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4,442 results on '"WATTS, D."'

151. First Measurement of the Polarization Observable E in the $\vec p(\vec \gamma,\pi^+)n$ Reaction up to 2.25 GeV

Author: Strauch, S., Briscoe, W. J., Döring, M., Klempt, E., Nikonov, V. A., Pasyuk, E., Rönchen, D., Sarantsev, A. V., Strakovsky, I., Workman, R., Adhikari, K. P., Adikaram, D., Anderson, M. D., Pereira, S. Anefalos, Anisovich, A. V., Badui, R. A., Ball, J., Batourine, V., Battaglieri, M., Bedlinskiy, I., Benmouna, N., Biselli, A. S., Brock, J., Brooks, W. K., Burkert, V. D., Cao, T., Carlin, C., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., Dashyan, N., D'Angelo, A., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Gevorgyan, N., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keith, C. D., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., McKinnon, B., Meekins, D. G., Meyer, C. A., Mokeev, V., Montgomery, R. A., Moody, C. I., Moutarde, H., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Park, K., Peng, P., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Roy, P., Sabatié, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seely, M. L., Senderovich, I, Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stoler, P., Stepanyan, S., Sytnik, V., Taiuti, M., Tian, Ye, Trivedi, A., Tucker, R., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction $\vec \gamma \vec p \to \pi^+n$, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn-Gatchina, J\"ulich, and SAID groups., Comment: 6 pages, 3 figures
Published: 2015
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152. Association of schistosomiasis and HIV infections: A systematic review and meta-analysis

Author: Patel, Pragna, Rose, Charles E., Kjetland, Eyrun F., Downs, Jennifer A., Mbabazi, Pamela Sabina, Sabin, Keith, Chege, Wairimu, Watts, D. Heather, and Secor, W. Evan
Published: 2021
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153. Effect of Gypsum, Cover Crop, and Crop Rotation on Bulk Density and Aggregate Properties of Soils.

Author: Shedekar, V. S., Watts, D. B., Islam, K. R., Raut, Y., Gonzalez, J. M., Dick, W. A., Fausey, N. R., Flanagan, D. C., Reeder, R. C., VanToai, T., and Batte, M. T.
Subjects: *CROP management, *SOIL amendments, *SOIL structure, *SOIL classification, *GYPSUM in soils, *COVER crops, *CROP rotation
Abstract: Soybean production, worldwide, typically involves full tillage resulting in much less biomass than other crops, leading to decreased soil organic matter and increased soil degradation. The goal of this study was to evaluate the potential benefits of an innovative management system that includes the combinations of no-till, crop rotation, cover crop, and gypsum application on continuous soybean production. The response of soil physical properties, i.e. bulk density and water-stable aggregates, was evaluated across a range of soil types and climatic conditions. Treatments consisted of comparing (1) continuous soybean to a soybean-corn and corn-soybean rotation, (2) cereal rye [Secale cereale (L.)] cover crop to no cover crop, and (3) gypsum surface‐applied at 0, 1.1, and 2.2 Mg ha−1. The study was replicated at four different sites in the United States, including Shorter (AL), Farmland (IN), Hoytville (OH), and Piketon (OH). At the end of the 5-year study, soil bulk density and aggregate stability were determined. Soil bulk density and water-stable aggregates were unaffected by gypsum addition regardless of the location. Including cereal rye as a winter cover increased soil aggregation and bulk density at the Hoytville location only. Rotating the soybeans with corn (compared to continuous soybeans) resulted in soil aggregation and bulk density improvements at all research locations. Results indicated that soybean production that included crop rotation into management system improved soil aggregate stability, whereas cover crop benefits were less effective and amending the soil with gypsum did not significantly affect these soil properties. [ABSTRACT FROM AUTHOR]
Published: 2024
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154. Measurement of the helicity dependence for single π0 photoproduction from the deuteron

Author: Cividini, F., Dieterle, M., Abt, S., Achenbach, P., Adlarson, P., Afzal, F., Ahmed, Z., Annand, J. R. M., Arends, H. J., Bashkanov, M., Beck, R., Biroth, M., Borisov, N., Braghieri, A., Briscoe, W. J., Collicott, C., Costanza, S., Denig, A., Dolzhikov, A. S., Downie, E. J., Drexler, P., Fegan, S., Fix, A., Gardner, S., Ghosal, D., Glazier, D. I., Gorodnov, I., Gradl, W., Günther, M., Gurevich, D., Heijkenskjöld, L., Hornidge, D., Huber, G. M., Käser, A., Kashevarov, V. L., Kay, S. J. D., Korolija, M., Krusche, B., Lazarev, A., Livingston, K., Lutterer, S., MacGregor, I. J. D., Manley, D. M., Martel, P. P., Miskimen, R., Mocanu, M., Mornacchi, E., Mullen, C., Neganov, A., Neiser, A., Ostrick, M., Paudyal, D., Pedroni, P., Powell, A., Rostomyan, T., Sokhoyan, V., Spieker, K., Steffen, O., Strakovsky, I., Strub, T., Thiel, A., Thiel, M., Thomas, A., Usov, Yu. A., Wagner, S., Watts, D. P., Werthmüller, D., Wettig, J., Witthauer, L., Wolfes, M., and Zachariou, N.
Published: 2022
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155. The CLAS12 Forward Tagger

Author: Acker, A., Attié, D., Aune, S., Ball, J., Baron, P., Bashkanov, M., Battaglieri, M., Behary, R., Benmokhtar, F., Bersani, A., Bertrand, Q., Besin, D., Bey, T., Black, P., Bonneau, P., Bossù, F., Boudouin, R., Boyer, M., Campero Rojas, P., Casale, A., Celentano, A., Cereseto, R., Ciarma, A., Cipro, F., Charles, G., Christiaens, G., Contrepois, P., Cook, M., D’Angelo, A., De Vita, R., Defurne, M., Delagnes, E., Fanchini, E., Fegan, S., Fleming, J., Filippi, A., Garçon, M., Georges, F., Giovanetti, K.L., Glazier, D.I., Granelli, R., Grouas, N., Hicks, K., Hoebel, A., Hughes, S.M., Lahonde, C., Lanza, L., Leffel, M., Lerch, T., Lemon, T., Livingston, K., Manco, A., Mandjavidze, I., Mann, H.S., McKinnon, B., Meunier, O., Miller, R., Miní, G., Mouden, Y., Musico, P., Osipenko, M., Ottonello, G., Parodi, F., Pasyuk, E., Pollovio, P., Pratolongo, F., Procureur, S., Puppo, R., Rossi, C., Riallot, M., Ripani, M., Rizzo, A., Sabatié, F., Salgado, C., Smith, G.D., Sokhan, D., Stankovic, I., Taiuti, M., Trovato, A., Vandenbroucke, M., Vigo, V., Virique, E., Watts, D., Wiggins, C., Zachariou, N., and Zana, L.
Published: 2020
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156. The CLAS12 Spectrometer at Jefferson Laboratory

Author: Burkert, V.D., Elouadrhiri, L., Adhikari, K.P., Adhikari, S., Amaryan, M.J., Anderson, D., Angelini, G., Antonioli, M., Atac, H., Aune, S., Avakian, H., Gayoso, C. Ayerbe, Baltzell, N., Barion, L., Battaglieri, M., Baturin, V., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A.S., Bonneau, P., Bossù, F., Boyarinov, S., Briscoe, W.J., Brooks, W.K., Bruhwel, K., Carman, D.S., Celentano, A., Charles, G., Chatagnon, P., Chetry, T., Christiaens, G., Christo, S., Ciullo, G., Clary, B.A., Cole, P.L., Contalbrigo, M., Cook, M., Crede, V., Cruz-Torres, R., Cuevas, C., D’Angelo, A., Dashyan, N., Defurne, M., Deur, A., De Vita, R., Diehl, S., Djalali, C., Dodge, G., Dupre, R., Ehrhart, M., El Fassi, L., Eng, B., Ewing, T., Fair, R., Fedotov, G., Filippi, A., Forest, T.A., Garçon, M., Gavalian, G., Ghoshal, P., Gilfoyle, G.P., Giovanetti, K., Girod, F.X., Glazier, D.I., Golovatch, E., Gothe, R.W., Gotra, Y., Griffioen, K.A., Guidal, M., Gyurjyan, V., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hauenstein, F., Hayward, T.B., Heddle, D., Hemler, P., Hen, O.A., Hicks, K., Hobart, A., Hogan, J., Holtrop, M., Ilieva, Y., Illari, I., Insley, D., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jacobs, G., Jo, H.S., Johnston, R., Joo, K., Joosten, S., Kageya, T., Kashy, D., Keith, C., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, C.W., Kim, W., Kubarovsky, V., Kuhn, S.E., Lanza, L., Leffel, M., Lucherini, V., Lung, A., Kabir, M.L., Leali, M., Lee, S., Lenisa, P., Livingston, K., Lowry, M., MacGregor, I.J.D., Mandjavidze, I., Marchand, D., Markov, N., Mascagna, V., McKinnon, B., McMullen, M., Mealer, C., Mestayer, M.D., Meziani, Z.E., Miller, R., Milner, R.G., Mineeva, T., Mirazita, M., Mokeev, V., Moran, P., Movsisyan, A., Camacho, C. Munoz, Naidoo, P., Nanda, S., Newton, J., Niccolai, S., Niculescu, G., Osipenko, M., Paolone, M., Pappalardo, L.L., Paremuzyan, R., Pastor, O., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J.W., Price, K., Procureur, S., Prok, Y., Protopopescu, D., Rajput-Ghoshal, R., Raue, B.A., Raydo, B., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rossi, P., Rowley, J., Roy, B.J., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Segarra, E.P., Sergeyeva, V., Sharabian, Y.G., Shrestha, U., Skorodumina, Iu., Smith, G.D., Smith, L.C., Sokhan, D., Soto, O., N.Sparveris, Stepanyan, S., Stoler, P., Strauch, S., Tan, J.A., Taylor, M., Tilles, D., Turisini, M., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D., Wei, X., Weinstein, L.B., Wiggins, C., Wiseman, M., Wood, M.H., Yegneswaran, A., Young, G., Zachariou, N., Zarecky, M., Zhang, J., Zhao, Z.W., and Ziegler, V.
Published: 2020
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157. A new measurement of the neutron detection efficiency for the NaI Crystal Ball detector

Author: Martemianov, M., Kulikov, V., Demissie, B. T., Marinides, Z., Akondi, C. S., Annand, J. R. M., Arends, H. J., Beck, R., Borisov, N., Braghieri, A., Briscoe, W. J., Cherepnya, S., Collicott, C., Costanza, S., Downie, E. J., Dieterle, M., Bondy, M. I. Ferretti, Filkov, L. V., Garni, S., Glazier, D. I., Glowa, D., Gradl, W., Gurevich, G., Hornidge, D., Huber, G. M., Kaeser, A., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Krusche, B., Lazarev, A., Linturi, J. M., Lisin, V., Livingston, K., MacGregor, I. J. D., Manley, D. M., Martel, P. P., Middleton, D. G., Miskimen, R., Mushkarenkov, A., Neganov, A., Neiser, A., Oberle, M., Ostrick, M., Ott, P., Otte, P. B., Oussena, B., Pedroni, P., Polonski, A., Prakhov, S., Ron, G., Rostomyan, T., Sarty, A., Schott, D. M., Schumann, S., Sokhoyan, V., Steffen, O., Strakovsky, I. I., Strub, Th., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Usov, Yu. A., Wagner, S., Watts, D. P., Wettig, J., Werthmuller, D., Witthauer, L., and Wolfes, M.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report on a measurement of the neutron detection efficiency in NaI crystals in the Crystal Ball detector obtained from a study of single p0 photoproduction on deuterium using the tagged photon beam at the Mainz Microtron. The results were obtained up to a neutron energy of 400 MeV. They are compared to previous measurements made more than 15 years ago at the pion beam at the BNL AGS.
Published: 2015
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158. A precision measurement of the $p$($e,e^\prime p\,$)$\pi^0$ reaction at threshold

Author: Chirapatpimol, K., Shabestari, M. H., Lindgren, R. A., Smith, L. C., Annand, J. R. M., Higinbotham, D. W., Moffit, B., Nelyubin, V., Norum, B. E., Allada, K., Aniol, K., Ardashev, K., Armstrong, D. S., Arndt, R. A., Benmokhtar, F., Bernstein, A. M., Bertozzi, W., Briscoe, W. J., Bimbot, L., Camsonne, A., Chen, J. -P., Choi, S., Chudakov, E., Cisbani, E., Cusanno, F., Dalton, M. M., Dutta, C., Egiyan, K., Fernandez-Ramirez, C., Feuerbach, R., Fissum, K. G., Frullani, S., Garibaldi, F., Gayou, O., Gilman, R., Gilad, S., Goity, J., Gomez, J., Hahn, B., Hamilton, D., Hansen, J. -O., Huang, J., Igarashi, R., Ireland, D., de Jager, C. W., Jin, X., Jiang, X., Jinasundera, T., Kellie, J., Keppel, C. E., Kolb, N., LeRose, J., Liyanage, N., Livingston, K., McNulty, D., Mercado, L., Michaels, R., Mihovilovic, M., Qian, S., Qian, X., Mailyan, S., Mamyan, V., Marrone, S., Monaghan, P., Nanda, S., Perdrisat, C. F., Piasetzky, E., Protopopescu, D., Punjabi, V., Qiang, Y., Rachek, I. A., Rakhman, A., Ron, G., Rosner, G., Saha, A., Sawatzky, B., Shahinyan, A., Sirca, S., Sparveris, N., Subedi, R. R., Suleiman, R., Strakovsky, I., Sulkosky, V., Moinelo, J., Voskanyan, H., Wang, K., Wang, Y., Watson, J., Watts, D., Wojtsekhowski, B., Workman, R. L., Yao, H., Zhan, X., and Zhang, Y.
Subjects: Nuclear Experiment
Abstract: New results are reported from a measurement of $\pi^0$ electroproduction near threshold using the $p(e,e^{\prime} p)\pi^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $\phi^*_{\pi}$ and $\theta^*_{\pi}$ angles in the $p \pi^0$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. The 4-momentum transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement., Comment: 5 pages, 6 figures
Published: 2015
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159. Stokes-parameter representation for Compton scattering of entangled and classically correlated two-photon systems

Author: Caradonna, P., primary, D'Amico, I., additional, Jenkins, D. G., additional, and Watts, D. P., additional
Published: 2024
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160. Toward Earlier Inclusion of Pregnant and Postpartum Women in Tuberculosis Drug Trials: Consensus Statements From an International Expert Panel

Author: Gupta, Amita, Mathad, Jyoti S, Abdel-Rahman, Susan M, Albano, Jessica D, Botgros, Radu, Brown, Vikki, Browning, Renee S, Dawson, Liza, Dooley, Kelly E, Gnanashanmugam, Devasena, Grinsztejn, Beatriz, Hernandez-Diaz, Sonia, Jean-Philippe, Patrick, Kim, Peter, Lyerly, Anne D, Mirochnick, Mark, Mofenson, Lynne M, Montepiedra, Grace, Piper, Jeanna, Sahin, Leyla, Savic, Radojka, Smith, Betsy, Spiegel, Hans, Swaminathan, Soumya, Watts, D Heather, and White, Amina
Subjects: Reproductive Medicine, Biomedical and Clinical Sciences, Clinical Trials and Supportive Activities, Prevention, Infectious Diseases, Rare Diseases, Tuberculosis, Orphan Drug, Clinical Research, Development of treatments and therapeutic interventions, 5.1 Pharmaceuticals, 6.1 Pharmaceuticals, Evaluation of treatments and therapeutic interventions, Infection, Reproductive health and childbirth, Good Health and Well Being, Adult, Antitubercular Agents, Clinical Trials as Topic, Female, HIV Infections, Humans, Latent Tuberculosis, Postpartum Period, Pregnancy, Tuberculosis, Multidrug-Resistant, United States, tuberculosis, MDR tuberculosis, latent tuberculosis infection, pregnancy, clinical trials, Biological Sciences, Medical and Health Sciences, Microbiology, Clinical sciences
Abstract: Tuberculosis is a major cause of morbidity and mortality in women of childbearing age (15-44 years). Despite increased tuberculosis risk during pregnancy, optimal clinical treatment remains unclear: safety, tolerability, and pharmacokinetic data for many tuberculosis drugs are lacking, and trials of promising new tuberculosis drugs exclude pregnant women. To advance inclusion of pregnant and postpartum women in tuberculosis drug trials, the US National Institutes of Health convened an international expert panel. Discussions generated consensus statements (>75% agreement among panelists) identifying high-priority research areas during pregnancy, including: (1) preventing progression of latent tuberculosis infection, especially in women coinfected with human immunodeficiency virus; (2) evaluating new agents/regimens for treatment of multidrug-resistant tuberculosis; and (3) evaluating safety, tolerability and pharmacokinetics of tuberculosis drugs already in use during pregnancy and postpartum. Incorporating pregnant women into clinical trials would extend evidence-based tuberculosis prevention and treatment standards to this special population.
Published: 2016

161. Analysis Tools for Next-Generation Hadron Spectroscopy Experiments

Author: Battaglieri, M., Briscoe, B. J., Celentano, A., Chung, S. -U., D'Angelo, A., De Vita, R., Döring, M., Dudek, J., Eidelman, S., Fegan, S., Ferretti, J., Filippi, A., Fox, G., Galata, G., Garcia-Tecocoatzi, H., Glazier, D. I., Grube, B., Hanhart, C., Hoferichter, M., Hughes, S. M., Ireland, D. G., Ketzer, B., Klein, F. J., Kubis, B., Liu, B., Masjuan, P., Mathieu, V., McKinnon, B., Mitchell, R., Nerling, F., Paul, S., Pelaez, J. R., Rademacker, J., Rizzo, A., Salgado, C., Santopinto, E., Sarantsev, A. V., Sato, T., Schlüter, T., da Silva, M. L. L., Stankovic, I., Strakovsky, I., Szczepaniak, A., Vassallo, A., Walford, N. K., Watts, D. P., and Zana, L.
Subjects: High Energy Physics - Phenomenology
Abstract: The series of workshops on New Partial-Wave Analysis Tools for Next-Generation Hadron Spectroscopy Experiments was initiated with the ATHOS 2012 meeting, which took place in Camogli, Italy, June 20-22, 2012. It was followed by ATHOS 2013 in Kloster Seeon near Munich, Germany, May 21-24, 2013. The third, ATHOS3, meeting is planned for April 13-17, 2015 at The George Washington University Virginia Science and Technology Campus, USA. The workshops focus on the development of amplitude analysis tools for meson and baryon spectroscopy, and complement other programs in hadron spectroscopy organized in the recent past including the INT-JLab Workshop on Hadron Spectroscopy in Seattle in 2009, the International Workshop on Amplitude Analysis in Hadron Spectroscopy at the ECT*-Trento in 2011, the School on Amplitude Analysis in Modern Physics in Bad Honnef in 2011, the Jefferson Lab Advanced Study Institute Summer School in 2012, and the School on Concepts of Modern Amplitude Analysis Techniques in Flecken-Zechlin near Berlin in September 2013. The aim of this document is to summarize the discussions that took place at the ATHOS 2012 and ATHOS 2013 meetings. We do not attempt a comprehensive review of the field of amplitude analysis, but offer a collection of thoughts that we hope may lay the ground for such a document., Comment: 28 pages, 11 figures, proceedings of the ATHOS 2012 and ATHOS 2013 meetings
Published: 2014
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162. Momentum sharing in imbalanced Fermi systems

Author: Hen, O., Sargsian, M., Weinstein, L. B., Piasetzky, E., Hakobyan, H., Higinbotham, D. W., Braverman, M., Brooks, W. K., Gilad, S., Adhikari, K. P., Arrington, J., Asryan, G., Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Beck, A., Beck, S. May-Tal, Bedlinskiy, I., Bertozzi, W., Biselli, A., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Colaneri, L., Cole, P. L., Crede, V., DAngelo, A., De Vita, R., Deur, A., Djalali, C., Doughty, D., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fedotov, G., Fegan, S., Forest, T., Garillon, B., Garcon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Goetz, J. T., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hanretty, C., Hattawy, M., Hicks, K., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkanov, B. I., Isupov, E. L., Jiang, H., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Koirala, S., Korover, I., Kuhn, S. E., Kubarovsky, V., Lenisa, P., Levine, W. I., Livingston, K., Lowry, M., Lu, H. Y., MacGregor, I. J. D., Markov, N., Mayer, M., McKinnon, B., Mineeva, T., Mokeev, V., Movsisyan, A., Camacho, C. Munoz, Mustapha, B., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Rimal, D., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatie, F., Schott, D., Schumacher, R. A., Sharabian, Y. G., Smith, G. D., Shneor, R., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Stoler, P., Strauch, S., Sytnik, V., Taiuti, M., Tkachenko, S., Ungaro, M., Vlassov, A. V., Voutier, E., Watts, D., Walford, N. K., Wei, X., Wood, M. H., Wood, S. A., Zachariou, N., Zana, L., Zhao, Z. W., Zheng, X., and Zonta, I.
Subjects: Nuclear Experiment, Condensed Matter - Quantum Gases, Nuclear Theory
Abstract: The atomic nucleus is composed of two different kinds of fermions, protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority fermions (usually neutrons) to have a higher average momentum. Our high-energy electron scattering measurements using 12C, 27Al, 56Fe and 208Pb targets show that, even in heavy neutron-rich nuclei, short-range interactions between the fermions form correlated high-momentum neutron-proton pairs. Thus, in neutron-rich nuclei, protons have a greater probability than neutrons to have momentum greater than the Fermi momentum. This finding has implications ranging from nuclear few body systems to neutron stars and may also be observable experimentally in two-spin state, ultra-cold atomic gas systems., Comment: Published in Science. 10 pages, 3 figures
Published: 2014
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163. Towards a resolution of the proton form factor problem: new electron and positron scattering data

Author: Adikaram, D., Rimal, D., Weinstein, L. B., Raue, B., Khetarpal, P., Bennett, R. P., Arrington, J., Brooks, W. K., Adhikari, K. P., Afanasev, A. V., Amaryan, M. J., Anderson, M. D., Ball, J., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Contalbrigo, M., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Fradi, A., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S. M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jiang, H., Joo, K., Joosten, S., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McKinnon, B., Mestayer, M. D., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Moody, C. I., Moutarde, H., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Park, K., Pasyuk, E., Pisano, S., Pogorelko, O., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Schott, D., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, I., Smith, E. S., Smith, G. D., Sober, D. I., Sparveris, N., Stepanyan, S., Strauch, S., Sytnik, V., Taiuti, M., Tian, Ye, Trivedi, A., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., Zonta, I., and Collaboration, The CLAS
Subjects: Nuclear Experiment
Abstract: There is a significant discrepancy between the values of the proton electric form factor, $G_E^p$, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of $G_E^p$ from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization ($\varepsilon$) and momentum transfer ($Q^2$) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing $\varepsilon$ at $Q^2 = 1.45 \text{ GeV}^2$. This measurement is consistent with the size of the form factor discrepancy at $Q^2\approx 1.75$ GeV$^2$ and with hadronic calculations including nucleon and $\Delta$ intermediate states, which have been shown to resolve the discrepancy up to $2-3$ GeV$^2$., Comment: 6 pages, 4 figures, submitted to PRL
Published: 2014
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164. Experimental access to Transition Distribution Amplitudes with the \={P}ANDA experiment at FAIR

Author: PANDA Collaboration, Singh, B. P., Erni, W., Keshelashvili, I., Krusche, B., M. Steinacher, Liu, B., Liu, H., Liu, Z., Shen, X., Wang, C., J. Zhao, Albrecht, M., Fink, M., Heinsius, F. H., Held, T., Holtmann, T., Koch, H., Kopf, B., Kümmel, M., Kuhl, G., Kuhlmann, M., Leyhe, M., Mikirtychyants, M., Musiol, P., Mustafa, A., Pelizäus, M., Pychy, J., Richter, M., Schnier, C., Schröder, T., Sowa, C., Steinke, M., Triffterer, T., Wiedner, U., Beck, R., Hammann, C., Kaiser, D., Ketzer, B., Kube, M., Mahlberg, P., Rossbach, M., Schmidt, C., Schmitz, R., Thoma, U., Walther, D., Wendel, C., Wilson, A., Bianconi, A., Bragadireanu, M., Caprini, M., Pantea, D., Pietreanu, D., Vasile, M. E., Patel, B., Kaplan, D., Brandys, P., Czyzewski, T., Czyzycki, W., Domagala, M., Hawryluk, M., Filo, G., Krawczyk, M., Kwiatkowski, D., Lisowski, E., Lisowski, F., Fiutowski, T., Idzik, M., Mindur, B., Przyborowski, D., Swientek, K., Czech, B., Kliczewski, S., Korcyl, K., Kozela, A., Kulessa, P., Lebiedowicz, P., Malgorzata, K., Pysz, K., Schäfer, W., Siudak, R., Szczurek, A., Biernat, J., Jowzaee, S., Kamys, B., Kistryn, S., Korcyl, G., Krzemien, W., Magiera, A., Moskal, P., Palka, M., Psyzniak, A., Rudy, Z., Salabura, P., Smyrski, J., Strzempek, P., Wrońska, A., Augustin, I., Lehmann, I., Nicmorus, D., Schepers, G., Schmitt, L., Al-Turany, M., Cahit, U., Capozza, L., Dbeyssi, A., Deppe, H., Dzhygadlo, R., Ehret, A., Flemming, H., Gerhardt, A., Götzen, K., Karabowicz, R., Kliemt, R., Kunkel, J., Kurilla, U., Lehmann, D., Lühning, J., Maas, F., Morales, C. Morales, Espí, M. C. Mora, Nerling, F., Orth, H., Peters, K., Pineiro, D. Rodríguez, Saito, N., Saito, T., Lorente, A. Sánchez, Schmidt, C. J., Schwarz, C., Schwiening, J., Traxler, M., Valente, R., Voss, B., Wieczorek, P., Wilms, A., Zühlsdorf, M., Abazov, V. M., Alexeev, G., Arefiev, A., Astakhov, V. I., Barabanov, M. Yu., Batyunya, B. V., Davydov, Yu. I., Dodokhov, V. Kh., Efremov, A. A., Fedunov, A. G., Festchenko, A. A., Galoyan, A. S., Grigoryan, S., Karmokov, A., Koshurnikov, E. K., Lobanov, V. I., Lobanov, Yu. Yu., Makarov, A. F., Malinina, L. V., Malyshev, V. L., Mustafaev, G. A., Olshevskiy, A., Pasyuk, M. A., Perevalova, E. A., Piskun, A. A., Pocheptsov, T. A., Pontecorvo, G., Rodionov, V. K., Rogov, Yu. N., Salmin, R. A., Samartsev, A. G., Sapozhnikov, M. G., Shabratova, G. S., Skachkov, N. B., Skachkova, A. N., Strokovsky, E. A., Suleimanov, M. K., Teshev, R. Sh., Tokmenin, V. V., Uzhinsky, V. V., Vodopyanov, A. S., Zaporozhets, S. A., Zhuravlev, N. I., Zorin, A. G., Branford, D., Glazier, D., Watts, D., Woods, P., Britting, A., Eyrich, W., Lehmann, A., Uhlig, F., Dobbs, S., Seth, K., Tomaradze, A., Xiao, T., Bettoni, D., Carassiti, V., Ramusino, A. Cotta, Dalpiaz, P., Drago, A., Fioravanti, E., Garzia, I., Savriè, M., Stancari, G., Akishina, V., Kisel, I., Kulakov, I., Zyzak, M., Arora, R., Bel, T., Gromliuk, A., Kalicy, G., Krebs, M., Patsyuk, M., Zuehlsdorf, M., Bianchi, N., Gianotti, P., Guaraldo, C., Lucherini, V., Pace, E., Bersani, A., Bracco, G., Macri, M., Parodi, R. F., Bianco, S., Bremer, D., Brinkmann, K. T., Diehl, S., Dormenev, V., Drexler, P., Düren, M., Eissner, T., Etzelmüller, E., Föhl, K., Galuska, M., Gessler, T., Gutz, E., Hayrapetyan, A., Hu, J., Kröck, B., Kühn, W., Kuske, T., Lange, S., Liang, Y., Merle, O., Metag, V., Mülhheim, D., Münchow, D., Nanova, M., Novotny, R., Pitka, A., Quagli, T., Rieke, J., Rosenbaum, C., Schnell, R., Spruck, B., Stenzel, H., Thöring, U., Ullrich, M., Wasem, T., Werner, M., Zaunick, H. G., Ireland, D., Rosner, G., Seitz, B., Deepak, P. N., Kulkarni, A. V., Apostolou, A., Babai, M., Kavatsyuk, M., Lemmens, P., Lindemulder, M., Löhner, H., Messchendorp, J., Schakel, P., Smit, H., van der Weele, J. C., Tiemens, M., Veenstra, R., Vejdani, S., Kalita, K., Mohanta, D. P., Kumar, A., Roy, A., Sahoo, R., Sohlbach, H., Büscher, M., Cao, L., Cebulla, A., Deermann, D., Dosdall, R., Esch, S., Georgadze, I., Gillitzer, A., Goerres, A., Goldenbaum, F., Grunwald, D., Herten, A., Hu, Q., Kemmerling, G., Kleines, H., Kozlov, V., Lehrach, A., Leiber, S., Maier, R., Nellen, R., Ohm, H., Orfanitski, S., Prasuhn, D., Prencipe, E., Ritman, J., Schadmand, S., Schumann, J., Sefzick, T., Serdyuk, V., Sterzenbach, G., Stockmanns, T., Wintz, P., Wüstner, P., Xu, H., Li, S., Li, Z., Sun, Z., Rigato, V., Fissum, S., Hansen, K., Isaksson, L., Lundin, M., Schröder, B., Achenbach, P., Bleser, S., Cardinali, M., Corell, O., Deiseroth, M., Denig, A., Distler, M., Feldbauer, F., Fritsch, M., Jasinski, P., Hoek, M., Kangh, D., Karavdina, A., Lauth, W., Leithoff, H., Merkel, H., Michel, M., Motzko, C., Müller, U., Noll, O., Plueger, S., Pochodzalla, J., Sanchez, S., Schlimme, S., Sfienti, C., Steinen, M., Thiel, M., Weber, T., Zambrana, M., Dormenev, V. I., Fedorov, A. A., Korzihik, M. V., Missevitch, O. V., Balanutsa, P., Balanutsa, V., Chernetsky, V., Demekhin, A., Dolgolenko, A., Fedorets, P., Gerasimov, A., Goryachev, V., Varentsov, V., Boukharov, A., Malyshev, O., Marishev, I., Semenov, A., Konorov, I., Paul, S., Grieser, S., Hergemöller, A. K., Khoukaz, A., Köhler, E., Täschner, A., Wessels, J., Dash, S., Jadhav, M., Kumar, S., Sarin, P., Varma, R., Chandratre, V. B., Datar, V., Dutta, D., Jha, V., Kumawat, H., Mohanty, A. K., Roy, B., Yan, Y., Chinorat, K., Khanchai, K., Ayut, L., Pornrad, S., Barnyakov, A. Y., Blinov, A. E., Blinov, V. E., Bobrovnikov, V. S., Kononov, S. A., Kravchenko, E. A., Kuyanov, I. A., Onuchin, A. P., Sokolov, A. A., Tikhonov, Y. A., Atomssa, E., Hennino, T., Imre, M., Kunne, R., Galliard, C. Le, Ma, B., Marchand, D., Ong, S., Ramstein, B., Rosier, P., Tomasi-Gustafsson, E., Van de Wiele, J., Boca, G., Costanza, S., Genova, P., Lavezzi, L., Montagna, P., Rotondi, A., Abramov, V., Belikov, N., Bukreeva, S., Davidenko, A., Derevschikov, A., Goncharenko, Y., Grishin, V., Kachanov, V., Kormilitsin, V., Melnik, Y., Levin, A., Minaev, N., Mochalov, V., Morozov, D., Nogach, L., Poslavskiy, S., Ryazantsev, A., Ryzhikov, S., Semenov, P., Shein, I., Uzunian, A., Vasiliev, A., Yakutin, A., Yabsley, B., Bäck, T., Cederwall, B., Makónyi, K., Tegnér, P. E., von Würtemberg, K. M., Belostotski, S., Gavrilov, G., Izotov, A., Kashchuk, A., Levitskaya, O., Manaenkov, S., Miklukho, O., Naryshkin, Y., Suvorov, K., Veretennikov, D., Zhadanov, A., Rai, A. K., Godre, S. S., Duchat, R., Amoroso, A., Bussa, M. P., Busso, L., De Mori, F., Destefanis, M., Fava, L., Ferrero, L., Greco, M., Maggiora, M., Maniscalco, G., Marcello, S., Sosio, S., Spataro, S., Zotti, L., Calvo, D., Coli, S., De Remigis, P., Filippi, A., Giraudo, G., Lusso, S., Mazza, G., Mingnore, M., Rivetti, A., Wheadon, R., Balestra, F., Iazzi, F., Introzzi, R., Lavagno, A., Younis, H., Birsa, R., Bradamante, F., Bressan, A., Martin, A., Clement, H., Gålnander, B., Balkeståhl, L. Caldeira, Calén, H., Fransson, K., Johansson, T., Kupsc, A., Marciniewski, P., Pettersson, J., Schönning, K., Wolke, M., Zlomanczuk, J., Díaz, J., Ortiz, A., Vinodkumar, P. C., Parmar, A., Chlopik, A., Melnychuk, D., Slowinski, B., Trzcinski, A., Wojciechowski, M., Wronka, S., Zwieglinski, B., Bühler, P., Marton, J., Suzuki, K., Widmann, E., Zmeskal, J., Fröhlich, B., Khaneft, D., Lin, D., Zimmermann, I., and Semenov-Tian-Shansky, K.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion ($\pi N$) TDAs from $\bar{p}p \to e^+e^- \pi^0$ reaction with the future \={P}ANDA detector at the FAIR facility. At high center of mass energy and high invariant mass squared of the lepton pair $q^2$, the amplitude of the signal channel $\bar{p}p \to e^+e^- \pi^0$ admits a QCD factorized description in terms of $\pi N$ TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring $\bar{p}p \to e^+e^- \pi^0$ with the \={P}ANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. $\bar{p}p \to \pi^+\pi^- \pi^0$ were performed for the center of mass energy squared $s = 5$ GeV$^2$ and $s = 10$ GeV$^2$, in the kinematic regions $3.0 < q^2 < 4.3$ GeV$^2$ and $5 < q^2 < 9$ GeV$^2$, respectively, with a neutral pion scattered in the forward or backward cone $| \cos\theta_{\pi^0}| > 0.5 $ in the proton-antiproton center of mass frame. Results of the simulation show that the particle identification capabilities of the \={P}ANDA detector will allow to achieve a background rejection factor of $5\cdot 10^7$ ($1\cdot 10^7$) at low (high) $q^2$ for $s=5$ GeV$^2$, and of $1\cdot 10^8$ ($6\cdot 10^6$) at low (high) $q^2$ for $s=10$ GeV$^2$, while keeping the signal reconstruction efficiency at around $40\%$. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to $2$ fb$^{-1}$ of integrated luminosity. (.../...), Comment: 19 pages, 7 figures (some multiple), 2 tables (each double), preprint of an article for epj - v2
Published: 2014

165. Measurement of the transverse target and beam-target asymmetries in $\eta$ meson photoproduction at MAMI

Author: Akondi, C. S., Annand, J. R. M., Arends, H. J., Beck, R., Bernstein, A., Borisov, N., Braghieri, A., Briscoe, W. J., Cherepnya, S., Collicott, C., Costanza, S., Downie, E. J., Dieterle, M., Fix, A., Fil'kov, L. V., Garni, S., Glazier, D. I., Gradl, W., Gurevich, G., Barrientos, P. Hall, Hamilton, D., Hornidge, D., Howdle, D., Huber, G. M., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Krusche, B., Lazarev, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Mancel, J., Manley, D. M., Martel, P., McNicoll, E. F., Meyer, W., Middleton, D., Miskimen, R., Mushkarenkov, A., Nefkens, B. M. K., Neganov, A., Nikolaev, A., Oberle, M., Ostrick, M., Ortega, H., Ott, P., Otte, P. B., Oussena, B., Pedroni, P., Polonski, A., Polyanski, V. V., Prakhov, S., Reicherz, G., Rostomyan, T., Sarty, A., Schumann, S., Steffen, O., Strakovsky, I. I., Strub, Th., Supek, I., Tiator, L., Thomas, A., Unverzagt, M., Usov, Yu. A., Watts, D. P., Werthmüller, D., Witthauer, L., and Wolfes, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract: We present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the $\vec \gamma \vec p\to\eta p$ reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. All existing model predictions fail to reproduce the new data indicating a significant impact on our understanding of the underlying dynamics of $\eta$ meson photoproduction. The peculiar nodal structure observed in existing T data close to threshold is not confirmed., Comment: 5 pages, 3 figures, accepted for publication in PRL
Published: 2014
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166. Measurements of Double-Polarized Compton Scattering Asymmetries and Extraction of the Proton Spin Polarizabilities

Author: Martel, P. P., Miskimen, R., Aguar-Bartolome, P., Ahrens, J., Akondi, C. S., Annand, J. R. M., Arends, H. J., Barnes, W., Beck, R., Bernstein, A., Borisov, N., Braghieri, A., Briscoe, W. J., Cherepnya, S., Collicott, C., Costanza, S., Denig, A., Dieterle, M., Downie, E. J., Fil'kov, L. V., Garni, S., Glazier, D. I., Gradl, W., Gurevich, G., Barrientos, P. Hall, Hamilton, D., Hornidge, D., Howdle, D., Huber, G. M., Jude, T. C., Kaeser, A., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Krusche, B., Lazarev, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Mancell, J., Manley, D. M., Meyer, W., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Neganov, A., Nikolaev, A., Oberle, M., Spina, H. Ortega, Ostrick, M., Ott, P., Otte, P. B., Oussena, B., Pedroni, P., Polonski, A., Polyansky, V., Prakhov, S., Rajabi, A., Reicherz, G., Rostomyan, T., Sarty, A., Schrauf, S., Schumann, S., Sikora, M. H., Starostin, A., Steffen, O., Strakovsky, I. I., Strub, T., Supek, I., Thiel, M., Tiator, L., Thomas, A., Unverzagt, M., Usov, Y., Watts, D. P., Witthauer, L., Werthmüller, D., and Wolfes, M.
Subjects: Nuclear Experiment
Abstract: The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to measure the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the $\Delta(1232)$ region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields $\gamma_{E1E1} = -3.5 \pm 1.2$, $\gamma_{M1M1}= 3.16 \pm 0.85$, $\gamma_{E1M2} = -0.7 \pm 1.2$, and $\gamma_{M1E2} = 1.99 \pm 0.29$, in units of $10^{-4}$ fm$^4$., Comment: 5 pages, 3 figures, 2 tables
Published: 2014
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167. Quasifree photoproduction of $\eta$ mesons off protons and neutrons

Author: A2 Collaboration, Werthmüller, D., Witthauer, L., Keshelashvili, I., Aguar-Bartolomé, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Costanza, S., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Hamilton, D., Heid, E., Hornidge, D., Howdle, D., Huber, G. M., Jaegle, I., Jahn, O., Jude, T. C., Käser, A., Kashevarov, V. L., Kondratiev, R., Korolija, M., Kruglov, S. P., Krusche, B., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancell, J., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McNicoll, E. F., Metag, V., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Oberle, M., Ostrick, M., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S. N., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., and Watts, D. P.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract: Differential and total cross sections for the quasifree reactions $\gamma p\rightarrow\eta p$ and $\gamma n\rightarrow\eta n$ have been determined at the MAMI-C electron accelerator using a liquid deuterium target. Photons were produced via bremsstrahlung from the 1.5 GeV incident electron beam and energy-tagged with the Glasgow photon tagger. Decay photons of the neutral decay modes $\eta\rightarrow 2\gamma$ and $\eta\rightarrow 3\pi^0 \rightarrow 6\gamma$ and coincident recoil nucleons were detected in a combined setup of the Crystal Ball and the TAPS calorimeters. The $\eta$-production cross sections were measured in coincidence with recoil protons, recoil neutrons, and in an inclusive mode without a condition on recoil nucleons, which allowed a check of the internal consistency of the data. The effects from nuclear Fermi motion were removed by a kinematic reconstruction of the final-state invariant mass and possible nuclear effects on the quasifree cross section were investigated by a comparison of free and quasifree proton data. The results, which represent a significant improvement in statistical quality compared to previous measurements, agree with the known neutron-to-proton cross-section ratio in the peak of the $S_{11}(1535)$ resonance and confirm a peak in the neutron cross section, which is absent for the proton, at a center-of-mass energy $W = (1670\pm 5)$ MeV with an intrinsic width of $\Gamma\approx 30$ MeV.
Published: 2014
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168. Photoproduction of the $\omega$ meson off the proton near threshold

Author: Strakovsky, I. I., Prakhov, S., Azimov, Y. I., Aguar-Bartolome, P., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Berghaeuser, H., Braghieri, A., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Collicott, C., Costanza, S., Demissie, B. T., Downie, E. J., Drexler, P., Fil'kov, L. V., Glazier, D. I., Gregor, R., Hamilton, D. J., Heid, E., Hornidge, D., Jaegle, I., Jahn, O., Jude, T. C., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Kotulla, M., Koulbardis, A., Kruglov, S., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Manley, D. M., Marinides, Z., McGeorge, J. C., McNicoll, E. F., Mekterovic, D., Metag, V., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ortega, H., Ostrick, M., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Starostin, A., Supek, I., Taragin, M. F., Tarbert, C. M., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmueller, D., and Zehr, F.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: An experimental study of $\omega$ photoproduction on the proton was conducted by using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. The $\gamma p\to\omega p$ differential cross sections are measured from threshold to the incident-photon energy $E_\gamma=1.40$ GeV ($W=1.87$ GeV for the center-of-mass energy) with 15-MeV binning in $E_\gamma$ and full production-angle coverage. The quality of the present data near threshold gives access to a variety of interesting physics aspects. As an example, an estimation of the $\omega N$ scattering length $\alpha_{\omega p}$ is provided., Comment: 8 pages, 5 figures. Published version; some typos were fixed
Published: 2014
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169. Induced polarization of {\Lambda}(1116) in kaon electroproduction

Author: Gabrielyan, M., Raue, B. A., Carman, D. S., Park, K., Adhikari, K. P., Adikaram, D., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Baturin, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, T., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., DAngelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Garillon, B., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lenisa, P., Levine, W. I., Livingston, K., MacGregor, I. J. D., Mayer, M., McKinnon, B., Meyer, C. A., Mestayer, M. D., Mirazita, M., Mokeev, V., Moody, C. I., Moutarde, H., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Peng, P., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Rimal, D., Ripani, M., Rizzo, A., Sabatie, F., Salgado, C., Schott, D., Schumacher, R. A., Simonyan, A., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sytnik, V., Tang, W., Ungaro, M., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., Zana, L., and Zhang, J.
Subjects: Nuclear Experiment
Abstract: We have measured the induced polarization of the ${\Lambda}(1116)$ in the reaction $ep\rightarrow e'K^+{\Lambda}$, detecting the scattered $e'$ and $K^+$ in the final state along with the proton from the decay $\Lambda\rightarrow p\pi^-$.The present study used the CEBAF Large Acceptance Spectrometer (CLAS), which allowed for a large kinematic acceptance in invariant energy $W$ ($1.6\leq W \leq 2.7$ GeV) and covered the full range of the kaon production angle at an average momentum transfer $Q^2=1.90$ GeV$^2$.In this experiment a 5.50 GeV electron beam was incident upon an unpolarized liquid-hydrogen target. We have mapped out the $W$ and kaon production angle dependencies of the induced polarization and found striking differences from photoproduction data over most of the kinematic range studied. However, we also found that the induced polarization is essentially $Q^2$ independent in our kinematic domain, suggesting that somewhere below the $Q^2$ covered here there must be a strong $Q^2$ dependence. Along with previously published photo- and electroproduction cross sections and polarization observables, these data are needed for the development of models, such as effective field theories, and as input to coupled-channel analyses that can provide evidence of previously unobserved $s$-channel resonances., Comment: 13 figures
Published: 2014
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170. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

Author: BDX Collaboration, Battaglieri, M., Celentano, A., De Vita, R., Izaguirre, E., Krnjaic, G., Smith, E., Stepanyan, S., Bersani, A., Fanchini, E., Fegan, S., Musico, P., Osipenko, M., Ripani, M., Santopinto, E., Taiuti, M., Schuster, P., Toro, N., Dalton, M., Freyberger, A., Girod, F. -X., Kubarovsky, V., Ungaro, M., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Nappi, E., Perrino, R., Carpinelli, M., Sipala, V., Aiello, S., Bellini, V., De Napoli, M., Giusa, A., Mammoliti, F., Leonora, E., Noto, F., Randazzo, N., Russo, G., Sperduto, M., Sutera, C., Ventura, C., Barion, L., Ciullo, G., Contalbrigo, M., Lenisa, P., Movsisyan, A., Spizzo, F., Turisini, M., De Persio, F., Cisbani, E., Fanelli, C., Garibaldi, F., Meddi, F., Urciuoli, G. M., Pereira, S. Anefalos, De Sanctis, E., Hasch, D., Lucherini, V., Mirazita, M., Montgomery, R., Pisano, S., Simi, G., D'Angelo, A., Lanza, L. Colaneri L., Rizzo, A., Schaerf, C., Zonta, I., Calvo, D., Filippi, A., Holtrop, M., Peremuzyan, R., Glazier, D., Ireland, D., McKinnon, B., Afanasev, D. Sokhan A., Briscoe, B., Kalantarians, N., Fassi, L. El, Weinstein, L., Beltrame, P., Murphy, A., Watts, D., Zana, L., and Hicks, K.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This Letter of Intent presents the MeV-GeV DM discovery potential for a 1 m$^3$ segmented plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls, receiving up to 10$^{22}$ electrons-on-target (EOT) in a one-year period. This experiment (Beam-Dump eXperiment or BDX) is sensitive to DM-nucleon elastic scattering at the level of a thousand counts per year, with very low threshold recoil energies ($\sim$1 MeV), and limited only by reducible cosmogenic backgrounds. Sensitivity to DM-electron elastic scattering and/or inelastic DM would be below 10 counts per year after requiring all electromagnetic showers in the detector to exceed a few-hundred MeV, which dramatically reduces or altogether eliminates all backgrounds. Detailed Monte Carlo simulations are in progress to finalize the detector design and experimental set up. An existing 0.036 m$^3$ prototype based on the same technology will be used to validate simulations with background rate estimates, driving the necessary R$\&$D towards an optimized detector. The final detector design and experimental set up will be presented in a full proposal to be submitted to the next JLab PAC. A fully realized experiment would be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments by two orders of magnitude in the MeV-GeV DM mass range., Comment: 28 pages, 17 figures, submitted to JLab PAC 42
Published: 2014

171. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

Author: Nefkens, B. M. K., Prakhov, S., Aguar-Bartolomé, P., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Berghäuser, H., Braghieri, A., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Collicott, C., Costanza, S., Danilkin, I. V., Denig, A., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Garni, S., Glazier, D. I., Gregor, R., Hamilton, D., Heid, E., Hornidge, D., Howdle, D., Jahn, O., Jude, T. C., Kashevarov, V. L., Käser, A., Keshelashvili, I., Kondratiev, R., Korolija, M., Kotulla, M., Koulbardis, A., Kruglov, S., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancel, J., Manley, D. M., McNicoll, E. F., Mekterovic, D., Metag, V., Mushkarenkov, A., Nikolaev, A., Novotny, R., Oberle, M., Ortega, H., Ostrick, M., Ott, P., Otte, P. B., Oussena, B., Pedroni, P., Polonski, A., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Starostin, A., Strakovsky, I. I., Strub, T., Suarez, I. M., Supek, I., Tarbert, C. M., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmüller, D., and Witthauer., L.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence., Comment: 10 pages, 8 figures, 1 table
Published: 2014
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172. Exclusive ${\pi}^0$ electroproduction at $W>2$ GeV with CLAS

Author: Bedlinskiy, I., Kubarovsky, V., Niccolai, S., Stoler, P., Adhikari, K. P., Anderson, M. D., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Biselli, A. S., Boiarinov, S., Bono, J., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Garillon, B., Garçon, M., Gavalian, G., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guegan, B., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kuhn, S. E., Kuleshov, S. V., Lenisa, P., Levine, W. I., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McKinnon, B., Mirazita, M., Mokeev, V., Montgomery, R. A., Moody, C. I., Moutarde, H., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Park, K., Park, S., Pasyuk, E., Phelps, E., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Procureur, S., Puckett, A. J. R., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Senderovich, I., Sharabian, Y. G., Simonyan, A., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Strauch, S., Sytnik, V., Tang, W., Tian, Ye, Ungaro, M., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D., Wei, X., Weinstein, L. B., Yurov, M., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Exclusive neutral-pion electroproduction ($ep\to e^\prime p^\prime \pi^0$) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\pi$ and structure functions $\sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$ as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. The data are compared with Regge and handbag theoretical calculations. Analyses in both frameworks find that a large dominance of transverse processes is necessary to explain the experimental results. For the Regge analysis it is found that the inclusion of vector meson rescattering processes is necessary to bring the magnitude of the calculated and measured structure functions into rough agreement. In the handbag framework, there are two independent calculations, both of which appear to roughly explain the magnitude of the structure functions in terms of transversity generalized parton distributions., Comment: 28 pages, 25 figures, Submitted to Phys. Rev. C
Published: 2014
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173. Precision measurements of $g_1$ of the proton and the deuteron with 6 GeV electrons

Author: Prok, Y., Bosted, P., Kvaltine, N., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Biselli, A. S., Bono, J., Briscoe, W. J., Brock, J., Brooks, W. K., Bültmann, S., Burkert, V. D., Carlin, C., Carman, D. S., Celentano, A., Chandavar, S., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crabb, D., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Forest, T. A., Garcon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Giovanetti, K. L., Goetz, J. T., Gohn, W., Gothe, R. W., Griffioen, K. A., Guegan, B., Guler, N., Haffidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jawalkar, S., Jiang, X., Jo, H. S., Joo, K., Kalantarians, N., Keith, C., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J. D., Markov, N., Mayee, M., McKinnon, B., Meekins, D., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Peng, P., Phillips, J. J., Pierce, J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Rimal, D., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Smith, C., Smith, G., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Tang, W., Tkachenko, S., Ungaro, M., Vernarsky, B ., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D . P., Weinstein, L. B., Zachariou, N., Zana, L., Zhang, J., Zhao, B., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: The inclusive polarized structure functions of the proton and deuteron, g1p and g1d, were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory. Electrons scattered at lab angles between 18 and 45 degrees were detected using the CEBAF Large Acceptance Spectrometer (CLAS). For the usual DIS kinematics, Q^2>1 GeV^2 and the final-state invariant mass W>2 GeV, the ratio of polarized to unpolarized structure functions g1/F1 is found to be nearly independent of Q^2 at fixed x. Significant resonant structure is apparent at values of W up to 2.3 GeV. In the framework of perturbative QCD, the high-W results can be used to better constrain the polarization of quarks and gluons in the nucleon, as well as high-twist contributions.
Published: 2014
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174. Photoproduction of pi0-mesons off neutrons in the nucleon resonance region

Author: Dieterle, M., Keshelashvili, I., Ahrens, J., Annand, J. R. M., Arends, H. J., Bantawa, K., Bartolome, P. A., Beck, R., Bekrenev, V., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Demissie, B., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Hamilton, D., Heid, E., Hornidge, D., Howdle, D., Huber, G. M., Jaegle, I., Jahn, O., Jude, T. C., Kaeser, A., Kashevarov, V. L., Kondratiev, R., Korolija, M., Kruglov, S. P., Krusche, B., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancell, J., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McNicoll, E., Mekterovic, D., Metag, V., Micanovic, S., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Oberle, M., Ostrick, M., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S. N., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmueller, D., and Witthauer, L.
Subjects: Nuclear Experiment
Abstract: Precise angular distributions have been measured for the first time for the photoproduction of $\pi^{0}$-mesons off neutrons bound in the deuteron. The effects from nuclear Fermi motion have been eliminated by a complete kinematic reconstruction of the final state. The influence of final-state-interaction effects has been estimated by a comparison of the reaction cross section for quasi-free protons bound in the deuteron to the results for free protons and then applied as a correction to the quasi-free neutron data. The experiment was performed at the tagged photon facility of the Mainz Microtron MAMI with the Crystal Ball and TAPS detector setup for incident photon energies between $0.45$~GeV and $1.4$~GeV. The results are compared to the predictions from reaction models and partial-wave analyses based on data from other isospin channels. The model predictions show large discrepancies among each other and the present data will provide much tighter constraints. This is demonstrated by the results of a new analysis in the framework of the Bonn-Gatchina coupled-channel analysis which included the present data., Comment: accepted for publication in Phys; Rev. Lett
Published: 2014
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175. Measurement of the beam-helicity asymmetry $I^{\odot}$ in the photoproduction of $\pi^0\pi^{\pm}$-pairs off protons and off neutrons

Author: Oberle, M., Ahrens, J., Annand, J. R. M., Arends, H. J., Bantawa, K., Bartolome, P. A., Beck, R., Bekrenev, V., Berghaeuser, H., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Heid, E., Hornidge, D., Howdle, D., Huber, G. M., Jahn, O., Jaegle, I., Jude, T. C., Kaeser, A., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Kruglov, S. P., Krusche, B., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancell, J., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McNicoll, E., Mekterovic, D., Metag, V., Micanovic, S., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ostrick, M., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S. N., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D. I., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmueller, D., Witthauer, L., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz for the photoproduction of mixed-charge pion pairs in the reactions $\boldsymbol{\gamma}p\rightarrow n\pi^0\pi^+$ off free protons and $\boldsymbol{\gamma}d\rightarrow (p)p\pi^0\pi^-$ and $\boldsymbol{\gamma}d\rightarrow (n)n\pi^0\pi^+$ off quasi-free nucleons bound in the deuteron for incident photon energies up to 1.4 GeV. Circularly polarized photons were produced from bremsstrahlung of longitudinally polarized electrons and tagged with the Glasgow-Mainz magnetic spectrometer. The charged pions, recoil protons, recoil neutrons, and decay photons from $\pi^0$ mesons were detected in the 4$\pi$ electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. Using a complete kinematic reconstruction of the final state, excellent agreement was found between the results for free and quasi-free protons, suggesting that the quasi-free neutron results are also a close approximation of the free-neutron asymmetries. A comparison of the results to the predictions of the Two-Pion-MAID reaction model shows that the reaction mechanisms are still not well understood, in particular at low incident photon energies in the second nucleon-resonance region., Comment: accepted for publication in Eur. phys. J. A
Published: 2014
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176. Measurement of the structure function of the nearly free neutron using spectator tagging in inelastic $^2$H(e, e'p)X scattering with CLAS

Author: Tkachenko, S., Baillie, N., Kuhn, S. E., Zhang, J., Arrington, J., Bosted, P., Bültmann, S., Christy, M. E., Dutta, D., Ent, R., Fenker, H., Griffioen, K. A., Ispiryan, M., Kalantarians, N., Keppel, C. E., Melnitchouk, W., Tvaskis, V., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fleming, J. A., Garillon, B., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Golovatch, E., Gothe, R. W., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hyde, C . E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jo, H. S., Keller, D., Khandaker, M., Kim, A., Kim, W., King, P. M., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuleshov, S. V., Lenisa, P., Lewis, S., Livingston, K., Lu, H., MacCormick, M., MacGregor, I. J. D., Markov, N., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J . R., Rimal, D., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Schott, D., Schumacher, R. A., Seder, E., Senderovich, I., Sharabian, Y. G., Simonyan, A., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S., Stepanyan, S. S., Strauch, S., Tang, W., Ungaro, M., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D., Wei, X., Weinstein, L. B., Wood, M. H., Zana, L., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: Much less is known about neutron structure than that of the proton due to the absence of free neutron targets. Neutron information is usually extracted from data on nuclear targets such as deuterium, requiring corrections for nuclear binding and nucleon off-shell effects. These corrections are model dependent and have significant uncertainties, especially for large values of the Bjorken scaling variable x. The Barely Off-shell Nucleon Structure (BONuS) experiment at Jefferson Lab measured the inelastic electron deuteron scattering cross section, tagging spectator protons in coincidence with the scattered electrons. This method reduces nuclear binding uncertainties significantly and has allowed for the first time a (nearly) model independent extraction of the neutron structure function. A novel compact radial time projection chamber was built to detect protons with momentum between 70 and 150 MeV/c. For the extraction of the free neutron structure function $F_{2n}$, spectator protons at backward angle and with momenta below 100 MeV/c were selected, ensuring that the scattering took place on a nearly free neutron. The scattered electrons were detected with Jefferson Lab's CLAS spectrometer. The extracted neutron structure function $F_{2n}$ and its ratio to the deuteron structure function $F_{2d}$ are presented in both the resonance and deep inelastic regions. The dependence of the cross section on the spectator proton momentum and angle is investigated, and tests of the spectator mechanism for different kinematics are performed. Our data set can be used to study neutron resonance excitations, test quark hadron duality in the neutron, develop more precise parametrizations of structure functions, as well as investigate binding effects (including possible mechanisms for the nuclear EMC effect) and provide a first glimpse of the asymptotic behavior of d/u as x goes to 1., Comment: 28 pages, 22 figures; published in Phys. Rev. C. Revised to include three authors inadvertently left off the original version: D. Dutta, R. Ent, and M. Ispiryan
Published: 2014
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177. CCR5 Expression Levels in HIV-Uninfected Women Receiving Hormonal Contraception

Author: Sciaranghella, Gaia, Wang, Cuiwei, Hu, Haihong, Anastos, Kathryn, Merhi, Zaher, Nowicki, Marek, Stanczyk, Frank Z, Greenblatt, Ruth M, Cohen, Mardge, Golub, Elizabeth T, Watts, D Heather, Alter, Galit, Young, Mary A, and Tsibris, Athe MN
Subjects: Medical Microbiology, Reproductive Medicine, Biomedical and Clinical Sciences, Immunology, Infectious Diseases, HIV/AIDS, Prevention, Contraception/Reproduction, Sexually Transmitted Infections, Good Health and Well Being, Adult, CD4-Positive T-Lymphocytes, CD8-Positive T-Lymphocytes, Contraception, Contraceptives, Oral, Combined, Educational Status, Female, HIV Seronegativity, Humans, Levonorgestrel, Medroxyprogesterone Acetate, Receptors, CCR5, Receptors, CXCR4, T-Lymphocyte Subsets, HIV-1, hormonal contraception, CCR5, medroxyprogesterone acetate, levonorgestrel, oral contraceptive pills, peripheral blood mononuclear cells, CD4, CXCR4, Biological Sciences, Medical and Health Sciences, Microbiology, Biological sciences, Biomedical and clinical sciences, Health sciences
Abstract: Human immunodeficiency virus (HIV) infectivity increases as receptor/coreceptor expression levels increase. We determined peripheral CD4, CCR5, and CXCR4 expression levels in HIV-uninfected women who used depot medroxyprogesterone acetate (DMPA; n = 32), the levonorgestrel-releasing intrauterine device (LNG-IUD; n = 27), oral contraceptive pills (n = 32), or no hormonal contraception (n = 33). The use of LNG-IUD increased the proportion of CD4(+) and CD8(+) T cells that expressed CCR5; increases in the magnitude of T-cell subset CCR5 expression were observed with DMPA and LNG-IUD use (P < .01 for all comparisons). LNG-IUD and, to a lesser extent, DMPA use were associated with increased peripheral T-cell CCR5 expression.
Published: 2015

178. Depot Medroxyprogesterone Acetate in Combination with a Twice-Daily Lopinavir-Ritonavir-Based Regimen in HIV-Infected Women Showed Effective Contraception and a Lack of Clinically Significant Interactions, with Good Safety and Tolerability: Results of the ACTG 5283 Study

Author: Luque, Amneris E, Cohn, Susan E, Park, Jeong-Gun, Cramer, Yoninah, Weinberg, Adriana, Livingston, Elizabeth, Klingman, Karin L, Aweeka, Francesca, and Watts, D Heather
Subjects: Medical Microbiology, Biomedical and Clinical Sciences, Clinical Research, HIV/AIDS, Sexually Transmitted Infections, Contraception/Reproduction, Infectious Diseases, 6.1 Pharmaceuticals, 5.1 Pharmaceuticals, Infection, Good Health and Well Being, Adolescent, Contraceptives, Oral, Synthetic, Delayed-Action Preparations, Drug Interactions, Female, HIV Infections, HIV Protease Inhibitors, Humans, Lopinavir, Medroxyprogesterone Acetate, Middle Aged, Ovulation, Progesterone, Ritonavir, Young Adult, Microbiology, Pharmacology and Pharmaceutical Sciences, Medical microbiology, Pharmacology and pharmaceutical sciences
Abstract: We conducted an open-label, steady-state pharmacokinetic (PK) study of drug-drug interactions between depot medroxyprogesterone acetate (DMPA) and twice-daily lopinavir (LPV) plus low-dose ritonavir (RTV) (LPV/r) among 24 HIV-infected women and compared the results to those for HIV-infected women receiving DMPA while on no antiretroviral therapy or on nucleosides only (n = 14 subjects from the control arm of AIDS Clinical Trials Group [ACTG] study 5093). The objectives of the study were to address the effect of LPV/r on DMPA and to address the effect of DMPA on LPV/r therapy. PK parameters were estimated using noncompartmental analysis with between-group comparisons of medroxyprogesterone acetate (MPA) PKs and within-subject comparisons of LPV and RTV PKs before and 4 weeks after DMPA dosing. Plasma progesterone concentrations were measured every 2 weeks after DMPA dosing through week 12. Although the MPA area under the concentration-time curve and maximum concentration of drug in plasma were statistically significantly increased in the study women on LPV/r compared to those in the historical controls, these increases were not considered clinically significant. There were no changes in LPV or RTV exposure after DMPA. DMPA was well tolerated, and suppression of ovulation was maintained. (This study has been registered at ClinicalTrials.gov under registration no. NCT01296152.).
Published: 2015

179. Quasi-free photoproduction of eta-mesons off 3He nuclei

Author: Witthauer, L., Werthmueller, D., Keshelashvili, I., Aguar-Bartolome, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Hamilton, D., Heid, E., Hornidge, D., Howdle, D., Huber, G. M., Jaegle, I., Jahn, O., Jude, T. C., Kaeser, A., Kashevarov, V. L., Kondratiev, R., Korolija, M., Kruglov, S. P., Krusche, B., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancell, J., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McNicoll, E., Metag, V., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Oberle, M., Ostrick, M., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Robinson, J., Rosner, G., Rost, M., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., and Watts, D. P.
Subjects: Nuclear Experiment
Abstract: Quasi-free photoproduction of $\eta$-mesons has been measured off nucleons bound in $^3$He nuclei for incident photon energies from the threshold region up to 1.4 GeV. The experiment was performed at the tagged photon facility of the Mainz MAMI accelerator with an almost $4\pi$ covering electromagnetic calorimeter, combining the TAPS and Crystal Ball detectors. The $\eta$-mesons were detected in coincidence with the recoil nucleons. This allowed a comparison of the production cross section off quasi-free protons and quasi-free neutrons and a full kinematic reconstruction of the final state, eliminating effects from nuclear Fermi motion. In the $S_{11}$(1535) resonance peak, the data agree with the neutron/proton cross section ratio extracted from measurements with deuteron targets. More importantly, the prominent structure observed in photoproduction off quasi-free neutrons bound in the deuteron is also clearly observed. Its parameters (width, strength) are consistent with the expectations from the deuteron results. On an absolute scale the cross sections for both quasi-free protons and neutrons are suppressed with respect to the deuteron target pointing to significant nuclear final state interaction effects., Comment: accepted for publication in Eur. Phys. J. A
Published: 2013
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180. A narrow structure in the excitation function of eta-photoproduction off the neutron

Author: Werthmueller, D., Witthauer, L., Keshelashvili, I., Aguar-Bartolome, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Hamilton, D., Heid, E., Hornidge, D., Howdle, D., Huber, G. M., Jaegle, I., Jahn, O., Jude, T. C., Kaeser, A., Kashevarov, V. L., Kondratiev, R., Korolija, M., Kruglov, S. P., Krusche, B., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancell, J., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McNicoll, E. F., Metag, V., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Oberle, M., Ostrick, M., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S. N., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., and Watts, D. P.
Subjects: Nuclear Experiment
Abstract: The photoproduction of $\eta$-mesons off nucleons bound in $^2$H and $^3$He has been measured in coincidence with recoil protons and recoil neutrons for incident photon energies from threshold up to 1.4 GeV. The experiments were performed at the Mainz MAMI accelerator, using the Glasgow tagged photon facility. Decay photons from the $\eta\rightarrow 2\gamma$ and $\eta\rightarrow 3\pi^0$ decays and the recoil nucleons were detected with an almost $4\pi$ electromagnetic calorimeter combining the Crystal Ball and TAPS detectors. The data from both targets are of excellent statistical quality and show a narrow structure in the excitation function of $\gamma n\rightarrow n\eta$. The results from the two measurements are consistent taking into account the expected effects from nuclear Fermi motion. The best estimates for position and intrinsic width of the structure are $W$ = (1670$\pm$5) MeV and $\Gamma$ =(30$\pm$15) MeV. For the first time precise results for the angular dependence of this structure have been extracted., Comment: Accepted for publication in Phys. Rev. Lett
Published: 2013
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181. Neutron skin of $^{208}$Pb from Coherent Pion Photoproduction

Author: Tarbert, C. M., Watts, D. P., Glazier, D. I., Aguar, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R., Downie, E. J., Foehl, K., Grabmayr, P., Gregor, R., Heid, E., Hornidge, D., Jahn, O., Kashevarov, V. L., Knezevic, A., Kondratiev, R., Korolija, M., Kotulla, M., Krambrich, D., Krusche, B., Lang, M., Lisin, V., Livingston, K., Lugert, S., MacGregor, I. J. D., Manley, D. M., Martinez, M., McGeorge, J. C., Mekterovic, D., Metag, V., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Owens, R. O., Pedroni, P., Polonski, A., Prakhov, S. N., Price, J. W., Rosner, G., Rost, M., Rostomyan, T., Schadmand, S., Schumann, S., Sober, D., Starostin, A., Supek, I., Thomas, A., Unverzagt, M., Walcher, Th., and Zehr, F.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: Information on the size and shape of the neutron skin on $^{208}$Pb has been extracted from coherent pion photoproduction cross sections measured using the Crystal Ball together with the Glasgow tagger at the MAMI electron beam facility. On exploitation of an interpolated fit of a theoretical model to the measured cross sections the half-height radius and diffuseness of the neutron distribution are found to be 6.70$\pm 0.03(stat)$ fm and 0.55$\pm 0.01(stat)$$^{+0.02}_{-0.03}(sys)$ fm respectively, corresponding to a neutron skin thickness $\Delta r_{np}$=0.15$\pm 0.03(stat)$$^{+0.01}_{-0.03}(sys)$ fm. The results give the first successful extraction of a neutron skin with an electromagnetic probe and indicate the skin of $^{208}$Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron-rich matter., Comment: 4 figures 5 pages. Version submitted to journal. Includes additional studies of systematic effects in the extracted diffuseness, which led to a small increase in the quoted systematic error. These additional studies are discussed in the revised manuscript. Also includes minor editorial improvements to the text
Published: 2013
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182. Measurement of the $^{1}H$($\vec{\gamma}$, $\vec{p}$)$\pi^{0}$ reaction using a novel nucleon spin polarimeter

Author: Watts, D. P., Glazier, D. I., Aguar-Bartolomé, P., Akasoy, L. K., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V. S., Berghäuser, H., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Demissie, B. T., Downie, E. J., Drexler, P., Fil'kov, L. V., Freehart, B., Gregor, R., Hamilton, D., Heid, E., Hornidge, D., Jaegle, I., Jahn, O., Jude, T. C., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Kotulla, M., Koulbardis, A. A., Kruglov, S. P., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McKinnon, B., McNicoll, E. F., Mekterovic, D., Metag, V., Micanovic, S., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ostrick, M., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sober, D. I., Starostin, A., Strakovsky, I. I., Suarez, I. M., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Werthmüller, D., Workman, R. L., Zamboni, I., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon, pioneering a novel polarimetry technique with wide application to future nuclear and hadronic physics experiments. The commissioning measurement of polarization transfer in the $^{1}H$($\vec{\gamma}$,$\vec{p}$)$\pi^{0}$ reaction in the range $0.4
Published: 2013
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183. A new determination of the eta transition form factor in the Dalitz decay eta -> e^+ e^- gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

Author: Aguar-Bartolomé, P., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Berghäuser, H., Braghieri, A., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Collicott, C., Costanza, S., Denig, A., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Gregor, R., Hamilton, D. J., Heid, E., Hornidge, D., Isaksson, L., Jaegle, I., Jahn, O., Jude, T. C., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Kotulla, M., Koulbardis, A., Kruglov, S., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Manley, D. M., Masjuan, P., McGeorge, J. C., McNicoll, E. F., Mekterovic, D., Metag, V., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ortega, H., Ostrick, M., Ott, P., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D. I., Starostin, A., Strakovsky, I. I., Suarez, I. M., Supek, I., Tarbert, C. M., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmüller, D., and Zehr., F.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: The Dalitz decay eta -> e^+ e^- gamma has been measured in the gamma p -> eta p reaction with the Crystal Ball and TAPS multiphoton spectrometers, together with the photon tagging facility at the Mainz Microtron MAMI. The experimental statistic used in this work is one order of magnitude greater than in any previous measurement of eta -> e^+ e^- gamma. The value obtained for the slope parameter 1/Lambda^2 of the eta transition form factor, 1/Lambda^2 = (1.95 +/- 0.15_stat +/- 0.10_syst) [1/GeV^2], is in good agreement with recent measurements conducted in eta -> e^+ e^- gamma and eta -> mu^+ mu^- gamma decays, as well as with recent form-factor calculations. The uncertainty obtained in the value of 1/Lambda^2 is lower compared to results from previous measurements of the eta -> e^+ e^- gamma decay., Comment: 11 pages, 10 figures, 1 table
Published: 2013
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184. $K^+\Lambda$ and $K^+\Sigma^0$ photoproduction with fine center-of-mass energy resolution

Author: Jude, T. C., Glazier, D. I., Watts, D. P., Aguar-Bartolome, P., Akasoy, L. K., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V. S., Berghauser, H., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Demissie, B. T., Dieterle, M., Downie, E. J., Fil'kov, L. V., Gregor, R., Heid, E., Hornidge, D., Jaegle, I., Jahn, O., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Koulbardis, A. A., Kruglov, S. P., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Manley, D. M., Marinides, Z., Mart, T., Martinez, M., McGeorge, J. C., McNicoll, E. F., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Nikonov, V. A., Oberle, M., Ostrick, M., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Robinson, J., Rosner, G., Rostomyan, T., Sarantsev, A. V., Schumann, S., Sikora, M. H., Sober, D. I., Starostin, A., Strakovsky, I., Suarez, I. M., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Werthmueller, D., Witthauer, L., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: Measurements of $\gamma p \rightarrow K^{+} \Lambda$ and $\gamma p \rightarrow K^{+} \Sigma^0$ cross-sections have been obtained with the photon tagging facility and the Crystal Ball calorimeter at MAMI-C. The measurement uses a novel $K^+$ meson identification technique in which the weak decay products are characterized using the energy and timing characteristics of the energy deposit in the calorimeter, a method that has the potential to be applied at many other facilities. The fine center-of-mass energy ($W$) resolution and statistical accuracy of the new data results in a significant impact on partial wave analyses aiming to better establish the excitation spectrum of the nucleon. The new analyses disfavor a strong role for quark-diquark dynamics in the nucleon., Comment: 7 pages, 8 figures
Published: 2013
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185. Measurement of the g p -> K^0 Sigma^+ reaction with the Crystal Ball/TAPS detectors at the Mainz Microtron

Author: Aguar-Bartolomé, P., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Berghäuser, H., Braghieri, A., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Collicott, C., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Gregor, R., Hamilton, D., Heid, E., Hornidge, D., Howdle, D., Isaksson, L., Jaegle, I., Jahn, O., Jude, T. C., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Kotulla, M., Koulbardis, A., Kruglov, S., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancel, J., Manley, D. M., McNicoll, E. F., Mekterovic, D., Metag, V., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Oberle, M., Ortega, H., Ostrick, M., Ott, P., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D. I., Starostin, A., Strakovsky, I. I., Suarez, I. M., Supek, I., Tarbert, C. M., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmüller, D., Witthauer, L., and Zehr., F.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: The g p -> K^0 Sigma^+ reaction has been measured from threshold to Eg=1.45 GeV (W_cm=1.9 GeV) using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. In the present experiment, this reaction was searched for in the 3pi^0 p final state, by assuming K^0_S -> pi^0 pi^0 and Sigma^+ -> pi^0 p. The experimental results include total and differential cross sections as well as the polarization of the recoil hyperon. The new data significantly improve empirical knowledge about the g p -> K^0 Sigma^+ reaction in the measured energy range. The results are compared to previous measurements and model predictions. It is demonstrated that adding the present g p -> K^0 Sigma^+ results to existing data allowed a better description of this reaction with various models., Comment: 12 pages, 10 figures, 4 tables
Published: 2013
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186. Double pion photoproduction off nuclei - are there effects beyond final-state interaction?

Author: Maghrbi, Y., Gregor, R., Lugert, S., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R., Downie, E. J., Dexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Heid, E., Hornidge, D., Jahn, O., Jaegle, I., Kashevarov, V. L., Keshelashvili, I., Knezevic, A., Kondratiev, A., Korolija, M., Kotulla, M., Krambrich, D., Krusche, B., Lang, M., Lisin, V., Livingston, K., MacGregor, I. J. D., Manley, D. M., Martinez, M., McGeorge, J. C., Mekterovic, D., Metag, V., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ostrick, M., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S. N., Price, J. W., Rosner, G., Rost, M., Rostomyan, T., Schadmand, S., Schumann, S., Sober, D., Starostin, S., Supek, I., Thomas, A., Unverzagt, M., Watts, D. P., Werthmueller, D., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: Photoproduction of $\pi^{0}\pi^{0}$ and $\pi^{0}\pi^{\pm}$ pairs from nuclei has been measured over a wide mass range ($^2$H, $^{7}$Li, $^{12}$C, $^{40}$Ca, and $^{\rm nat}$Pb) for photon energies from threshold to 600 MeV. The experiments were performed at the MAMI accelerator in Mainz, using the Glasgow photon tagging spectrometer and a 4$\pi$ electromagnetic calorimeter consisting of the Crystal Ball and TAPS detectors. A shift of the pion-pion invariant mass spectra for heavy nuclei to small invariant masses has been observed for $\pi^0$ pairs but also for the mixed-charge pairs. The precise results allow for the first time a model-independent analysis of the influence of pion final-state interactions. The corresponding effects are found to be large and must be carefully considered in the search for possible in-medium modifications of the $\sigma$-meson. Results from a transport model calculation reproduce the shape of the invariant-mass distributions for the mixed-charge pairs better than for the neutral pairs, but also for the latter differences between model results and experiment are not large, leaving not much room for $\sigma$-in-medium modification., Comment: accepted for publication in Phys. Lett. B
Published: 2013
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187. Measurement of the beam-helicity asymmetry $I^{\odot}$ in the photoproduction of $\pi^0$-pairs off the proton and off the neutron

Author: Oberle, M., Krusche, B., Ahrens, J., Annand, J. R. M., Arends, H. J., Bantawa, K., Bartolome, P. A., Beck, R., Bekrenev, V., Berghaeuser, H., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Heid, E., Hornidge, D., Howdle, D., Huber, G. M., Jahn, O., Jaegle, I., Jude, T. C., Kaeser, A., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Kruglov, S. P., Kulbardis, A., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancell, J., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McNicoll, E., Mekterovic, D., Metag, V., Micanovic, S., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ostrick, M., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S. N., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D. I., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmueller, D., Witthauer, L., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz for the photoproduction of neutral pion pairs in the reactions $\vec{\gamma}p\rightarrow p\pi^0\pi^0$ and $\vec{\gamma}d\rightarrow (n)p\pi^0\pi^0$, $\vec{\gamma}d\rightarrow (p)n\pi^0\pi^0$ off free protons and off quasi-free nucleons bound in the deuteron for incident photon energies up to 1.4 GeV. Circularly polarized photons were produced from bremsstrahlung of longitudinally polarized electrons and tagged with the Glasgow magnetic spectrometer. Decay photons from the $\pi^0$ mesons, recoil protons, and recoil neutrons were detected in the 4$\pi$ covering electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. After kinematic reconstruction of the final state, excellent agreement was found between the results for free and quasi-free protons. This demonstrates that the free-nucleon behavior of such observables can be extracted from measurements with quasi-free nucleons, which is the only possibility for the neutron. Contrary to expectations, the measured asymmetries are very similar for reactions off protons and neutrons. The results are compared to the predictions from the Two-Pion-MAID reaction model and (for the proton) also to the Bonn-Gatchina coupled channel analysis., Comment: accepted for publication in Phys. Lett. B
Published: 2013
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188. Hard Two-body Photodisintegration of 3He

Author: Pomerantz, I., Ilieva, Y., Gilman, R., Higinbotham, D. W., Piasetzky, E., Strauch, S., Adhikari, K. P., Aghasyan, M., Allada, K., Amaryan, M. J., Pereira, S. Anefalos, Anghinolfi, M., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Beck, A., Beck, S., Bedlinskiy, I., Berman, B. L., Biselli, A. S., Boeglin, W., Bono, J., Bookwalter, C., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bubis, N., Burkert, V., Camsonne, A., Canan, M., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chirapatpimol, K., Cisbani, E., Cole, P. L., Contalbrigo, M., Crede, V., Cusanno, F., D'Angelo, A., Daniel, A., Dashyan, N., de Jager, C. W., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Dutta, C., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Fradi, A., Garibaldi, F., Geagla, O., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Glister, J., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jiang, X., Jo, H. S., Joo, K., Katramatou, A. T., Keller, D., Khandaker, M., Khetarpal, P., Khrosinkova, E., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuleshov, S. V., Kvaltine, N. D., Lee, B., LeRose, J. J., Lewis, S., Lindgren, R., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Martinez, D., Mayer, M., McCullough, E., McKinnon, B., Meekins, D., Meyer, C. A., Michaels, R., Mineeva, T., Mirazita, M., Moffit, B., Mokeev, V., Montgomery, R. A., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., Nepali, C. S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Petratos, G. G., Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Procureur, S., Protopopescu, D., Puckett, A. J. R., Qian, X., Qiang, Y., Ricco, G., Rimal, D., Ripani, M., Ritchie, B. G., Rodriguez, I., Ron, G., Rosner, G., Rossi, P., Sabatie, F., Saha, A., Saini, M. S., Sarty, A. J., Sawatzky, B., Saylor, N. A., Schott, D., Schulte, E., Schumacher, R. A., Seder, E., Seraydaryan, H., Shneor, R., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S. S., Stepanyan, S., Stoler, P., Subedi, R., Sulkosky, V., Taiuti, M., Tang, W., Taylor, C. E., Tkachenko, S., Ungaro, M., Vernarsky, B., Vineyard, M. F., Voskanyan, H., Voutier, E., Walford, N. K., Wang, Y., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wojtsekhowski, B., Wood, M. H., Yan, X., Yao, H., Zachariou, N., Zhan, X., Zhang, J., Zhao, Z. W., Zheng, X., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: We have measured cross sections for the gamma+3He->p+d reaction at photon energies of 0.4 - 1.4 GeV and a center-of-mass angle of 90 deg. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.
Published: 2013
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189. Coherent photoproduction of pi^0- and eta-mesons off 7Li

Author: Maghrbi, Y., Krusche, B., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Downie, E. J., Drexler, P., Fil'kov, L. V., Fix, A., Glazier, D. I., Gregor, R., Heid, E., Hornidge, D., Jaegle, I., Jahn, O., Kashevarov, V. L., Keshelashvili, I., Knezevic, A., Kondratiev, R., Korolija, M., Krambrich, D., Lang, M., Lisin, V., Livingston, K., Lugert, S., MacGregor, I. J. D., Manley, D. M., Martinez, M., McGeorge, J. C., Mekterovic, D., Metag, V., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ostrick, M., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Price, J. W., Rosner, G., Rost, M., Rostomyan, T., Schadmand, S., Schumann, S., Sober, D., Starostin, A., Supek, I., Tarbert, C. M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmueller, D., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: Coherent photoproduction of $\pi^0$-mesons from threshold ($E_{th} \approx$ 136 MeV) throughout the $\Delta$-resonance region and of $\eta$-mesons close to the production threshold ($E_{th} \approx$ 570 MeV for $\eta$) has been measured for $^7$Li nuclei. The experiment was performed using the tagged-photon beam of the Mainz MAMI accelerator with the Crystal Ball and TAPS detectors combined to give an almost 4$\pi$ solid-angle electromagnetic calorimeter. The reactions were identified by a combined invariant-mass and missing-energy analysis. A comparison of the pion data to plane-wave impulse modelling tests the nuclear mass form factor. So far coherent $\eta$-production had been only identified for the lightest nuclear systems ($^2$H and $^3$He). For $^3$He a large enhancement of the cross section above plane-wave approximations had been reported, indicating the formation of a quasi-bound state. The present Li-data for $\eta$-production agree with a plane-wave approximation. Contrary to $^3$He, neither a threshold enhancement of the total cross section nor a deviation of the angular distributions from the expected form-factor dependence were observed., Comment: accepted for publication in Eur. Phys. J. A
Published: 2013
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190. Urethrocutaneous fistulas after voluntary medical male circumcision for HIV prevention—15 African Countries, 2015–2019

Author: Lucas, Todd, Hines, Jonas Z., Samuelson, Julia, Hargreave, Timothy, Davis, Stephanie M., Fellows, Ian, Prainito, Amber, Watts, D. Heather, Kiggundu, Valerian, Thomas, Anne G., Ntsuape, Onkemetse Conrad, Dare, Kunle, Odoyo-June, Elijah, Soo, Leonard, Toti-Mokoteli, Likabelo, Manda, Robert, Kapito, Martin, Msungama, Wezi, Odek, James, Come, Jotamo, Canda, Marcos, Gaspar, Nuno, Mekondjo, Aupokolo, Zemburuka, Brigitte, Bonnecwe, Collen, Vranken, Peter, Mmbando, Susan, Simbeye, Daimon, Rwegerera, Fredrick, Wamai, Nafuna, Kyobutungi, Shelia, Zulu, James Exnobert, Chituwo, Omega, Xaba, Sinokuthemba, Mandisarisa, John, and Toledo, Carlos
Published: 2021
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191. Transverse Polarization of $\Sigma^{+}(1189)$ in Photoproduction on a Hydrogen Target in CLAS

Author: Nepali, C. S., Amaryan, M., Adhikari, K. P., Aghasyan, M., Pereira, S. Anefalos, Baghdasaryan, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Collins, P., Contalbrigo, M., Crede, V., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Alaoui, A. El, Fassi, L. El, Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gabrielyan, M. Y., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Rimal, D., Ripani, M., Ritchie, B. G., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Torayev, B., Vernarsky, B., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: Experimental results on the $\Sigma^+(1189)$ hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson laboratory are presented. The $\Sigma^+(1189)$ was reconstructed in the exclusive reaction $\gamma+p\rightarrow K^{0}_{S} + \Sigma^+(1189)$ via the $\Sigma^{+} \to p \pi^{0}$ decay mode. The $K^{0}_S$ was reconstructed in the invariant mass of two oppositely charged pions with the $\pi^0$ identified in the missing mass of the detected $p\pi^+\pi^-$ final state. Experimental data were collected in the photon energy range $E_{\gamma}$ = 1.0-3.5 GeV ($\sqrt{s}$ range 1.66-2.73 GeV). We observe a large negative polarization of up to 95%. As the mechanism of transverse polarization of hyperons produced in unpolarized photoproduction experiments is still not well understood, these results will help to distinguish between different theoretical models on hyperon production and provide valuable information for the searches of missing baryon resonances., Comment: pages 11
Published: 2013
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192. Accurate Test of Chiral Dynamics in the \boldmath$\vec{\gamma} p \rightarrow \pi^0p$ Reaction

Author: Hornidge, D., Bartolome, P. Aguar, Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Berghaeuser, H., Bernstein, A. M., Braghieri, A., Briscoe, W. J., Cherepnya, S., Dieterle, M., Downie, E. J., Drexler, P., Fernandez-Ramirez, C., Filkov, L. V., Glazier, D. I., Barrientos, P. Hall, Heid, E., Hilt, M., Jaegle, I., Jahn, O., Jude, T. C., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Koulbardis, A., Krambrich, D., Kruglov, S., Krusche, B., Laffoley, A. T., Lisin, V., Livingston, K., MacGregor, I. J. D., Mancell, J., Manley, D. M., McNicoll, E. F., Mekterovic, D., Metag, V., Micanovic, S., Middleton, D. G., Moores, K. W., Mushkarenkov, A., Nefkens, B. M. K., Oberle, M., Ostrick, M., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Robinson, J., Rostomyan, T., Scherer, S., Schumann, S., Sikora, M. H., Starostin, A., Supek, I., Thiel, M., Thomas, A., Tiator, L., Unverzagt, M., Watts, D. P., Werthmueller, D., and Witthauer, L.
Subjects: Nuclear Experiment
Abstract: A precision measurement of the differential cross sections $d\sigma/d\Omega$ and the linearly polarized photon asymmetry $\Sigma \equiv (d\sigma_\perp - d\sigma_\parallel) \slash (d\sigma_\perp + d\sigma_\parallel)$ for the $\vec{\gamma} p \rightarrow \pi^0p$ reaction in the near-threshold region has been performed with a tagged photon beam and almost $4\pi$ detector at the Mainz Microtron. The Glasgow-Mainz photon tagging facility along with the Crystal Ball/TAPS multi-photon detector system and a cryogenic liquid hydrogen target were used. These data allowed for a precise determination of the energy dependence of the real parts of the $S$- and all three $P$-wave amplitudes for the first time and provide the most stringent test to date of the predictions of Chiral Perturbation Theory and its energy region of agreement with experiment., Comment: 5 pages, 2 figures
Published: 2012
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193. Technical Design Report for the: PANDA Micro Vertex Detector

Author: PANDA Collaboration, Erni, W., Keshelashvili, I., Krusche, B., Steinacher, M., Heng, Y., Liu, Z., Liu, H., Shen, X., Wang, Q., Xu, H., Albrecht, M., Becker, J., Eickel, K., Feldbauer, F., Fink, M., Friedel, P., Heinsius, F. H., Held, T., Koch, H., Kopf, B., Leyhe, M., Motzko, C., Pelizäus, M., Pychy, J., Roth, B., Schröder, T., Schulze, J., Steinke, M., Trifterer, T., Wiedner, U., Zhong, J., Beck, R., Becker, M., Bianco, S., Brinkmann, K. -Th., Hammann, C., Hinterberger, F., Jäkel, R., Kaiser, D., Kliemt, R., Koop, K., Schmidt, C., Schnell, R., Thoma, U., Vlasov, P., Wendel, C., Winnebeck, A., Würschig, Th., Zaunick, H. -G., Bianconi, A., Bragadireanu, M., Caprini, M., Ciubancan, M., Pantea, D., Tarta, P. -D, De Napoli, M., Giacoppo, F., Rapisarda, E., Sfienti, C., Fiutowski, T., Idzik, N., Mindur, B., Przyborowski, D., Swientek, K., Bialkowski, E., Budzanowski, A., Czech, B., Kliczewski, S., Kozela, A., Kulessa, P., Lebiedowicz, P., Malgorzata, K., Pysz, K., Schäfer, W., Siudak, R., Szczurek, A., Brandys, P., Czyzewski, T., Czyzycki, W., Domagala, M., Hawryluk, M., Filo, G., Kwiatkowski, D., Lisowski, E., Lisowski, F., Bardan, W., Gil, D., Kamys, B., Kistryn, St., Korcyl, K., Krzemieñ, W., Magiera, A., Moskal, P., Rudy, Z., Salabura, P., Smyrski, J., Wroñska, A., Al-Turany, M., Arora, R., Augustin, I., Deppe, H., Dutta, D., Flemming, H., Götzen, K., Hohler, G., Karabowicz, R., Lehmann, D., Lewandowski, B., Lühning, J., Maas, F., Orth, H., Peters, K., Saito, T., Schepers, G., Schmidt, C. J., Schmitt, L., Schwarz, C., Schwiening, J., Voss, B., Wieczorek, P., Wilms, A., Abazov, V. M., Alexeev, G. D., Arefiev, V. A., Astakhov, V. I., Barabanov, M. Yu., Batyunya, B. V., Davydov, Yu. I., Dodokhov, V. Kh., Efremov, A. A., Fedunov, A. G., Feshchenko, A. A., Galoyan, A. S., Grigoryan, S., Karmokov, A., Koshurnikov, E. K., Lobanov, V. I., Lobanov, Yu. Yu., Makarov, A. F., Malinina, L. V., Malyshev, V. L., Mustafaev, G. A., Olshevski, A. G., Pasyuk, M. A., Perevalova, E. A., Piskun, A. A., Pocheptsov, T. A., Pontecorvo, G., Rodionov, V. K., Rogov, Yu. N., Salmin, R. A., Samartsev, A. G., Sapozhnikov, M. G., Shabratova, G. S., Skachkova, A. N., Skachkov, N. B., Strokovsky, E. A., Suleimanov, M. K., Teshev, R. Sh., Tokmenin, V. V., Uzhinsky, V. V., Vodopyanov, A. S., Zaporozhets, S. A., Zhuravlev, N. I., Zorin, A. G., Branford, D., Glazier, D., Watts, D., Woods, P., Britting, A., Eyrich, W., Lehmann, A., Uhlig, F., Dobbs, S., Metreveli, Z., Seth, K., Tann, B., Tomaradze, A., Bettoni, D., Carassiti, V., Dalpiaz, P., Drago, A., Fioravanti, E., Garzia, I., Negrini, M., Savriè, M., Stancari, G., Dulach, B., Gianotti, P., Guaraldo, C., Lucherini, V., Pace, E., Bersani, A., Macri, M., Marinelli, M., Parodi, R. F., Dormenev, V., Drexler, P., Düren, M., Eisner, T., Foehl, K., Hayrapetyan, A., Koch, P., Krïoch, B., Kühn, W., Lange, S., Liang, Y., Liu, M., Merle, O., Metag, V., Moritz, M., Nanova, M., Novotny, R., Spruck, B., Stenzel, H., Strackbein, C., Thiel, M., Clarkson, T., Euan, C., Hill, G., Hoek, M., Ireland, D., Kaiser, R., Keri, T., Lehmann, I., Livingston, K., Lumsden, P., MacGregor, D., McKinnon, B., Montgomery, R., Murray, M., Protopopescu, D., Rosner, G., Seitz, B., Yang, G., Babai, M., Biegun, A. K., Glazenborg-Kluttig, A., Guliyev, E., Jothi, V. S., Kavatsyuk, M., Lemmens, P., Löhner, H., Messchendorp, J., Poelman, T., Smit, H., van der Weele, J. C., Sohlbach, H., Büscher, M., Dosdall, R., Dzhygadlo, R., Esch, S., Gillitzer, A., Goldenbaum, F., Grunwald, D., Jha, V., Kemmerling, G., Kleines, H., Lehrach, A., Maier, R., Mertens, M., Ohm, H., Pohl, D. L., Prasuhn, D., Randriamalala, T., Ritman, J., Roeder, M., Sterzenbach, G., Stockmanns, T., Wintz, P., Wüstner, P., Kisiel, J., Li, S., Li, Z., Sun, Z., Fissum, K., Hansen, K., Isaksson, L., Lundin, M., Schröder, B., Achenbach, P., Denig, A., Distler, M., Fritsch, M., Kangh, D., Karavdina, A., Lauth, W., Michel, M., Espi, M. C. Mora, Pochodzalla, J., Sanchez, S., Sanchez-Lorente, A., Weber, T., Dormenev, V. I., Fedorov, A. A., Korzhik, M. V., Missevitch, O. V., Balanutsa, V., Chernetsky, V., Demekhin, A., Dolgolenko, A., Fedorets, P., Gerasimov, A., Goryachev, V., Boukharov, A., Malyshev, O., Marishev, I., Semenov, A., Varma, R., Ketzer, B., Konorov, I., Mann, A., Neubert, S., Paul, S., Vandenbroucke, M., Zhang, Q., Khoukaz, A., Rausmann, T., Täschner, A., Wessels, J., Baldin, E., Kotov, K., Peleganchuk, S., Tikhonov, Yu., Hennino, T., Imre, M., Kunne, R., Galliard, C. Le, Normand, J. P. Le, Marchand, D., Maroni, A., Ong, S., Pouthas, J., Ramstein, B., Rosier, P., Sudol, M., Theneau, C., Tomasi-Gustafsson, E., Van de Wiele, J., Zerguerras, T., Boca, G., Braghieri, A., Costanza, S., Fontana, A., Genova, P., Lavezzi, L., Montagna, P., Rotondi, A., Buda, V., Abramov, V. V., Davidenko, A. M., Derevschikov, A. A., Goncharenko, Y. M., Grishin, V. N., Kachanov, V. A., Konstantinov, D. A., Kormilitsin, V. A., Matulenko, Y. A., Melnik, Y. M., Meschanin, A. P., Minaev, N. G., Mochalov, V. V., Morozov, D. A., Nogach, L. V., Nurushev, S. B., Ryazantsev, A. V., Semenov, P. A., Soloviev, L. F., Uzunian, A. V., Vasiliev, A. N., Yakutin, A. E., Belostotski, S., Gavrilov, G., Itzotov, A., Kisselev, A., Kravchenko, P., Manaenkov, S., Miklukho, O., Naryshkin, Y., Veretennikov, D., Vikhrov, V., Zhadanov, A., Bäck, T., Cederwall, B., Bargholtz, C., Gerén, L., Tegnér, P. E., Thørngren, P., von Würtemberg, K. M., Fava, L., Alberto, D., Amoroso, A., Bussa, M. P., Busso, L., De Mori, F., Destefanis, M., Ferrero, L., Greco, M., Kugathasan, T., Maggiora, M., Marcello, S., Sosio, S., Spataro, S., Calvo, D., Coli, S., De Remigis, P., Filippi, A., Giraudo, G., Lusso, S., Mazza, G., Mignone, M., Rivetti, A., Wheadon, R., Zotti, L., Morra, O., Iazzi, F., Lavagno, A., Quarati, P., Szymanska, K., Birsa, R., Bradamante, F., Bressan, A., Martin, A., Clement, H., Galnander, B., Calén, H., Fransson, K., Johansson, T., Kupsc, A., Marciniewski, P., Thomé, E., Wolke, M., Zlomanczuk, J., Díaz, J., Ortiz, A., Buda, P., Dmowski, K., Korzeniewski, R., Przemyslaw, D., Slowinski, B., Borsuk, S., Chlopik, A., Guzik, Z., Kopec, J., Kozlowski, T., Melnychuk, D., Plominski, M., Szewinski, J., Traczyk, K., Zwieglinski, B., Bühler, P., Gruber, A., Kienle, P., Marton, J., Widmann, E., and Zmeskal, J.
Subjects: Physics - Instrumentation and Detectors
Abstract: This document illustrates the technical layout and the expected performance of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect charged particles as close as possible to the interaction zone. Design criteria and the optimisation process as well as the technical solutions chosen are discussed and the results of this process are subjected to extensive Monte Carlo physics studies. The route towards realisation of the detector is outlined., Comment: 189 pages, 225 figures, 41 tables
Published: 2012

194. Determination of the {\eta} mass with the Crystal Ball at MAMI-B

Author: Nikolaev, A., Aguar-Bartolomé, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J. W., Cherepnya, S., Codling, R., Dehn, M., Downie, E. J., Fil'kov, L. V., Glazier, D. I., Gregor, R., Heid, E., Hornidge, D., Jahn, O., Jankowiak, A., Kaiser, K. -H., Kashevarov, V. L., Kondratiev, R., Korolija, M., Kotulla, M., Krambrich, D., Krusche, B., Lang, M., Lisin, V., Livingston, K., Ludwig-Mertin, U., Lugert, S., MacGregor, I. J. D., Manley, D. M., Martinez-Fabregate, M., McGeorge, J. C., Mekterovic, D., Metag, V., Nefkens, B. M. K., Novotny, R., Owens, R. O., Pedroni, P., Polonski, A., Prakhov, S. N., Price, J. W., Reiter, A., Rosner, G., Rost, M., Rostomyan, T., Schumann, S., Sober, D., Starostin, A., Supek, I., Tarbert, C. M., Thomas, A., Unverzagt, M., Walcher, Th., Watts, D. P., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: A new precise determination of the {\eta} meson mass is presented. It is based on a measurement of the threshold for the {\gamma}p -> p{\eta} reaction using the tagger focal-plane microscope detector at the MAMI-B facility in Mainz. The tagger microscope has a higher energy resolution than the standard tagging spectrometer and, hence, allowed an improvement in the accuracy compared to the previous {\eta} mass measurement at MAMI-B. The result m{\eta} = (547.851 +- 0.031 stat. +- 0.062 syst.) MeV agrees very well with the precise values of the NA48, KLOE and CLEO collaborations and deviates by about 5{\sigma} from the smaller, but also very precise value obtained by the GEM collaboration at COSY., Comment: Submitted for publication in EPJA
Published: 2012

195. Photoproduction of pi0pi0 and pi0pi+-pairs off the proton from threshold to the second resonance region

Author: Zehr, F., Krusche, B., Aguar, P., Ahrens, J., Annand, J. R. M., Arends, H. J., Beck, R., Bekrenev, V., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Downie, E. J., Drexler, P., Glazier, D. I., Fil'kov, L. V., Gregor, R., Heid, E., Hornidge, D., Jaegle, I., Jahn, O., Kashevarov, V. L., Knezevic, A., Kondratiev, R., Korolija, M., Kotulla, M., Krambrich, D., Kulbardis, A., Lang, M., Lisin, V., Livingston, K., Lugert, S., MacGregor, I. J. D., Manley, D. M., Maghrbi, Y., Martinez, M., McGeorge, J. C., Mekterovic, D., Metag, V., Nefkens, B. M. K., Nikolaev, A., Ostrick, M., Pedroni, P., Pheron, F., Polonski, A., Prakhov, S., Price, J. W., Rosner, G., Rost, M., Rostomyan, T., Schumann, S., Sober, D., Starostin, A., Supek, I., Tarbert, C. M., Thomas, A., Unverzagt, M., Walcher, Th., and Watts, D. P.
Subjects: Nuclear Experiment
Abstract: Precise total cross-sections and invariant-mass distributions have been measured for photoproduction of pion pairs off the proton producing $p\pi^0\pi^0$ and $n\pi^+\pi^0$ final states from the threshold region up to 800 MeV incident photon energy. Additionally, beam helicity asymmetries have been measured in the second resonance region (550 MeV - 820 MeV). The experiment was performed at the tagged photon beam of the Mainz MAMI accelerator with the Crystal Ball and TAPS detectors combined to give an almost 4$\pi$ solid-angle electromagnetic calorimeter. The results are much more precise than any previous measurements and confirm the chiral perturbation theory predictions for the threshold behavior of these reactions. In the second resonance region, the invariant-mass distributions of meson-meson and meson-nucleon pairs are in reasonable agreement with model predictions, but none of the models reproduce the asymmetries for the mixed-charge channel., Comment: accepted for publication in Eur. Phys. J. A
Published: 2012
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196. Measurement of Exclusive $\pi^0$ Electroproduction Structure Functions and their Relationship to Transversity GPDs

Author: CLAS Collaboration, Bedlinskiy, I., Kubarovsky, V., Niccolai, S., Stoler, P., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bennett, R. P., Biselli, A. S., Bookwalter, C., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Garçon, M., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Gohn, W., Gothe, R. W., Graham, L., Griffioen, K. A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Markov, N., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Saylor, N., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Ungaro, M., Vineyard, M. F., Vlassov, A., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: Exclusive $\pi^0$ electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in $Q^2$, $x_B$, $t$, and $\phi_\pi$, in the $Q^2$ range from 1.0 to 4.6 GeV$^2$,\ $-t$ up to 2 GeV$^2$, and $x_B$ from 0.1 to 0.58. Structure functions $\sigma_T +\epsilon \sigma_L, \sigma_{TT}$ and $\sigma_{LT}$ were extracted as functions of $t$ for each of 17 combinations of $Q^2$ and $x_B$. The data were compared directly with two handbag-based calculations including both longitudinal and transversity GPDs. Inclusion of only longitudinal GPDs very strongly underestimates $\sigma_T +\epsilon \sigma_L$ and fails to account for $\sigma_{TT}$ and $\sigma_{LT}$, while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity flip and helicity non-flip processes. The results confirm that exclusive $\pi^0$ electroproduction offers direct experimental access to the transversity GPDs., Comment: 6 pages, 2 figures
Published: 2012
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197. Deep exclusive $\pi^+$ electroproduction off the proton at CLAS

Author: Park, K., Guidal, M., Gothe, R. W., Laget, J. M., Garçon, M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bedlinsky, I., Bennett, R. P., Biselli, A. S., Bookwalter, C., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Fradi, A., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Graham, L., Griffioen, K. A., Guegan, B., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jo, H. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Markov, N., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nepali, C. S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatie, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Trivedi, A., Ungaro, M., Vernarsky, B ., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: The exclusive electroproduction of $\pi^+$ above the resonance region was studied using the $\rm{CEBAF}$ Large Acceptance Spectrometer ($\rm{CLAS}$) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of $\rm{CLAS}$, together with the high luminosity, allowed us to measure the cross section for the $\gamma^* p \to n \pi^+$ process in 140 ($Q^2$, $x_B$, $t$) bins: $0.16
Published: 2012
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198. Technical Design Report for the: PANDA Straw Tube Tracker

Author: PANDA Collaboration, Erni, W., Keshelashvili, I., Krusche, B., Steinacher, M., Heng, Y., Liu, Z., Liu, H., Shen, X., Wang, Q., Xu, H., Aab, A., Albrecht, M., Becker, J., Csapó, A., Feldbauer, F., Fink, M., Friedel, P., Heinsius, F. H., Held, T., Klask, L., Koch, H., Kopf, B., Leiber, S., Leyhe, M., Motzko, C., Pelizäus, M., Pychy, J., Roth, B., Schröder, T., Schulze, J., Sowa, C., Steinke, M., Trifterer, T., Wiedner, U., Zhong, J., Beck, R., Bianco, S., Brinkmann, K. T., Hammann, C., Hinterberger, F., Kaiser, D., Kliemt, R., Kube, M., Pitka, A., Quagli, T., Schmidt, C., Schmitz, R., Schnell, R., Thoma, U., Vlasov, P., Walther, D., Wendel, C., Würschig, T., Zaunick, H. G., Bianconi, A., Bragadireanu, M., Caprini, M., Pantea, D., Pantelica, D., Pietreanu, D., Serbina, L., Tarta, P. D., Kaplan, D., Fiutowski, T., Idzik, M., Mindur, B., Przyborowski, D., Swientek, K., Czech, B., Kistryn, M., Kliczewski, S., Kozela, A., Kulessa, P., Lebiedowicz, P., Pysz, K., Schäfer, W., Siudak, R., Szczurek, A., Jowzaee, S., Kajetanowicz, M., Kamys, B., Kistryn, S., Korcyl, G., Korcyl, K., Krzemien, W., Magiera, A., Moskal, P., Palka, M., Rudy, Z., Salabura, P., Smyrski, J., Wrońska, A., Augustin, I., Lehmann, I., Nimorus, D., Schepers, G., Al-Turany, M., Arora, R., Deppe, H., Flemming, H., Gerhardt, A., Götzen, K., Jordi, A. F., Kalicy, G., Karabowicz, R., Lehmann, D., Lewandowski, B., Lühning, J., Maas, F., Orth, H., Patsyuk, M., Peters, K., Saito, T., Schmidt, C. J., Schmitt, L., Schwarz, C., Schwiening, J., Traxler, M., Voss, B., Wieczorek, P., Wilms, A., Zühlsdorf, M., Abazov, V. M., Alexeev, G., Arefiev, A., Astakhov, V. I., Barabanov, M. Yu., Batyunya, B. V., Davydov, Yu. I., Dodokhov, V. Kh., Efremov, A. A., Fedunov, A. G., Festchenko, A. A., Galoyan, A. S., Grigoryan, S., Karmokov, A., Koshurnikov, E. K., Lobanov, V. I., Lobanov, Yu. Yu., Makarov, A. F., Malinina, L. V., Malyshev, V. L., Mustafaev, G. A., Olshevskiy, A., Pasyuk, M. A., Perevalova, E. A., Piskun, A. A., Pocheptsov, T. A., Pontecorvo, G., Rodionov, V. K., Rogov, Yu. N., Salmin, R. A., Samartsev, A. G., Sapozhnikov, M. G., Shabratova, G. S., Skachkova, A. N., Skachkov, N. B., Strokovsky, E. A., Suleimanov, M. K., Teshev, R. Sh., Tokmenin, V. V., Uzhinsky, V. V., Vodopyanov, A. S., Zaporozhets, S. A., Zhuravlev, N. I., Zorin, A. G., Branford, D., Glazier, D., Watts, D., Woods, P., Britting, A., Eyrich, W., Lehmann, A., Uhlig, F., Dobbs, S., Metreveli, Z., Seth, K., Tomaradze, A., Xiao, T., Bettoni, D., Carassiti, V., Ramusino, A. Cotta, Dalpiaz, P., Drago, A., Fioravanti, E., Garzia, I., Savriè, M., Stancari, G., Bianchi, N., Gianotti, P., Guaraldo, C., Lucherini, V., Orecchini, D., Pace, E., Bersani, A., Bracco, G., Macri, M., Parodi, R. F., Bremer, D., Dormenev, V., Drexler, P., Düren, M., Eissner, T., Föhl, K., Galuska, M., Gessler, T., Hayrapetyan, A., Hu, J., Koch, P., Kröck, B., Kühn, W., Lange, S., Liang, Y., Merle, O., Metag, V., Moritz, M., Münchow, D., Nanova, M., Novotny, R., Spruck, B., Stenzel, H., Ullrich, T., Werner, M., Euan, C., Hoek, M., Ireland, D., Keri, T., Montgomery, R., Protopopescu, D., Rosner, G., Seitz, B., Babai, M., Glazenborg-Kluttig, A., Kavatsyuk, M., Lemmens, P., Lindemulder, M., Löhner, H., Messchendorp, J., Moeini, H., Schakel, P., Schreuder, F., Smit, H., Tambave, G., van der Weele, J. C., Veenstra, R., Sohlbach, H., Büscher, M., Deermann, D., Dosdall, R., Esch, S., Gillitzer, A., Goldenbaum, F., Grunwald, D., Henssler, S., Herten, A., Hu, Q., Kemmerling, G., Kleines, H., Kozlov, V., Lehrach, A., Maier, R., Mertens, M., Ohm, H., Orfanitski, S., Prasuhn, D., Randriamalala, T., Ritman, J., Schadmand, S., Serdyuk, V., Sterzenbach, G., Stockmanns, T., Wintz, P., Wüstner, P., Kisiel, J., Li, S., Li, Z., Sun, Z., Rigato, V., Fissum, S., Hansen, K., Isaksson, L., Lundin, M., Schröder, B., Achenbach, P., Bleser, S., Cahit, U., Cardinali, M., Denig, A., Distler, M., Fritsch, M., Kangh, D., Karavdina, A., Lauth, W., Merkel, H., Michel, M., Espi, M. C. Mora, Müller, U., Pochodzalla, J., Prometeusz, J., Sanchez, S., Sanchez-Lorente, A., Schlimme, S., Sfienti, C., Thiel, M., Weber, T., Dormenev, V. I., Fedorov, A. A., Korzhik, M. V., Missevitch, O. V., Balanutsa, V., Chernetsky, V., Demekhin, A., Dolgolenko, A., Fedorets, P., Gerasimov, A., Goryachev, V., Varentsov, V., Boukharov, A., Malyshev, O., Marishev, I., Semenov, A., Böhmer, F., Dørheim, S., Ketzer, B., Paul, S., Hergemöller, A. K., Khoukaz, A., Köhler, E., Täschner, A., Wessels, J., Varma, R., Chaterjee, A., Jha, V., Kailas, S., Roy, B., Yan, Y., Chinorat, K., Khanchai, K., Ayut, L., Pomrad, S., Baldin, E., Kotov, K., Peleganchuk, S., Tikhonov, Yu., Boucher, J., Chambert, V., Dbeyssi, A., Hennino, T., Imre, M., Kunne, R., Galliard, C. Le, Ma, B., Marchand, D., Maroni, A., Ong, S., Ramstein, B., Rosier, P., Sudol, M., Tomasi-Gustafsson, E., Van de Wiele, J., Boca, G., Braghieri, A., Costanza, S., Genova, P., Lavezzi, L., Montagna, P., Rotondi, A., Abramov, V., Belikov, N., Davidenko, A., Derevschikov, A., Goncharenko, Y., Grishin, V., Kachanov, V., Konstantinov, D., Kormilitsin, V., Melnik, Y., Levin, A., Minaev, N., Mochalov, V., Morozov, D., Nogach, L., Poslavskiy, S., Ryazantsev, A., Ryzhikov, S., Semenov, P., Shein, I., Uzunian, A., Vasiliev, A., Yakutin, A., Bäck, T., Cederwall, B., Makónyi, K., Tegnér, P. E., von Würtemberg, K. M., Belostotski, S., Gavrilov, G., Itzotov, A., Kashchuk, A., Kisselev, A., Kravchenko, P., Levitskaya, O., Manaenkov, S., Miklukho, O., Naryshkin, Y., Veretennikov, D., Vikhrov, V., Zhadanov, A., Alberto, D., Amoroso, A., Bussa, M. P., Busso, L., De Mori, F., Destefanis, M., Fava, L., Ferrero, L., Greco, M., Maggiora, M., Marcello, S., Sosio, S., Spataro, S., Zotti, L., Calvo, D., Coli, S., De Remigis, P., Filippi, A., Giraudo, G., Lusso, S., Mazza, G., Morra, O., Rivetti, A., Wheadon, R., Iazzi, F., Lavagno, A., Younis, H., Birsa, R., Bradamante, F., Bressan, A., Martin, A., Clement, H., Galander, B., Balkeståhl, L. Caldeira, Calén, H., Fransson, K., Johansson, T., Kupsc, A., Marciniewski, P., Thomé, E., Wolke, M., Zlomanczuk, J., Díaz, J., Ortiz, A., Dmowski, K., Duda, P., Korzeniewski, R., Slowinski, B., Chlopik, A., Guzik, Z., Kosinski, K., Melnychuk, D., Wasilewski, A., Wojciechowski, M., Wronka, S., Wysocka, A., Zwieglinski, B., Bühler, P., Hartman, O., Kienle, P., Marton, J., Suzuki, K., Widmann, E., and Zmeskal, J.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM-stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy-loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described., Comment: accepted for publication on EPJA
Published: 2012
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199. Study of the gamma p --> pi0 pi0 p reaction with the Crystal Ball/TAPS at the Mainz

Author: Kashevarov, V. L., Fix, A., Prakhov, S., Aguar-Bartolomé, P., Annand, J. R. M., Arends, H. J., Bantawa, K., Beck, R., Bekrenev, V., Berghäuser, H., Braghieri, A., Briscoe, W. J., Brudvik, J., Cherepnya, S., Codling, R. F. B., Downie, E. J., Drexler, P., Fil'kov, L. V., Glazier, D. I., Gregor, R., Heid, E., Hornidge, D., Isaksson, L., Jaegle, I., Jahn, O., Jude, T. C., Keshelashvili, I., Kondratiev, R., Korolija, M., Kotulla, M., Koulbardis, A., Kruglov, S., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Manley, D. M., McGeorge, J. C., McNicoll, E. F., Mekterovic, D., Metag, V., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Ortega, H., Ostrick, M., Ott, P., Otte, P. B., Oussena, B., Pedroni, P., Pheron, F., Polonski, A., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D. I., Starostin, A., Strakovsky, I. I., Suarez, I. M., Supek, I., Tarbert, C. M., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmüller, D., and Zehr, F.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract: The gamma p --> pi0 pi0 p reaction has been measured from threshold to 1.4 GeV using the Crystal Ball and TAPS photon spectrometers together with the photon tagging facility at the Mainz Microtron. The experimental results include total and differential cross sections as well as specific angular distributions, which were used to extract partial-wave amplitudes. In particular, the energy region below the D13(1520) resonance was studied., Comment: 12 pages, 13 figures, corrected version, published in PRC
Published: 2012
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200. Coherent photoproduction of eta-mesons off 3He - search for eta-mesic nuclei

Author: Pheron, F., Ahrens, J., Annand, J. R. M., Arends, H. J., Bantawa, K., Bartolome, P. A., Beck, R., Bekrenev, V., Berghaeuser, H., Boillat, B., Braghieri, A., Branford, D., Briscoe, W. J., Brudvik, J., Cherepnya, S., Demissie, B., Dieterle, M., Downie, E. J., Drexler, P., Glazier, D. I., Heid, E., Fil'kov, L. V., Hornidge, D., Howdle, D., Jahn, O., Jaegle, I., Jude, T. C., Kashevarov, V. L., Keshelashvili, I., Kondratiev, R., Korolija, M., Kotulla, M., Kulbardis, A., Kruglov, S. P., Krusche, B., Lisin, V., Livingston, K., MacGregor, I. J. D., Maghrbi, Y., Mancell, J., Manley, D. M., Marinides, Z., Martinez, M., McGeorge, J. C., McNicoll, E., Mekterovic, D., Metag, V., Micanovic, S., Middleton, D. G., Mushkarenkov, A., Nefkens, B. M. K., Nikolaev, A., Novotny, R., Oberle, M., Ostrick, M., Oussena, B., Pedroni, P., Polonski, A., Prakhov, S. N., Robinson, J., Rosner, G., Rostomyan, T., Schumann, S., Sikora, M. H., Sober, D. I., Starostin, A., Supek, I., Thiel, M., Thomas, A., Unverzagt, M., Watts, D. P., Werthmueller, D., Witthauer, L., and Zehr, F.
Subjects: Nuclear Experiment
Abstract: Coherent photoproduction of $\eta$-mesons off $^3$He, i.e. the reaction $\gamma ^3{He}\rightarrow \eta ^3{He}$, has been investigated in the near-threshold region. The experiment was performed at the Glasgow tagged photon facility of the Mainz MAMI accelerator with the combined Crystal Ball - TAPS detector. Angular distributions and the total cross section were measured using the $\eta\rightarrow \gamma\gamma$ and $\eta\rightarrow 3\pi^0\rightarrow 6\gamma$ decay channels. The observed extremely sharp rise of the cross section at threshold and the behavior of the angular distributions are evidence for a strong $\eta {^3{He}}$ final state interaction, pointing to the existence of a resonant state. The search for further evidence of this state in the excitation function of $\pi^0$-proton back-to-back emission in the $\gamma ^3{He}\rightarrow \pi^0 pX$ reaction revealed a very complicated structure of the background and could not support previous conclusions., Comment: accepted for publication in Phys. Lett. B
Published: 2012
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