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5. Influence of Surface Tension Forces of Modifiers on Some Properties of Composite Materials

Author

Pichugin, A., Pchelnikov, A., Smirnova, O., Tkachenko, S., di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Radionov, Andrey A., editor, Ulrikh, Dmitrii V., editor, Timofeeva, Svetlana S., editor, Alekhin, Vladimir N., editor, and Gasiyarov, Vadim R., editor

Published
2023
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8. Oxygen-vacancy centers in Y3Al5O12 garnet crystals: electron paramagnetic resonance and dielectric spectroscopy study

Author

Laguta, V., Buryi, M., Tkachenko, S., Arhipov, P., Gerasymov, I., Sidletskiy, O., Laguta, O., and Nikl, M.

Subjects
Condensed Matter - Materials Science
Abstract

F+ center, an electron trapped at oxygen vacancy (VO), was investigated in the oxygen deficient Y3Al5O12 (YAG) crystals by EPR. The measurements were performed at temperatures 5-450 K and frequencies 9.4-350 GHz with using both the continue wave and pulse EPR technique. The pulse electron-nuclear double resonance was applied to resolve the hyperfine interaction of the trapped electron with surrounding nuclei. The measurements show that at low temperatures, T < 50 K, EPR spectrum of the F+ center is anisotropic with g factors in the range 1.999-1.988 and originates from three magnetically inequivalent positions of the center in garnet lattice according to different directions of the Al(IV)-VO-Al(VI) chains, where Al(IV) and Al(VI) are the tetrahedral and octahedral Al sites, respectively. As the temperature increases, the EPR spectrum becomes isotropic suggesting a motional averaging of the anisotropy due to motion of electron between neighboring oxygen vacancies. With further increase of the temperature to T > 200 K, we observed delocalization of the electron into the conduction band with the activation energy about 0.4-0.5 eV that resulted in substantial narrowing of the EPR spectral line with simultaneous change of its shape from the Gaussian to Lorentzian due to diminish up to zero of the Fermi contact hyperfine field at 27Al and 89Y nuclei. Such temperature behavior of the F+-center electron in YAG is completely similar to behavior of a donor electron in a semiconductor. Our findings is further supported by measurements of the conductivity and dielectric properties. In particular, these data show that the conduction electrons are not homogeneously distributed in the crystal: there are high-conductive regions separated by poorly-conductive dielectric layers. This leads to the so-called Maxwell-Wagner dielectric relaxation with huge apparent dielectric constant at low frequencies.

Published
2018
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10. The slow relaxation of non-equilibrium state in metal target excited by picosecond electron beam: interferometric and simulation studies

Author

Barakhvostov, S. V., Volkov, N. B., Lipchak, F. I., Tarakanov, V. P., Tkachenko, S. I., Turmyshev, I. S., and Yalovets, A. P.

Subjects
Physics - Plasma Physics
Abstract

The experimental EXCITOR setup for obtaining the intense electron beams of picosecond duration is presented in this work. Cathodes of tungsten, graphite, copper and samarium of the same shape were used in these experiments. The interelectrode gap varied from 0.5 to 6 mm. Interferometric technique to detect anode rear side displacement was used. The time evolution of the displacement and speed of the rear side of copper anode of 0.1 and 3.0 mm thickness was experimentally obtained. Simulation of the space-time characteristics evolution of the anode material is presented., Comment: Submitted to 6th International Congress Energy Fluxes and Radiation Effects (EFRE 2018), September 16-21, 2018, Tomsk, Russia. To be published in Journal of Physics: Conference Series, 10 pages, 11 figures

Published
2018
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11. The peculiarities of near-cathode processes in air discharge at atmospheric pressure

Author

Parkevich, E V, Medvedev, M A, Agafonov, A V, Tkachenko, S I, Oginov, A V, Khirianova, A I, Mingaleev, A R, Shelkovenko, T A, and Pikuz, S A

Subjects
Physics - Plasma Physics
Abstract

Formation of near-cathode plasma at the instant of breakdown of the air gap was studied by the methods of picosecond laser probing. It was demonstrated that 1-2 ns after a sharp rise of the current through the discharge gap dense plasma clots with Ne~10^20 cm^-3 and dNe/dx ~ 10^24 cm^-4 are formed on the cathode surface. It was shown that these highly ionized regions lead to initiation and development of the spark channel originating from the cathode. We propose that the observed formations correspond to erosive plasma formed from the cathode material., Comment: 9 pages, 7 figures, XXXIII International Conference on Equations of State for Matter, March 1-6, 2018, Elbrus, Kabardino-Balkaria, Russia, to be published in Journal of Physics: Conference Series

Published
2018

14. Resolution of Hydroacoustic Noise Signals under Conditions of Spatial–Temporal Variability of Ocean Environment.

Author

Kuz'kin, V. M., Pereselkov, S. A., Rybyanets, P. V., and Tkachenko, S. A.

Abstract

Holographic processing of hydroacoustic noise signals in randomly inhomogeneous ocean environment is presented. A method of hologram purification from a perturbed field is described. An algorithm of resolving signals using a single detector is presented. Focusing of signal spectral density on a hologram is considered. Criteria of signal resolution are proposed. Results of numerical simulation of the resolution of two hydroacoustic signals against the background of intense internal waves, conditioning coupling of sound field modes, are shown. [ABSTRACT FROM AUTHOR]

Published
2024
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17. BRCA-associated ovarian cancer in the russian patient population. Analysis of the non-interventional study Ovatar

Author

Tikhomirova, T. T., primary, Tyulyandina, A. S., additional, Rumyantsev, A. A., additional, Israelyan, E. R., additional, Kekeeva, T. V., additional, Vedrova, O. V., additional, Filipenko, M. L., additional, Lyubchenko, L. N., additional, Demidova, I. A., additional, Imyanitov, E. N., additional, Andreev, S. Y., additional, Khokhlova, S. V., additional, Saevets, V. V., additional, Statsenko, G. B., additional, Kolomiets, L. A., additional, Tkachenko, S. A., additional, Koroleva, I. A., additional, Lisyanskaya, A. S., additional, Bakashvili, O. A., additional, Krikunova, L. I., additional, Solovieva, E. P., additional, Ponomarenko, D. M., additional, Vladimirova, L. Y., additional, Krasilnikov, S. E., additional, Shirinkin, V. B., additional, Sakaeva, D. D., additional, Rumyantseva, E. A., additional, Emeliyanov, S. A., additional, Stroyakovskiy, D. L., additional, Novikova, E. G., additional, Ronina, E. A., additional, Vladimirov, V. I., additional, Novikova, O. Y., additional, Zagumennova, L. S., additional, Gorobtsova, V. V., additional, Cherepanova, E. V., additional, Pashkova, E. N., additional, Moiseyenko, V. M., additional, Ivanova, F. G., additional, Udovitsa, D. P., additional, Karaseva, V. V., additional, and Tyulyandin, S. A., additional

Published
2024
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23. Measurement of the EMC Effect in the Deuteron

Author

Griffioen, K. A., Arrington, J., Christy, M. E., Ent, R., Kalantarians, N., Keppel, C. E., Kuhn, S. E., Melnitchouk, W., Niculescu, G., Niculescu, I., Tkachenko, S., and Zhang, J.

Subjects
High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

We have determined the structure function ratio $R^d_{\rm EMC}=F_2^d/(F_2^n+F_2^p)$ from recently published $F_2^n/F_2^d$ data taken by the BONuS experiment using CLAS at Jefferson Lab. This ratio deviates from unity, with a slope $dR_{\rm EMC}^{d}/dx= -0.10\pm 0.05$ in the range of Bjorken $x$ from 0.35 to 0.7, for invariant mass $W>1.4$ GeV and $Q^2>1$ GeV$^2$. The observed EMC effect for these kinematics is consistent with conventional nuclear physics models that include off-shell corrections, as well as with empirical analyses that find the EMC effect proportional to the probability of short-range nucleon-nucleon correlations., Comment: 5 pages, 3 figures

Published
2015
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24. Precise Determination of the Deuteron Spin Structure at Low to Moderate $Q^2$ with CLAS and Extraction of the Neutron Contribution

Author

Guler, N., Fersch, R. G., Kuhn, S. E., Bosted, P., Griffioen, K. A., Keith, C., Minehart, R., Prok, Y., Adhikari, K. P., Adikaram, D., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Briscoe, W. J., Brooks, W. K., Bultmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Contalbrigo, M., Crabb, D., Crede, V., Angelo, A. D, Dashyan, N., Deur, A., Djalali, C., Dodge, G. E., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Forest, T. A., Garillon, B., Garcon, M., Gevorgyan, N., 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., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Hyde, C. E., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Livingston, K., Lu, H. Y., MacGregor, I. J. D., McKinnon, B., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Park, K., Pasyuk, E., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatie, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Simonyan, A., Skorodumina, Iu., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Sytnik, V., Tian, Ye, Tkachenko, S., Ungaro, M., Voutier, E., Walford, N. K., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

We present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron ($^{15}$ND$_3$) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry $A_1^d$ and the polarized structure function $g_1^d$ were extracted over a wide kinematic range (0.05 GeV$^2 < Q^2 <$ 5 GeV$^2$ and 0.9 GeV $< W <$ 3 GeV). We use an unfolding procedure and a parametrization of the corresponding proton results to extract from these data the polarized structure functions $A_1^n$ and $g_1^n$ of the (bound) neutron, which are so far unknown in the resonance region, $W < 2$ GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large $x$, a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the Operator Product Expansion., Comment: To be published in Phys. Rev. C

Published
2015
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25. Direct observation of quark-hadron duality in the free neutron F_2 structure function

Author

Niculescu, I., Niculescu, G., Melnitchouk, W., Arrington, J., Christy, M. E., Ent, R., Griffioen, K. A., Kalantarians, N., Keppel, C. E., Kuhn, S., Tkachenko, S., and Zhang, J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Theory
Abstract

Using data from the recent BONuS experiment at Jefferson Lab, which utilized a novel spectator tagging technique to extract the inclusive electron-free neutron scattering cross section, we obtain the first direct observation of quark-hadron duality in the neutron F_2 structure function. The data are used to reconstruct the lowest few (N=2, 4 and 6) moments of F_2 in the three prominent nucleon resonance regions, as well as the moments integrated over the entire resonance region. Comparison with moments computed from global parametrizations of parton distribution functions suggest that quark--hadron duality holds locally for the neutron in the second and third resonance regions down to Q^2 ~ 1 GeV^2, with violations possibly up to 20% observed in the first resonance region., Comment: 7 pages, 5 figures

Published
2015
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26. 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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27. A Conceptual Future for the Kuzbass Region: Strategic Outlines of Developmental Priorities Through 2071, a 50-Year Perspective

Author

Kvint, Vladimir, primary, Alimuradov, M. K., primary, Astapov, Kirill, primary, Alabina, Tatiana A, primary, Bahtizin, Al'bert, primary, Beleckiy, A., primary, Boiko, K. V., primary, Vlasyuk, L. I., primary, Voronin, V. L, primary, Gavrilina, D. N., primary, Gordeev, Yu., primary, Grebeshkova, A., primary, Gribelyuk, L. A., primary, Dudovceva, Yu. V., primary, Evdokimov, Dmitriy, primary, Egorova, A. I., primary, Kravchenko, D., primary, Zadorozhnaya, G. V., primary, Krivoruchko, M., primary, Kuksheeva, O., primary, Kuznecov, A., primary, Kuznecova, K. V., primary, Leuhova, Maria, primary, Makarov, V., primary, Maslov, Alexey Alexeyevich, primary, Midov, A. Z., primary, Myaskov, A. V., primary, Novikova, Irina, primary, Onuchin, A., primary, Paymurzina, T., primary, Pimenov, A., primary, Prosekov, Alekxander Yu, primary, Sadovnichaya, A. V., primary, Sasaev, Nikita, primary, Skalon, N., primary, Suschev, D., primary, Tkachenko, I. S., primary, Tkachenko, S. N., primary, Khvorostyanaya, Anna, primary, Chotua, I. Z., primary, and Shimko, T. G., primary

Published
2021
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32. 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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33. 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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36. Strategizing of Kuzbass Region water resources

Author

Sasaev, N. I., primary, Zadorozhnaya, G. V., primary, Alabina, T. A., primary, Boiko, K. V., primary, Brel, O. A., primary, Voronin, V. L, primary, Gavrilina, D. N., primary, Gribelyuk, L. A., primary, Egorova, A. I., primary, Zaytseva, A. I., primary, Kvint, Vladimir, primary, Krikota, S. N., primary, Kurteev, V. V., primary, Luzyanin, S. L., primary, Makarov, K. A., primary, Merzlikina, J. B., primary, Midov, A. Z., primary, Myaskov, A. V., primary, Novikova, I. V., primary, Osipova, M. O., primary, Savelyeva, L. N., primary, Tkachenko, I. S., primary, Tkachenko, S. N., primary, Khvorostyanaya, A. S., primary, Tsarev, M. A., primary, Shevchuk, A. V., primary, and Shimko, T. G., primary

Published
2021
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37. Strategizing of Kuzbass Region Economic and Investing Development

Author

Kvint, Vladimir, primary, Alimuradov, M. K., primary, Astapov, K. L., primary, Alekseev, G. F., primary, Bagaev, D. V., primary, Boksgorn, A. A., primary, Bondarev, N. S., primary, Veys, E. A., primary, Venger, K. G., primary, Vladimirov, D. Ya., primary, Vlasyuk, L. I., primary, Gavrilina, D. N., primary, Ganieva, I. A., primary, Egorova, A. I., primary, Kosinskiy, P., primary, Kuznecova, K. V., primary, Maslov, A., primary, Midov, A. Z., primary, Myaskov, A. V., primary, Nikitenko, S. M., primary, Pleshkan', P. Yu., primary, Sasaev, N. I., primary, Sizemov, D. N., primary, Tkachenko, I. S., primary, Tkachenko, S. N., primary, Haritonov, A. V., primary, Habekova, M. K., primary, Khvorostyanaya, A. S., primary, Chernoskutov, D. Yu., primary, Chotua, I. Z., primary, and Shevchuk, A. V., primary

Published
2021
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44. Demonstration of a novel technique to measure two-photon exchange effects in elastic $e^\pm p$ scattering

Author

Moteabbed, M., Niroula, M., Raue, B. A., Weinstein, L. B., Adikaram, D., Arrington, J., Brooks, W. K., Lachniet, J., Rimal, Dipak, Ungaro, M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bennett, R. P., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Cole, P. L., Collins, P., 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., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., 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., Joo, K., Keller, D., Khandaker, M., Kim, A., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lewis, S., Lu, H. Y., MacCormick, M., MacGregor, I . J . D., Martinez, D., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moriya, K., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Ripani, M., Rosner, G., Rossi, P., Sabatié, 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., Strauch, S., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Voskanyan, H., Voutier, E., Walford, N. K., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations of TPE corrections have significant model dependence, and there is limited direct experimental evidence for such corrections. We present the results of a new experimental technique for making direct $e^\pm p$ comparisons, which has the potential to make precise measurements over a broad range in $Q^2$ and scattering angles. We use the Jefferson Lab electron beam and the Hall B photon tagger to generate a clean but untagged photon beam. The photon beam impinges on a converter foil to generate a mixed beam of electrons, positrons, and photons. A chicane is used to separate and recombine the electron and positron beams while the photon beam is stopped by a photon blocker. This provides a combined electron and positron beam, with energies from 0.5 to 3.2 GeV, which impinges on a liquid hydrogen target. The large acceptance CLAS detector is used to identify and reconstruct elastic scattering events, determining both the initial lepton energy and the sign of the scattered lepton. The data were collected in two days with a primary electron beam energy of only 3.3 GeV, limiting the data from this run to smaller values of $Q^2$ and scattering angle. Nonetheless, this measurement yields a data sample for $e^\pm p$ with statistics comparable to those of the best previous measurements. We have shown that we can cleanly identify elastic scattering events and correct for the difference in acceptance for electron and positron scattering. The final ratio of positron to electron scattering: $R=1.027\pm0.005\pm0.05$ for $=0.206$ GeV$^2$ and $0.830\leq \epsilon\leq 0.943$.

Published
2013
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45. 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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46. 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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48. Near Threshold Neutral Pion Electroproduction at High Momentum Transfers and Generalized Form Factors

Author

Khetarpal, P., Stoler, P., Aznauryan, I. G., Kubarovsky, V., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Charles, G., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Fradi, A., Gabrielyan, M. Y., Garçon, M., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kuleshov, S. V., Kvaltine, N. D., Lewis, S., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., 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., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Saylor, N. A., 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., Tkachenko, S., Ungaro, M., Vernarsky, B., Voskanyan, H., Voutier, E., Walford, N. K., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

We report the measurement of near threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range $Q^2$ from 2 to 4.5 GeV$^2$ and $W$ from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles $E_{0+}$ and $S_{0+}$ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors $G_1^{\pi^0 p}(Q^2)$ and $G_2^{\pi^0 p}(Q^2)$. The data are compared to these generalized form factors and the results for $G_1^{\pi^0 p}(Q^2)$ are found to be in good agreement with the LCSR predictions, but the level of agreement with $G_2^{\pi^0 p}(Q^2)$ is poor., Comment: 17 pages, 18 figures, Journal article (Physical Review C)

Published
2012
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50. 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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