161 results on '"Oganessyan, K."'
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2. Azimuthal Asymmetries: Access to Novel Structure Functions
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Oganessyan, K. A., Asilyan, L. S., De Sanctis, E., and Muccifora, V.
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High Energy Physics - Phenomenology - Abstract
One of the most interesting consequence of non-zero intrinsic transverse momentum of partons in the nucleon is the nontrivial azimuthal dependence of the cross section of hard scattering processes. Many of the observable asymmetries contain unknown functions which provide essential information on the quark and gluon structure. Several of them have been studied in the last few years; we discuss their qualitative and quantitative features in semi-inclusive DIS., Comment: 6 pages, LaTeX, 7 eps figures, Talk presented at the 15th International Spin Physics Symposium, Spin 2002, Brookhaven National Laboratory, September 9-14, 2002
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- 2002
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3. Spin-independent and double-spin cos(phi) asymmetries in semi-inclusive pion electroproduction
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Oganessyan, K. A., Asilyan, L. S., Anselmino, M., and De Sanctis, E.
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High Energy Physics - Phenomenology - Abstract
We consider the cos(phi) dependence of the longitudinal double-spin asymmetry for charged pion electroproduction in semi-inclusive deep inelastic scattering, emphasizing intrinsic transverse momentum effects. This azimuthal asymmetry allows to measure the cos(phi) moments of the unpolarized and double-spin cross-section, simultaneously. The size of the asymmetry, in the approximation where all twist-3 interaction-dependent distribution and fragmentation functions are set to zero, is estimated for HERMES kinematics; both the spin-independent and the double-spin cos(phi) moments are predicted to be sizeable and negative., Comment: LaTeX, 4 pages, 4 figures. Discussion on the acceptance effects added; recent parameterizations of distribution and fragmentation functions used, figures replaced. Final version to appear in Physics Letters B
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- 2002
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4. Kinematical contributions to the transverse asymmetry in semi-inclusive DIS
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Oganessyan, K. A., Mulders, P. J., De Sanctis, E., and Asilyan, L. S.
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High Energy Physics - Phenomenology - Abstract
We discuss the contributions of the transverse spin component of the target to the double-spin asymmetries in semi-inclusive deep inelastic scattering of longitudinally polarized electrons off longitudinally polarized protons., Comment: LaTeX, 4 pages, 4 figures, uses espcrc1.sty, talk presented at the European Workshop on the QCD Structure of the Nucleon (QCD-N'02), Ferrara, Italy, April 3-6, 2002
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- 2002
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5. Double-spin cos(phi) Asymmetry in Semi-inclusive Electroproduction
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Oganessyan, K. A., Mulders, P. J., and De Sanctis, E.
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High Energy Physics - Phenomenology - Abstract
We consider the double-spin cos(phi) asymmetry for pion electroproduction in semi-inclusive deep inelastic scattering of longitudinally polarized leptons off longitudinally polarized protons. We estimate the size of the asymmetry in the approximation where all twist-3 interaction-dependent distribution and fragmentation functions are set to zero. In that approximation at HERMES kinematics a sizable negative cos(phi) double-spin asymmetry for pi+ electroproduction is predicted., Comment: LaTeX, 5 pages, 2 figures. Minor changes, figure modified. Final version to appear in Phys.Lett. B
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- 2002
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6. Azimuthal Asymmetries in Inclusive Single Pion Electroproduction
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Oganessyan, K. A.
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High Energy Physics - Phenomenology - Abstract
The leading and sub-leading order results for pion electroproduction in polarized and unpolarized semi-inclusive deep-inelastic scattering, are considered putting emphasis on transverse momentum dependent effects appearing in azimuthal asymmetries. In particular the spin-dependent (single, double) and spin-independent asymmetries of the distributions in the azimuthal angle of the pion related to the lepton scattering plane are discussed., Comment: 10 pages, 7 figures, LaTeX using wrapfig.sty; invited talk given at the IX workshop on high energy spin physics, August 2-7, 2001, JINR Dubna, Russia
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- 2002
7. Electron Scattering with Polarized Targets at TESLA
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Group, The TESLA-N Study, Anselmino, M., Aschenauer, E. C., Belostotski, S., Bialowons, W., Bluemlein, J., Braun, V., Brinkmann, R., Dueren, M., Ellinghaus, F., Goeke, K., Goertz, St., Gute, A., Harmsen, J., Harrach, D. v., Jakob, R., Kabuss, E. M., Kaiser, R., Korotkov, V., Kroll, P., Leader, E., Lehmann-Dronke, B., Mankiewicz, L., Meier, A., Meyer, W., Meyners, N., Mueller, D., Mulders, P. J., Nowak, W. -D., Niedermeier, L., Oganessyan, K., Pobilitsa, P. V., Polyakov, M. V., Reicherz, G., Rith, K., Ryckbosch, D., Schaefer, A., Sinram, K., Steenhoven, G. v. d., Steffens, E., Steijger, J., and Weiss, C.
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High Energy Physics - Phenomenology - Abstract
Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q^2-dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q^2-evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics., Comment: 24 pages, 10 figures
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- 2000
8. Single Spin Asymmetries in Semi-Inclusive Electroproduction: Access to Transversity
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Oganessyan, K. A., Bianchi, N., De Sanctis, E., and Nowak, W. -D.
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High Energy Physics - Phenomenology - Abstract
We discuss the quark transversity distribution function and a possible way to access it through the measurement of single spin azimuthal asymmetry in semi-inclusive single pion electroproduction on a transversely polarized target., Comment: 5 pages, Latex using aipproc.sty (included), to appear in proceedings of "Second Workshop on Physics with an Electron Polarized Light Ion Collider", Sept. 14-16, 2000, MIT, Cambridge, USA
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- 2000
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9. Investigation of single spin asymmetries in pi^{+} electroproduction
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Oganessyan, K. A., Bianchi, N., De Sanctis, E., and Nowak, W. -D.
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High Energy Physics - Phenomenology ,High Energy Physics - Experiment - Abstract
The azimuthal single target-spin asymmetries for pi^{+} production in semi-inclusive deep inelastic scattering of leptons off longitudinally polarized protons are evaluated using two main approaches available in the literature. It is shown that the approximation where the twist-2 transverse quark spin distribution in the longitudinally polarized nucleon is small enough to be neglected leads to a consistent description of all existing asymmetries observed by the HERMES experiment., Comment: 11 pages with 4 figures, LaTeX
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- 2000
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10. Perturbative contribution to the sin(phi) asymmetry in inclusive pi^{+} electroproduction
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Oganessyan, K. A., Bianchi, N., De Sanctis, E., and Nowak, W. -D.
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High Energy Physics - Phenomenology ,High Energy Physics - Experiment - Abstract
We consider the sin(phi) single target-spin asymmetry in deep-inelastic pi^{+} inclusive electroproduction off a longitudinally polarized target. We show that at larger transverse momentum of the outgoing hadron the evaluated asymmetry decreases if one takes into account the first order alpha_S perturbative contribution to the cross section, integrated over the azimuthal angle. This leads to good agreement with recent HERMES data., Comment: 4 pages with one figure, LaTeX, typos corrected. Contribution to the Proceedings of the QCD'00 Euroconference, Montpellier, 6-13th July 2000, to appear in the Nucl. Phys. B (Proc. Suppl.)
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- 2000
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11. Transversity Distribution and Polarized Fragmentation Function from Semi-inclusive Pion Electroproduction
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Korotkov, V. A., Nowak, W. -D., and Oganessyan, K. A.
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High Energy Physics - Phenomenology - Abstract
A method is discussed to determine the hitherto unknown u-quark transversity distribution from a planned HERMES measurement of a single-spin asymmetry in semi-inclusive pion electroproduction off a transversely polarized target. Assuming u-quark dominance, the measurement yields the shapes of the transversity distribution and of the ratio of a polarized and the unpolarized u-quark fragmentation functions. The unknown relative normalization can be obtained by identifying the transversity distribution with the well-known helicity distribution at large x. The systematic uncertainty of the method is dominated by the assumption of u-quark dominance., Comment: 5 pages, 5 figures, revised version as will be published in EPJ C
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- 2000
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12. Single-spin Azimuthal Asymmetries in the 'Reduced Twist-3 Approximation'
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De Sanctis, E., Nowak, W. -D., and Oganessyan, K. A.
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High Energy Physics - Phenomenology ,High Energy Physics - Experiment - Abstract
We consider the single-spin azimuthal asymmetries recently measured at the HERMES experiment for charged pions produced in semi-inclusive deep inelastic scattering of leptons off longitudinally polarized protons. Guided by the experimental results and assuming a vanishing twist-2 transverse quark spin distribution in the longitudinally polarized nucleon, denoted as ``reduced twist-3 approximation'', a self-consistent description of the observed single-spin asymmetries is obtained. In addition, predictions are given for the z dependence of the single target-spin asymmetry., Comment: 8 pages, 2 figures, typos corrected, very small changes to text, reference added
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- 2000
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13. Single target-spin asymmetries in semi-inclusive pion electroproduction on longitudinally polarized protons
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Kotzinian, A. M., Oganessyan, K. A., Avakian, H. R., and De Sanctis, E.
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High Energy Physics - Phenomenology ,High Energy Physics - Experiment - Abstract
We evaluate the single target-spin sin(phi_h) and sin(2\phi_h) azimuthal asymmetries in the semi-inclusive deep inelastic lepton scattering off longitudinally polarized proton target under HERMES kinematic conditions. A good agreement with the HERMES data can be achieved using only the twist-2 distribution and fragmentation functions., Comment: 6 pages with figures, LaTex, uses espcrc1.sty and epsfig.sty. Contribution to the Proceedings of the Workshop on "The Structure of the Nucleon" (N99), Frascati, June 7-9, 1999; to appear in the Nucl. Phys. A (Proc. Suppl.)
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- 1999
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14. Sin(phi) azimuthal asymmetry in semi-inclusive electroproduction on longitudinally polarized nucleon
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Oganessyan, K. A., Avakian, H. R., Bianchi, N., and Kotzinian, A. M.
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High Energy Physics - Phenomenology - Abstract
We investigate the $sin \phi$ azimuthal asymmetry in the semi-inclusive deep-inelastic lepton scattering off longitudinally polarized nucleon target arising from the time reversal odd structures. The order 1/Q contributions of the leading twist and twist-three distribution and fragmentation functions to that asymmetry for the certain kinematical conditions are numerically estimated., Comment: 9 pages, Revtex, 4 Postscript figures
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- 1998
15. Time-reversal-odd asymmetry in pion leptoproduction at HERMES
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Oganessyan, K. A.
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High Energy Physics - Phenomenology - Abstract
We estimate the size of the azimuthal asymmetry of the semi-inclusive pion production in the deep-inelastic scattering of a polarized lepton beam off an unpolarized nucleon target for the produced hadron, arising due to both nonperturbative and perturbative effects., Comment: 2 pages, 1 figure, to appear in the proceedings of DIS'98, Brussels, 4-8 April'98
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- 1998
16. An Ising spin - S model on generalized recursive lattice
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Ananikian, N. S., Izmailian, N. Sh., and Oganessyan, K. A.
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Condensed Matter - Statistical Mechanics - Abstract
The Ising spin - S model on recursive p - polygonal structures in the external magnetic field is considered and the general form of the free energy and magnetization for arbitrary spin is derived. The exact relation between the free energies on infinite entire tree and on its infinite "interior" is obtained., Comment: 9 pages, 1 figure, to be published in Physica A
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- 1998
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17. Chaos in the Z(2) Gauge Model on a Generalized Bethe Lattice of Plaquettes
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Ananikian, N. S., Dallakian, S. K., Izmailian, N. Sh., and Oganessyan, K. A.
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High Energy Physics - Lattice - Abstract
We investigate the Z(2) gauge model on a generalized Bethe lattice with three plaquette representation of the action. We obtain the cascade of phase transitions according to Feigenbaum scheme leading to chaotic states for some values of parameters of the model. The duality between this gauge model and three site Ising spin model on Husimi tree is shown. The Lyapunov exponent as a new order parameter for the characterization of the model in the chaotic region is considered. The line of the second order phase transition, which corresponds to the points of the first period doubling bifurcation, is also obtained., Comment: LaTeX, 7 pages, 4 Postscript figures
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- 1997
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18. Investigations of Azimuthal Asymmetry in Semi-Inclusive Leptoproduction
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Oganessyan, K. A., Avakian, H. R., Bianchi, N., and Di Nezza, P.
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High Energy Physics - Phenomenology - Abstract
We consider the azimuthal asymmetries in semi-inclusive deep inelastic leptoproduction arising due to both perturbative and nonperturbative effects at HERMES energies and show that the $k_T^2/Q^2$ order corrections to $< \cos\phi >$ and $< \cos2\phi >$ are significant. We also reconsider the results of perturbative effects for $< \cos\phi >$ at large momentum transfers \cite{A1} using the more recent sets of scale-dependent distribution and fragmentation functions, which bring up to $18{%}$ difference in $< \cos\phi >$. In the same approach we calculate the $< \cos2\phi >$ as well., Comment: 8 pages, LaTeX, 6 PS figures, final version, to appear in EPJC
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- 1997
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19. On the properties of Konishi-Kaneko map
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Gurzadyan, V. G., Melkonian, A., and Oganessyan, K.
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Astrophysics - Abstract
The existence of period-doubling bifurcations is shown for the Konishi-Kaneko map. The value of the control parameter $k_{\infty}$ corresponding to the transition to the chaotic phase is estimated, along with the Feigenbaum universal number. This type of facts can be crucial in diagnosis of chaos in stellar dynamics., Comment: Latex file 4 pages; Il Nuovo Cimento, vol.112B, 1997
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- 1997
20. Chaotic Repellers in Antiferromagnetic Ising Model
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Ananikian, N. S., Dallakian, S. K., Izmailian, N. Sh., and Oganessyan, K. A.
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Condensed Matter - Abstract
For the first time we present the consideration of the antiferromagnetic Ising model in case of fully developed chaos and obtain the exact connection between this model and chaotic repellers. We describe the chaotic properties of this statistical mechanical system via the invariants characterizing a fractal set and show that in chaotic region it displays phase transition at {\it positive} "temperature" $ \beta_c = 0.89 $. We obtain the density of the invariant measure on the chaotic repeller., Comment: LaTeX file, 10 pages, 4 PS figurs upon request
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- 1995
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21. The Multisite Antiferromagnetic Ising Spin Model and Universality of Feigenbaum Constants
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Ananikian, N. S., Lusiniants, R. R., and Oganessyan, K. A.
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High Energy Physics - Theory ,Nonlinear Sciences - Chaotic Dynamics - Abstract
The Feigenbaum constants $\alpha$ and $\delta$ for the three-site antiferromagnetic Ising spin model on Husimi tree are calculated. It is shown that the numerical values of these constants for this real physical system coincide with the famous universal Feigenbaum constants with high accuracy. The quantitative description from ordering to chaos is also obtained., Comment: 7 pages, LaTeX, preprint: YERPHY-1418(5)-94
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- 1994
22. The HERMES polarized hydrogen and deuterium gas target in the HERA electron storage ring
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Andrus, A., Aschenauer, E.C., Augustyniak, W., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Balin, D., Baumgarten, C., Beckmann, M., Belostotski, S., Bianchi, N., Blok, H.P., Böttcher, H., Borissov, A., Borysenko, A., Bouwhuis, M., Braun, B., Brüll, A., Bryzgalov, V., Capitani, G.P., Capiluppi, M., Chen, T., Ciullo, G., Contalbrigo, M., Court, G., Dalpiaz, P.F., De Leo, R., Demey, M., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Düren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Gregor, I.M., Hadjidakis, C., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Hristova, I., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H.E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Kobayashi, T., Koch, N., Kolster, H., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V.G., Lagamba, L., Lapikás, L., Laziev, A., Lenisa, P., Liebing, P., Linden-Levy, L.A., Lorenzon, W., Lu, H., Lu, J., Lu, S., Ma, B.-Q., Maiheu, B., Makins, N.C.R., Mao, Y., Marianski, B., Marukyan, H., Mexner, V., Meyners, N., Mussa, R., Mikloukho, O., Miller, C.A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.-D., Oganessyan, K., Ohsuga, H., Osborne, A., Pickert, N., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P.E., Reischl, A., Reolon, A.R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Schill, C., Schnell, G., Schüler, K.P., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T.-A., Shutov, V., Sinram, K., Sommer, W., Stancari, M., Statera, M., Steffens, E., Steijger, J.J.M., Stenzel, H., Stewart, J., Stinzing, F., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P., van der Steenhoven, G., van Haarlem, Y., Vetterli, M.C., Vikhrov, V., Vincter, M.G., Vogel, C., Volmer, J., Wang, S., Wendland, J., Wilbert, J., Wise, T., Ybeles Smit, G., Ye, Y., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.
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- 2005
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23. Konishi-Kaneko map and Feigenbaum universality
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Gurzadyan, V. G., Melkonyan, A., and Oganessyan, K.
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- 1995
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24. Hard exclusive electroproduction of π+π− pairs
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Andrus, A., Aschenauer, E.C., Augustyniak, W., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Balin, D., Baturin, V., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Blok, H.P., Böttcher, H., Borissov, A., Borysenko, A., Bouwhuis, M., Brack, J., Brüll, A., Bryzgalov, V., Capitani, G.P., Chen, T., Ciullo, G., Contalbrigo, M., Dalpiaz, P.F., De Leo, R., Demey, M., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Düren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Garutti, E., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Greeniaus, L.G., Gregor, I.M., Griffioen, K.A., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H.E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V.G., Lagamba, L., Lapikás, L., Laziev, A., Lenisa, P., Liebing, P., Linden-Levy, L.A., Lipka, K., Lorenzon, W., Lu, H., Lu, J., Lu, S., Ma, B.-Q., Maiheu, B., Makins, N.C.R., Mao, Y., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C.A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.-D., Oganessyan, K., Ohsuga, H., Osborne, A., Pickert, N., Potashov, S., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P.E., Reischl, A., Reolon, A.R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Schäfer, A., Schill, C., Schnell, G., Schüler, K.P., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T.-A., Shutov, V., Sinram, K., Sommer, W., Stancari, M., Statera, M., Steffens, E., Steijger, J.J.M., Stenzel, H., Stewart, J., Stinzing, F., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Tkabladze, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P., van der Steenhoven, G., van Haarlem, Y., Vetterli, M.C., Vikhrov, V., Vincter, M.G., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Ybeles Smit, G., Ye, Y., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.
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Nuclear and High Energy Physics - Published
- 2004
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25. Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electroproduction
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Airapetian, A., Akopov, N., Beckmann, M., Krivokhijine, V. G., Kurisuno, M., Kyle, G., Lachnit, W., Lenisa, P., Lorenzon, W., Makins, N. C. R., Martens, F. K., Martin, J. W., Masoli, F., Belostotski, S., Mateos, A., McAndrew, M., McIlhany, K., McKeown, R. D., Meissner, F., Menden, F., Metz, A., Meyners, N., Mikloukho, O., Miller, C. A., Belz, J. E., Miller, M. A., Milner, R., Most, A., Muccifora, V., Mussa, R., Nagaitsev, A., Naryshkin, Y., Nathan, A. M., Neunreither, F., Niczyporuk, M., Benisch, Th., Nowak, W.-D., Nupieri, M., Oganessyan, K. A., O'Neill, T. G., Openshaw, R., Ouyang, J., Owen, B. R., Papavassiliou, V., Pate, S. F., Pitt, M., Bernreuther, S., Potashov, S., Potterveld, D. H., Rakness, G., Reali, A., Redwine, R., Reolon, A. R., Ristinen, R., Rith, K., Rossi, P., Rudnitsky, S., Bianchi, N., Ruh, M., Ryckbosch, D., Sakemi, Y., Savin, I., Scarlett, C., Schäfer, A., Schmidt, F., Schmitt, H., Schnell, G., Schüler, K. P., Blouw, J., Schwind, A., Seibert, J., Shibata, T.-A., Shibatani, K., Shin, T., Shutov, V., Simani, C., Simon, A., Sinram, K., Slavich, P., Böttcher, H., Spengos, M., Steffens, E., Stenger, J., Stewart, J., Stoesslein, U., Sutter, M., Tallini, H., Taroian, S., Terkulov, A., Teryaev, O., Borissov, A., Thomas, E., Tipton, B., Tytgat, M., Urciuoli, G. M., van den Brand, J. F. J., van der Steenhoven, G., van de Vyver, R., van Hunen, J. J., Vetterli, M. C., Vikhrov, V., Bouwhuis, M., Vincter, M. G., Visser, J., Volk, E., Wander, W., Wendland, J., Williamson, S. E., Wise, T., Woller, K., Yoneyama, S., Zohrabian, H., Amarian, M., Brack, J., HERMES Collaboration, Brauksiepe, S., Braun, B., Bray, B., Brons, St., Brückner, W., Brüll, A., Bruins, E. E. W., Bulten, H. J., Capitani, G. P., Aschenauer, E. C., Carter, P., Chumney, P., Cisbani, E., Court, G. R., Dalpiaz, P. F., De Sanctis, E., De Schepper, D., Devitsin, E., de Witt Huberts, P. K. A., Di Nezza, P., Avakian, H., Düren, M., Dvoredsky, A., Elbakian, G., Ely, J., Fantoni, A., Fechtchenko, A., Ferstl, M., Fiedler, K., Filippone, B. W., Fischer, H., Avakian, R., Fox, B., Franz, J., Frullani, S., Funk, M.-A., Gärber, Y., Gao, H., Garibaldi, F., Gavrilov, G., Geiger, P., Gharibyan, V., Avetissian, A., Golendukhin, A., Graw, G., Grebeniouk, O., Green, P. W., Greeniaus, L. G., Grosshauser, C., Guidal, M., Gute, A., Gyurjyan, V., Haas, J. P., Avetissian, E., Haeberli, W., Hansen, J.-O., Hartig, M., Hasch, D., Häusser, O., Heinsius, F. H., Henderson, R., Henoch, M., Hertenberger, R., Holler, Y., Bains, B., Holt, R. J., Hoprich, W., Ihssen, H., Iodice, M., Izotov, A., Jackson, H. E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Baumgarten, C., Kitching, P., Kobayashi, H., Koch, N., Königsmann, K., Kolstein, M., Kolster, H., Korotkov, V., Korsch, W., Kozlov, V., Kramer, L. H., and (Astro)-Particles Physics
- Subjects
Quark ,Particle physics ,Proton structure ,FRAGMENTATION FUNCTIONS ,media_common.quotation_subject ,General Physics and Astronomy ,BEAM ,NUCLEONS ,01 natural sciences ,Asymmetry ,Nuclear physics ,Pion ,LEPTOPRODUCTION ,0103 physical sciences ,ddc:550 ,DISTRIBUTIONS ,Nuclear Experiment ,010306 general physics ,media_common ,Physics ,010308 nuclear & particles physics ,Scattering ,polarized target internal ,Deep inelastic scattering ,Transverse plane ,Distribution function ,ANALYZING POWER ,High Energy Physics::Experiment ,Lepton - Abstract
Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle straight phi of the pion relative to the lepton scattering plane was formed for pi(+) electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sinstraight phi moment of the cross section is 0.022+/-0.005+/-0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a chiral-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.
- Published
- 2000
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26. Transverse polarization of Λ and Λ̅ hyperons in quasireal photoproduction
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V. V., Andrus, A., Aschenauer, E. C., Augustyniak, W., 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., Brunn, I., Capitani, G. P., Chiang, H. C., Ciullo, Giuseppe, Contalbrigo, Marco, Court, G. R., Ferretti, Paola, 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., Elschenbroich, U., Ely, J., Fabbri, Riccardo, 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., W. H. A., Hillenbrand, A., Holler, Y., Hommez, B., Iarygin, G., 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, Paolo, Liebing, P., Lindemann, T., Lipka, K., Lorenzon, W., N. C. R., Marukyan, H., Masoli, Francesco Antonio, 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, Davide, 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., Seibert, J., Seitz, B., Shanidze, R., Shibata, T. A., Shutov, V., Simani, M. C., Sinram, K., Stancari, Michelle Dawn, Statera, Marco, Steffens, E., J. J. M., Stewart, J., Stosslein, U., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Tessarin, S., Thomas, E., Tkabladze, A., Trzcinski, A., Tytgat, M., Urciuoli, G. M., Van, P. B., van der, G., van de, R., Veretennikov, D., Vetterli, M. C., Vikhrov, V., Vincter, M. G., Visser, J., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Zihlmann, B., Zohrabian, H., and Zupranski, P.
- Subjects
13.88.+e ,13.60.−r ,13.60.Rj - Published
- 2007
27. Transverse Polarization of Lambda and Lambda-bar Hyperons in Quasi-Real Photon-Nucleon Scattering at HERMES
- Author
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Airapetian, A., Akopov, N., Avetissian, E., Mikloukho, O., Miller, C. A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Nowak, W.-D., Oganessyan, K., Bailey, P., Ohsuga, H., Orlandi, G., Potashov, S., Potterveld, D. H., Raithel, M., Reggiani, D., Reimer, P. E., Reischl, A., Reolon, A. R., Rith, K., Baturin, V., Rosner, G., Rostomyan, A., Ryckbosch, D., Sanjiev, I., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K. P., Baumgarten, C., Schwind, A., Seibert, J., Seitz, B., Shanidze, R., Shibata, T.-A., Shutov, V., Simani, M. C., Sinram, K., Stancari, M., Statera, M., Beckmann, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stosslein, U., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Tessarin, S., Thomas, E., Belostotski, S., Tkabladze, A., Trzcinski, A., Tytgat, M., Urciuoli, G. M., van der Nat, P. B., van der Steenhoven, G., van de Vyver, R., Veretennikov, D., Vetterli, M. C., Vikhrov, V., Bernreuther, S., Vincter, M. G., Visser, J., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Bianchi, N., Zihlmann, B., Zohrabian, H., Zupranski, P., HERMES Collaboration, Blok, H. P., Bottcher, H., Akopov, Z., Borissov, A., Bouwhuis, M., Brack, J., Brull, A., Brunn, I., Capitani, G. P., Chiang, H. C., Ciullo, G., Contalbrigo, M., Court, G. R., Amarian, 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., Elbakian, G., Ammosov, V. V., Ellinghaus, F., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Franz, J., Frullani, S., Andrus, A., Garber, Y., Gapienko, G., Gapienko, V., Garibaldi, F., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Aschenauer, E. C., Greeniaus, L. G., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W. H. A., Hillenbrand, A., Augustyniak, W., Holler, Y., Hommez, B., Iarygin, G., Izotov, A., Jackson, H. E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Konigsmann, K., Avakian, R., Kolster, H., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, P., Avetissian, A., Liebing, P., Lindemann, T., Lipka, K., Lorenzon, W., Makins, N. C. R., Marukyan, H., Masoli, F., Menden, F., Mexner, V., and Meyners, N.
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+Lambda+positron+anything%22">positron nucleon --> Lambda positron anything ,longitudinal [polarized target] ,transverse [polarization] ,momentum dependence ,HERMES ,transverse momentum dependence ,deep inelastic scattering [positron nucleon] ,polarized target: longitudinal ,polarization: transverse ,ddc:530 ,Nuclear Experiment ,Antilambda: polarization ,longitudinal [polarized beam] ,photoproduction [Lambda] ,27.6 GeV ,High Energy Physics::Phenomenology ,Lambda: polarization ,Lambda: photoproduction ,DESY HERA Stor ,positron nucleon: deep inelastic scattering ,polarized beam: longitudinal ,High Energy Physics::Experiment ,polarization [Antilambda] ,polarization [Lambda] ,experimental results - Abstract
Physical review / D 76(9), 092008 (2007). doi:10.1103/PhysRevD.76.092008, The HERMES experiment has measured the transverse polarization of Lambda and Lambda-bar hyperons produced inclusively in quasireal photoproduction at a positron beam energy of 27.6 GeV. The transverse polarization of the Lambda hyperon is found to be positive while the observed Lambda-bar polarization is compatible with zero. The transverse polarization values averaged over the kinematic acceptance of HERMES are 0.078 +/- 0.006(stat) +/- 0.012(syst) and -0.025 +/- 0.015(stat) +/- 0.018(syst) for Lambda and Lambda-bar hyperons, respectively. The dependences of Lambda and Lambda-bar polarizations on the fraction $\zeta$ of the beam's light-cone momentum carried by the hyperon and on the hyperon's transverse momentum $p_T$ were investigated. The measured Lambda polarization rises linearly with $p_T$ and exhibits a different behavior for low and high values of $\zeta$, which approximately correspond to the backward and forward regions in the center-of-mass frame of the $\gamma^*N$ reaction., Published by Soc., [S.l.]
- Published
- 2007
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28. Search for an exotic S =-2, Q =-2 baryon resonance at a mass near 1862 MeV in quasireal photoproduction
- Author
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Airapetian, A, Akopov, N, Akopov, Z, Amarian, M, Andrus, A, Aschenauer, Ec, Augustyniak, W, Avakian, R, Avetissian, A, Avetissian, E, Bailey, P, Balin, D, Beckmann, M, Belostotski, S, Bianchi, N, Blok, Hp, Bottcher, H, Borissov, A, Borysenko, A, Bouwhuis, M, Brull, A, Bryzgalov, V, Capiluppi, Marco, Capitani, Gp, Chen, T, Ciullo, Giuseppe, Contalbrigo, Marco, Ferretti, Paola, Deconinck, W, DE LEO, R, Demey, M, DE NARDO, L, DE SANCTIS, E, Devitsin, E, Diefenthaler, M, DI NEZZA, P, Drechsler, J, Duren, M, Ehrenfried, M, ELALAOUI MOULAY, A, Elbakian, G, Ellinghaus, F, Elschenbroich, U, Fabbri, R, Fantoni, A, Felawka, L, Frullani, S, Funel, A, Gapienko, G, Gapienko, V, Garibaldi, F, Garrow, K, Gavrilov, G, Gharibyan, V, Giordano, Francesca, Grebeniouk, O, Gregor, Im, Hadjidakis, C, Hafidi, K, Hartig, M, Hasch, D, Hesselink, Wha, Hillenbrand, A, Hoek, M, Holler, Y, Hommez, B, Hristova, I, Iarygin, G, Ivanilov, A, Izotov, A, Jackson, He, Jgoun, A, Kaiser, R, Keri, T, Kinney, E, Kisselev, A, Kobayashi, T, Kopytin, M, Korotkov, V, Kozlov, V, Krauss, B, Krivokhijine, Vg, Lagamba, L, Lapikas, L, Laziev, A, Lenisa, Paolo, Liebing, P, LINDEN LEVY LA, Lorenzon, W, Lu, H, Lu, J, Lu, S, Ma, Bq, Maiheu, B, Makins, Ncr, Mao, Y, Marianski, B, Marukyan, H, Masoli, Francesco Antonio, Mexner, V, Meyners, N, Michler, T, Mikloukho, O, Miller, Ca, Miyachi, Y, Muccifora, V, Murray, M, Nagaitsev, A, Nappi, E, Naryshkin, Y, Negodaev, M, Nowak, Wd, Oganessyan, K, Ohsuga, H, Osborne, A, Pickert, N, Potterveld, Dh, Raithel, M, Reggiani, D, Reimer, Pe, Reischl, A, Reolon, Ar, Riedl, C, Rith, K, Rosner, G, Rostomyan, A, Rubacek, L, Rubin, J, Ryckbosch, D, Salomatin, Y, Sanjiev, I, Savin, I, Schafer, A, Schnell, G, Schuler, Kp, Seele, J, Seidl, R, Seitz, B, Shearer, C, Shibata, Ta, Shutov, V, Sinram, K, Sommer, W, Stancari, Michelle Dawn, Statera, Marco, Steffens, E, Steijger, Jjm, Stenzel, H, Stewart, J, Stinzing, F, Tait, P, Tanaka, H, Taroian, S, Tchuiko, B, Terkulov, A, Trzcinski, A, Tytgat, M, Vandenbroucke, A, VAN DER NAT PB, VAN DER STEENHOVEN, G, VAN HAARLEM, Y, Vikhrov, V, Vincter, Mg, Vogel, C, Volmer, J, Wang, S, Wendland, J, Ye, Y, Ye, Z, Yen, S, Zihlmann, B, and Zupranski, P.
- Subjects
14.20.–c ,12.39.Mk ,13.60.–r ,13.60.Rj ,NO - Published
- 2005
29. Search for an exotic S = -2, Q = -2 baryon resonance at a mass near 1862-MeV in quasi-real photoproduction
- Author
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Airapetian, A., Akopov, N., Bailey, P., Meyners, N., Michler, T., Mikloukho, O., Miller, C. A., Miyachi, Y., Muccifora, V., Murray, M., Nagaitsev, A., Nappi, E., Naryshkin, Y., Balin, D., Negodaev, M., Nowak, W.-D., Oganessyan, K., Ohsuga, H., Osborne, A., Pickert, N., Potterveld, D. H., Raithel, M., Reggiani, D., Reimer, P. E., Beckmann, M., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Belostotski, S., Sanjiev, I., Savin, I., Schafer, A., Schnell, G., Schuler, K. P., Seele, J., Seidl, R., Seitz, B., Shearer, C., Shibata, T.-A., Bianchi, N., Shutov, V., Sinram, K., Sommer, W., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Blok, H. P., 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., Bottcher, H., van Haarlem, Y., Vikhrov, V., Vincter, M. G., Vogel, C., Volmer, J., Wang, S., Wendland, J., Ye, Y., Ye, Z., Yen, S., Borissov, A., Zihlmann, B., Zupranski, P., HERMES Collaboration, Borysenko, A., Bouwhuis, M., Akopov, Z., Brull, A., Bryzgalov, V., Capiluppi, M., Capitani, G. P., Chen, T., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., Amarian, M., Demey, M., De Nardo, L., De Sanctis, E., Devitsin, E., Diefenthaler, M., Di Nezza, P., Drechsler, J., Duren, M., Ehrenfried, M., Elalaoui-Moulay, A., Andrus, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Funel, A., Gapienko, G., Gapienko, V., Aschenauer, E. C., Garibaldi, F., Garrow, K., Gavrilov, G., Gharibyan, V., Giordano, F., Grebeniouk, O., Gregor, I. M., Hadjidakis, C., Hafidi, K., Hartig, M., Augustyniak, W., Hasch, D., Hesselink, W. H. A., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Hristova, I., Iarygin, G., Ivanilov, A., Izotov, A., Avakian, R., Jackson, H. E., Jgoun, A., Kaiser, R., Keri, T., Kinney, E., Kisselev, A., Kobayashi, T., Kopytin, M., Korotkov, V., Kozlov, V., Avetissian, A., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, P., Liebing, P., Linden-Levy, L. A., Lorenzon, W., Lu, H., Avetissian, E., Lu, J., Lu, S., Ma, B.-Q., Maiheu, B., Makins, N. C. R., Mao, Y., Marianski, B., Marukyan, H., Masoli, F., and Mexner, V.
- Subjects
inclusive reaction [positron deuteron] ,(p 3pi-) [mass spectrum] ,branching ratio [channel cross section] ,DESY HERA Stor ,27.5 GeV ,search for [pentaquark] ,ddc:530 ,exotic [baryon resonance] ,hadroproduction [Xi(1530)] ,(p pi+ 2pi-) [mass spectrum] ,Xi(1862) [postulated particle] ,upper limit - Abstract
A search for an exotic baryon resonance with $S=-2, Q=-2$ has been performed in quasi-real photoproduction on a deuterium target through the decay channel $\Xi^- \pi^- \to \Lambda \pi^- \pi^- \to p \pi^- \pi^- \pi^-$. No evidence for a previously reported $\Xi^{--}(1860)$ resonance is found in the $\Xi^- \pi^-$invariant mass spectrum. An upper limit for the photoproduction cross section of 2.1 nb is found at the 90% confidence level. The photoproduction cross section for the $\Xi^{0}(1530)$ is found to be between 9 and 24 nb.
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- 2005
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- View/download PDF
30. First measurement of the tensor structure function $b_1$ of the deuteron
- Author
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Airapetian, A., Akopov, N., Avetissian, E., Makins, N. C. R., Mao, Y., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C. A., Miyachi, Y., Bailey, P., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.-D., Oganessyan, K., Ohsuga, H., Pickert, N., Balin, D., Potashov, S., Potterveld, D. H., Raithel, M., Reggiani, D., Reimer, P. E., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Baturin, V., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Schafer, A., Schill, C., Schnell, G., Beckmann, M., Schuler, K. P., 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., Stinzing, F., Stosslein, U., Tait, P., Tanaka, H., Bernreuther, S., Taroian, S., Tchuiko, B., Terkulov, A., Tkabladze, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P. B., van der Steenhoven, G., Vetterli, M. C., Bianchi, N., Vikhrov, V., Vincter, M. G., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Ye, Y., Ye, Z., Blok, H. P., Yen, S., Zihlmann, B., Zupranski, P., HERMES Collaboration, Bottcher, H., Akopov, Z., Borissov, A., Borysenko, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G. P., Chen, T., Chiang, H. C., Ciullo, G., Amarian, M., Contalbrigo, M., Dalpiaz, P. F., Leo, R. De, Demey, M., Nardo, L. De, Sanctis, E. De, Devitsin, E., Nezza, P. Di, Dreschler, J., Duren, M., Ammosov, V. V., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., 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., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, L., Laziev, A., Avetissian, A., Lenisa, P., Liebing, P., Linden-Levy, L. A., Lipka, K., Lorenzon, W., Lu, H., Lu, J., Lu, S., Ma, B.-Q., and Maiheu, B.
- Subjects
DESY HERA Stor ,27.6 GeV/c ,structure function [deuteron] ,deep inelastic scattering [positron deuteron] ,asymmetry [polarization] ,ddc:550 ,tensor [polarization] ,HERMES ,moment [structure function] ,polarized target [deuteron] ,momentum transfer dependence ,x-dependence ,experimental results - Published
- 2005
- Full Text
- View/download PDF
31. Quark helicity distributions in the nucleon for up, down, and strange quarks from semi-inclusive deep-inelastic scattering
- Author
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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
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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.
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- 2005
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32. Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target
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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
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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.
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- 2005
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33. Nuclear polarization of molecular hydrogen recombined on a non-metallic surface
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Airapetian, A, Akopov, N, Akopov, Z, Amarian, M, Ammosov, Vv, Andrus, A, Aschenauer, Ec, Augustymak, W, Avakian, R, Avetissian, A, Avetissian, E, Bailey, P, Baturin, V, Baumgarten, C, Beckmann, M, Belostotski, S, Bernreuther, S, Bianchi, N, Blok, Hp, Bottcher, H, Borissov, A, Borysenko, A, Bouwhuis, M, Brack, J, Brull, A, Bryzgalov, V, Capitanilo, Gp, Chiang, Hc, Ciullo, Giuseppe, Contalbrigo, Marco, Court, G, Ferretti, Paola, 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, Elschenbroich, U, Ely, J, Fabbri, Riccardo, Fantoni, A, Fechtchenko, A, Felawka, L, Fox, B, Franz, J, Frullani, S, Gapienko, G, Gapienko, V, Garibaldi, F, Garrow, K, Garutti, E, Gaskell, D, Gavrilov, G, Gharibyan, V, Graw, G, Grebeniouk, O, Greeniaus, Lg, Gregor, Im, Haeberli, W, Hafidi, K, Hartig, M, Hasch, D, Heesbeen, D, Henoch, M, Hertenberger, R, Hesselink, Wha, Hillenbrand, A, Hoek, M, Holler, Y, Hommez, B, Iarygin, G, Ivanilov, A, Izotov, A, Jackson, He, Jgoun, A, Kaiser, R, Kinney, E, Kisselev, A, Kolster, H, Konigsmann, K, Kopytin, M, Korotkov, V, Kozlov, V, Krauss, B, Krivokhijine, Vg, Lagamba, L, Lapikas, L, Laziev, A, Lenisa, Paolo, Liebing, P, LINDEN LEVY LA, Lipka, K, Lorenzon, W, Lu, J, Maiheu, B, Makins, Ncr, Marianski, B, Marukyan, H, Masoli, Francesco Antonio, Mexner, V, Meyners, N, Mikloukho, O, Miller, Ca, Miyachi, Y, Muccifora, V, Nagaitsev, A, Nappi, E, Naryshkin, Y, Nass, A, Negodaev, M, Nowak, Wd, Oganessyan, K, Ohsuga, H, Pickert, N, Potashov, S, Potterveld, Dh, Raithel, M, Reggiani, Davide, Reimer, Pe, Reischl, A, Reolon, Ar, Riedl, C, Rith, K, Rosner, G, Rostomyan, A, Rubacek, L, Rubin, J, Ryckbosch, D, Salomatin, Y, Sanjiev, I, Savin, I, Scarlett, C, Schill, C, Schnell, G, Schuler, Kp, Schwind, A, Seele, J, Seidl, R, Seitz, B, Shanidze, R, Shearer, C, Shibata, Ta, Shutov, V, Simani, Mc, Sinram, K, Stancari, Michelle Dawn, Statera, Marco, Steffens, E, Steijger, Jjm, Stenzel, H, Stewart, J, Stosslein, U, Tait, P, Tanaka, H, Taroian, S, Tchuiko, B, Terkulov, A, Tkabladze, A, Trzcinski, A, Tytgat, M, Vandenbroucke, A, VAN DER NAT, P, VAN DER STEENHOVEN, G, Vetterli, Mc, Vikhrov, V, Vincter, Mg, Vogel, C, Vogt, M, (Astro)-Particles Physics, Photo Conversion Materials, Student Lab and Education, and Airapetian, A
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Silicon ,Atomic Physics (physics.atom-ph) ,media_common.quotation_subject ,Nuclear Theory ,chemistry.chemical_element ,FOS: Physical sciences ,Asymmetry ,Physics - Atomic Physics ,Metal ,Physics - Chemical Physics ,29.25.Pj - Polarized and other targets ,34. - Atomic and molecular collision processes and interactions ,39.10.+j - Atomic and molecular beam sources and techniques ,13.88.+e - Polarization in interactions and scattering ,Molecule ,Nuclear Experiment ,media_common ,chemistry.chemical_classification ,Physics ,Chemical Physics (physics.chem-ph) ,Scattering ,Polymer ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,chemistry ,visual_art ,visual_art.visual_art_medium ,Atomic physics ,Recombination - Abstract
The nuclear polarization of $\mathrm{H}_2$ molecules formed by recombination of nuclear polarized H atoms on the surface of a storage cell initially coated with a silicon-based polymer has been measured by using the longitudinal double-spin asymmetry in deep-inelastic positron-proton scattering. The molecules are found to have a substantial nuclear polarization, which is evidence that initially polarized atoms retain their nuclear polarization when absorbed on this type of surface
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- 2004
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34. Hard exclusive electroproduction of π+π− pairs
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Airapetian, A, Akopov, N, Akopov, Z, Amarian, M, Ammosov, Vv, Andrus, A, Aschenauer, Ec, Augustyniak, W, Avakian, R, Avetissian, A, Avetissian, E, Bailey, P, Balin, D, Baturin, V, Beckmann, M, Belostotski, S, Bernreuther, S, Bianchi, N, Blok, Hp, Bottcher, H, Borissov, A, Borysenko, A, Bouwhuis, M, Brack, J, Brull, A, Bryzgalov, V, Capitani, Gp, Chen, T, Ciullo, Giuseppe, Contalbrigo, Marco, Ferretti, Paola, DE LEO, R, Demey, M, DE NARDO, L, DE SANCTIS, E, Devitsin, E, DI NEZZA, P, Duren, M, Ehrenfried, M, ELALAOUI MOULAY, A, Elbakian, G, Ellinghaus, F, Elschenbroich, U, Fabbri, Riccardo, Fantoni, A, Fechtchenko, A, Felawka, L, Frullani, S, Gapienko, G, Gapienko, V, Garibaldi, F, Garrow, K, Garutti, E, Gavrilov, G, Gharibyan, V, Graw, G, Grebeniouk, O, Greeniaus, Lg, Gregor, Im, Griffioen, Ka, Hafidi, K, Hartig, M, Hasch, D, Heesbeen, D, Henoch, M, Hertenberger, R, Hesselink, Wha, Hillenbrand, A, Hoek, M, Holler, Y, Hommez, B, Iarygin, G, Ivanilov, A, Izotov, A, Jackson, He, Jgoun, A, Kaiser, R, Kinney, E, Kisselev, A, Kopytin, M, Korotkov, V, Kozlov, V, Krauss, B, Krivokhijine, Vg, Lagamba, L, Lapikas, L, Laziev, A, Lenisa, Paolo, Liebing, P, LINDEN LEVY LA, Lipka, K, Lorenzon, W, Lu, H, Lu, J, Lu, S, Ma, Bq, Maiheu, B, Makins, Ncr, Mao, Y, Marianski, B, Marukyan, H, Masoli, Francesco Antonio, Mexner, V, Meyners, N, Mikloukho, O, Miller, Ca, Miyachi, Y, Muccifora, V, Nagaitsev, A, Nappi, E, Naryshkin, Y, Nass, A, Negodaev, M, Nowak, Wd, Oganessyan, K, Ohsuga, H, Osborne, A, Pickert, N, Potashov, S, Potterveld, Dh, Raithel, M, Reggiani, Davide, Reimer, Pe, Reischl, A, Reolon, Ar, Riedl, C, Rith, K, Rosner, G, Rostomyan, A, Rubacek, L, Rubin, J, Ryckbosch, D, Salomatin, Y, Sanjiev, I, Savin, I, Schafer, A, Schill, C, Schnell, G, Schuler, Kp, Seele, J, Seidl, R, Seitz, B, Shanidze, R, Shearer, C, Shibata, Ta, Shutov, V, Sinram, K, Sommer, W, Stancari, Michelle Dawn, Statera, Marco, Steffens, E, Steijger, Jjm, Stenzel, H, Stewart, J, Stinzing, F, Tait, P, Tanaka, H, Taroian, S, Tchuiko, B, Terkulov, A, Tkabladze, A, Trzcinski, A, Tytgat, M, Vandenbroucke, A, VAN DER NAT, P, VAN DER STEENHOVEN, G, VAN HAARLEM, Y, Vetterli, Mc, Vikhrov, V, Vincter, Mg, Vogel, C, Vogt, M, Volmer, J, Weiskopf, C, and W. E. N. D. L. A. N. D. .
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14.40.Cs ,13.88.+e ,13.60.Le ,25.30.Rw - Published
- 2004
35. Flavor decomposition of the sea quark helicity distributions in the nucleon from semiinclusive deep inelastic scattering
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Airapetian, A., Akopov, N., Avetissian, E., Mexner, V., Meyners, N., Mikloukho, O., Miller, C. A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Bailey, P., Negodaev, M., Nowak, W.-D., Oganessyan, K., Ohsuga, H., Orlandi, G., Pickert, N., Potashov, S., Potterveld, D. H., Raithel, M., Reggiani, D., Baturin, V., Reimer, P. E., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Ryckbosch, D., Salomatin, Y., Baumgarten, C., Sanjiev, I., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K. P., Schwind, A., Seele, J., Seidl, R., Beckmann, M., Seitz, B., Shanidze, R., Shearer, C., Shibata, T.-A., Shutov, V., Simani, M. C., Sinram, K., Stancari, M., Statera, M., Steffens, E., Belostotski, S., Steijger, J. J. M., Stewart, J., Stosslein, U., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Tkabladze, A., Trzcinski, A., Bernreuther, S., Tytgat, M., Vandenbroucke, A., van der Nat, P., van der Steenhoven, G., Vetterli, M. C., Vikhrov, V., Vincter, M. G., Visser, J., Vogel, C., Vogt, M., Bianchi, N., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Ybeles Smit, G., Yen, S., Zihlmann, B., Zohrabian, H., Zupranski, P., HERMES Collaboration, Blok, H. P., Bottcher, H., Akopov, Z., Borissov, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G. P., Chiang, H. C., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Amarian, M., 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., Ammosov, V. V., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Franz, J., Frullani, S., Garber, Y., Andrus, A., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Aschenauer, E. C., Greeniaus, L. G., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W. H. A., Hillenbrand, A., Hoek, M., Augustyniak, W., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H. E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Avakian, R., Konigsmann, K., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, P., Avetissian, A., Liebing, P., Lindemann, T., Lipka, K., Lorenzon, W., Lu, J., Maiheu, B., Makins, N. C. R., Marianski, B., Marukyan, H., and Masoli, F.
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sea [quark] ,momentum spectrum [quark] ,High Energy Physics::Lattice ,deep inelastic scattering [positron deuteron] ,Nuclear Theory ,HERMES ,absorption [photon] ,x-dependence ,inclusive reaction [positron deuteron] ,helicity [quark] ,ddc:550 ,Nuclear Experiment ,27.6 GeV ,High Energy Physics::Phenomenology ,DESY HERA Stor ,electroproduction [K+] ,electroproduction [K-] ,flavor [quark] ,High Energy Physics::Experiment ,asymmetry [flavor] ,polarized beam [positron] ,polarized target [deuteron] ,electroproduction [pi+] ,asymmetry [spin] ,electroproduction [pi-] ,experimental results - Abstract
Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.
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- 2004
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36. Evidence for a narrow |S|=1 baryon state at a mass of 1528 MeV in quasi-real photoproduction
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Andrus, A., Aschenauer, E.C., Augustyniak, W., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Balin, D., Baturin, V., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Blok, H.P., Bottcher, H., Borissov, A., Borysenko, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G.P., Chen, T., Chen, X., Chiang, H.C., Ciullo, G., Contalbrigo, M., Dalpiaz, P.F., Deconinck, W., 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., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, Y., Garrow, K., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Greeniaus, L.G., Gregor, I.M., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H.E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V.G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, P., Liebing, P., Linden-Levy, L.A., Lipka, K., Lorenzon, W., Lu, H., Lu, J., Lu, S., Lu, X., Ma, B.Q., Maiheu, B., Makins, N.C.R., Mao, Y., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C.A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.D., Oganessyan, K., Ohsuga, H., Pickert, N., Potashov, S., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P.E., Reischl, A., Reolon, A.R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Schafer, A., Schill, C., Schnell, G., Schuler, K.P., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T.A., Shutov, V., Simani, M.C., Sinram, K., Stancari, M., Statera, M., Steffens, E., Steijger, J.J.M., Stenzel, H., Stewart, J., Stinzing, F., Stosslein, U., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terklov, A., Tkabladze, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P., van der Steenhoven, G., Vetterli, M.C., Vikhrov, V., Vincter, M.G., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Smit, G.Y., Ye, Y., Ye, Z., Yen, Z., Yu, W., Zihlmann, B., Zohrabian, H., and Zupranski, P.
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Nuclear Theory ,High Energy Physics::Experiment ,Nuclear Experiment ,QC - Abstract
Evidence for a narrow baryon state is found in quasi-real photoproduction on a deuterium target through the decay channel pK(S)(0) → ppi(+)pi(-). A peak is observed in the pK(S)(0) invariant mass spectrum at 1528 +/- 2.6(stat) +/- 2.1(syst) MeV. Depending on the background model, the naive statistical significance of the peak is 4-6 standard deviations and its width may be somewhat larger than the experimental resolution of sigma = 4.3-6.2 MeV. This state may be interpreted as the predicted S = +1 exotic Theta(+)(uudd (s) over bar) pentaquark baryon. No signal for an hypothetical Theta(++) baryon was observed in the pK(+) invariant mass distribution. The absence of such a signal indicates that an isotensor Theta is excluded and an isovector Theta is unlikely.
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- 2004
37. Nuclear polarization of molecular hydrogen recombined on a non-metallic surface
- Author
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Airapetian, A., Akopov, N., Avetissian, E., Makins, N. C. R., Marianski, B., Marukian, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C. A., Miyachi, Y., Muccifora, V., Bailey, P., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. D., Oganessyan, K., Ohsuga, H., Pickert, N., Potashov, S., Baturin, V., Potterveld, David H., Raithel, M., Reggiani, D., Reimer, P. E., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomian, A., Baumgarten, C., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, Igor A., Scarlett, C., 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., Belostotsky, 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., Chuiko, 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., Wise, T., Ybeles Smit, G., Zihlmann, B., Blok, H. P., Zohrabian, H., Zupranski, P., HERMES Collaboration, Bottcher, H., Akopov, Z., Borissov, A., Borisenko, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G. P., Chiang, H. C., Ciullo, G., Contalbrigo, M., Amarian, M., Court, G., 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., Feshchenko, 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., Grebenyuk, O., Greeniaus, L. G., Gregor, I. M., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Augustyniak, W., Hesselink, W. H. A., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Yarygin, G., Ivanilov, A., Izotov, A., Jackson, H. E., Jgoun, A., Avakian, R., Kaiser, R., Kinney, E., Kiselev, A., Kolster, H., Konigsmann, Kay, Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhizhin, V. G., Avetissian, A., Lagamba, L., Lapikas, Louk, Laziev, A., Lenisa, P., Liebing, P., Linden-Levy, L. A., Lipka, K., Lorenzon, W., Lu, J., and Maiheu, B.
- Subjects
fabrication [polarized target] ,DESY HERA Stor ,13.88.+e ,molecule [hydrogen] ,polarized target [hydrogen] ,39.10.+j ,measurement [polarization] ,34.09.+q ,ddc:530 ,silicon [plastics] ,HERMES ,surface [plastics] ,29.25.P - Abstract
The nuclear polarization of ${\rm H}_2$ molecules formed by recombination of nuclear polarized H atoms on
- Published
- 2004
- Full Text
- View/download PDF
38. Double-spin asymmetries in the cross section of rho /sup 0/ and phi production at intermediate energies
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Andrus, A., Aschenauer, E.C., Augustyniak, W., 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., Elschenbroich, 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., Maiheu, B., Makins, N.C.R., Marianski, B., 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., Pickert, N., Potashov, S., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P., Reischl, A., Reolon, A.R., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K.P., Schwind, A., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T.A., Shutov, V., Simani, M.C., Sinram, K., Stancari, M., Statera, M., Steffens, E., Steijger, J.J.M., Stewart, J., Stosslein, U., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Thomas, E., Tkabladze, A., Trzcinski, A., Tytgat, M., 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., and Zupranski, P.
- Subjects
High Energy Physics::Phenomenology ,Nuclear Theory ,High Energy Physics::Experiment ,Nuclear Experiment ,QC - Abstract
Double-spin asymmetries in the cross section of electroproduction of rho /sup 0/ and phi mesons on the proton and deuteron are measured at the HERMES experiment. The photoabsorption asymmetry in exclusive rho /sup 0/ electroproduction on the proton exhibits a positive tendency. This is consistent with theoretical predictions that the exchange of an object with unnatural parity contributes to exclusive rho /sup 0/ electroproduction by transverse photons. The photoabsorption asymmetry on the deuteron is found to be consistent with zero. Double-spin asymmetries in rho /sup 0/ and phi meson electroproduction by quasireal photons were also found to be consistent with zero; the asymmetry in the case of the phi meson is compatible with a theoretical prediction which involves ss knockout from the nucleon.
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- 2003
39. Evidence for quark-hadron duality in the proton spin asymmetry A1
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Aschenauer, E.C., 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., Bouhali, O., Bouwhuis, M., Brack, J., Brauksiepe, S., Brull, A., Brunn, I., Bulten, H.J., Capitani, G.P., Cisbani, E., Ciullo, G., Court, G.R., Dalpiaz, P.F., De Leo, R., De Nardo, L., De Sanctis, E., Devitsin, E., Witt Huberts, P.K.A., Di Nezza, P., Duren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Filippone, B.W., Fischer, H., Fox, B., Franz, J., Frullani, S., Garber, Y., Gapienko, V., Garibaldi, F., Garutti, E., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Green, P.W., Greeniaus, L.G., Gute, A., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Heinsius, F.H., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hofman, G., Holler, Y., Holt, R.J., Hommez, B., Iarygin, G., Izotov, A., Jackson, H.E., Jgoun, A., Jung, P., Kaiser, R., Kinney, E., Kisselev, A., Kitching, P., Konigsmann, K., Kolster, H., Kopytin, M., Korotkov, V., Kotik, E., Kozlov, V., Krauss, B., Krivokhijine, V.G., Kyle, G., Lagamba, L., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Lorenzon, W., Maas, A., Makins, N.C.R., Marukyan, H., Masoli, F., Menden, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C.A., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaeva, K., Nowak, W.D., Oganessyan, K., Orlandi, G., Podiatchev, S., Potashov, S., Potterveld, D.H., Raithel, M., Rappoport, V., Reggiani, D., Reimer, P., Reischl, A., Reolon, A.R., Rith, K., Rostomyan, A., Ryckbosch, D., Sakemi, Y., Sanjiev, I., Sato, F., Savin, I., Scarlett, C., Schafer, A., Schill, C., SChmidt, F., Schnell, G., Schuler, K.P., Schwind, A., Seibert, J., Seitz, B., Shanidze, R., Shibata, T.A., Shutov, V., Simani, M.C., Sinram, K., Stancari, M., Steffens, E., Steijger, J.J.M., Stewart, J., Stosslein, U., Suetsugu, K., Taroian, S., Terkulov, A., Tessarin, S., Thomas, E., Tipton, B., Tytgat, M., Urciuoli, G.M., van den Brand, J.F.J., van der Steenhoven, G., Van de Vyver, R., Vetterli, M.C., Vikhrov, V., Vincter, M.G., Visser, J., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Zihlmann, B., and Zohrabian, H.
- Subjects
High Energy Physics::Experiment ,QC - Abstract
Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A1. Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q2 between 1.2 and 12 GeV2 and values of W2 between 1 and 4 GeV/2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable x. This finding implies that the description of A1 in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q2 above 1.6 GeV2.
- Published
- 2003
40. Quark fragmentation to pi(+/-), pi(0), K-+/-, p and (p)over-bar in the nuclear environment
- Author
-
Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Andrus, A., Aschenauer, E.C., Augustyniak, W., 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., Borysenko, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G.P., Chiang, H.C., Ciullo, G., Contalbrigo, M., Dalpiaz, P.F., De Leo, R., De Nardo, L., De Santis, E., Devitsin, E., Di Nezza, P., Duren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Franz, J., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Greeniaus, L.G., Gregor, I.M., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H.E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Konigsmann, K., Kopytin, M., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Lipka, K., Lorenzon, W., Lu, J., Maiheu, B., Makins, N.C.R., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C.A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.D., Oganessyan, K., Ohsuga, H., Pickert, N., Potashov, S., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P.E., Reischl, A., Reolon, A.R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K.P., Schwind, A., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T.A., Shutov, V., Simani, M.C., Sinram, K., Stancari, M., Statera, M., Steffens, E., Steijger, J.J.M., Stenzel, H., Stewart, J., Stosslein, U., Tait, P., Tanaka, H., Taroian, 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., Vincter, M.G., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Smit, G.Y., Yen, S., Zihlmann, B., Zohrabian, H., and Zupranski, P.
- Subjects
High Energy Physics::Phenomenology ,Nuclear Theory ,High Energy Physics::Experiment ,Nuclear Experiment ,QC - Abstract
The influence of the nuclear medium on lepto-production of hadrons was studied in the HERMES experiment at DESY in semi- inclusive deep-inelastic scattering of 27.6 GeV positrons off deuterium, nitrogen and krypton targets. The differential multiplicity for krypton relative to that of deuterium has been measured for the first time for various identified hadrons (pi(+), pi(-), pi(0), K+, K-, p and (p) over bar) as a function of the virtual photon energy v, the fraction z of this energy transferred to the hadron, and the hadron transverse momentum squared p(t)(2). The multiplicity ratio is strongly reduced in the nuclear medium at low v and high z, with significant differences among the various hadrons. The distribution of the hadron transverse momentum is broadened towards high p(t)(2) in the nuclear medium, in a manner resembling the Cronin effect previously observed in collisions of heavy ions and protons with nuclei.
- Published
- 2003
41. The Q(2)-dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron
- Author
-
Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Aschenauer, E.C., 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., Bouhali, O., Bouwhuis, M., Brack, J., Brauksiepe, S., Brull, A., Brunn, I., Capitani, G.P., Chiang, H.C., Ciullo, G., 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., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fischer, H., Fox, B., Franz, J., Frullani, S., Garber, Y., Gapienko, G., Gapienko, V., Garibaldi, F., Garutti, E., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Green, P.W., Greeniaus, L.G., Gute, A., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Heinsius, F.H., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hillenbrand, A., Holler, Y., Hommez, B., Iarygin, G., Izotov, A., Jackson, H.E., Jgoun, A., Kaiser, R, Kinney, E., Kisselev, A., Kitching, P., Konigsmann, K., Kolster, H., Kopytin, M., Korotkov, V., Kotik, E., Kozlov, V., Krauss, B., Krivokhijine, V.G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Lipka, K., Lorenzon, W., 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., Podiatchev, S., Potashov, S., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P.E., Reisch, A., Reolon, A.R., Rith, K., Rosner, G., Rostomyan, A., Ryckbosch, D., Sanjiev, I., Sato, F., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K.P., Schwind, A., Seibert, J., Seitz, B., Shanidze, R., Shibata, T.A., Shutov, V., Simani, M.C., Sinram, K., Stancari, M., Statera, M., Steffens, E., Steijger, J.J.M., Stewart, J., Stosslein, U., Suetsugu, K., Tanaka, H., Taroian, S., Terkulov, A., Teryaev, O., Tessarin, S., Thomas, E., Tkabladze, A., Tytgat, M., 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., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Zihlmann, B., Zohrabian, H., and Zupranski, P.
- Subjects
Nuclear Theory ,Nuclear Experiment ,QC - Abstract
The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution to the magnetic moment of the target nucleus with an energy-weighted integral of the difference of the helicity- dependent photoabsorption cross sections. Originally conceived for real photons, the GDH integral can be generalised to the case of photons with virtuality Q(2). For spin-1/2 targets such as the nucleon, it then represents the non-perturbative limit of the first moment Gamma(1) of the spin structure function g(1)(x,Q(2)) in deep inelastic scattering (DIS). The data collected by HERMES with a deuterium target are presented together with a re-analysis of previous measurements on the proton. This provides an unprecedented and complete measurement of the generalised GDH integral for photon-virtuality ranging over 1.2 lt Q(2) lt 12.0 GeV2 and for photon-nucleon invariant mass squared W-2 ranging over I lt W2 lt 45 GeV2. thus covering simultaneously the nucleon-resonance and the deep inelastic scattering regions. These data allow the study of the Q(2)- dependence of the full GDH integral, which is sensitive to both the Q(2)-evolution of the resonance form factors and contributions of higher twist. The contribution of the nucleon- resonance region is seen to decrease rapidly with increasing Q(2). The DIS contribution is sizeable over the full measured range, even down to the lowest measured Q(2). As expected, at higher Q(2) the data are found to be in agreement with previous measurements of the first moment of g(1). From data on the deuteron and proton, the GDH integral for the neutron has been derived and the proton-neutron difference evaluated. This difference is found to satisfy the fundamental Bjorken sum rule at Q(2) = 5 GeV2.
- Published
- 2003
42. Double-spin asymmetries in the cross section of rho(0) and phi production at intermediate energies
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V. V., Andrus, A., Aschenauer, E. C., Augustyniak, W., 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, Giuseppe, Contalbrigo, Marco, Court, G. R., Ferretti, Paola, 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., Elschenbroich, U., Ely, J., Fabbri, Riccardo, 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, Kay C., Kolster, H., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, Paolo, Liebing, P., Lindemann, T., Lipka, K., Lorenzon, W., Maiheu, B., Makins, N. C. R., Marianski, B., Marukyan, H., Masoli, Francesco Antonio, 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., Pickert, N., Potashov, S., Potterveld, D. H., Raithel, M., Reggiani, Davide, Reimer, P., Reischl, A., Reolon, A. R., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, Igor A., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K. P., Schwind, A., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T. A., Shutov, V., Simani, M. C., Sinram, K., Stancari, Michelle Dawn, Statera, Marco, Steffens, E., Steijger, J. J. M., Stewart, J., Stosslein, U., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Thomas, E., Tkabladze, A., Trzcinski, A., Tytgat, M., 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., and (Astro)-Particles Physics
- Subjects
HERMES experiment ,Particle physics ,Photon ,Physics and Astronomy (miscellaneous) ,Meson ,media_common.quotation_subject ,Nuclear Theory ,rho(770) electroproduction ,electron p inelastic scattering ,electron deuteron inelastic scattering ,electron polarized beam ,polarized target ,Phi(1020) electroproduction ,spin asymmetry ,x-dependence ,momentum transfer dependence ,transverse momentum dependence ,quark strangeness ,quark sea ,pomeron exchange ,magnetic spectrometer ,HERMES experimental results ,DESY HERA Stored 27.5 GeV ,01 natural sciences ,7. Clean energy ,Asymmetry ,High Energy Physics - Experiment ,0103 physical sciences ,010306 general physics ,Nuclear Experiment ,Engineering (miscellaneous) ,media_common ,Physics ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Parity (physics) ,3. Good health ,Deuterium ,High Energy Physics::Experiment ,Nucleon - Abstract
Double-spin asymmetries in the cross section of electroproduction of $\rho^0$ and $\phi$ mesons on the proton and deuteron are measured at the HERMES experiment. The photoabsorption asymmetry in exclusive $\rho^0$ electroproduction on the proton exhibits a positive tendency. This is consistent with theoretical predictions that the exchange of an object with unnatural parity contributes to exclusive $\rho^0$ electroproduction by transverse photons. The photoabsorption asymmetry on the deuteron is found to be consistent with zero. Double-spin asymmetries in $\rho^0$ and $\phi $ meson electroproduction by quasi-real photons were also found to be consistent with zero; the asymmetry in the case of the $\phi$ meson is compatible with a theoretical prediction which involves $s\bar{s}$ knockout from the nucleon., Comment: 8 pages, 7 figures
- Published
- 2003
- Full Text
- View/download PDF
43. Nuclear effects on R = sigma(L)/sigma(T) in deep-inelastic scattering (vol 475, pg 386, 2000)
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V. V., Aschenauer, E. C., 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., Bouhali, O., Bouwhuis, M., Brack, J., Brauksiepe, S., Brull, A., Brunn, I., Capitani, G. P., Chiang, H. C., Ciullo, Giuseppe, Court, G. R., Ferretti, Paola, Leo, R. D., Nardo, L. D., Sanctis, E. D., Devitsin, E., P. K. A., Nezza, P. D., Duren, M., Ehrenfried, M., Elalaoui Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Ely, J., Fabbri, Riccardo, Fantoni, A., Fechtchenko, A., Felawka, L., Fischer, H., Fox, B., Franz, J., Frullani, S., Garber, Y., Gapienko, G., Gapienko, V., Garibaldi, F., Garutti, E., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Green, P. W., Greeniaus, L. G., Gute, A., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Heinsius, F. H., Henoch, M., Hertenberger, R., W. H. A., Holler, Y., Hommez, B., Iarygin, G., Izotov, A., Jackson, H. E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Kitching, P., Konigsmann, K., Kolster, H., Kopytin, M., Korotkov, V., Kotik, E., Kozlov, V., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, Paolo, Liebing, P., Lindemann, T., Lorenzon, W., N. C. R., Marukyan, H., Masoli, Francesco Antonio, Menden, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C. A., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaeva, K., Nowak, W. D., Oganessyan, K., Ohsuga, H., Orlandi, G., Podiatchev, S., Potashov, S., Potterveld, D. H., Raithel, M., Reggiani, Davide, Reimer, P. E., Reischl, A., Reolon, A. R., Rith, K., Rosner, G., Rostomyan, A., Ryckbosch, D., Sakemi, Y., Sanjiev, I., Sato, F., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K. P., Schwind, A., Seibert, J., Seitz, B., Shanidze, R., Shibata, T. A., Shutov, V., Simani, M. C., Sinram, K., Stancari, Michelle Dawn, Statera, Marco, Steffens, E., J. J. M., Stewart, J., Stosslein, U., Suetsugu, K., Tanaka, H., Taroian, S., Terkulov, A., Tessarin, S., Thomas, E., Tkabladze, A., Tytgat, M., Urciuoli, G. M., Der, G. v., R. v., De, Vetterli, M. C., Vikhrov, V., Vincter, M. G., Visser, J., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Zihlmann, B., and Zohrabian, H.
- Subjects
ELECTRON-SCATTERING ,DEPENDENCE ,MUON SCATTERING ,STRUCTURE-FUNCTION RATIOS ,R=SIGMA-L/SIGMA-T - Published
- 2003
44. The Q(2)-dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron
- Author
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Airapetian, A, Akopov, N, Akopov, Z, Amarian, M, Ammosov, Vv, Aschenauer, Ec, Avakian, R, Avetissian, A, Avetissian, E, Bailey, P, Baturin, V, Baumgarten, C, Beckmann, M, Belostotski, S, Bernreuther, S, Bianchi, N, Blok, Hp, Bottcher, H, Borissov, A, Bouhali, O, Bouwhuis, M, Brack, J, Brauksiepe, S, Brull, A, Brunn, I, Capitani, Gp, Chiang, Hc, Ciullo, Giuseppe, Court, Gr, Ferretti, Paola, 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, Elschenbroich, U, Ely, J, Fabbri, Riccardo, Fantoni, A, Fechtchenko, A, Felawka, L, Fischer, H, Fox, B, Franz, J, Frullani, S, Garber, Y, Gapienko, G, Gapienko, V, Garibaldi, F, Garutti, E, Gavrilov, G, Gharibyan, V, Graw, G, Grebeniouk, O, Green, Pw, Greeniaus, Lg, Gute, A, Haeberli, W, Hafidi, K, Hartig, M, Hasch, D, Heesbeen, D, Heinsius, Fh, Henoch, M, Hertenberger, R, Hesselink, Wha, Hillenbrand, A, Holler, Y, Hommez, B, Iarygin, G, Izotov, A, Jackson, He, Jgoun, A, Kaiser, R, Kinney, E, Kisselev, A, Kitching, P, Konigsmann, K, Kolster, H, Kopytin, M, Korotkov, V, Kotik, E, Kozlov, V, Krauss, B, Krivokhijine, Vg, Lagamba, L, Lapikas, L, Laziev, A, Lenisa, Paolo, Liebing, P, Lindemann, T, Lipka, K, Lorenzon, W, Makins, Ncr, Marukyan, H, Masoli, Francesco Antonio, Menden, F, Mexner, V, Meyners, N, Mikloukho, O, Miller, Ca, Miyachi, Y, Muccifora, V, Nagaitsev, A, Nappi, E, Naryshkin, Y, Nass, A, Nowak, Wd, Oganessyan, K, Ohsuga, H, Orlandi, G, Podiatchev, S, Potashov, S, Potterveld, Dh, Raithel, M, Reggiani, Davide, Reimer, Pe, Reisch, A, Reolon, Ar, Rith, K, Rosner, G, Rostomyan, A, Ryckbosch, D, Sanjiev, I, Sato, F, Savin, I, Scarlett, C, Schafer, A, Schill, C, Schnell, G, Schuler, Kp, Schwind, A, Seibert, J, Seitz, B, Shanidze, R, Shibata, Ta, Shutov, V, Simani, Mc, Sinram, K, Stancari, Michelle Dawn, Statera, Marco, Steffens, E, Steijger, Jjm, Stewart, J, Stosslein, U, Suetsugu, K, Tanaka, H, Taroian, S, Terkulov, A, Teryaev, O, Tessarin, S, Thomas, E, Tkabladze, A, Tytgat, M, Urciuoli, Gm, VAN DER NAT, P, VAN DER STEENHOVEN, G, VAN DE VYVER, R, Vetterli, Mc, Vikhrov, V, Vincter, Mg, Visser, J, Vogt, M, Volmer, J, Weiskopf, C, Wendland, J, Wilbert, J, Wise, T, and Yen, S
- Subjects
DEEP-INELASTIC SCATTERING ,EXTRACTION ,TARGET ,RESONANCE REGION ,POLARIMETER ,SPIN STRUCTURE-FUNCTION ,STRUCTURE-FUNCTION G(1) ,SUM-RULE ,POLARIZED HYDROGEN ,NUCLEON - Published
- 2003
45. Measurement of single-spin azimuthal asymmetries in semi-inclusive electroproduction of pions and kaons on a longitudinally polarised deuterium target
- Author
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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
- Full Text
- View/download PDF
46. Hadron formation in deep-inelastic positron scattering in a nuclear environment
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Akushevich, I., Amarian, T., Arrington, J., Aschenauer, E.C., Avakian, H., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Bains, B., Baumgarten, C., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Bottcher, H., Borissov, A., Bouwhuis, M., Brack, J., Brauksiepe, S., Braun, B., Bruckner, W., Brull, A., Budz, P., Bulten, H.J., Capitani, G.P., Carter, P., Chumney, P., Cisbani, E., Court, G.R., Dalpiaz, P.F., De Leo, R., De Nardo, L., De Sanctis, E., De Schepper, D., Devitsin, E., Witt Huberts, P.K.A., Di Nezza, P., Djordadze, V., Duren, M., Dvoredsky, A., Elbakian, G., Ely, J., Fantoni, A., Fechtchenko, A., Felawka, L., Ferro-Luzzi, M, Fiedler, K., Filippone, B.W., Fischer, H., Fox, B., Franz, J., Frullani, S., Garber, Y., Garibaldi, F., Garutti, E., Gavrilov, G., Gharibyan, V., Golendukhin, A., Graw, G., Grebeniouk, O., Green, P.W., Greeniaus, L.G., Gute, A., Haeberli, W., Hartig, M., Hasch, D., Heesbeen, D., Heinsius, F.H., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hofman, G., Holer, Y., Holt, R.J., Hommez, B., Iarygin, G., Iodice, M., Izotov, A., Jackson, H.E., Jgoun, A., Jung, P., Kaiser, R., Kanesaka, J., Kinnev, E., Kisselev, A., Kitching, P., Koch, N., Konigsmann, K., Kolster, H., Korotkov, V., Kotik, E., Kozlov, V., Krivokhijine, V.G., Kyle, G., Lagamba, L., Laziev, A., Lenisa, P., Lindemann, T., Lorenzon, W., Makins, N.C.R., Martin, J.W., Marukyan, H., Masoli, F., McAndrew, M., McIlhany, K., Mckeown, R.D., Meissner, F., Menden, F., Metz, A., Meyners, N., Mikloukho, O., Miller, C.A., Milner, R., Muccifora, V., Mussa, R., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaeva, K., Nowak, W.D., Oganessyan, K., O'Neill, T.G., Openshaw, R., Ouyang, J., Owen, B.R., Pate, S.F., Potashov, S., Potterveld, D.H., Rakness, G., Rappoport, V., Redwine, R., Reggiani, D., Reolon, A.R., Ristinen, R., Rith, K., Robinson, D., Rostomyan, A., Ruh, M., Ryckbosch, D., Sakemi, Y., Sato, T., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schmidt, F., Schnell, G., Schuler, K., Schwind, A., Seibert, J., Seitz, B., Shibata, T.A., Shin, T., Shutov, V., Simani, M.C., Simon, A., Sinram, K., Steffens, E., Steijger, J.J.M., Stewart, J., Stosslein, U., Suetsugu, K., Sutter, M., Taroian, S., Terklov, A., Tessarin, S., Thomas, E., Tipton, B., Tytgat, M., Urciuoli, G.M., van den Brand, J.F.J., van der Stennhoven, G., Van de Vyver, R., van Hunen, J.J., Vetterli, M.C., Vikhrov, V., Vincter, M.G., Visser, J., Volk, E., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., and Zohrabian, H.
- Subjects
Nuclear Theory ,High Energy Physics::Experiment ,Nuclear Experiment ,QC - Abstract
The influence of the nuclear medium on the production of charged hadrons in semi-inclusive deep-inelastic scattering has been studied by the HERMES experiment at DESY using a 27.5 GeV positron beam. The differential multiplicity of charged hadrons and identified charged pions from nitrogen relative to that from deuterium has been measured as a function of the virtual photon energy nu and the fraction z of this energy transferred to the hadron. There are observed substantial reductions of the multiplicity ratio R/sub M//sup h/ at low nu and at high z, both of which are well described by a gluon-bremsstrahlung model of hadronization. A significant difference of the nu -dependence of R/sub M//sup h/ is found between positive and negative hadrons. This is interpreted in terms of a difference between the formation times of protons and pions, using a phenomenological model to describe the nu - and z-dependence of R/sub M//sup h/.
- Published
- 2001
47. Double-Spin Asymmetry in the Cross Section for Exclusive tho(0) production in Lepton Proton Scattering
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Arrington, J., Aschenauer, E.C., Avakian, H., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Bains, B., Baumgarten, C., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Bottcher, H., Borissov, A., Bouwhuis, M., Brack, J., Brauksiepe, S., Braun, B., Bruckner, W., Brull, A., Budz, P., Bulten, H.J., Capitani, G.P., Carter, P., Chumney, P., Cisbani, E., Court, G.R., Dalpiaz, P.F., De Leo, R., De Nardo, L., De Sanctis, E., De Schepper, D., Devitsin, E., Witt Huberts, P.K.A., Di Nezza, P., Djordjadze, V., Duren, M., Dvoredsky, A., Elbakian, G., Ely, J., Fantoni, A., Fechtchenko, A., Felawka, L., Ferro-Luzzi, M., Fiedler, K., Filippone, B.W., Fischer, H., Fox, B., Franz, J., Frullani, S., Garber, Y., Garibaldi, F., Garutti, E., Gavrilov, G., Gharibyan, V., Golendukhin, A., Graw, G., Grebeniouk, O., Green, P.W., Greeniaus, L.G., Gute, A., Haeberli, W., Hartig, M., Hasch, D., Heesbeen, D., Heinsius, F.H., Henoch, M., Hertenberger, R., Hesselink, W., Hofman, G., Holler, Y., Holt, R.J., Hommez, B., Iarygin, G., Iodice, M., Izotov, A., Jackson, H.E., Jgoun, A., Jung, P., Kaiser, R., Kanesaka, J., Kinney, E., Kisselev, A., Kitching, P., Kobayashi, H., Koch, N., Konigsmann, K., Kolster, H., Korotkov, V., Kotik, E., Kozlov, V., Krivokhijine, V.G., Kyle, G., Lagamba, L., Laziev, A., Lenisa, P., Lindemann, T., Lorenzon, W., Makins, N.C.R., Martin, J.W., Marukyan, H., Masoli, F., McAndrew, M., McIlhany, K., Mckeown, R.D., Meissner, F., Menden, F., Metz, A., Meyners, N., Mikloukho, O., Miller, C.A., Milner, R., Muccifora, V., Mussa, R., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaeva, K., Nowak, W.D., Oganessyan, K., O'Neill, T.G., Openshaw, R., Ouyang, J., Owen, B.R., Pate, S.F., Potashov, S., Potterveld, D.H., Rakness, G., Rappoport, V., Redwine, R., Reggiani, D., Reolon, A.R., Ristinen, R., Rith, K., Robinson, D., Rostomyan, A., Ruh, M., Ryckbosch, D., Sakemi, Y., Sato, F., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schmidt, F., Schnell, G., Schuler, K.P., Schwind, A., Seibert, J., Seitz, B., Shibata, T.A., Shin, T., Shutov, V., Simani, C., Simon, A., Sinram, K., Steffens, E., Steijger, J.J.M., Stewart, J., Stosslein, U., Suetsugu, K., Sutter, M., Szymanowski, L., Taroian, S., Terkulov, A., Teryaev, O., Tessarin, S., Thomas, E., Tipton, B., Tytgat, M., Urciuoli, G.M., van den Brand, J.F.J., van der Steenhoven, G., Van de Vyver, R., van Hunen, J.J., Vetterli, M.C., Vikhrov, V., Vincter, M.G., Visser, J., Volk, E., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Zohrabian, H., (Astro)-Particles Physics, and Photo Conversion Materials
- Subjects
HERMES experiment ,Nuclear and High Energy Physics ,Particle physics ,media_common.quotation_subject ,FOS: Physical sciences ,Virtual particle ,01 natural sciences ,Asymmetry ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,0103 physical sciences ,mental disorders ,Invariant mass ,Vector meson ,010306 general physics ,Nuclear Experiment ,QC ,media_common ,Physics ,010308 nuclear & particles physics ,Scattering ,Vector meson dominance ,HERA ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,Condensed Matter::Strongly Correlated Electrons ,psychological phenomena and processes - Abstract
Evidence for a positive longitudinal double-spin asymmetry = 0.24 +-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive rho^0(770) vector meson production in polarised lepton-proton scattering was observed by the HERMES experiment. The longitudinally polarised 27.56 GeV HERA positron beam was scattered off a longitudinally polarised pure hydrogen gas target. The average invariant mass of the photon-proton system has a value of = 4.9 GeV, while the average negative squared four-momentum of the virtual photon is = 1.7 GeV^2. The ratio of the present result to the corresponding spin asymmetry in inclusive deep-inelastic scattering is in agreement with an early theoretical prediction based on the generalised vector meson dominance model., Comment: 10 pages, 4 embedded figures, LaTeX
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- 2001
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48. Single spin azimuthal asymmetries in electroproduction of neutral pions in semiinclusive deep inelastic scattering
- Author
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Aschenauer, E. C., Avakian, H., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Bains, B., Baturin, V., Baumgarten, C., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Bottcher, H., Borissov, A., Bouhali, O., Bouwhuis, M., Brack, J., Brauksiepe, S., Bruckner, W., Brull, A., Brunn, I., Bulten, H. J., Capitani, G. P., Chumney, P., Cisbani, E., Ciullo, G., Court, G. R., Dalpiaz, P. F., De Leo, R., De Nardo, L., De Sanctis, E., De Schepper, D., Devitsin, E., De Witt Huberts, P. K. A., Di Nezza, P., Djordjadze, V., Duren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Ely, J., Fantoni, A., Fechtchenko, A., Felawka, L., Filippone, B. W., Fischer, H., Fox, B., Franz, J., Frullani, S., Garber, Y., Garibaldi, F., Garutti, E., Gavrilov, G., Gharibyan, V., Golendukhin, A., Graw, G., Grebeniouk, O., Green, P. W., Greeniaus, L. G., Gute, A., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Heinsius, F. H., Henoch, M., Hertenberger, R., Hesselink, W. H. A., Hofman, G., Holler, Y., Holt, R. J., Hommez, B., Iarygin, G., Izotov, A., Jackson, H. E., Jgoun, A., Jung, P., Kaiser, R., Kanesaka, J., Kinney, E., Kisselev, A., Kitching, P., Kobayashi, H., Koch, N., Konigsmann, K., Kolster, H., Korotkov, V., Kotik, E., Kozlov, V., Krauss, B., Krivokhijine, V. G., Kyle, G., Lagamba, L., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Lorenzon, W., Maas, A., Makins, N. C. R., Marukyan, H., Masoli, F., McAndrew, M., McIlhany, K., Meissner, F., Menden, F., Meyners, N., Mikloukho, O., Miller, C. A., Milner, R., Muccifora, V., Mussa, R., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaeva, K., Nowak, W.-D., Oganessyan, K., O'Neill, T. G., Owen, B. R., Pate, S. F., Potashov, S., Potterveld, D. H., Raithel, M., Rakness, G., Rappoport, V., Redwine, R., Reggiani, D., Reolon, A. R., Rith, K., Robinson, D., Rostomyan, A., Ruh, M., Ryckbosch, D., Sakemi, Y., Sanjiev, I., Sato, F., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schmidt, F., Schnell, G., Schuler, K. P., Schwind, A., Seibert, J., Seitz, B., Shibata, T.-A., Shutov, V., Simani, M. C., Simon, A., Sinram, K., Steffens, E., Steijger, J. J. M., Stewart, J., Stosslein, U., Suetsugu, K., Taroian, S., Terkulov, A., Teryaev, O., Tessarin, S., Thomas, E., Tipton, B., Tytgat, M., Urciuoli, G. M., Van Den Brand, J. F. J., Van Der Steenhoven, G., Van De Vyver, R., Van Hunen, J. J., Vetterli, M. C., Vikhrov, V., Vincter, M. G., Visser, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., and Zohrabian, H.
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positron p: deep inelastic scattering ,polarization: longitudinal ,HERMES ,transverse momentum dependence ,fragmentation function ,energy dependence ,x-dependence ,DESY HERA Stor ,27.5 GeV ,p: polarized target ,pi0: electroproduction ,analyzing power ,polarization: transverse ,quark: polarization ,spin: asymmetry ,experimental results - Abstract
Physical review / D 64(9), 097101 (2001). doi:10.1103/PhysRevD.64.097101, A single-spin asymmetry in the azimuthal distribution of neutral pions relative to the lepton scattering plane has been measured for the first time in deep-inelastic scattering of positrons off longitudinally polarized protons. The analysing power in the sin(phi) moment of the cross section is 0.019 +/- 0.007(stat.) +/- 0.003(syst.). This result is compared to single-spin asymmetries for charged pion production measured in the same kinematic range. The pi^0 asymmetry is of the same size as the pi^+ asymmetry and shows a similar dependence on the relevant kinematic variables. The asymmetry is described by a phenomenological calculation based on a fragmentation function that represents sensitivity to the transverse polarization of the struck quark., Published by Inst., Woodbury, NY
- Published
- 2001
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49. Measurement of the beam spin azimuthal asymmetry associated with deeply virtual Compton scattering
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Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Aschenauer, E. C., Avakian, H., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Bains, B., Baturin, V., Baumgarten, C., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Bottcher, H., Borissov, A., Bouhali, O., Bouwhuis, M., Brack, J., Brauksiepe, S., Bruckner, W., Brull, A., Brunn, I., Bulten, H. J., Capitani, G. P., Chumney, P., Cisbani, E., Ciullo, G., Court, G. R., Dalpiaz, P. F., De Leo, R., De Nardo, L., De Sanctis, E., De Schepper, D., Devitsin, E., De Witt Huberts, P. K. A., Di Nezza, P., Duren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Filippone, B. W., Fischer, H., Fox, B., Franz, J., Frullani, S., Garber, Y., Garibaldi, F., Garutti, E., Gavrilov, G., Gharibyan, V., Golendukhin, A., Graw, G., Grebeniouk, O., Green, P. W., Greeniaus, L. G., Gute, A., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Heinsius, F. H., Henoch, M., Hertenberger, R., Hesselink, W. H. A., Hofman, G., Holler, Y., Holt, R. J., Hommez, B., Iarygin, G., Izotov, A., Jackson, H. E., Jgoun, A., Jung, P., Kaiser, R., Kanesaka, J., Kinney, E., Kisselev, A., Kitching, P., Kobayashi, H., Koch, N., Konigsmann, K., Kolster, H., Korotkov, V., Kotik, E., Kozlov, V., Krauss, B., Krivokhijine, V. G., Kyle, G., Lagamba, L., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Lorenzon, W., Maas, A., Makins, N. C. R., Marukyan, H., Masoli, F., McAndrew, M., McIlhany, K., Meissner, F., Menden, F., Meyners, N., Mikloukho, O., Miller, C. A., Milner, R., Muccifora, V., Mussa, R., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaeva, K., Nowak, W.-D, Oganessyan, K., O'Neill, T. G., Owen, B. R., Pate, S. F., Potashov, S., Potterveld, D. H., Raithel, M., Rakness, G., Rappoport, V., Redwine, R., Reggiani, D., Reolon, A. R., Rith, K., Robinson, D., Rostomyan, A., Ruh, M., Ryckbosch, D., Sakemi, Y., Sanjiev, I., Sato, F., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schmidt, F., Schnell, G., Schuler, K. P., Schwind, A., Seibert, J., Seitz, B., Shibata, T.-A., Shutov, V., Simani, M. C., Simon, A., Sinram, K., Steffens, E., Steijger, J. J. M., Stewart, J., Stosslein, U., Suetsugu, K., Taroian, S., Terkulov, A., Tessarin, S., Thomas, E., Tipton, B., Tytgat, M., Urciuoli, G. M., Van Den Brand, J. F. J., Van Steenhoven, G., Van Vyver, R., Van Hunen, J. J., Vetterli, M. C., Vikhrov, V., Vincter, M. G., Visser, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., and Zohrabian, H.
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positron: polarized beam ,angular distribution: asymmetry ,positron p: deep inelastic scattering ,polarization: longitudinal ,approximation: Bethe-Heitler ,interference ,HERMES ,photon: electroproduction ,helicity: dependence ,DESY HERA Stor ,analyzing power ,Compton scattering: off-shell ,26.7 GeV ,experimental results - Abstract
Physical review letters 87(18), 182001 (2001). doi:10.1103/PhysRevLett.87.182001, The beam-spin asymmetry in hard electroproduction of photons has been measured for the first time. The data have been accumulated by the HERMES experiment at DESY using the HERA 27.6 GeV longitudinally polarized positron beam and an unpolarized hydrogen gas target. The asymmetry in the azimuthal distribution of the produced photons in the angle phi relative to the lepton scattering plane was determined with respect to the helicity state of the incoming positron beam. The beam-spin analyzing power in the sin(phi) moment was measured to be -0.23 +/- 0.04(stat) +/- 0.03(syst) in the missing-mass range below 1.7 GeV. The observed asymmetry is attributed to the interference of the Bethe-Heitler and deeply-virtual Compton scattering processes., Published by APS, College Park, Md.
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- 2001
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- View/download PDF
50. Electron Scattering with Polarized Targets at TESLA
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N Study Group, Anselmino, M., Aschenauer, E. C., Belostotski, S., Bialowons, W., Bluemlein, J., Braun, V., Brinkmann, R., Dueren, M., Ellinghaus, F., Goeke, K., Goertz, St., Gute, A., Harmsen, J., Harrach, D. v., Jakob, R., Kabuss, E. M., Kaiser, R., Korotkov, V., Kroll, P., Leader, E., Lehmann-Dronke, B., Mankiewicz, L., Meier, A., Meyer, W., Meyners, N., Mueller, D., Mulders, P. J., Nowak, W. -D., Niedermeier, L., Oganessyan, K., Pobilitsa, P. V., Polyakov, M. V., Reicherz, G., Rith, K., Ryckbosch, D., Schaefer, A., Sinram, K., Steenhoven, G. v. d., Steffens, E., Steijger, J., and Weiss, C.
- Subjects
High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,FOS: Physical sciences - Abstract
Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q^2-dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q^2-evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics., 24 pages, 10 figures
- Published
- 2000
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