M. M. Ito, D. Jenkins, K. Joo, J. H. Kelley, J. D. Kellie, M. Khandaker, K. Y. Kim, K. Kim, W. Kim, A. Klein, F. J. Klein, M. Klusman, M. Kossov, L. H. Kramer, Y. Kuang, J. Kuhn, S. E. Kuhn, J. Lachniet, J. M. Laget, D. Lawrence, Ji Li, K. Livingston, A. Longhi, K. Loukachine, M. Lucas, W. Major, J. J. Manak, C. Marchand, S. McAleer, J. McCarthy, J. W. C. McNabb, B. A. Mecking, M. D. Mestayer, C. A. Meyer, K. Mikhailov, M. Mirazita, R. Miskimen, V. Mokeev, V. Muccifora, J. Mueller, G. S. Mutchler, J. Napolitano, S. O. Nelson, G. Niculescu, I. Niculescu, B. B. Niczyporuk, R. A. Niyazov, A. K. Opper, G. V. O'Rielly, M. Osipenko, K. Park, E. Pasyuk, G. Peterson, S. A. Philips, N. Pivnyuk, D. Pocanic, O. Pogorelko, E. Polli, S. Pozdniakov, B. M. Preedom, J. W. Price, Y. Prok, D. Protopopescu, L. M. Qin, B. A. Raue, A. R. Reolon, G. Riccardi, G. Ricco, M. Ripani, B. G. Ritchie, S. Rock, F. Ronchetti, P. Rossi, D. Rowntree, P. D. Rubin, F. Sabatié, K. Sabourov, C. Salgado, V. Sapunenko, M. Sargsyan, R. A. Schumacher, V. S. Serov, A. Shafi, Y. G. Sharabian, J. Shaw, A. V. Skabelin, E. S. Smith, T. Smith, L. C. Smith, D. I. Sober, L. Sorrell, M. Spraker, A. Stavinsky, S. Stepanyan, P. Stoler, I. I. Strakovsky, S. Taylor, D. J. Tedeschi, R. Thompson, L. Todor, M. Ungaro, M. F. Vineyard, A. V. Vlassov, K. Wang, L. B. Weinstein, A. Weisberg, D. P. Weygand, C. S. Whisnant, E. Wolin, A. Yegneswaran, J. Yun, B. Zhang, J. Zhao, and Z. Zhou

Subjects
Physics, media_common.quotation_subject, Pi, General Physics and Astronomy, Resonance, Angular dependence, Atomic physics, Spin (physics), Asymmetry, Helicity, media_common
Published
2002

22. First Measurement of the Double Spin Asymmetry ine→p→→e′π+nin the Resonance Region

Author

Elton Smith, B. S. Ishkanov, E. Golovatch, M. Ungaro, V. Frolov, M. J. Amaryan, D. S. Armstrong, J. R. Calarco, S. A. Philips, J. Ficenec, L. Ciciani, R. A. Schumacher, Shalev Gilad, R. A. Demirchyan, L. C. Dennis, B. E. Bonner, M. Anghinolfi, James Mueller, T. A. Forest, S. Stepanyan, Avraham Klein, H. Avakian, A.V. Stavinsky, P. D. Rubin, Hall Crannell, Y. G. Sharabian, K. L. Giovanetti, B. Asavapibhop, L. Elouadrhiri, M. Osipenko, M. Klusman, G. E. Dodge, B. B. Niczyporuk, D. J. Tedeschi, K. Beard, Kalvir S. Dhuga, J. P. Cummings, Dinko Pocanic, R. C. Minehart, C. A. Meyer, M. Taiuti, N. Pivnyuk, J. Napolitano, R. J. Feuerbach, J. Lachniet, D. Rowntree, J. Yun, D. Cords, A. Yegneswaran, P. V. Degtyarenko, K. Kim, K. Loukachine, I. Niculescu, D. Lawrence, G. S. Adams, K. Joo, A. Cazes, Bernhard Mecking, M. Guidal, G. Niculescu, E. Pasyuk, C. Marchand, Larry Weinstein, S. A. Dytman, I. I. Strakovsky, G. Gavalian, J. S. McCarthy, K. V. Dharmawardane, R. De Vita, G. V. O'Rielly, G. Asryan, M. Holtrop, Thomas E. Smith, K. Park, M. Kossov, S. E. Kuhn, D. P. Weygand, E. Anciant, R. A. Niyazov, B. Carnahan, J. H. Kelley, D. G. Jenkins, M. Battaglieri, W. K. Brooks, A. K. Opper, A. Empl, O. Pogorelko, P. Dragovitsch, F. Sabatié, Daniel S. Carman, Sylvain Bouchigny, K. Sabourov, Federico Ronchetti, L. M. Qin, L. C. Smith, M. Khandaker, S. J. Gaff, G. Riccardi, J. W C McNabb, E. De Sanctis, P. Corvisiero, Victor Mokeev, C. E. Hyde-Wright, G. Audit, L. Sorrell, Thierry Auger, P. Rossi, Barry Ritchie, Baile Zhang, A. Weisberg, A. R. Reolon, D. Protopopescu, J. Hardie, M. Ripani, Michael Vineyard, Patrick Girard, J. Shaw, S. Pozdniakov, M. Garçon, D. Doughty, M. Bektasoglu, S. McAleer, V. Gyurjyan, C. Djalali, W. Kim, Cynthia Marie Hadjidakis, P. Stoler, H. Denizli, D. Heddle, M. Lucas, V. S. Serov, F. W. Hersman, W. Major, K. A. Griffioen, Y. Kuang, Michael Dugger, S. O. Nelson, Z. L. Zhou, H. Bagdasaryan, A. Shafi, H. Egiyan, K. Hicks, Roy Thompson, D. I. Sober, D. Hancock, E. Polli, J. Connelly, A. Coleman, Stephen M. Rock, K. S. Egiyan, M. Guillo, G. Ricco, Ji Li, C. S. Whisnant, A. Longhi, E. Wolin, K. Mikhailov, H. Funsten, P. Bosted, P. Heimberg, J. Hu, J. P. Ball, Y. Prok, J. W. Price, M. Eckhause, Philip L. Cole, M. D. Mestayer, K. Y. Kim, M. Sargsyan, J. D. Kellie, D. G. Crabb, M. Spraker, G. P. Capitani, Nicola Bianchi, K. Livingston, S. Taylor, S. Bueltmann, G. A. Peterson, S. Barrow, R. Fatemi, A. V. Vlassov, S. Boiarinov, B. M. Preedom, A. V. Skabelin, G. S. Mutchler, Moshe Gai, H. R. Weller, Friedrich Klein, R. S. Hicks, K. Wang, Brian Raue, C. Salgado, J. J. Manak, M. M. Ito, L. Todor, Laird Kramer, Jing Zhao, L. Farhi, V. Sapunenko, Valeria Muccifora, Volker D. Burkert, A. S. Biselli, Gerard Gilfoyle, R. A. Miskimen, D. Branford, M. Mirazita, and J. M. Laget

Subjects
Physics, Nuclear physics, media_common.quotation_subject, Cathode ray, General Physics and Astronomy, Resonance, High Energy Physics::Experiment, Nuclear Experiment, Spin (physics), Asymmetry, Helicity, media_common
Abstract

The double spin asymmetry in the (-->)e(-->)p --> e(prime)pi(+)n reaction has been measured for the first time in the resonance region for four-momentum transfer Q2 = 0.35-1.5 GeV(2). Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH3 target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q(2) of the helicity asymmetry A1 for the F(15)(1680) resonance than expected from the analysis of the unpolarized data.

Published
2002

23. Corrected Article: Exclusive electroproduction of φ mesons at 4.2 GeV [Phys. Rev. C63, 065205 (2001)]

Author

J. Domingo, R. A. Schumacher, R. A. Niyazov, John T. O'Brien, G. S. Mutchler, H. O. Funsten, Dinko Pocanic, E. S. Smith, A. Coleman, H. R. Weller, M. D. Mestayer, J. J. Manak, S. E. Kuhn, P. Corvisiero, S. McAleer, J. H. Kelley, Stephen Taylor, Sylvain Bouchigny, P. Rossi, T. A. Forest, S. Stepanyan, K. S. Dhuga, G. Gavalian, S. Boiarinov, J. R. Ficenec, M. Anghinolfi, K. A. Griffioen, J. R. Calarco, S. A. Philips, L. C. Dennis, B. E. Bonner, H. Avakian, K. S. Egiyan, M. M. Ito, Laird Kramer, B. B. Niczyporuk, Jing Zhao, James Mueller, L. C. Smith, S. J. Gaff, K. Mikhailov, Shalev Gilad, G. E. Dodge, J. S. McCarthy, M. Taiuti, R. Fatemi, Y. G. Sharabian, J. Hu, M. Ripani, N. Pivnyuk, K. Lukashin, J. Napolitano, E. Wolin, Michael Vineyard, P. Dragovitsch, G. V. O'Rielly, Baile Zhang, M. Guidal, A. K. Opper, W. J. Briscoe, E. Pasyuk, M. Battaglieri, A. V. Vlassov, D. G. Jenkins, K. Park, B. A. Mecking, J. P. Ball, D. S. Carman, P. Rubin, M. Eckhause, H. Egiyan, C. Djalali, S. Whisnant, B. M. Preedom, K. Sabourov, G. Niculescu, J. P. Cummings, L. M. Qin, S. A. Dytman, R. A. Miskimen, Volker D. Burkert, A. S. Biselli, D. G. Crabb, J. Hardie, V. Gyurjyan, E. Polli, P. Stoler, Kevin Fissum, M. Holtrop, A.V. Stavinsky, D. Branford, M. Guillo, M. Kossov, M. Mirazita, S. O. Nelson, K. Wang, W. Kim, J. M. Laget, S. Pozdniakov, L. Elouadrhiri, D. J. Tedeschi, K. Hicks, C. Salgado, Robert E. Welsh, Roy Thompson, K. Paschke, I. I. Strakovsky, Z. L. Zhou, M. Klusman, Andreas Klein, V. Sapunenko, Valeria Muccifora, J. W. Price, Kwangsoo Kim, G. Riccardi, A. Longhi, G. S. Adams, R. Clark, Gerard Gilfoyle, R. DeVita, J. W C McNabb, A. Empl, Pavel Degtiarenko, E. De Sanctis, G. Audit, O. Pogorelko, C. E. Hyde-Wright, D. I. Sober, R. J. Feuerbach, K. Beard, Frank Klein, G. A. Peterson, S. Barrow, M. Bektasoglu, K. Joo, Patrick Girard, J. Shaw, J. Yun, D. Cords, A. Yegneswaran, Nicola Bianchi, B. Carnahan, F. Sabatié, V. S. Serov, Thierry Auger, A. R. Reolon, A. P. Freyberger, Federico Ronchetti, G. Ricco, Moshe Gai, R. S. Hicks, Brian Raue, Barry Ritchie, R. C. Minehart, C. A. Meyer, L. Ciciani, S. Simionatto, K. L. Giovanetti, B. Asavapibhop, Larry Weinstein, William Bertozzi, E. Anciant, M. Khandaker, D. P. Weygand, D. Doughty, D. Heddle, A. V. Skabelin, K. Kim, I. Niculescu, D. Lawrence, William Brooks, Hall Crannell, C. Marchand, D. Rowntree, L. Yanik, P. L. Cole, and F. W. Hersman

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, Particle physics, Meson production, Proton, Meson, Vector meson dominance, Production (computer science), HERA
Abstract

We studied the exclusive reaction $e\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{'}}{p}^{\ensuremath{'}}\ensuremath{\varphi}$ using the $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\varphi}}{K}^{+}{K}^{\ensuremath{-}}$ decay mode. The data were collected using a 4.2 GeV incident electron beam and the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. Our experiment covers the range in ${Q}^{2}$ from 0.7 to 2.2 ${\mathrm{GeV}}^{2},$ and W from 2.0 to 2.6 GeV. Taken together with all previous data, we find a consistent picture of $\ensuremath{\varphi}$ production on the proton. Our measurement shows the expected decrease of the t slope with the vector-meson formation time $c\ensuremath{\Delta}\ensuremath{\tau}$ below 2 fm. At $〈c\ensuremath{\Delta}\ensuremath{\tau}〉=0.6$ fm, we measure ${b}_{\ensuremath{\varphi}}=2.27\ifmmode\pm\else\textpm\fi{}0.42$ ${\mathrm{GeV}}^{\ensuremath{-}2}.$ The cross section dependence on W as ${W}^{0.2\ifmmode\pm\else\textpm\fi{}0.1}$ at ${Q}^{2}=1.3$ ${\mathrm{GeV}}^{2}$ was determined by comparison with $\ensuremath{\varphi}$ production at HERA after correcting for threshold effects. This is the same dependence as observed in photoproduction.

Published
2001

24. Photoproduction of theρ0Meson on the Proton at Large Momentum Transfer

Author

V. Frolov, M. J. Amaryan, V. Mokeev, A. Cazes, J. P. Cummings, R. De Vita, P. Dragovitsch, Roy Thompson, R. Demirchyan, K. V. Dharmawardane, G. Asryan, R. A. Niyazov, M. Kossov, Volker D. Burkert, A. S. Biselli, J. Hardie, K. L. Giovanetti, B. Asavapibhop, R. A. Miskimen, John T. O'Brien, M. Spraker, Larry Weinstein, Laird Kramer, G. S. Adams, B. L. Berman, P. Corvisiero, G. Riccardi, M. Taiuti, M. Battaglieri, Susan Taylor, L. M. Qin, K. Joo, K. Beard, E. Anciant, L. Todor, D. Protopopescu, Kalvir S. Dhuga, K. S. Egiyan, B. A. Mecking, J. R. Calarco, A.V. Stavinsky, M. Klusman, M. M. Ito, H. Egiyan, W. Kim, R. W. Major, E. Wolin, J. W C McNabb, A. P. Freyberger, K. Mikhailov, D. J. Tedeschi, M. Khandaker, D. Branford, K. A. Griffioen, M. Mirazita, Z. L. Zhou, A. Shafi, Dinko Pocanic, L. Farhi, M. Sanzone-Arenhovel, Federico Ronchetti, J. M. Laget, B. B. Niczyporuk, D. Doughty, Shalev Gilad, B. Carnahan, G. Ricco, D. G. Crabb, N. Pivnyuk, D. Heddle, C. S. Whisnant, S. E. Kuhn, J. Napolitano, P. Stoler, A. Coleman, Philip L. Cole, H. R. Weller, Thierry Auger, A. Weisberg, A. R. Reolon, Moshe Gai, K. Sabourov, S. O. Nelson, J. Shaw, K. Hicks, M. Eckhause, P. Rossi, C. Djalali, Michael Wood, M. Lucas, R. J. Feuerbach, Friedrich Klein, R. S. Hicks, Brian Raue, V. S. Serov, V. Sapunenko, Valeria Muccifora, Michael Dugger, J. H. Kelley, F. W. Hersman, H. O. Funsten, M. Guillo, S. McAleer, J. S. McCarthy, A. V. Vlassov, Gerard Gilfoyle, O. Pogorelko, K. Lukashin, L. C. Dennis, L. C. Smith, S. J. Gaff, Nicola Bianchi, H. Avakian, L. Elouadrhiri, G. S. Mutchler, Jing Zhao, W. J. Briscoe, M. Ripani, S. A. Dytman, Elton Smith, E. N. Golovach, G. A. Peterson, W. K. Brooks, S. Barrow, J. R. Ficenec, D. S. Armstrong, M. Anghinolfi, J. Yun, D. Cords, James Mueller, A. Yegneswaran, P. D. Rubin, Y. G. Sharabian, E. DeSanctis, Baile Zhang, J. J. Manak, A. K. Opper, Y. Kuang, V. Gyurjyan, E. Polli, D. I. Sober, J. W. Price, D. Hancock, H. Denizli, A. V. Skabelin, R. C. Minehart, C. A. Meyer, D. P. Weygand, Barry Ritchie, Daniel S. Carman, G. Audit, C. E. Hyde-Wright, M. Bektasoglu, S. A. Philips, M. Guidal, M. D. Mestayer, M. Holtrop, Thomas E. Smith, S. Boiarinov, R. A. Schumacher, T. A. Forest, S. Stepanyan, Avraham Klein, Hall Crannell, C. Cetina, C. Marchand, G. E. Dodge, Michael Vineyard, B. M. Preedom, P. V. Degtyarenko, D. Lawrence, G. P. Capitani, C. Salgado, and D. Rowntree

Subjects
Nuclear physics, Physics, Proton, Meson, Momentum transfer, General Physics and Astronomy
Published
2001

25. The11B(p→,γ)12Creaction below 100 keV

Author

D. R. Tilley, M. Spraker, J. H. Kelley, H. R. Weller, S. J. Gaff, B. J. Rice, R. M. Prior, E. A. Wulf, R. S. Canon, and E. C. Schreiber

Subjects
Physics, Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Excited state, Radiative capture, Resonance, Relative phase, Atomic physics, Energy (signal processing)
Abstract

The ${}^{11}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{p},\ensuremath{\gamma}{)}^{12}\mathrm{C}$ reaction was studied by measuring the $\ensuremath{\gamma}$ rays that were produced when 80--100-keV polarized protons were stopped in a thick ${}^{11}\mathrm{B}$ target. Cross sections and vector analyzing powers at $90\ifmmode^\circ\else\textdegree\fi{}$ were determined as a function of energy for capture to the ground and first excited states of ${}^{12}\mathrm{C}.$ These analyzing powers are particularly sensitive to the interference between s- and p-wave contributions, and to the relative phase between direct and resonance amplitudes. The results were used to produce a reliable extrapolation of the astrophysical S factor at 0 keV by means of a direct-capture-plus-resonances model calculation. The value of $S(0)$ that was obtained for ${}^{11}\mathrm{B}(p,{\ensuremath{\gamma}}_{0}),$ $1.8\ifmmode\pm\else\textpm\fi{}0.4 \mathrm{keV}\mathrm{}\mathrm{b},$ is in agreement with previously determined values, but for ${}^{11}\mathrm{B}(p,{\ensuremath{\gamma}}_{1})$ the value of $S(0)$ is $3.5\ifmmode\pm\else\textpm\fi{}0.6 \mathrm{keV}\mathrm{}\mathrm{b}$ and is more than twice as large as previously determined values.

Published
2000

26. New photodisintegration threshold observable in3He

Author

S. Rosati, E. A. Wulf, E. C. Schreiber, R. S. Canon, S. J. Gaff, A. Kievsky, Michele Viviani, H. R. Weller, R. M. Prior, M. C. Spraker, Rocco Schiavilla, J. H. Kelley, and D. R. Tilley

Subjects
Physics, Nuclear and High Energy Physics, Photodisintegration, Helium-3, Ab initio, Observable, Sum rule in quantum mechanics, Atomic physics, Few-body systems, Polarization (waves), Order of magnitude
Abstract

Measurements of the cross section, vector and tensor analyzing powers, and linear gamma-ray polarization in the radiative capture reactions $D(p,\ensuremath{\gamma}{)}^{3}\mathrm{He}$ and $p(d,\ensuremath{\gamma}{)}^{3}\mathrm{He}$ at c.m. energies in the range 0--53 keV allow the determination of the reduced matrix elements (RMEs) relevant for these transitions. From these RMEs the value of the integral which determines the Gerasimov-Drell-Hearn sum rule for ${}^{3}\mathrm{He}$ is obtained in the threshold region, corresponding to two-body breakup, and compared with the results of an ab initio microscopic three-body model calculation. The theoretical predictions for the value of this integral based on a ``nucleons-only'' assumption are an order of magnitude smaller than experiment. The discrepancy is reduced to about a factor of 2 when two-body currents are taken into account. This factor of 2 is due to an almost exact cancellation between the dominant $E1$ RMEs in the theoretical calculation. The excess $E1$ strength observed experimentally could provide useful insights into the nuclear interaction at low energies.

Published
1999

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