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Start Over Author "Fabbri, R." Topic high energy physics - experiment
28 results on '"Fabbri, R."'

1. Bose-Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

Author

HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., García, J. Garay, Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Lu, X. -G., Ma, B. -Q., Mahon, D., Makins, N. C. R., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stahl, M., Stancari, M., Statera, M., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

Bose-Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of $^1$H, $^2$H, $^3$He, $^4$He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose-Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose-Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidence for a dependence on the invariant mass W of the photon-nucleon system is found when the results are compared to those of previous experiments.

Published
2015

2. Pentaquark $\Theta^+$ search at HERMES

Author

The HERMES Collaboration, Akopov, N., Akopov, Z., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Blok, H. P., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Di Nezza, P., Elbakian, G., Etzelmüller, E., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., García, J. Garay, Garibaldi, F., Gavrilov, G., Giordano, F., Gliske, S., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Ruiz, A. López, Lorenzon, W., Lu, X., Ma, B. -Q., Mahon, D., Manaenkov, S. I., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Nappi, E., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schnell, G., Schüler, K. P., Seitz, B., Shibata, T. -A., Stancari, M., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

The earlier search at HERMES for narrow baryon states excited in quasi-real photoproduction, decaying through the channel $pK_S^0\rightarrow p\pi^+\pi^-$, has been extended with improved decay-particle reconstruction, more advanced particle identification, and increased event samples. The structure observed earlier at an invariant mass of 1528 MeV shifts to 1522 MeV and the statistical significance drops to about 2$\sigma$ for data taken with a deuterium target. The number of events above background is $68_{-31}^{+98}\text{(stat)}\pm13\text{(sys)}$. No such structure is observed in the hydrogen data set.

Published
2014
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3. Spin density matrix elements in exclusive $\omega$ electroproduction on $^1$H and $^2$H targets at 27.5 GeV beam energy

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Augustyniak, W., Avetissian, A., Blok, H. P., Borissov, A., Bryzgalov, V., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Lorenzon, W., Ma, B. -Q., Mahon, D., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Movsisyan, A., Murray, M., Naryshkin, Y., Nass, A., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rostomyan, A., Ryckbosch, D., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shibata, T. -A., Stahl, M., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Yen, S., Zeiler, D., Zihlmann, B., and Zupranski, P.

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

Exclusive electroproduction of $\omega$ mesons on unpolarized hydrogen and deuterium targets is studied in the kinematic region of Q$^2$>1.0 GeV$^2$, 3.0 GeV < W < 6.3 GeV, and -t'< 0.2 GeV$^2$. Results on the angular distribution of the $\omega$ meson, including its decay products, are presented. The data were accumulated with the HERMES forward spectrometer during the 1996-2007 running period using the 27.6 GeV longitudinally polarized electron or positron beam of HERA. The determination of the virtual-photon longitudinal-to-transverse cross-section ratio reveals that a considerable part of the cross section arises from transversely polarized photons. Spin density matrix elements are presented in projections of Q$^2$ or -t'. Violation of s-channel helicity conservation is observed for some of these elements. A sizable contribution from unnatural-parity-exchange amplitudes is found and the phase shift between those amplitudes that describe transverse $\omega$ production by longitudinal and transverse virtual photons, $\gamma^{*}_{L} \to \omega_{T}$ and $\gamma^{*}_{T} \to \omega_{T}$, is determined for the first time. A hierarchy of helicity amplitudes is established, which mainly means that the unnatural-parity-exchange amplitude describing the $\gamma^*_T \to \omega_T$ transition dominates over the two natural-parity-exchange amplitudes describing the $\gamma^*_L \to \omega_L$ and $\gamma^*_T \to \omega_T$ transitions, with the latter two being of similar magnitude. Good agreement is found between the HERMES proton data and results of a pQCD-inspired phenomenological model that includes pion-pole contributions, which are of unnatural parity., Comment: "Erratum version", e.g., includes the corrected version of Figure 6, to be published in "Erratum to: Spin density matrix elements in exclusive omega electroproduction on 1H and 2H targets at 27.5 GeV beam energy". Three SDMEs were mislabeled in the figure of the previously published version [EPJC74(2014)3110]. The labels have been fixed, while none of the results or conclusions changed

Published
2014

4. Transverse polarization of $\Lambda$ hyperons from quasireal photoproduction on nuclei

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Lu, X. -G., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yu, W., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The transverse polarization of $\Lambda$ hyperons was measured in inclusive quasireal photoproduction for various target nuclei ranging from hydrogen to xenon. The data were obtained by the HERMES experiment at HERA using the 27.6 GeV lepton beam and nuclear gas targets internal to the lepton storage ring. The polarization observed is positive for light target nuclei and is compatible with zero for krypton and xenon., Comment: final version to be published in Phys. Rev. D (in press)

Published
2014
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5. Transverse target single-spin asymmetry in inclusive electroproduction of charged pions and kaons

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Yu, W., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle $\psi$ about the beam direction between the target-spin direction and the hadron production plane, the transverse hadron momentum relative to the direction of the incident beam, and the Feynman variable $x_F$. The $\sin(\psi)$ amplitudes are positive for positive pions and kaons, slightly negative for negative pions and consistent with zero for negative kaons, with particular transverse-momentum but weak $x_F$ dependences. Especially large asymmetries are observed for two small subsamples of events, where also the scattered electron was recorded by the spectrometer., Comment: 10 pages, 5 figures

Published
2013

6. Beam-helicity asymmetry in associated electroproduction of real photons $ep \to e\gamma \pi N$ in the $\Delta$-resonance region

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Blok, H. P., Böttcher, H., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Frullani, S., Gapienko, G., Gapienko, V., García, J. Garay, Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Lorenzon, W., Lu, X. -G., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Stahl, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zagrebelnyy, V., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The beam-helicity asymmetry in associated electroproduction of real photons, $ep\to e\gamma \pi N$, in the $\Delta$(1232)-resonance region is measured using the longitudinally polarized HERA positron beam and an unpolarized hydrogen target. Azimuthal Fourier amplitudes of this asymmetry are extracted separately for two channels, $ep\to e\gamma \pi^0 p$ and $ep\to e\gamma \pi^+ n$, from a data set collected with a recoil detector. All asymmetry amplitudes are found to be consistent with zero., Comment: 17 pages, 4 figures, (minor changes wit respect to previous arXiv version)

Published
2013
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7. Multiplicities of charged pions and kaons from semi-inclusive deep-inelastic scattering by the proton and the deuteron

Author

HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Izotov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Ma, B. -Q., Mahon, D., Maiheu, B., Makins, N. C. R., Manaenkov, S. I., Manfré, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Yu, W., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

Multiplicities in semi-inclusive deep-inelastic scattering are presented for each charge state of \pi^\pm and K^\pm mesons. The data were collected by the HERMES experiment at the HERA storage ring using 27.6 GeV electron and positron beams incident on a hydrogen or deuterium gas target. The results are presented as a function of the kinematic quantities x_B, Q^2, z, and P_h\perp. They represent a unique data set for identified hadrons that will significantly enhance our understanding of the fragmentation of quarks into final-state hadrons in deep-inelastic scattering.

Published
2012
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8. Beam-helicity asymmetry arising from deeply virtual Compton scattering measured with kinematically complete event reconstruction

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Gregor, I. M., Guler, H., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Krauss, B., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Lu, S., Lu, X., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfré, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Osborne, A., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shearer, C., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steijger, J. J. M., Stewart, J., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

The beam-helicity asymmetry in exclusive electroproduction of real photons by the longitudinally polarized HERA positron beam scattering off an unpolarized hydrogen target is measured at HERMES. The asymmetry arises from deeply virtual Compton scattering and its interference with the Bethe--Heitler process. Azimuthal amplitudes of the beam-helicity asymmetry are extracted from a data sample consisting of $ep\rightarrow ep\gamma$ events with detection of all particles in the final state including the recoiling proton. The installation of a recoil detector, while reducing the acceptance of the experiment, allows the elimination of background from $ep\rightarrow eN\pi\gamma$ events, which was estimated to contribute an average of about 12% to the signal in previous HERMES publications. The removal of this background from the present data sample is shown to increase the magnitude of the leading asymmetry amplitude by 0.054 +/- 0.016 to -0.328 +/- 0.027 (stat.) +/- 0.045 (syst.).

Published
2012
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9. Multidimensional Study of Hadronization in Nuclei

Author

HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Grigoryan, L., Hadjidakis, C., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Lu, X. -G., Lu, X. -R., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfré, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Truty, R., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Yu, W., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

Hadron multiplicities in semi-inclusive deep-inelastic scattering were measured on neon, krypton and xenon targets relative to deuterium at an electron(positron)-beam energy of 27.6 GeV at HERMES. These ratios were determined as a function of the virtual-photon energy nu, its virtuality Q2, the fractional hadron energy z and the transverse hadron momentum with respect to the virtual-photon direction pt . Dependences were analysed separately for positively and negatively charged pions and kaons as well as protons and antiprotons in a two-dimensional representation. Compared to the one-dimensional dependences, some new features were observed. In particular, when z > 0.4 positive kaons do not show the strong monotonic rise of the multiplicity ratio with nu as exhibited by pions and negative kaons. Protons were found to behave very differently from the other hadrons.

Published
2011
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10. Measurement of double-spin asymmetries associated with deeply virtual Compton scattering on a transversely polarized hydrogen target

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Di Nezza, P., Dueren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hartig, M., Hasch, D., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikas, L., Lehmann, I., Lenisa, P., Ruiz, A. Lopez, Lorenzon, W., Lu, X. -G., Lu, X. -R., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., de la Ossa, B. Marianski A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schaefer, A., Schnell, G., Schueler, K. P., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

Double-spin asymmetries in exclusive electroproduction of real photons from a transversely polarized hydrogen target are measured with respect to the product of target polarization with beam helicity and beam charge, and with respect to the product of target polarization with beam helicity alone. The asymmetries arise from the deeply virtual Compton scattering process and its interference with the Bethe--Heitler process. They are related to the real part of the same combination of Compton form factors as that determining the previously published transverse target single-spin asymmetries through the imaginary part. The results for the double-spin asymmetries are found to be compatible with zero within the uncertainties of the measurement, and are not incompatible with the predictions of the only available GPD-based calculation., Comment: 9 pages, 4 figures, and 3 tables

Published
2011
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11. Inclusive Measurements of Inelastic Electron and Positron Scattering from Unpolarized Hydrogen and Deuterium Targets

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dueren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lamb, R., Lapikas, L., Lehmann, I., Lenisa, P., Linden-Levy, L. A., Ruiz, A. Lopez, Lorenzon, W., Lu, X. -G., Lu, X. -R., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Pickert, N., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schaefer, A., Schnell, G., Schueler, K. P., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Taroian, S., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yen, S., Yu, W., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

Results of inclusive measurements of inelastic electron and positron scattering from unpolarized protons and deuterons at the HERMES experiment are presented. The structure functions $F_2^p$ and $F_2^d$ are determined using a parameterization of existing data for the longitudinal-to-transverse virtual-photon absorption cross-section ratio. The HERMES results provide data in the ranges $0.006\leq x\leq 0.9$ and 0.1 GeV$^2\leq Q^2\leq$ 20 GeV$^2$, covering the transition region between the perturbative and the non-perturbative regimes of QCD in a so-far largely unexplored kinematic region. They are in agreement with existing world data in the region of overlap. The measured cross sections are used, in combination with data from other experiments, to perform fits to the photon-nucleon cross section using the functional form of the ALLM model. The deuteron-to-proton cross-section ratio is also determined., Comment: 38 pages, 11 Figures, 9 Tables; Fig. 9 modified, Ref. [46] added, minor textual additions on pages 12 and 17

Published
2011
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12. Ratios of Helicity Amplitudes for Exclusive rho-0 Electroproduction

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dueren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lamb, R., Lapikas, L., Lehmann, I., Lenisa, P., Linden-Levy, L. A., Ruiz, A. Lopez, Lorenzon, W., Lu, X. -G., Lu, X. -R., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Pickert, N., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schaefer, A., Schnell, G., Schueler, K. P., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stinzing, F., Taroian, S., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Yen, S., Yu, W., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

Exclusive rho^0-meson electroproduction is studied in the HERMES experiment, using a 27.6 GeV longitudinally polarized electron/positron beam and unpolarized hydrogen and deuterium targets in the kinematic region 0.5 GeV^2 < Q^2 < 7.0 GeV^2, 3.0 GeV < W < 6.3 GeV, and -t' < 0.4 GeV^2. Real and imaginary parts of the ratios of the natural-parity-exchange helicity amplitudes T_{11} (\gamma^*_T --> \rho_T), T_{01} (\gamma^*_T --> \rho_L), T_{10} (\gamma^*_L --> \rho_T), and T_{1-1} (\gamma^*_{-T} -->\rho_T) to T_{00} (\gamma^*_L --> \rho_L) are extracted from the data. For the unnatural-parity-exchange amplitude U_{11}, the ratio |U_{11}/T_{00}| is obtained. The Q^2 and t' dependences of these ratios are presented and compared with perturbative QCD predictions., Comment: 27 pages, 8 tables, 13 figures; minor textual changes on pages 2, 3,9, 10, 11, and some changes to the list of references

Published
2010
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13. Effects of transversity in deep-inelastic scattering by polarized protons

Author

HERMES collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Bacchetta, A., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dueren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Izotov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Lagamba, L., Lamb, R., Lapikas, L., Lehmann, I., Lenisa, P., Linden-Levy, L. A., Ruiz, A. Lopez, Lorenzon, W., Lu, X. -G., Lu, X. -R., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Pickert, N., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schaefer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Trzcinski, A., Tytgat, M., van der Nat, P. B., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yen, S., Yu, W., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons and electrons off a transversely nuclear-polarized hydrogen target. The dependence of the cross section on the azimuthal angles of the target polarization (phi_S)and the produced hadron (phi) is found to have a substantial sin(phi+phi_S) modulation for the production of pi+, pi- and K+. This Fourier component can be interpreted in terms of non-zero transversity distribution functions and non-zero favored and disfavored Collins fragmentation functions with opposite sign. For pi0 and K- production the amplitude of this Fourier component is consistent with zero., Comment: 7 pages, 3 figures

Published
2010
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14. Study of the interactions of pions in the CALICE silicon-tungsten calorimeter prototype

Author

Adloff, C., Karyotakis, Y., Repond, J., Yu, J., Eigen, G., Mikami, Y., Watson, N. K., Wilson, J. A., Goto, T., Mavromanolakis, G., Thomson, M. A., Ward, D. R., Yan, W., Benchekroun, D., Hoummada, A., Khoulaki, Y., Apostolakis, J., Ribon, A., Uzhinskiy, V., Benyamna, M., Cârloganu, C., Fehr, F., Gay, P., Blazey, G. C., Chakraborty, D., Dyshkant, A., Francis, K., Hedin, D., Lima, J. G., Zutshi, V., Hostachy, J. -Y., Krastev, K., Morin, L., D'Ascenzo, N., Cornett, U., David, D., Fabbri, R., Falley, G., Gadow, K., Garutti, E., Göttlicher, P., Jung, T., Karstensen, S., Lucaci-Timoce, A. -I., Lutz, B., Meyer, N., Morgunov, V., Reinecke, M., Sefkow, F., Smirnov, P., Vargas-Trevino, A., Wattimena, N., Wendt, O., Feege, N., Groll, M., Haller, J., Heuer, R. -D., Morozov, S., Richter, S., Samson, J., Kaplan, A., Schultz-Coulon, H. -Ch., Shen, W., Tadday, A., Bilki, B., Norbeck, E., Onel, Y., Kim, E. J., Kim, G., Kim, D-W., Lee, K., Lee, S. C., Kawagoe, K., Tamura, Y., Dauncey, P. D., Magnan, A. -M., Yilmaz, H., Zorba, O., Bartsch, V., Postranecky, M., Warren, M., Wing, M., Green, M. G., Salvatore, F., Bedjidian, M., Kieffer, R., Laktineh, I., Fouz, M. -C., Bailey, D. S., Barlow, R. J., Kelly, M., Thompson, R. J., Danilov, M., Tarkovsky, E., Baranova, N., Karmanov, D., Korolev, M., Merkin, M., Voronin, A., Frey, A., Lu, S., Seidel, K., Simon, F., Soldner, C., Weuste, L., Bonis, J., Bouquet, B., Callier, S., Cornebise, P., Doublet, Ph., Giannelli, M. Faucci, Fleury, J., Li, H., Martin-Chassard, G., Richard, F., de la Taille, Ch., Poeschl, R., Raux, L., Seguin-Moreau, N., Wicek, F., Anduze, M., Boudry, V., Brient, J-C., Gaycken, G., Jeans, D., de Freitas, P. Mora, Musat, G., Reinhard, M., Rougé, A., Ruan, M., Vanel, J-Ch., Videau, H., Park, K-H., Zacek, J., Cvach, J., Gallus, P., Havranek, M., Janata, M., Marcisovsky, M., Polak, I., Popule, J., Tomasek, L., Tomasek, M., Ruzicka, P., Sicho, P., Smolik, J., Vrba, V., Zalesak, J., Belhorma, B., Belmir, M., Nam, S. W., Park, I. H., Yang, J., Chai, Jong-Seo, Kim, Jong-Tae, Kim, Geun-Bum, Kang, J., and Kwon, Y. -J.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

A prototype silicon-tungsten electromagnetic calorimeter for an ILC detector was tested in 2007 at the CERN SPS test beam. Data were collected with electron and hadron beams in the energy range 8 to 80 GeV. The analysis described here focuses on the interactions of pions in the calorimeter. One of the main objectives of the CALICE program is to validate the Monte Carlo tools available for the design of a full-sized detector. The interactions of pions in the Si-W calorimeter are therefore confronted with the predictions of various physical models implemented in the GEANT4 simulation framework.

Published
2010
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15. Exclusive Leptoproduction of Real Photons on a Longitudinally Polarised Hydrogen Target

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Ball, B., Belostotski, S., Bianchi, N., Blok, H. P., Boettcher, H., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dueren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Izotov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijne, V. G., Lagamba, L., Lamb, R., Lapikas, L., Lehmann, I., Lenisa, P., Linden-Levy, L. A., Lopez~Ruiz, A., Lorenzon, W., Lu, X. -G., Lu, X. -R., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Pickert, N., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schaefer, A., Schnell, G., Schueler, K. P., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P. B., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yen, S., Yu, W., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
High Energy Physics - Experiment
Abstract

Polarisation asymmetries are measured for the hard exclusive leptoproduction of real photons from a longitudinally polarised hydrogen target. These asymmetries arise from the deeply virtual Compton scattering and Bethe-Heitler processes. From the data are extracted two asymmetries in the azimuthal distribution of produced real photons about the direction of the exchanged virtual photon: A_UL with respect to the target polarisation and A_LL with respect to the product of the beam and target polarisations. Results for both asymmetries are compared to the predictions from a generalised parton distribution model. The sin(phi) and cos(0*phi) amplitudes observed respectively for the A_UL and A_LL asymmetries are compatible with the sizeable predictions from the model. Unexpectedly, a sin(2*phi) modulation in the A_UL asymmetry with a magnitude similar to that of the sin(phi) modulation is observed., Comment: 18 pages, 2 figures, 5 tables

Published
2010
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16. Construction and Commissioning of the CALICE Analog Hadron Calorimeter Prototype

Author

Adloff, C., Karyotakis, Y., Repond, J., Brandt, A., Brown, H., De, K., Medina, C., Smith, J., Li, J., Sosebee, M., White, A., Yu, J., Buanes, T., Eigen, G., Mikami, Y., Miller, O., Watson, N. K., Wilson, J. A., Goto, T., Mavromanolakis, G., Thomson, M. A., Ward, D. R., Yan, W., Benchekroun, D., Hoummada, A., Khoulaki, Y., Oreglia, M., Benyamna, M., Cârloganu, C., Gay, P., Ha, J., Blazey, G. C., Chakraborty, D., Dyshkant, A., Francis, K., Hedin, D., Lima, G., Zutshi, V., Babkin, V. A., Bazylev, S. N., Fedotov, Yu. I., Slepnev, V. M., Tiapkin, I. A., Volgin, S. V., Hostachy, J. -Y., Morin, L., D?Ascenzo, N., Cornett, U., David, D., Fabbri, R., Falley, G., Feege, N., Gadow, K., Garutti, E., Göttlicher, P., Jung, T., Karstensen, S., Korbel, V., Lucaci-Timoce, A. -I., Lutz, B., Meyer, N., Morgunov, V., Reinecke, M., Schätzel, S., Schmidt, S., Sefkow, F., Smirnov, P., Vargas-Trevino, A., Wattimena, N., Wendt, O., Groll, M., Heuer, R. -D., Richter, S., Samson, J., Kaplan, A., Schultz-Coulon, H. -Ch., Shen, W., Tadday, A., Bilki, B., Norbeck, E., Onel, Y., Kim, E. J., Kim, G., Kim, D-W., Lee, K., Lee, S. C., Kawagoe, K., Tamura, Y., Ballin, J. A., Dauncey, P. D., Magnan, A. -M., Yilmaz, H., Zorba, O., Bartsch, V., Postranecky, M., Warren, M., Wing, M., Giannelli, M. Faucci, Green, M. G., Salvatore, F., Kieffer, R., Laktineh, I., Fouz, M. C, Bailey, D. S., Barlow, R. J., Thompson, R. J., Batouritski, M., Dvornikov, O., Shulhevich, Yu., Shumeiko, N., Solin, A., Starovoitov, P., Tchekhovski, V., Terletski, A., Bobchenko, B., Chadeeva, M., Danilov, M., Markin, O., Mizuk, R., Novikov, E., Rusinov, V., Tarkovsky, E., Andreev, V., Kirikova, N., Komar, A., Kozlov, V., Soloviev, Y., Terkulov, A., Buzhan, P., Dolgoshein, B., Ilyin, A., Kantserov, V., Kaplin, V., Karakash, A., Popova, E., Smirnov, S., Baranova, N., Boos, E., Gladilin, L., Karmanov, D., Korolev, M., Merkin, M., Savin, A., Voronin, A., Topkar, A., Freyk, A., Kiesling, C., Lu, S., Prothmann, K., Seidel, K., Simon, F., Soldner, C., Weuste, L., Bouquet, B., Callier, S., Cornebise, P., Dulucq, F., Fleury, J., Li, H., Martin-Chassard, G., Richard, F., de la Taille, Ch., Poeschl, R., Raux, L., Ruan, M., Seguin-Moreau, N., Wicek, F., Anduze, M., Boudry, V., Brient, J-C., Gaycken, G., Cornat, R., Jeans, D., de Freitas, P. Mora, Musat, G., Reinhard, M., Rougé, A., Vanel, J-Ch., Videau, H., Park, K-H., Zacek, J., Cvach, J., Gallus, P., Havranek, M., Janata, M., Kvasnicka, J., Marcisovsky, M., Polak, I., Popule, J., Tomasek, L., Tomasek, M., Ruzicka, P., Sicho, P., Smolik, J., Vrba, V., Zalesak, J., Arestov, Yu., Ammosov, V., Chuiko, B., Gapienko, V., Gilitski, Y., Koreshev, V., Semak, A., Sviridov, Yu., Zaets, V., Belhorma, B., Belmir, M., Baird, A., Halsall, R. N., Nam, S. W., Park, I. H., Yang, J., Chai, Jong-Seo, Kim, Jong-Tae, Kim, Geun-Bum, Kim, Y., Kang, J., Kwon, Y. -J., Kim, Ilgoo, Lee, Taeyun, Park, Jaehong, Sung, Jinho, Itoh, S., Kotera, K., Nishiyama, M., Takeshita, T., Weber, S., and Zeitnitz, C.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

An analog hadron calorimeter (AHCAL) prototype of 5.3 nuclear interaction lengths thickness has been constructed by members of the CALICE Collaboration. The AHCAL prototype consists of a 38-layer sandwich structure of steel plates and highly-segmented scintillator tiles that are read out by wavelength-shifting fibers coupled to SiPMs. The signal is amplified and shaped with a custom-designed ASIC. A calibration/monitoring system based on LED light was developed to monitor the SiPM gain and to measure the full SiPM response curve in order to correct for non-linearity. Ultimately, the physics goals are the study of hadron shower shapes and testing the concept of particle flow. The technical goal consists of measuring the performance and reliability of 7608 SiPMs. The AHCAL was commissioned in test beams at DESY and CERN. The entire prototype was completed in 2007 and recorded hadron showers, electron showers and muons at different energies and incident angles in test beams at CERN and Fermilab., Comment: 36 pages, 32 figures

Published
2010
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17. Hard Exclusive Electroproduction of Two Pions off Proton and Deuteron at HERMES

Author

di Nezza, P. and Fabbri, R.

Subjects
High Energy Physics - Experiment
Abstract

Exclusive electroproduction of $\pi^+\pi^-$ pairs off hydrogen and deuterium targets has been studied with the HERMES experiment. The angular distribution of the $\pi^+$ in the $\pi^+\pi^-$ rest system has been studied in the invariant mass range $0.3 < m_{\pi\pi} <1.5$ GeV. Theoretical models derived in the framework of the Generalized Parton Distributions show that this angular distribution receives only contributions from the interference between the isoscalar channel I=0 and the isovector channel I=1., Comment: 5 pages, LaTex, 9 EPS figures. Talk given by R.Fabbri at SPIN 2002, BNL. References modified

Published
2002
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18. Spin density matrix elements in exclusive rho (0) electroproduction on H-1 and H-2 targets at 27.5 GeV beam energy

Author

Airapetian, A., Akopov, N., Akopov, Z., Andrus, A., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetissian, E., Belostotski, S., Bianchi, N., Blok, H. P., Böttcher, H., Bonomo, C., Borissov, A., Brüll, A., Bryzgalov, V., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., Demey, M., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dreschler, J., Düren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Funel, A., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Grebeniouk, O., Gregor, I. M., Guler, H., Hadjidakis, C., Hartig, M., Hasch, D., Hasegawa, T., Hesselink, W. H. A., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Hristova, I., Iarygin, G., Imazu, Y., Ivanilov, A., Izotov, A., Jackson, H. E., Jgoun, A., Kaiser, R., Keri, T., Kinney, E., Kisselev, A., Kobayashi, T., Kopytin, M., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lamb, R., Lapikás, L., Lehmann, I., Lenisa, P., Liebing, P., Linden-Levy, L. A., Lorenzon, W., Lu, S., Lu, X.-R., Ma, B.-Q., Maiheu, B., Makins, N. C. R., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Mexner, V., Miller, C. A., Miyachi, Y., Muccifora, V., Murray, M., Mussgiller, A., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.-D., Osborne, A., Pappalardo, L. L., Perez-Benito, R., Pickert, N., Raithel, M., Reggiani, D., Reimer, P. E., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rock, S. E., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shearer, C., Shibata, T.-A., Shutov, V., Stancari, M., Statera, M., Steffens, J. E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Streit, J., Tait, P., Taroian, S., Tchuiko, B., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P. B., van der Steenhoven, G., Van Haarlem, Y., Van Hulse, C., Varanda, M., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, H., Ye, Y., Ye, Z., Yen, S., Yu, W., Zeiler, D., Zihlmann, B., Zupranski, P., (Astro)-Particles Physics, Photo Conversion Materials, Network Institute, Student Lab and Education, and Artificial Intelligence (section level)

Subjects
HERMES experiment, Particle physics, Hydrogen, Physics and Astronomy (miscellaneous), FOS: Physical sciences, chemistry.chemical_element, Kinematics, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, SDG 14 - Life Below Water, Nuclear Experiment, 010306 general physics, Engineering (miscellaneous), Physics, 010308 nuclear & particles physics, Polarization (waves), Helicity, Amplitude, Deuterium, chemistry, High Energy Physics::Experiment, Condensed Matter::Strongly Correlated Electrons, Beam energy
Abstract

Spin Density Matrix Elements (SDMEs) describing the angular distribution of exclusive rho^0 electroproduction and decay are determined in the HERMES experiment with 27.6 GeV beam energy and unpolarized hydrogen and deuterium targets. Eight (fifteen) SDMEs that are related (unrelated) to the longitudinal polarization of the beam are extracted in the kinematic region 1 GeV^2 < Q^2 < 7 GeV^2, 3.0 GeV < W < 6.3 GeV, and -t < 0.4 GeV^2. Within the given experimental uncertainties, a hierarchy of relative sizes of helicity amplitudes is observed. Kinematic dependences of all SDMEs on Q^2 and t are presented, as well as the longitudinal-to-transverse rho^0 electroproduction cross section ratio as a function of Q^2. A small but statistically significant deviation from the hypothesis of s-channel helicity conservation is observed. An indication is seen of a contribution of unnatural-parity-exchange amplitudes; these amplitudes are naturally generated with a quark-exchange mechanism., 41 pages, 20 figures, 16 table; revised version corrects small typos, text clarified on 6 pages, two references added and new data added to figure 20

Published
2009
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19. Bose–Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

Author

Airapetian, A., Akopov, N., Blok, H. P., Statera, M., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Borissov, A., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zihlmann, B., Zupranski, P., HERMES Collaboration, Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Akopov, Z., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Aschenauer, E. C., Fantoni, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Garay Garcia, Jasone, Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Augustyniak, W., Gliske, S., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Avakian, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Avetissian, A., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Lu, X. -G., Ma, B. -Q., Mahon, D., Makins, N. C. R., Mao, Y., Marianski, B., Avetisyan, E., Martinez de la Ossa, Alberto, Marukyan, H., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Belostotski, S., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, Anush, Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Bianchi, N., Rubin, J., Ryckbosch, D., Salomatin, Y., Schäfer, A., Schnell, Gunar, Seitz, B., Shibata, T. -A., Shutov, V., Stahl, M., and Stancari, M.

Subjects
High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, ddc:530, Nuclear Experiment (nucl-ex), Nuclear Experiment, High Energy Physics - Experiment
Abstract

Bose-Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of $^1$H, $^2$H, $^3$He, $^4$He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose-Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose-Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidence for a dependence on the invariant mass $W$ of the photon-nucleon system is found when the results are compared to those of previous experiments.

Published
2015
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20. Leading-order determination of the gluon polarization from high-p T hadron electroproduction

Author

Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Ball, B., Belostotski, S., Bianchi, N., Blok, H. P., Bottcher, H., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capiluppi, Marco, Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, Marco, Ferretti, Paola, Deconinck, W., Leo, R. D., Nardo, L. D., Sanctis, E. D., Diefenthaler, M., Nezza, P. D., Duren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, Francesca, Gliske, S., Guler, H., Guzey, V., Haan, S., Hadjidakis, C., Hartig, M., Hasch, D., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., H. S., Jo, Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Lagamba, L., Lamb, R., Lapikas, L., Lehmann, I., Lenisa, Paolo, Ruiz, A. L., Lorenzon, W., X. G., Lu, X. R., Lu, B. Q., Ma, Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., Marianski, B., de la Ossa, A. M., Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. D., Pappalardo, Luciano Libero, Perez Benito, R., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schafer, A., Schnell, G., Schuler, K. P., Shanidze, R., Shibata, T. A., Shutov, V., Stancari, Michelle Dawn, Statera, Marco, Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Haarlem, Y. V., Hulse, C. V., Varanda, M., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yu, W., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
Nuclear and High Energy Physics, Particle physics, High Energy Physics::Lattice, Nuclear Theory, Lepton-Nucleon Scattering, Hadron, Monte Carlo method, FOS: Physical sciences, neutron spin structure, transverse momentum, 01 natural sciences, High Energy Physics - Experiment, NO, High Energy Physics - Experiment (hep-ex), deep inelastic scattering, 0103 physical sciences, ddc:530, Nuclear Experiment, 010306 general physics, s Hermes experiment, Lepton-Nucleon Scattering, deep inelastic scattering, neutron spin structure, dependent structure functions, electron storage ring, parton distribution,s Hermes experiment, transverse momentum, proton scattering, EP scattering, Physics, electron storage ring, dependent structure functions, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, EP scattering, HERA, Polarization (waves), parton distribution, Gluon, Deuterium, proton scattering, Transverse momentum, High Energy Physics::Experiment, Nucleon
Abstract

Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum $p_T$ have been measured in electroproduction using the \hermes\ detector at \hera. Processes involving gluons in the nucleon have been enhanced relative to others by selecting hadrons with $p_T$ typically above 1 GeV. In this kinematic domain the gluon polarization has been extracted in leading order making use of the model embedded in the Monte Carlo Generator \Pythia\ 6.2. The gluon polarization obtained from single inclusive hadrons in the $p_T$ range 1 GeV $< p_T

Published
2010
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21. Separation of contributions from deeply virtual Compton scattering and its interference with the Bethe-Heitler process in measurements on a hydrogen target

Author

Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Bacchetta, A., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, Marco, Capitani, G. P., Cisbani, E., Ciullo, Giuseppe, Contalbrigo, Marco, Ferretti, Paola, Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dueren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gharibyan, V., Giordano, Francesca, Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Izotov, A., Jackson, H. E., H. S., Jo, Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Lagamba, L., Lamb, R., Lapikas, L., Lehmann, I., Lenisa, Paolo, Linden Levy, L. A., Lopez Ruiz, A., Lorenzon, W., X. G., Lu, X. R., Lu, B. Q., Ma, Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., Marianski, B., Martinez de la Ossa, A., Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. D., Pappalardo, Luciano Libero, Perez Benito, R., Pickert, N., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schaefer, A., Schnell, G., Seitz, B., Shibata, T. A., Shutov, V., Stancari, Michelle Dawn, Statera, Marco, Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Trzcinski, A., Tytgat, M., van der Nat, P. B., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yen, S., Yu, W., Zeiler, D., Zihlmann, B., Zupranski, P., and Biophotonics and Medical Imaging

Subjects
Nuclear and High Energy Physics, Particle physics, Photon, Proton, 12.39.-x Phenomenological quark models, FOS: Physical sciences, Parton, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Cross section (physics), Lepton-nucleon scattering, 0103 physical sciences, time reversal and other discrete symmetries, ddc:530, 010306 general physics, 11.30.Er Charge conjugation, Physics, Luminosity (scattering theory), 010308 nuclear & particles physics, Compton scattering, Helicity, 13.60.Fz Elastic and Compton scattering, parity, 11.30.Er Charge conjugation, parity, time reversal and other discrete symmetries, 13.60.Hb Total and inclusive cross sections (including deep-inelastic processes), Beam (structure)
Abstract

Hard exclusive leptoproduction of real photons from an unpolarized proton target is studied in an effort to elucidate generalized parton distributions. The data accumulated during the years 1996--2005 with the HERMES spectrometer are analyzed to yield asymmetries with respect to the combined dependence of the cross section on beam helicity and charge, thereby revealing previously unseparated contributions from deeply virtual Compton scattering and its interference with the Bethe--Heitler process. The integrated luminosity is sufficient to show correlated dependences on two kinematic variables, and provides the most precise determination of the dependence on only the beam charge., 21 pages, 5 Figures, and 5 Tables

Published
2009
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22. Single-spin azimuthal asymmetry in exclusive electroproduction of pi+ mesons on transversely polarized protons

Author

Airapetian, A, Akopov, N, Akopov, Z, Aschenauer, EC, Augustyniak, W, Avetissian, A, Avetisyan, E, Ball, B, Belostotski, S, Bianchi, N, Blok, HP, Bottcher, H, Bonomo, C, Borissov, A, Bryzgalov, V, Burns, J, Capiluppi, M, Capitani, GP, Cisbani, E, Ciullo, G, Contalbrigo, M, Dalpiaz, PF, Deconinck, W, De Leo, R, De Nardo, Lara, De Sanctis, E, Diefenthaler, M, Di Nezza, P, Dreschler, J, Duren, M, Ehrenfried, M, Elbakian, G, Ellinghaus, F, Fabbri, R, Fantoni, A, Felawka, L, Frullani, S, Gabbert, Dominik, Gapienko, V, Garibaldi, F, Gharibyan, V, Giordano, F, Gliske, S, Hadjidakis, C, Hartig, M, Hasch, D, Hill, G, Hillenbrand, A, Hoek, M, Holler, Y, Hristova, I, Imazu, Y, Ivanilov, A, Jackson, HE, Jo, HS, Joosten, S, Kaiser, R, Keri, T, Kinney, E, Kisselev, A, Kobayashi, N, Korotkov, V, Kravchenko, P, Lagamba, L, Lamb, R, Lapikas, L, Lehmann, I, Lenisa, P, Linden-Levy, LA, Lopez Ruiz, Alejandro, Lorenzon, W, Lu, XG, Lu, XR, Ma, BQ, Mahon, D, Makins, NCR, Manaenkov, SI, Manfre, L, Mao, Y, Marianski, B, de la Ossa, BM, Marukyan, H, Miller, CA, Miyachi, Y, Movsisyan, A, Muccifora, V, Murray, M, Mussgiller, A, Nappi, E, Naryshkin, Y, Nass, A, Nowak, WD, Pappalardo, LL, Perez-Benito, R, Reimer, PE, Reolon, AR, Riedl, C, Rith, K, Rosner, G, Rostomyan, A, Rubin, J, Ryckbosch, Dirk, Salomatin, Y, Sanftl, F, Schafer, A, Schnell, Gunar, Schuler, KP, Seitz, B, Shibata, TA, Shutov, V, Stancari, M, Statera, M, Steijger, JJM, Stenzel, H, Stewart, J, Taroian, S, Terkulov, A, Trzcinski, A, Tytgat, Michael, Vandenbroucke, A, van der Nat, PB, Van Haarlem, Y, Van Hulse, Charlotte, Varanda, M, Veretennikov, D, Vikhrov, V, Vilardi, I, Vogel, C, Wang, S, Yaschenko, S, Ye, H, Ye, Z, Yen, S, Yu, W, Zeiler, D, Zihlmann, B, and Zupranski, P

Subjects
14.40.Aq, RING, IMPACT PARAMETER SPACE, FOS: Physical sciences, HYDROGEN, 13.60.-rm, 13.60.Le, 13.85.Lg, 14.20.Dh, PHYSICS EVENT GENERATION, LIMIT, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), TARGET, Physics and Astronomy, GENERALIZED PARTON DISTRIBUTIONS, SCATTERING, ddc:530, High Energy Physics::Experiment, NUCLEON, Nuclear Experiment, TO-LEADING ORDER
Abstract

Exclusive electroproduction of pi+ mesons was studied by scattering 27.6 GeV positrons or electrons off a transversely polarized hydrogen target. The single-spin azimuthal asymmetry with respect to target polarization was measured as a function of the Mandelstam variable t, the Bjorken scaling variable x_B, and the virtuality Q^2 of the exchanged photon. The extracted Fourier components of the asymmetry were found to be consistent with zero, except one that was found to be large and that involves interference of contributions from longitudinal and transverse virtual photons., 7 pages, 2 figures

Published
2009
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23. Quark helicity distributions in the nucleon for up, down, and strange quarks from semi-inclusive deep-inelastic scattering

Author

Airapetian, A., Akopov, N., Avetissian, E., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C. A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Bailey, P., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. D., Oganessyan, K., Ohsuga, H., Pickert, N., Potashov, S., Potterveld, D. H., Baturin, V., Raithel, M., Reggiani, D., Reimer, P. E., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Baumgarten, C., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K. P., Beckmann, M., Schwind, A., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T. A., Shutov, V., Simani, M. C., Sinram, K., Belostotski, S., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stosslein, U., Tait, P., Tanaka, H., Taroian, S., Bernreuther, S., Tchuiko, B., Terkulov, A., Tkabladze, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P., van der Steenhoven, G., Vetterli, M. C., Vikhrov, V., Bianchi, N., Vincter, M. G., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Ybeles Smit, G., Yen, S., Zihlmann, B., Blok, H. P., Zohrabian, H., Zupranski, P., HERMES Collaboration, Blumlein, J., Akopov, Z., Bottcher, H., Borissov, A., Borysenko, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G. P., Chiang, H. C., Ciullo, G., Amarian, M., Contalbrigo, M., Dalpiaz, P. F., De Leo, R., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Duren, M., Ehrenfried, M., Elalaoui-Moulay, A., Ammosov, V. V., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Franz, J., Andrus, A., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Aschenauer, E. C., Grebeniouk, O., Greeniaus, L. G., Gregor, I. M., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W. H. A., Augustyniak, W., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H. E., Jgoun, A., Kaiser, R., Avakian, R., Kinney, E., Kisselev, A., Konigsmann, K., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, Louk, Avetissian, A., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Linden-Levy, L. A., Lipka, K., Lorenzon, W., Lu, J., Maiheu, B., Makins, N. C. R., (Astro)-Particles Physics, Photo Conversion Materials, and Student Lab and Education

Subjects
Quark, internal [polarized target], Nuclear and High Energy Physics, Particle physics, Strange quark, sea [quark], High Energy Physics::Lattice, deep inelastic scattering [positron deuteron], Hadron, Nuclear Theory, dependence [flavor], Down quark, FOS: Physical sciences, HERMES, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), density [helicity], 27.5 GeV, Pion, 0103 physical sciences, ddc:530, SDG 14 - Life Below Water, deep inelastic scattering [positron p], 010306 general physics, electroproduction [pi], Physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, polarization [quark], Deep inelastic scattering, moment, Baryon, DESY HERA Stor, electroproduction [K], Up quark, valence [quark], polarization [cross section], High Energy Physics::Experiment, polarized beam [positron], asymmetry [spin], experimental results
Abstract

Polarized deep-inelastic scattering data on longitudinally polarized hydrogen and deuterium targets have been used to determine double-spin asymmetries of cross sections. Inclusive and semi-inclusive asymmetries for the production of positive and negative pions from hydrogen were obtained in a reanalysis of previously published data. Inclusive and semi-inclusive asymmetries for the production of negative and positive pions and kaons were measured on a polarized deuterium target. The separate helicity densities for the up and down quarks and the anti-up, anti-down, and strange sea quarks were computed from these asymmetries in a "leading order" QCD analysis. The polarization of the up-quark is positive and that of the down-quark is negative. All extracted sea quark polarizations are consistent with zero, and the light quark sea helicity densities are flavor symmetric within the experimental uncertainties. First and second moments of the extracted quark helicity densities in the measured range are consistent with fits of inclusive data. © 2005 The American Physical Society.

Published
2005
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24. Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target

Author

Airapetian, A., Akopov, N., Bacchetta, A., Mikloukho, O., Miller, C. A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. D., Bailey, P., Oganessyan, K., Ohsuga, H., Osborne, A., Pickert, N., Potterveld, D. H., Raithel, M., Reggiani, D., Reimer, P. E., Reischl, A., Reolon, A. R., Balin, D., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, Igor A., Beckmann, M., Schafer, A., Schill, C., Schnell, G., Schuler, K. P., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T. A., Belostotski, S., Shutov, V., Sinram, K., Sommer, W., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Bianchi, N., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P. B., van der Steenhoven, G., Blok, H. P., van Haarlem, Y., Vetterli, M. C., Vikhrov, V., Vincter, M. G., Vogel, C., Volmer, J., Wang, S., Wendland, J., Wilbert, J., Ybeles Smit, G., Bottcher, H., Ye, Y., Ye, Z., Yen, S., Zihlmann, B., Zupranski, P., HERMES Collaboration, Borissov, A., Borysenko, A., Akopov, Z., Bouwhuis, M., Brull, A., Bryzgalov, V., Capitani, G. P., Cappiluppi, M., Chen, T., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., De Leo, R., Amarian, M., Demey, M., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Duren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Andrus, A., Elschenbroich, U., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Aschenauer, E. C., Gavrilov, G., Gharibyan, V., Grebeniouk, O., Gregor, I. M., Hadjidakis, C., Hafidi, K., Hartig, M., Hasch, D., Henoch, M., Hesselink, W. H. A., Augustyniak, W., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Hristova, I., Iarygin, G., Ilyichev, A., Ivanilov, A., Izotov, A., Jackson, H. E., Avakian, R., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Kobayashi, T., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V. G., Avetissian, A., Lagamba, L., Lapikas, Louk, Laziev, A., Lenisa, P., Liebing, P., Linden-Levy, L. A., Lorenzon, W., Lu, H., Lu, J., Lu, S., Avetissian, E., Ma, B. Q., Maiheu, B., Makins, N. C. R., Mao, Y., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Michler, T., (Astro)-Particles Physics, Photo Conversion Materials, and Student Lab and Education

Subjects
Particle physics, transverse [polarization], Nuclear Theory, FOS: Physical sciences, General Physics and Astronomy, HERMES, 13.60.–r, Inelastic scattering, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 27.5 GeV, Pion, 13.88.+e, ddc:550, Vector meson, SDG 14 - Life Below Water, deep inelastic scattering [positron p], 14.20.Dh, 14.65.–q, Nuclear Experiment, Physics, Scattering, polarized target [hydrogen], High Energy Physics::Phenomenology, polarization [quark], Deep inelastic scattering, +pi+positron+anything%22">positron p --> pi positron anything, angular dependence, DESY HERA Stor, Distribution function, High Energy Physics::Experiment, transverse momentum [quark], Nucleon, electroproduction [pi+], asymmetry [spin], electroproduction [pi-], Lepton, experimental results
Abstract

Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of both the pion ($\ensuremath{\phi}$) and the target spin axis (${\ensuremath{\phi}}_{S}$) about the virtual-photon direction and relative to the lepton scattering plane. The extracted Fourier component $\mathbf{⟨}\mathrm{sin} (\ensuremath{\phi}+{\ensuremath{\phi}}_{S}){\mathbf{⟩}}_{UT}^{\ensuremath{\pi}}$ is a signal of the previously unmeasured quark transversity distribution, in conjunction with the Collins fragmentation function, also unknown. The component $\mathbf{⟨}\mathrm{sin} (\ensuremath{\phi}\ensuremath{-}{\ensuremath{\phi}}_{S}{\mathbf{⟩}}_{UT}^{\ensuremath{\pi}}$ arises from a correlation between the transverse polarization of the target nucleon and the intrinsic transverse momentum of quarks, as represented by the previously unmeasured Sivers distribution function. Evidence for both signals is observed, but the Sivers asymmetry may be affected by exclusive vector meson production.

Published
2005
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25. Measurement of single-spin azimuthal asymmetries in semi-inclusive electroproduction of pions and kaons on a longitudinally polarised deuterium target

Author

Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Andrus, A., Aschenauer, E.C., Augustyniak, W., Avakian, H., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Baturin, V., Baumgarten, C., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Blok, H.P., Bottcher, H., Borissov, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G.P., Chiang, H.C., Ciullo, G., Contalbrigo, M., Court, G.R., Dalpiaz, P.F., De Leo, R., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Duren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Eischenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Franz, J., Frullani, S., Garber, Y., Gapienko, G., Gapienko, V., Garibaldi, F., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Greeniaus, L.G., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hillenbrand, A., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H.E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Konigsmann, K., Kolster, H., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V.G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T, Lipka, K., Lorenzon, W., Ma, B., Makins, N.C.R., Marukyan, H., Masoli, F., Menden, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C.A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Nowak, W.D., Oganessyan, K., Ohsuga, H., Orlandi, G., Potashov, S., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P.E., Reischl, A., Reolon, A.R., Rith, K., Rosner, G., Rostomyan, A., Ryckbosch, D., Sanjiev, I., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K.P., Schwind, A., Seidl, R., Seibert, J., Seitz, B., Shanidze, R., Shibata, T., Shutov, V., Simani, M.C., Sinram, K., Stancari, M., Statera, M., Steffens, E., Steijger, J.J.M., Stewart, J., Stosslein, U., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Tessarin, S., Thomas, E., Tkabladze, A., Trzcinski, A., Tytgat, A., Urciuoli, G.M., van der Nat, P., van der Steenhoven, G., Van de Vyver, R., Vetterli, M.C., Vikhrov, V., Vincter, M.G., Visser, J., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Zihlmann, B., Zohrabian, H., Zupranski, P., Photo Conversion Materials, (Astro)-Particles Physics, and Student Lab and Education

Subjects
Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, Hadron, Virtual particle, FOS: Physical sciences, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Pion, 13.88.+e, 0103 physical sciences, 010306 general physics, Nuclear Experiment, QC, Spin-½, 13.60.-r, Physics, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Deuterium, 13.87.Fh, 14.20.Dh, Condensed Matter::Strongly Correlated Electrons, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, SDG 6 - Clean Water and Sanitation, Lepton
Abstract

Single-spin asymmetries have been measured for semi-inclusive electroproduction of $\pi^+$, $\pi^-$, $\pi^0$ and $K^+$ mesons in deep-inelastic scattering off a longitudinally polarised deuterium target. The asymmetries appear in the distribution of the hadrons in the azimuthal angle $\phi$ around the virtual photon direction, relative to the lepton scattering plane. The corresponding analysing powers in the $\sin \phi$ moment of the cross section are $0.012 \pm 0.002 {(stat.)} \pm 0.002 {(syst.)}$ for $\pi^+$, $0.006 \pm 0.003 {(stat.)} \pm 0.002 {(syst.)}$ for $\pi^-$, $0.021 \pm 0.005 {(stat.)} \pm 0.003 {(syst.)}$ for $\pi^0$ and $0.013 \pm 0.006 {(stat.)} \pm 0.003 {(syst.)}$ for $K^+$. The $\sin 2\phi$ moments are compatible with zero for all particles., Comment: Revised version shortened 9 pages, 3 tables, 7 figures

Published
2002
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26. Evidence for a transverse single-spin asymmetry in leptoproduction of π+π−pairs

Author

Hermes, Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Andrus, A., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Barion, Luca, Belostotski, S., Bianchi, N., Blok, H. P., Böttcher, H., Bonomo, C., Borissov, A., Brüll, A., Bryzgalov, V., Burns, J., Capiluppi, Marco, Capitani, G. P., Cisbani, E., Ciullo, Giuseppe, Contalbrigo, Marco, Ferretti, Paola, Deconinck, W., De Leo, R., Demey, M., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dreschler, J., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Funel, A., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, Francesca, Gliske, S., Guler, H., Hadjidakis, C., Hasch, D., Hasegawa, T., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Iarygin, G., Imazu, Y., Ivanilov, A., Izotov, A., Jackson, H. E., Jgoun, A., Joosten, S., Kaiser, R., Keri, T., Kinney, E., Kisselev, A., Kopytin, M., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lamb, R., Lapikás, L., Lehmann, I., Lenisa, Paolo, Linden Levy, L. A., Lorenzon, W., Lu, S., Lu, X., B. Q., Ma, Mahon, D., Maiheu, B., Makins, N. C. R., Mao, Y., Marianski, B., Marukyan, H., Miller, C. A., Miyachi, Y., Muccifora, V., Murray, M., Mussgiller, A., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. D., Osborne, A., Pappalardo, Luciano Libero, Perez Benito, R., Pickert, N., Raithel, M., Reimer, P. E., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rock, S. E., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ruiz, A. L., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shearer, C., Shibata, T. A., Shutov, V., Stancari, Michelle Dawn, Statera, Marco, Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Tait, P., Taroian, S., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P. B., van der Steenhoven, G., Van Haarlem, Y., Van Hulse, C., Varanda, M., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yen, S., Yu, W., Zeiler, D., Zihlmann, B., and Zupranski, P.

Subjects
Quark, Nuclear and High Energy Physics, Particle physics, media_common.quotation_subject, FOS: Physical sciences, 01 natural sciences, Asymmetry, Molecular physics, NO, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 14.40.Aq pi K and eta mesons, 0103 physical sciences, Pi, ddc:530, Nuclear Experiment, 010306 general physics, media_common, Physics, 010308 nuclear & particles physics, Scattering, 25.30.-c Lepton-induced reactions, Polarization (waves), 24.70.+s polarization in electron scattering, Azimuth, Transverse plane, Distribution function, High Energy Physics::Experiment
Abstract

A single-spin asymmetry was measured in the azimuthal distribution of pi+pi- pairs produced in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target. For the first time, evidence is found for a correlation between the transverse target polarization and the azimuthal orientation of the plane containing the two pions.The corresponding single-spin asymmetry is expected to be related to the product of the little-known quark transversity distribution function and an unknown naive-T-odd chiral-odd dihadron fragmentation function., Comment: 18 pages, 4 figures, 1 table; minor revisions to content for clarity

Published
2008
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27. CALICE Report to the DESY Physics Research Committee

Author

Adloff, C., Blaha, J., Chefdeville, M., Drancourt, C., Espargilière, A., Gaglione, R., Geffroy, N., Karyotakis, Y., Prast, J., Vouters, G., Cundiff, T., De Lurgio, P., Drake, G., Francis, K., Haberichter, B., Guarino, V., Kreps, A., May, E., Repond, J., Schlereth, J., Skrzecz, F., Smith, J., Underwood, D., Wood, K., Xia, L., Zhang, Q., Zhao, A., Baldolemar, E., Brandt, A., De, K., Park, K.J., Park, S.T., Sosebee, M., White, A., Yu, J., Deng, Z., Li, Y., Wang, Y., Yue, Q., Yang, Z., Eigen, G., Fehlker, D., Sandaker, H., Watson, N.K., Butler, J., Hazen, E., Wu, S., Hommels, L.B.A., Marshall, J.S., Thomson, M.A., Ward, D.R., Benchekroun, D., Hoummada, A., Khoulaki, Y., Apostolakis, J., Dannheim, D., Dotti, A., Elsener, K., Folger, G., Grefe, C., Killenberg, M., Klempt, W., van der Kraaij, E., Linssen, L., Lucaci-Timoce, A.-I., Muennich, A., Nardulli, J., Perini, D., Poss, S., Sailer, A., Schlatter, D., Speckmayer, P., Uzhinskiy, V., Oreglia, M., Benyamna, M., Cârloganu, C., Fehr, F., Gay, P., Manen, S., Royer, L., Tytgat, M., Zaganidis, N., Ha, J., Abu-Ajamieh, F., Blazey, G.C., Chakraborty, D., Dyshkant, A., Hedin, D., Hill, J., Lima, J.G.R., Salcido, R., Rykalin, V., Zutshi, V., Astakhov, V., Babkin, V.A., Bazylev, S.N., Fedotov, Yu.I., Golovatyuk, S., Golutvin, I., Gorbunov, N., Malakhov, A., Slepnev, S., Tyapkin, I., Volgin, S.V., Zanevski, Y., Zintchenko, A., Dzahini, D., Gallin-Martel, L., Giraud, J., Grondin, D., Hostachy, J.-Y., Krastev, K., Morin, L., Rarbi, F-E., Cornett, U., David, D., Fabbri, R., Falley, G., Gadow, K., Garutti, E., Göttlicher, P., Günter, C., Karstensen, S., Krivan, F., Kschioneck, K., Lu, S., Lutz, B., Marchesini, I., Meyer, N., Morozov, S., Morgunov, V., Reinecke, M., Sefkow, F., Smirnov, P., Terwort, M., Vargas-Trevino, A., Wattimena, N., Wendt, O., Feege, N., Haller, J., Samson, J., Eckert, P., Harion, T., Kaplan, A., Schultz-Coulon, H.-Ch., Shen, W., Stamen, R., Tadday, A., Bilki, B., Norbeck, E., Northacker, D., Onel, Y., Kim, E.J., Kim, G., Kim, D-W., Lee, K., Lee, S.C., van Doren, B., Wilson, G.W., Kawagoe, K., Dauncey, P.D., Bartsch, V., Postranecky, M., Warren, M., Wing, M., Boisvert, V., Green, B., Misiejuk, A., Salvatore, F., Cortina Gil, E., Mannai, S., Nuessle, G., Bedjidian, M., Bonnevaux, A., Combaret, C., Caponetto, L., Grenier, G., Han, R., Ianigro, J.C., Kieffer, R., Laktineh, I., Lumb, N., Mathez, H., Vander Donckt, M., Berenguer Antequera, J., Calvo Alamillo, E., Fouz, M.-C., Marin, J., Puerta-Pelayo, J., Bailey, D.S., Barlow, R.J., Thompson, R.J., Batouritski, M., Dvornikov, O., Shulhevich, Yu., Shumeiko, N., Solin, A., Starovoitov, P., Tchekhovski, V., Terletski, A., Corriveau, F., Trojand, D., Balagura, V., Bobchenko, B., Chadeeva, M., Danilov, M., Markin, O., Mizuk, R., Novikov, E., Rusinov, V., Tarkovsky, E., Andreev, V., Kirikova, N., Komar, A., Kozlov, V., Negodaev, M., Soloviev, Y., Terkulov, A., Buzhan, P., Dolgoshein, B., Ilyin, A., Kantserov, V., Kaplin, V., Karakash, A., Popova, E., Smirnov, S., Baranova, N., Boos, E., Gladilin, L., Karmanov, D., Korolev, M., Merkin, M., Savin, A., Voronin, A., Singh, A., Topkar, A., Kiesling, C., Klenze, P., Seidel, K., Simon, F., Soldner, C., Tesar, M., Weuste, L., Bonis, J., Bouquet, B., Callier, S., Cornebise, P., Doublet, Ph., Dulucq, F., Faucci Giannelli, M., Fleury, J., Frisson, T., Guilhem, G., Li, H., Martin-Chassard, G., Richard, F., de la Taille, Ch., Poeschl, R., Raux, L., Seguin-Moreau, N., Wicek, F., Zhang, Z., Anduze, M., Amjad, M.S., Belkadhi, K., Bercher, M., Boudry, V., Brient, J-C., Clerc, C., Cornat, R., Decotigny, D., Frotin, M., Gastaldi, F., Jeans, D., Matthieu, A., Mora de Freitas, P., Musat, G., Roig, J.F., Ruan, M., Videau, H., Park, K-H., Bulanek, B., Zacek, J., Cvach, J., Gallus, P., Havranek, M., Janata, M., Kvasnicka, J., Lednicky, D., Marcisovsky, M., Polak, I., Popule, J., Tomasek, L., Tomasek, M., Ruzicka, P., Sicho, P., Smolik, J., Vrba, V., Zalesak, J., Arestov, Yu., Ammosov, V., Chuiko, B., Gapienko, V., Gilitski, Y., Koreshev, V., Semak, A., Sviridov, Yu., Zaets, V., Belhorma, B., Ghazlane, H., Coath, R.E., Crooks, J.P., Stanitzki, M., Strube, J., Turchetta, R., Tyndel, M., Nam, S.W., Park, I.H., Yang, J., Chai, Jong-Seo, Kim, Jong-Tae, Kim, Geun-Bum, Kim, Y., Kang, J., Kwon, Y.-J., Kim, Ilgoo, Lee, Taeyun, Park, Jaehong, Sung, Jinho, Kotera, K., Nishiyama, M., Takeshita, T., Khan, A., Kim, D.H., Kim, J.E., Kong, D.J., Oh, Y.D., Uozumi, S., Koike, H., Tanaka, K., Ukegawa, F., Sauer, J., Weber, S., Zeitnitz, C., Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), CALICE, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], FOS: Physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Instrumentation and Detectors (physics.ins-det), [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Detectors and Experimental Techniques, High Energy Physics - Experiment
Abstract

We present an overview of the CALICE activities on calorimeter development for a future linear collider. We report on test beam analysis results, the status of prototype development and future plans. We present an overview of the CALICE activities on calorimeter development for a future linear collider. We report on test beam analysis results, the status of prototype development and future plans.

28. Ratios of helicity amplitudes for exclusive ρ 0 electroproduction

Author

The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Dueren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hill, G., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lamb, R., Lapikas, L., Lehmann, I., Lenisa, P., Linden-Levy, L. A., Ruiz, A. Lopez, Lorenzon, W., Lu, X. -G., Lu, X. -R., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfre, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Pickert, N., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schaefer, A., Schnell, G., Schueler, K. P., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stinzing, F., Taroian, S., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Yen, S., Yu, W., Zihlmann, B., Zupranski, P., and (Astro)-Particles Physics

Subjects
HERMES experiment, Particle physics, J/PSI MESONS, Hydrogen, Physics and Astronomy (miscellaneous), Positron beam, Astrophysics::High Energy Astrophysical Phenomena, HERA, chemistry.chemical_element, FOS: Physical sciences, Electron, 01 natural sciences, High Energy Physics - Experiment, ELASTIC ELECTROPRODUCTION, High Energy Physics - Experiment (hep-ex), P(0) MESONS, GENERALIZED PARTON DISTRIBUTIONS, 0103 physical sciences, SCATTERING, ddc:530, DIFFRACTIVE ELECTROPRODUCTION, 010306 general physics, Nuclear Experiment, Engineering (miscellaneous), Physics, 010308 nuclear & particles physics, Perturbative QCD, HYDROGEN, VECTOR-MESON PRODUCTION, QCD, Helicity, Amplitude, Physics and Astronomy, chemistry, Deuterium, High Energy Physics::Experiment
Abstract

Exclusive rho^0-meson electroproduction is studied in the HERMES experiment, using a 27.6 GeV longitudinally polarized electron/positron beam and unpolarized hydrogen and deuterium targets in the kinematic region 0.5 GeV^2 < Q^2 < 7.0 GeV^2, 3.0 GeV < W < 6.3 GeV, and -t' < 0.4 GeV^2. Real and imaginary parts of the ratios of the natural-parity-exchange helicity amplitudes T_{11} (\gamma^*_T --> \rho_T), T_{01} (\gamma^*_T --> \rho_L), T_{10} (\gamma^*_L --> \rho_T), and T_{1-1} (\gamma^*_{-T} -->\rho_T) to T_{00} (\gamma^*_L --> \rho_L) are extracted from the data. For the unnatural-parity-exchange amplitude U_{11}, the ratio |U_{11}/T_{00}| is obtained. The Q^2 and t' dependences of these ratios are presented and compared with perturbative QCD predictions., Comment: 27 pages, 8 tables, 13 figures; minor textual changes on pages 2, 3,9, 10, 11, and some changes to the list of references

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