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19 results on '"exchange: pomeron"'

1. Higher order corrections to vector boson scattering at small scattering angles

Author

Peters, Krisztian

Subjects
Lipatov equation, scattering amplitude [gauge boson], gauge boson: elastic scattering, diffraction, dipole [color], quantum chromodynamics, photon photon: fusion, Regge [gluon], Z0: pair production, higher-order [Feynman graph], photon p: exclusive reaction, channel cross section: energy dependence, correction: higher-order, leading logarithm approximation, higher-order [correction], electroweak interaction, Feynman graph: higher-order, thesis, exchange: two-gluon, differential cross section: angular dependence, fusion [photon photon], energy dependence [channel cross section], helicity, pair production [Z0], quark: pair production, angular dependence [differential cross section], exclusive reaction [photon p], exchange: pomeron, two-gluon [exchange], pair production [quark], color: dipole, gauge boson: scattering amplitude, elastic scattering [gauge boson], gluon: Regge, pomeron [exchange], small-angle
Abstract

Universität Hamburg, Diss., 2004; 100 pp., (2004). doi:10.3204/DESY-THESIS-2004-025, Published by Deutsches Elektronen-Synchrotron, DESY, Hamburg

Published
2004
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2. The QCD pomeron at TESLA: Motivation and exclusive $J / \psi$ production

Author

Kwiecinski, J., Motyka, L., and De Roeck, A.

Subjects
two-photon [exchange], Lipatov equation, electron positron: inelastic scattering, exclusive reaction [photon photon], +2J%2Fpsi%283100%29%22">photon photon --> 2J/psi(3100), photoproduction [J/psi(3100)], counters and detectors: efficiency, +2J%2Fpsi%283100%29+positron+electron%22">electron positron --> 2J/psi(3100) positron electron, J/psi(3100): photoproduction, quantum chromodynamics, J/psi(3100): pair production, channel cross section: energy dependence, numerical calculations, J/psi(3100): electroproduction, Obernai 1999/10/16 [talk], exchange: two-photon, efficiency [counters and detectors], photon photon: exclusive reaction, inelastic scattering [electron positron], talk: Obernai 1999/10/16, pair production [J/psi(3100)], energy dependence [channel cross section], electroproduction [J/psi(3100)], exchange: pomeron, pomeron [exchange]
Abstract

8 pp. (2000)., We briefly present the motivation for studying the processes mediated by the QCD pomeron at high energy $e^+e^-$ colliders. We describe the behaviour of the cross-section for the reaction $\gamma \gamma \to J/\psi J/\psi$ obtained from the BFKL equation with dominant non-leading corrections. We give the predictions for the rates of anti-tagged $e^+e^- \to e^+e^- J/\psi J/\psi$ events in TESLA and conclude that such reactions may be excellent probes of the hard pomeron.

Published
2000

3. Vector Meson Photoproduction at Large Momentum Transfer at HERA

Author

Adamczyk, Leszek

Subjects
rho(770)0: hadronic decay, approx. 300 GeV-cms, Regge poles, thesis, diffraction, bibliography, +K%2B+K%22">Phi(1020) --> K+ K, ZEUS, +pi%2B+pi%22">rho(770)0 --> pi+ pi, positron p: colliding beams, energy dependence, p: dissociation, mass spectrum, J/psi(3100): leptonic decay, DESY HERA Stor, differential cross section: momentum transfer, exchange: pomeron, +positron+electron%22">J/psi(3100) --> positron electron, factorization, vector meson: photoproduction, +p+vector+meson+positron%22">positron p --> p vector meson positron, quantum chromodynamics: perturbation theory, exchange: one-photon, Phi(1020): hadronic decay, experimental results
Abstract

Akademia Gorniczo-Hutnicza, Diss., 1999; 52 pp., (1999). doi:10.3204/DESY-THESIS-1999-045, This thesis reports on a study of elastic and proton-dissociative production of $p^O, \phi$, and $J/\psi$ vector mesons ($ep\to eVp, ep \to eV N$) at the positron-proton collider HERA. The data used for this analysis were collected by the ZEUS experiment during 1995 and correspond to an integrated luminosity of 1.98 $pb^{-1}$. The data cover the kinematic range 85 < W < 10,5 GeY and $Q^2$ < 0.01 $GeV^2$ where W and $Q^2$ are the virtual photon-proton center of mass energy and the squared four-momentum transferred by the photon. The low values of $Q^2$ covered made it possible to precisely reconstruct the four-momentum transfer squared at the photon-vector meson vertex (t) and to extract from the data the cross sections for real photoproduction of vector mesons ($\gamma p \to Vp, \gamma p \to VN$) up to -t = 3 $GeV^{2}$. In the case of $p^O$ ($p^0 \to \pi^{+} \pi^{-}$) production, the $\pi^{+} \pi^{-}$ invariant mass distribution has been investigated as a function of t. The spectra show deviations from a simple relativistic Breit- 'Vigner shape as expected in models in which the asymmetry of the $\pi{+}\pi^{-}$ invariant mass shape is ascribed to the interference of resonant and non-resonant $\pi^{+}\pi^{-}$ production. The asymmetry of the $p^O$ mass shape decreases with increasing -t. The spin density matrix elements obtained from the decay angular distribution of $p^O, \phi$ and $J/\psi$ mesons are generally consistent with expectations based on s-channel helicity conservation, except for the highest -t range accessible in this analysis where $r^{04}_{1-1}$ was found to be different from zero for all mesons. However present accuracy does not allow to conclude about SCHC violation. The differential cross sections dO'/ dt for elastic and proton-dissociative $p^{O}, \phi$ and $J/\psi$ production have been measured and compared to predictions of QCD models. The proton-dissociative cross sections at -t > 1 $GeV^{2}$ could be successfully described by QCD models. However for $p^{O}$ and $\phi$ meson photoproduction the non-perturbative mechanisms still dominate in the considered kinematical range. The ratio of elastic to proton-dissociative cross sections decreases with increasing -t for all three vector mesons in a similar way thus confirming the Regge factorization hypothesis. The ratios of $\phi$ to $p^O$ and $J/\phi$ to $p^O$ photoproduction cross sections were studied as a function of t for both elastic and proton-dissociative processes. The ratios are lower than the expected ones assuming flavour independent interactions. The Pomeron trajectory has been determined from the study of the W dependence of dO'/ dt at fixed t for $p^O$ and $\phi$ mesons in the range 0.0 < -t < 0.9 $GeV^{2}$ and 0.0 < -t < 1.4 $GeV^2$ respectively. From elastic $p^O$ photoproduction the result is $\alpha_{IP}(t)$ = ($1.08 \pm 0.02$) + ($0.11 \pm 0.04$)t and from that of $\phi$ data $\alpha _{IP}(t)$ = ($1.08 \pm 0.01$) + ($0.15 \pm 0.04$)t.

Published
1999
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4. Probing the QCD pomeron in doubly tagged $e^+ e^-$ collisions

Author

Kwiecinski, J. and Motyka, L.

Subjects
two-photon [exchange], exchange: two-photon, energy dependence [total cross section], inelastic scattering [electron positron], electron positron: inelastic scattering, hadron: photoproduction, photoproduction [hadron], hadron: electroproduction, interaction [photon photon], photon photon: interaction, electroproduction [hadron], exchange: pomeron, solution [Lipatov equation], quantum chromodynamics, Lipatov equation: solution, ddc:530, numerical calculations, pomeron [exchange], total cross section: energy dependence
Abstract

12 pp. (1999)., We calculate the total cross-section for $\gamma^* \gamma^*$ collisions and for the process $e^+ e^− → e^+ e^−$ +hadrons with two tagged leptons assuming dominance of the QCD pomeron exchange. We solve the BFKL equation including the dominant subleading effects generated by the consistency constraint which restricts the available phase-space of the emitted gluons to the region in which the virtuality of the exchanged gluons is dominated by their transverse momentum squared. Estimate of the possible soft pomeron contribution to the $\gamma^* \gamma^*$ cross-section is also presented. At very high CM energies W the calculated total $\gamma^* \gamma^*$ cross-section exhibits effective power-law $(W^2)^λ$ behaviour with $\lambda \tilde{} 0.3$. We confront our results with the recent measurements at LEP and give predictions for the energies which can be accessible at TESLA and at other future linear e + e − colliders.

Published
1999

5. Electroproduction of $\phi$ mesons at 0.25 $GeV^2$ $<$ $Q^2$ $<$ 0.85 $GeV^2$ at HERA

Author

Groll, Marcus

Subjects
perturbation theory [quantum chromodynamics], vector dominance, approx. 300 GeV-cms, +Phi%281020%29+p+positron%22">positron p --> Phi(1020) p positron, +K%2B+K%22">Phi(1020) --> K+ K, differential cross section: momentum transfer, electroproduction [Phi(1020)], positron p: exclusive reaction, angular distribution, channel cross section: energy dependence, momentum transfer [differential cross section], spin: density matrix, quantum chromodynamics: perturbation theory, Regge poles, thesis, density matrix [spin], ZEUS, exclusive reaction [positron p], energy dependence [channel cross section], positron p: colliding beams, hadronic decay [Phi(1020)], colliding beams [positron p], DESY HERA Stor, exchange: pomeron, Phi(1020): electroproduction, pomeron [exchange], Phi(1020): hadronic decay, experimental results
Abstract

DESY, Diplomarbeit, 1998; 46 pp., (1998). doi:10.3204/PUBDB-2016-02733

Published
1998

6. Measurement of the proton structure function $F(2)$ at low $Q^2$ and very low $x$ with the ZEUS beam pipe calorimeter at HERA

Author

Surrow, Bernd

Subjects
vector dominance, approx. 300 GeV-cms, thesis, calorimeter: experimental results, bibliography, ZEUS, nonperturbative, momentum transfer dependence, positron p: colliding beams, x-dependence, DGLAP equation, DESY HERA Stor, exchange: pomeron, momentum transfer: low, photon p: interaction, positron p: inelastic scattering, structure function: small-x, p: structure function, quantum chromodynamics: perturbation theory, total cross section: energy dependence
Abstract

Universität Hamburg, Diss., 1998; 264 pp. (1998). = Universität Hamburg, Diss., 1998

Published
1998
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7. Photoproduction at HERA detecting a scattered proton with the H1 forward proton spectrometer

Author

Wittek, Carsten, Buesser, Friedrich-W., and Schmidt-Parzefall, Walter

Subjects
forward spectrometer: experimental results, approx. 300 GeV-cms, diffraction: dissociation, +p+positron+anything%22">positron p --> p positron anything, photoproduction [jet], leading particle [p], photoproduction [hadron], inclusive reaction [positron p], hard scattering, p: leading particle, (2jet) [final state], experimental results [forward spectrometer], production: small-angle, exchange [pi0], jet: photoproduction, Regge poles, positron p: inclusive reaction, thesis, bibliography, small-angle [production], hadron: photoproduction, pi0: exchange, positron p: colliding beams, final state: (2jet), colliding beams [positron p], DESY HERA Stor, exchange: pomeron, differential cross section: energy dependence, energy dependence [differential cross section], one-photon [exchange], H1, pomeron [exchange], dissociation [diffraction], exchange: one-photon
Abstract

140 pp. (1997)., In this thesis the measurement of the differential semi-inclusive cross section in Photoproduction with a leading proton is presented. The data were taken 1995 using the H1 detector at the HERA $ep$ storage ring, the corresponding integrated Luminosity is $\mathcal{L}$ = $2.05 pb^{-1}$. Protons were measured in the energy range of $580 GeV < E_{p\prime} < 740 GeV$ having a transverse momentum of $p\bot < 200MeV/c$. The cross section $d\sigma(\gamma p \to X p \prime)$/$dE_{p\prime}$, was calculated at $< W >$ = $$ = $90, 187 and 231 GeV$. The detection of leading protons with the H1 Forward Proton Spectometer (FPS) was possible for the first time in 1995. The FPS consists of two detector stations at 81 and 90 m and the proton magnets located between these stations and the interaction vertex. Using the measured proton track and the known beam optics, the proton energy $E_{p\prime}$ and the scattering angle $\vartheta_p \prime$, at vertex position are reconstructed. The resolution is $\Delta E_p \prime$ = $2 - 6 GeV, \Delta \vartheta_x$ = $5 - 10 \mu rad$ and $\Delta \vartheta_y$ = $5 - 100 \mu rad$ depending on the other quantities at a time. These values meet the design requirements.The selection efficiency and acceptance as well as corrections used for the cross section measurement are calculated. The differential cross section is of the order of $7 nb/GeV$ and does within errors not depend on $E_p \prime$ and $< W >$. A Regge fit shows the data to be compatible with $\pi^\circ$ exchange. To get information about the contribution from hard Photoproduction 2-jet events have been selected using a cone algorithm. The 2-jet cross section is of the order of $140 pb/GeV$. A comparison with predictions of the POMPYT model shows that the jet data can be described by Pion and Pomeron exchange within the Regge picture.

Published
1997

8. Low $x$ physics at HERA

Author

Levy, Anna

Subjects
lectures: Banz 1995/10/10, electron p: deep inelastic scattering, structure function: pomeron, small-x, gap [rapidity], DESY HERA Stor [interpretation of experiments], neutral current, Lipatov equation, interpretation of experiments: DESY HERA Stor, diffraction, structure function [p], photoproduction [hadron], Banz 1995/10/10 [lectures], charged current, DGLAP equation, strong interaction: coupling constant, quantum chromodynamics, photon: structure function, p: structure function, photon: resolved, numerical calculations, high energy behavior [total cross section], Regge poles, parametrization, bibliography, resolved [photon], hadron: photoproduction, one-pion [exchange], pomeron [structure function], total cross section: high energy behavior, rapidity: gap, parton [momentum spectrum], momentum spectrum: parton, structure function [photon], exchange: pomeron, deep inelastic scattering [electron p], exchange: one-pion, coupling constant [strong interaction], pomeron [exchange]
Abstract

440303 152 pp. (1997).

Published
1997

9. Inclusive properties of diffractive and non-diffractive photoproduction at HERA

Author

Kasprzak, Michal

Subjects
vector dominance, nondiffractive, photon: dissociation, Regge poles: multi-Regge, thesis, diffraction, charged particle: transverse momentum, bibliography, ZEUS, hadron: photoproduction, mass spectrum, DESY HERA Stor, electron p: colliding beams, exchange: pomeron, transverse momentum: spectrum, 300 GeV-cms, quantum chromodynamics: perturbation theory, photon p: inclusive reaction, exchange: one-photon, experimental results
Abstract

University of Warsaw, Diss., 1996; 95 pp. (1996). = University of Warsaw, Diss., 1996

Published
1996
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10. Hard diffractive scattering in photoproduction at HERA

Author

Sinclair, Laurel E.

Subjects
multiple production: jet, rapidity dependence, hard scattering, photoproduction: jet, jet: multiple production, positron p: inelastic scattering, hadron: multiple production, production: diffraction, pomeron: exchange, jet: photoproduction, thesis, one-photon: exchange, ZEUS, positron p: colliding beams, rapidity: gap, DESY HERA Stor, multiple production: hadron, exchange: pomeron, colliding beams: positron p, inelastic scattering: positron p, 300 GeV-cms, multiplicity: spectrum, spectrum: multiplicity, color: singlet, diffraction: production, exchange: one-photon, experimental results
Abstract

McGill University, Diss., 1996; 141 pp. (1996). = McGill University, Diss., 1996

Published
1996
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11. Measurement of the Cross-Section and t Distribution in Diffractive Deep Inelastic Scattering at HERA

Author

Barberis, Emanuela

Subjects
gap [rapidity], differential cross section: mass, diffraction: structure function, differential cross section: momentum transfer, deep inelastic scattering [positron p], structure function [diffraction], momentum transfer [differential cross section], momentum transfer dependence [charged current], positron p: deep inelastic scattering, Regge poles, thesis, parametrization, forward detector, ZEUS, positron p: colliding beams, rapidity: gap, charged current: momentum transfer dependence, colliding beams [positron p], mass [differential cross section], DESY HERA Stor, exchange: pomeron, 300 GeV-cms, particle identification: (p), pomeron [exchange], (p) [particle identification], experimental results
Abstract

166 pp. (1996)., Diffractive events in proton-positron deep inelastic scattering are studied at HERA with the ZEUS detector. The selection criterium is based either on the presence of rapidity gap, productd through the exchange of pomeron between the outgoing proton system and the remaining hadronic system, or on the identification of the diffracted proton by the ZEUS Leading Proton Spectrometer. The properties of the events are investigated and measurements of the diffractive cross section and the diffractive structure function are presented.

Published
1996
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12. Diffractive hard photoproduction at HERA and evidence for the gluon content of the pomeron

Author

Derrick, M., Krakauer, D., Magill, S., Mikunas, D., Musgrave, B., Repond, J., Stanek, R., Talaga, R. L., Zhang, H., Ayad, R., Bari, G., Basile, M., Bellagamba, L., Boscherini, D., Bruni, A., Bruni, G., Bruni, P., Cara Romeo, G., Castellini, G., Chiarini, M., Cifarelli, L., Cindolo, F., Contin, A., Corradi, M., Gialas, I., Giusti, P., Iacobucci, G., Laurenti, G., Levi, G., Margotti, A., Massam, T., Nania, R., Nemoz, C., Palmonari, F., Polini, A., Sartorelli, G., Timellini, R., Zamora Garcia, Y., Zichichi, A., Bargende, A., Crittenden, J., Desch, K., Diekmann, B., Doeker, T., Eckart, M., Feld, L., Frey, A., Geerts, M., Geitz, G., Grothe, M., Hartmann, H., Heinloth, K., Hilger, E., Jakob, H. P., Katz, U. F., Mari, S. M., Mass, A., Mengel, S., Mollen, J., Paul, E., Pfeiffer, M., Rembser, C., Schramm, D., Stamm, J., Wedemeyer, R., Campbell-Robson, S., Cassidy, A., Dyce, N., Foster, B., George, S., Gilmore, R., Heath, G. P., Heath, Helen F., Llewellyn, T. J., Morgado, C. J. S., Norman, D. J. P., O'Mara, J. A., Tapper, R. J., Wilson, S. S., Yoshida, R., Rau, R. R., Arneodo, M., Capua, M., Garfagnini, A., Iannotti, L., Schioppa, M., Susinno, G., Bernstein, A., Caldwell, A., Cartiglia, N., Parsons, J. A., Ritz, S., Sciulli, F., Straub, P. B., Wai, L., Yang, S., Zhu, Q., Borzemski, P., Chwastowski, J., Eskreys, A., Piotrzkowski, K., Zachara, M., Zawiejski, L., Adamczyk, L., Bednarek, B., Jelen, K., Kisielewska, D., Kowalski, T., Rulikowska-Zarebska, E., Suszycki, L., Zajac, J., Kotanski, A., Przybycien, M., Bauerdick, L. A. T., Behrens, U., Beier, H., Bienlein, J. K., Coldewey, C., Deppe, O., Desler, K., Drews, G., Flasinski, M., Gilkinson, D. J., Glasman, C., Gottlicher, P., Grosse-Knetter, J., Gutjahr, B., Haas, Tobias M., Hain, W., Hasell, D., Hessling, H., Iga, Y., Johnson, K., Joos, P., Kasemann, M., Klanner, R., Koch, W., Kopke, L., Kotz, U., Kowalski, H., Labs, J., Ladage, A., Lohr, B., Lowe, M., Luke, D., Mainusch, J., Manczak, O., Monteiro, T., Ng, J. S. T., Nickel, S., Notz, D., Ohrenberg, K., Roco, M., Rohde, M., Roldan, J., Schneekloth, U., Schulz, W., Selonke, F., Stiliaris, E., Surrow, B., Voss, T., Westphal, D., Wolf, G., Youngman, C., Zeuner, W., Zhou, J. F., Grabosch, H. J., Kharchilava, A., Leich, A., Mattingly, M., Meyer, A., Schlenstedt, S., Wulff, N., Barbagli, G., Pelfer, P., Anzivino, G., Maccarrone, G., De Pasquale, S., Votano, L., Bamberger, A., Eisenhardt, S., Freidhof, A., Soldner-Rembold, S., Schroder, J., Trefzger, T., Brook, N. H., Bussey, P. J., Doyle, A. T., Fleck, I., Saxon, D. H., Utley, M. L., Wilson, A. S., Dannemann, A., Holm, U., Horstmann, D., Neumann, T., Sinkus, R., Wick, K., Badura, E., Burow, B. D., Hagge, L., Lohrmann, E., Milewski, J., Nakahata, M., Pavel, N., Poelz, G., Schott, W., Zetsche, F., Bacon, T. C., Brummer, N., Butterworth, I., Gallo, E., Harris, V. L., Hung, B. H. Y., Long, K. R., Miller, D. B., Morawitz, P. P. O., Prinias, A., Sedgbeer, J. K., Whitfield, A., Mallik, U., McCliment, E., Wang, M. Z., Wang, S. M., Wu, J. T., Cloth, P., Filges, D., An, S. H., Hong, S. M., Nam, S. W., Park, S. K., Suh, M. H., Yon, S. H., Imlay, R., Kartik, S., Kim, H. J., McNeil, R. R., Metcalf, W., Nadendla, V. K., Barreiro, F., Cases, G., Fernandez, J. P., Graciani, R., Hernandez, J. M., Hervas, L., Labarga, L., Martinez, M., del Peso, J., Puga, J., Terron, J., de Troconiz, J. F., Smith, G. R., Corriveau, F., Hanna, D. S., Hartmann, J., Hung, L. W., Lim, J. N., Matthews, C., Patel, P. M., Sinclair, L. E., Stairs, D. G., St. Laurent, M., Ullmann, R., Zacek, G., Bashkirov, V., Dolgoshein, B. A., Stifutkin, A., Bashindzhagian, G. L., Ermolov, P. F., Gladilin, L. K., Golubkov, Yu. A., Kobrin, V. D. D., Korzhavina, I. A., Kuzmin, V. A., Lukina, O. Yu., Proskuryakov, A. S., Savin, A. A., Shcheglova, L. M., Solomin, A. N., Zotov, N. P., Botje, M., Chlebana, F., Dake, A., Engelen, J., de Kamps, M., Kooijman, P., Kruse, A., Tiecke, H., Verkerke, W., Vreeswijk, M., Wiggers, L., de Wolf, E., van Woudenberg, R., Acosta, D., Bylsma, B., Durkin, L. S., Honscheid, K., Li, C., Ling, T. Y., McLean, K. W., Murray, W. N., Park, I. H., Romanowski, T. A., Seidlein, R., Bailey, David C., Byrne, A., Cashmore, R. J., Cooper-Sarkar, Amanda M., Devenish, R. C. E., Harnew, N., Lancaster, M., Lindemann, L., McFall, J., Nath, C., Noyes, V. A., Quadt, A., Tickner, J. R., Uijterwaal, H., Walczak, R., Waters, D. S., Wilson, F. F., Yip, T., Abbiendi, G., Bertolin, A., Brugnera, R., Carlin, R., Dal Corso, F., De Giorgi, M., Dosselli, U., Limentani, S., Morandin, M., Posocco, M., Stanco, L., Stroili, R., Voci, C., Bulmahn, J., Butterworth, J. M., Feild, R. G., Oh, B. Y., Whitmore, J., D'Agostini, G., Marini, G., Nigro, A., Tassi, E., Hart, J. C., McCubbin, N. A., Prytz, K., Shah, T. P., Short, T. L., Barberis, E., Dubbs, T., Heusch, C., Van Hook, M., Lockman, William S., Rahn, J. T., Sadrozinski, H. F., Seiden, A., Williams, D. C., Biltzinger, J., Seifert, R. J., Schwarzer, O., Walenta, A. H., Zech, Gunter, Abramowicz, H., Briskin, G., Dagan, S., Levy, A., Hasegawa, T., Hazumi, M., Ishii, T., Kuze, M., Mine, S., Nagasawa, Y., Nakao, M., Suzuki, I., Tokushuku, K., Yamada, S., Yamazaki, Y., Chiba, M., Hamatsu, R., Hirose, T., Homma, K., Kitamura, S., Nakamitsu, Y., Yamauchi, K., Cirio, R., Costa, M., Ferrero, M. I., Lamberti, L., Maselli, S., Peroni, C., Sacchi, R., Solano, A., Staiano, A., Dardo, M., Bandyopadhyay, D., Benard, F., Brkic, M., Crombie, M. B., Gingrich, D. M., Hartner, G. F., Joo, K. K., Levman, G. M., Martin, J. F., Orr, R. S., Polenz, S., Sampson, Cortney R., Teuscher, R. J., Catterall, C. D., Jones, T. W., Kaziewicz, P. B., Lane, J. B., Saunders, R. L., Shulman, J., Blankenship, K., Lu, B., Mo, L. W., Bogusz, W., Charchula, K., Ciborowski, J., Gajewski, J., Grzelak, G., Kasprzak, M., Krzyzanowski, M., Muchorowski, K., Nowak, R. J., Pawlak, J. M., Tymieniecka, T., Wroblewski, A. K., Zakrzewski, Janusz Andrzej, Zarnecki, A. F., Adamus, M., Eisenberg, Y., Karshon, U., Revel, D., Zer-Zion, D., Ali, I., Badgett, W. F., Behrens, B., Dasu, S., Fordham, C., Foudas, C., Goussiou, A., Loveless, R. J., Reeder, D. D., Silverstein, S., Smith, W. H., Vaiciulis, A., Wodarczyk, M., Tsurugai, T., Bhadra, S., Cardy, M. L., Fagerstroem, C. P., Frisken, William R., Furutani, K. M., Khakzad, M., Schmidke, W. B., and ZEUS Collaboration

Subjects
perturbation theory [quantum chromodynamics], electron p: deep inelastic scattering, structure function: pomeron, gap [rapidity], rapidity dependence: differential cross section, rapidity dependence [differential cross section], electron p [deep inelastic scattering], differential cross section: rapidity dependence, high [transverse energy], diffraction, jet [electroproduction], 296 GeV-cms, +jet+anything%22">electron p --> jet anything, jet: electroproduction, hard scattering, deep inelastic scattering: electron p, differential cross section [rapidity dependence], ddc:530, quantum chromodynamics: perturbation theory, transverse energy: high, colliding beams [electron p], electroproduction [jet], pomeron: exchange, Regge poles, ZEUS, gluon, electron p [colliding beams], pomeron [structure function], rapidity: gap, electroproduction: jet, colliding beams: electron p, DESY HERA Stor, electron p: colliding beams, exchange: pomeron, deep inelastic scattering [electron p], exchange [pomeron], pomeron [exchange], experimental results
Abstract

24 pp. (1995)., Inclusive jet cross sections for events with a large rapidity gap with respect to the proton direction from the reaction ep → jet + X with quasi-real photons have been measured with the ZEUS detector. The cross sections refer to jets with transverse energies E T jet > 8 GeV. The data show the characteristics of a diffractive process mediated by pomeron exchange. Assuming that the events are due to the exchange of a pomeron with partonic structure, the quark and gluon content of the pomeron is probed at a scale ∼ ( E T jet ) 2 . A comparison of the measurements with model predictions based on QCD plus Regge phenomenology requires a contribution of partons with a hard momentum density in the pomeron. A combined analysis of the jet cross sections and recent ZEUS measurements of the diffractive structure function in deep inelastic scattering gives the first experimental evidence for the gluon content of the pomeron in diffractive hard scattering processes. The data indicate that between 30% and 80% of the momentum of the pomeron carried by partons is due to hard gluons.

Published
1995
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13. Measurement of the diffractive structure function in deep elastic scattering at HERA

Author

Derrick, M., Krakauer, D., Magill, S., Mikunas, D., Musgrave, B., Repond, J., Stanek, R., Talaga, R. L., Zhang, H., Ayad, R., Bari, G., Basile, M., Bellagamba, L., Boscherini, D., Bruni, A., Bruni, G., Bruni, P., Cara Romeo, G., Castellini, G., Chiarini, M., Cifarelli, L., Cindolo, F., Contin, A., Corradi, M., Gialas, I., Giusti, P., Iacobucci, G., Laurenti, G., Levi, G., Margotti, A., Massam, T., Nania, R., Nemoz, C., Palmonari, F., Polini, A., Sartorelli, G., Timellini, R., Zamora Garcia, Y., Zichichi, A., Bargende, A., Crittenden, J., Desch, K., Diekmann, B., Doeker, T., Eckart, M., Feld, L., Frey, A., Geerts, M., Geitz, G., Grothe, M., Hartmann, H., Heinloth, K., Hilger, E., Jakob, H. P., Katz, U. F., Mari, S. M., Mass, A., Mengel, S., Mollen, J., Paul, E., Rembser, C., Schramm, D., Stamm, J., Wedemeyer, R., Campbell-Robson, S., Cassidy, A., Dyce, N., Foster, B., George, S., Gilmore, R., Heath, G. P., Heath, Helen F., Llewellyn, T. J., Morgado, C. J. S., Norman, D. J. P., O'Mara, J. A., Tapper, R. J., Wilson, S. S., Yoshida, R., Rau, R. R., Arneodo, M., Capua, M., Garfagnini, A., Iannotti, L., Schioppa, M., Susinno, G., Bernstein, A., Caldwell, A., Cartiglia, N., Parsons, J. A., Ritz, S., Sciulli, F., Straub, P. B., Wai, L., Yang, S., Zhu, Q., Borzemski, P., Chwastowski, J., Eskreys, A., Piotrzkowski, K., Zachara, M., Zawiejski, L., Adamczyk, L., Bednarek, B., Jelen, K., Kisielewska, D., Kowalski, T., Rulikowska-Zarebska, E., Suszycki, L., Zajac, J., Kotanski, A., Przybycien, M., Bauerdick, L. A. T., Behrens, U., Beier, H., Bienlein, J. K., Coldewey, C., Deppe, O., Desler, K., Drews, G., Flasinski, M., Gilkinson, D. J., Glasman, C., Gottlicher, P., Grosse-Knetter, J., Gutjahr, B., Haas, Tobias M., Hain, W., Hasell, D., Hessling, H., Iga, Y., Joos, P., Kasemann, M., Klanner, R., Koch, W., Kopke, L., Kotz, U., Kowalski, H., Labs, J., Ladage, A., Lohr, B., Lowe, M., Luke, D., Mainusch, J., Manczak, O., Monteiro, T., Ng, J. S. T., Nickel, S., Notz, D., Ohrenberg, K., Roco, M., Rohde, M., Roldan, J., Schneekloth, U., Schulz, W., Selonke, F., Stiliaris, E., Surrow, B., Voss, T., Westphal, D., Wolf, G., Youngman, C., Zhou, J. F., Grabosch, H. J., Kharchilava, A., Leich, A., Mattingly, M., Meyer, A., Schlenstedt, S., Wulff, N., Barbagli, G., Pelfer, P., Anzivino, G., Maccarrone, G., De Pasquale, S., Votano, L., Bamberger, A., Eisenhardt, S., Freidhof, A., Soldner-Rembold, S., Schroder, J., Trefzger, T., Brook, N. H., Bussey, P. J., Doyle, A. T., Fleck, I., Saxon, D. H., Utley, M. L., Wilson, A. S., Dannemann, A., Holm, U., Horstmann, D., Neumann, T., Sinkus, R., Wick, K., Badura, E., Burow, B. D., Hagge, L., Lohrmann, E., Milewski, J., Nakahata, M., Pavel, N., Poelz, G., Schott, W., Zetsche, F., Bacon, T. C., Butterworth, I., Gallo, E., Harris, V. L., Hung, B. H. Y., Long, K. R., Miller, D. B., Morawitz, P. P. O., Prinias, A., Sedgbeer, J. K., Whitfield, A., Mallik, U., McCliment, E., Wang, M. Z., Wang, S. M., Wu, J. T., Zhang, Y., Cloth, P., Filges, D., An, S. H., Hong, S. M., Nam, S. W., Park, S. K., Suh, M. H., Yon, S. H., Imlay, R., Kartik, S., Kim, H. J., McNeil, R. R., Metcalf, W., Nadendla, V. K., Barreiro, F., Cases, G., Fernandez, J. P., Graciani, R., Hernandez, J. M., Hervas, L., Labarga, L., Martinez, M., del Peso, J., Puga, J., Terron, J., de Troconiz, J. F., Smith, G. R., Corriveau, F., Hanna, D. S., Hartmann, J., Hung, L. W., Lim, J. N., Matthews, C., Patel, P. M., Sinclair, L. E., Stairs, D. G., St. Laurent, M., Ullmann, R., Zacek, G., Bashkirov, V., Dolgoshein, B. A., Stifutkin, A., Bashindzhagian, G. L., Ermolov, P. F., Gladilin, L. K., Golubkov, Yu. A., Kobrin, V. D. D., Korzhavina, I. A., Kuzmin, V. A., Lukina, O. Yu., Proskuryakov, A. S., Savin, A. A., Shcheglova, L. M., Solomin, A. N., Zotov, N. P., Botje, M., Chlebana, F., Dake, A., Engelen, J., de Kamps, M., Kooijman, P., Kruse, A., Tiecke, H., Verkerke, W., Vreeswijk, M., Wiggers, L., de Wolf, E., van Woudenberg, R., Acosta, D., Bylsma, B., Durkin, L. S., Honscheid, K., Li, C., Ling, T. Y., McLean, K. W., Murray, W. N., Park, I. H., Romanowski, T. A., Seidlein, R., Bailey, David C., Byrne, A., Cashmore, R. J., Cooper-Sarkar, Amanda M., Devenish, R. C. E., Harnew, N., Lancaster, M., Lindemann, L., McFall, J., Nath, C., Noyes, V. A., Quadt, A., Tickner, J. R., Uijterwaal, H., Walczak, R., Waters, D. S., Wilson, F. F., Yip, T., Abbiendi, G., Bertolin, A., Brugnera, R., Carlin, R., Dal Corso, F., De Giorgi, M., Dosselli, U., Limentani, S., Morandin, M., Posocco, M., Stanco, L., Stroili, R., Voci, C., Bulmahn, J., Butterworth, J. M., Feild, R. G., Oh, B. Y., Whitmore, J., D'Agostini, G., Marini, G., Nigro, A., Tassi, E., Hart, J. C., McCubbin, N. A., Prytz, K., Shah, T. P., Short, T. L., Barberis, E., Dubbs, T., Heusch, C., Van Hook, M., Hubbard, B., Lockman, William S., Rahn, J. T., Sadrozinski, H. F., Seiden, A., Biltzinger, J., Seifert, R. J., Schwarzer, O., Walenta, A. H., Zech, Gunter, Abramowicz, H., Briskin, G., Dagan, S., Levy, A., Hasegawa, T., Hazumi, M., Ishii, T., Kuze, M., Mine, S., Nagasawa, Y., Nakao, M., Suzuki, I., Tokushuku, K., Yamada, S., Yamazaki, Y., Chiba, M., Hamatsu, R., Hirose, T., Homma, K., Kitamura, S., Nakamitsu, Y., Yamauchi, K., Cirio, R., Costa, M., Ferrero, M. I., Lamberti, L., Maselli, S., Peroni, C., Sacchi, R., Solano, A., Staiano, A., Dardo, M., Bandyopadhyay, D., Benard, F., Brkic, M., Crombie, M. B., Gingrich, D. M., Hartner, G. F., Joo, K. K., Levman, G. M., Martin, J. F., Orr, R. S., Sampson, Cortney R., Teuscher, R. J., Catterall, C. D., Jones, T. W., Kaziewicz, P. B., Lane, J. B., Saunders, R. L., Shulman, J., Blankenship, K., Lu, B., Mo, L. W., Bogusz, W., Charchula, K., Ciborowski, J., Gajewski, J., Grzelak, G., Kasprzak, M., Krzyzanowski, M., Muchorowski, K., Nowak, R. J., Pawlak, J. M., Tymieniecka, T., Wroblewski, A. K., Zakrzewski, Janusz Andrzej, Zarnecki, A. F., Adamus, M., Eisenberg, Y., Karshon, U., Revel, D., Zer-Zion, D., Ali, I., Badgett, W. F., Behrens, B., Dasu, S., Fordham, C., Foudas, C., Goussiou, A., Loveless, R. J., Reeder, D. D., Silverstein, S., Smith, W. H., Vaiciulis, A., Wodarczyk, M., Tsurugai, T., Bhadra, S., Cardy, M. L., Fagerstroem, C. P., Frisken, William R., Furutani, K. M., Khakzad, M., Schmidke, W. B., and ZEUS Collaboration

Subjects
electron p: deep inelastic scattering, structure function: pomeron, gap [rapidity], electron p [deep inelastic scattering], diffraction, momentum dependence, momentum transfer [dependence], 296 GeV-cms, parametrization [structure function], sum rule: momentum, deep inelastic scattering: electron p, structure function: parametrization, ddc:530, colliding beams [electron p], pomeron: exchange, momentum [sum rule], scaling, ZEUS, electron p [colliding beams], pomeron [structure function], rapidity: gap, colliding beams: electron p, DESY HERA Stor, electron p: colliding beams, exchange: pomeron, dependence: momentum transfer, deep inelastic scattering [electron p], exchange [pomeron], pomeron [exchange], experimental results
Abstract

31 pp. (1995)., This paper presents an analysis of the inclusive properties of diffractive deep inelastic scattering events produced in $ep$ interactions at HERA. The events are characterised by a rapidity gap between the outgoing proton system and the remaining hadronic system. Inclusive distributions are presented and compared with Monte Carlo models for diffractive processes. The data are consistent with models where the pomeron structure function has a hard and a soft contribution. The diffractive structure function is measured as a function of $x_{\mathbb p}$, the momentum fraction lost by the proton, of $\beta$, the momentum fraction of the struck quark with respect to $x_{\mathbb p}$, and of $Q^2$. The $x_{\mathbb p}$ dependence is consistent with the form$ (1/x_{\mathbb p})^a$ where $a=1.30\pm0.08(stat)~{+0.08}_{-0.14}(sys)$ in all bins of $\beta$ and $Q^2$. In the measured $Q^2$ range, the diffractive structure function approximately scales with $Q^2$ at fixed $\beta$. In an Ingelman-Schlein type model, where commonly used pomeron flux factor normalisations are assumed, it is found that the quarks within the pomeron do not saturate the momentum sum rule.

Published
1995

14. The BFKL Pomeron in deep inelastic diffractive dissociation near $t=0$

Author

Bartels, J., Lotter, H., and Wüsthoff, M.

Subjects
electron p: deep inelastic scattering, inclusive reaction: triple-Regge limit, invariance: conformal, perturbation theory [quantum chromodynamics], Lipatov equation, electron p [deep inelastic scattering], diffraction: dissociation, energy dependence, deep inelastic scattering: electron p, momentum transfer: low, quark [pair production], unitarity, ddc:530, dependence: mass, quantum chromodynamics: perturbation theory, conformal [invariance], gluon [multiple production], triple-Regge limit [inclusive reaction], cross section: formula, pomeron: exchange, mass [dependence], gluon: multiple production, formula [cross section], mass dependence, quark: pair production, pair production: quark, exchange: pomeron, multiple production [gluon], pair production [quark], deep inelastic scattering [electron p], exchange [pomeron], multiple production: gluon, dissociation [diffraction], low [momentum transfer], pomeron [exchange]
Abstract

43 pp. (1995)., The small-t behaviour of the deep inelastic diffractive dissociation cross section in the triple Regge region is investigated, using the BFKL approximation in perturbative QCD. We show that the cross section is finite at $t=0$, but the diffusion in lnkt2 leads to a large contribution of small momenta at the triple Pomeron vertex. We study the dependence upon the total energy and the invariant mass. Att=0, there is a decoupling of the three BFKL singularities which is a consequence of the conservation of the conformal dimension. For large invariant masses, the four gluon state in the uppert-channel plays an important role and cannot be neglected.

Published
1995

15. First measurement of the deep inelastic structure of proton diffraction

Author

Ahmed, T., Aid, S., Baranov, P., Ferencei, J., Ferrarotto, F., Flamm, K., Fleischer, M., Flieser, M., Flugge, G., Fomenko, A., Forbush, M., Formanek, J., Foster, J. M., Barrelet, E., Franke, G., Fretwurst, E., Gabathuler, E., Gabathuler, K., Gamerdinger, K., Garvey, J., Gayler, Joerg, Gebauer, M., Gellrich, A., Genzel, H., Bartel, W., Gerhards, R., Goerlach, U., Goerlich, L., Gogitidze, N., Goldberg, M., Goldner, D., Gonzalez-Pineiro, B., Gorelov, I., Gorichev, P., Grab, C., Barth, M., Grassler, H., Grassler, R., Greenshaw, T., Grindhammer, Guenter, Gruber, A., Gruber, C., Haack, J., Haidt, D., Hajduk, L., Hamon, O., Bassler, U., Hampel, M., Hanlon, E. M., Hapke, M., Haynes, W. J., Heatherington, J., Heinzelmann, G., Henderson, R. C. W., Henschel, H., Herynek, I., Hess, M. F., Beck, H. P., Hildesheim, W., Hill, P., Hiller, K. H., Hilton, C. D., Hladky, J., Hoeger, K. C., Hoppner, M., Horisberger, R., Hudgson, V. L., Huet, P., Behrend, H. J., Hutte, M., Hufnagel, H., Ibbotson, M., Itterbeck, H., Jabiol, M. A., Jacholkowska, A., Jacobsson, C., Jaffre, M., Janoth, J., Jansen, T., Belousov, A., Jonsson, L., Johnson, D. P., Johnson, L., Jung, H., Kalmus, P. I. P., Kant, D., Kaschowitz, R., Kasselmann, P., Kathage, U., Katzy, J., Berger, Christoph, Kaufmann, H. H., Ghazaryan, Samvel, Kenyon, I. R., Kermiche, S., Keuker, C., Kiesling, Christian M., Klein, M., Kleinwort, C., Knies, G., Ko, W., Bernardi, G., Kohler, T., Kohne, J., Kolanoski, H., Kole, F., Kolya, S. D., Korbel, V., Korn, M., Kostka, P., Kotelnikov, S. K., Kramerkamper, T., Andreev, V., Bernet, R., Krasny, M. W., Krehbiel, H., Krucker, D., Kruger, U., Kruner-Marquis, U., Kubenka, J. P., Kuster, H., Kuhlen, M., Kurca, T., Kurzhofer, J., Bertrand-Coremans, G., Kuznik, B., Lacour, D., Lamarche, F., Lander, R., Landon, M. P. J., Lange, W., Lanius, P., Laporte, J. F., Lebedev, A., Leverenz, C., Besancon, M., Levonian, S., Ley, C., Lindner, A., Lindstrom, G., Link, J., Linsel, F., Lipinski, J., List, B., Lobo, G., Loch, P., Beyer, R., Lohmander, H., Lomas, J., Lopez, G. C., Lyubimov, V., Luke, D., Magnussen, N., Malinovski, E., Mani, S., Maracek, R., Marage, P., Biddulph, P., Marks, J., Marshall, R., Martens, J., Martin, R., Martyn, H. U., Martyniak, J., Masson, S., Mavroidis, T., Maxfield, S. J., McMahon, S. J., Bispham, P., Mehta, A., Meier, K., Mercer, D., Merz, T., Meyer, C. A., Meyer, H., Meyer, J., Mikocki, S., Milstead, D., Moreau, F., Bizot, J. C., Morris, J. V., Mroczko, E., Muller, G., Muller, K., Murin, P., Nagovizin, V., Nahnhauer, R., Naroska, B., Naumann, T., Newman, Paul R., Blobel, V., Newton, D., Neyret, D., Nguyen, H. K., Nicholls, T. C., Niebergall, F., Niebuhr, C., Niedzballa, C., Nisius, R., Nowak, G., Noyes, G. W., Borras, K., Nyberg-Werther, M., Oakden, M., Oberlack, H., Obrock, U., Olsson, J. E., Ozerov, D., Panaro, E., Panitch, A., Pascaud, C., Patel, G. D., Botterweck, F., Peppel, E., Perez, E., Phillips, J. P., Pichler, C., Pitzl, D., Pope, G., Prell, Soeren A., Prosi, R., Rabbertz, K., Radel, G., Andrieu, B., Boudry, V., Raupach, F., Reimer, P., Reinshagen, S., Ribarics, P., Rick, H., Riech, V., Riedlberger, J., Riess, S., Rietz, M., Rizvi, E., Braemer, A., Robertson, S. M., Robmann, P., Roloff, H. E., Roosen, R., Rosenbauer, K., Rostovtsev, A., Rouse, F., Royon, C., Ruter, K., Rusakov, S., Brasse, F., Rybicki, K., Rylko, R., Sahlmann, N., Sanchez, E., Sankey, D. P., Schacht, P., Schiek, S., Schleper, P., von Schlippe, W., Schmidt, C., Braunschweig, W., Schmidt, D., Schmidt, G., Schoning, A., Schroder, V., Schuhmann, E., Schwab, B., Schwind, A., Sefkow, F., Seidel, M., Sell, R., Brisson, V., Semenov, A., Chekelian, V. I., Sheviakov, I., Shooshtari, H., Shtarkov, L. N., Siegmon, G., Siewert, U., Sirois, Y., Skillicorn, I. O., Smirnov, P., Bruncko, D., Smith, J. R., Solochenko, V., Solovev, Ya., Spiekermann, J., Spitzer, H., Starosta, R., Steenbock, M., Steffen, P., Steinberg, R., Stella, B., Brune, C., Stephens, K., Stier, J., Stiewe, J., Stosslein, U., Stolze, K., Strachota, J., Straumann, U., Struczinski, W., Sutton, J. P., Tapprogge, S., Buchholz, R., Taylor, Richard E., Chernyshov, V., Thiebaux, C., Thompson, Graham, Truoel, Peter, Turnau, J., Tutas, J., Ulkes, P., Usik, A., Valkar, S., Bungener, L., Valkarova, A., Vallee, C., Van Esch, P., Van Mechelen, P., Vartapetian, A., Vazdik, Y., Verrecchia, P., Villet, G., Wacker, K., Wagener, A., Burger, J., Wagener, M., Walker, I. W., Walther, A., Weber, G., Weber, M., Wegener, D., Wegner, A., Wellisch, H. P., West, L. R., Willard, S., Appuhn, R. D., Busser, F. W., Winde, M., Winter, G. G., Wittek, C., Wright, A. E., Wunsch, E., Wulff, N., Yiou, T. P., Zacek, J., Zarbock, D., Zhang, Z., Bunyatyan, A., Zhokin, A., Zimmer, M., Zimmermann, W., Zomer, F., Zuber, K., H1 Collaboration, Burke, Stephen, Burton, M., Buschhorn, G., Campbell, A. J., Carli, T., Charles, F., Clarke, D., Clegg, Arthur B., Arpagaus, M., Clerbaux, B., Colombo, M., Contreras, J. G., Cormack, C., Coughlan, J. A., Courau, A., Coutures, C., Cozzika, G., Criegee, L., Cussans, D. G., Babaev, A., Cvach, J., Dagoret, S., Dainton, J. B., Dau, W. D., Daum, K., David, M., Deffur, E., Delcourt, B., Del Buono, L., de Roeck, A., Baehr, J., De Wolf, E. A., Di Nezza, P., Dollfus, C., Dowell, J. D., Dreis, H. B., Droutskoi, V., Duboc, J., Duellmann, Dirk, Dunger, O., Duhm, H., Ban, J., Ebert, J., Ebert, T. R., Eckerlin, Guenter, Efremenko, V., Egli, S., Ehrlichmann, H., Eichenberger, S., Eichler, R., Eisele, F., Eisenhandler, E., Ban, Y., Ellison, R. J., Elsen, E., Erdmann, M., Erdmann, W., Evrard, E., Favart, L., Fedotov, A., Feeken, D., Felst, R., and Feltesse, J.

Subjects
electron p: deep inelastic scattering, structure function: pomeron, gap [rapidity], electron p [deep inelastic scattering], diffraction, structure function [p], momentum transfer [dependence], factorization [structure function], x-dependence, deep inelastic scattering: electron p, ddc:530, p: structure function, colliding beams [electron p], pomeron: exchange, DESY DESY HERA Stor Stor, scaling, 296 GeV-cms: 8.5 < Q**2 < 50 GeV**2, electron p [colliding beams], 8.5 < Q**2 < 50 GeV**2 [296 GeV-cms], pomeron [structure function], structure function: factorization, rapidity: gap, colliding beams: electron p, electron p: colliding beams, exchange: pomeron, dependence: momentum transfer, deep inelastic scattering [electron p], exchange [pomeron], H1, pomeron [exchange], experimental results
Abstract

16 pp. (1995)., A measurement is presented, using data taken with the H1 detector at HERA, of the contribution of diffractive interactions to deep-inelastic electron-proton ( ep ) scattering in the kinematic range 8.5 < Q 2 < 50GeV 2 , 2.4 × 10 −4 < Bjorken- x < 0.0133, and 3.7 × 10 −4 < χ p < 0.043. The diffractive contribution to the proton structure function F 2 ( x , Q 2 ) is evaluated as a function of the appropriate deep-inelastic scattering variables χ p , Q 2 , β (= χ χ p ) using a class of deep-inelastic ep scattering events with no hadronic energy flow in an interval of pseudo-rapidity adjacent to the proton beam direction. the dependence of this contribution on χ p is measured to be χ p − n with n = 1.19 ± 0.06 (stat.) ± 0.07 (syst.) independent of β and Q 2 , which is consistent with both a diffractive interpretation and a factorisable ep diffractive cross section. A first measurement of the deep-inelastic structure of the pomeron in the form of the Q 2 and β dependences of a factorised structure function is presented. For all measured β, this structure function is observed to be consistent with scale invariance.

Published
1995
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16. Diffractive photoproduction of jets with a direct pomeron coupling at HERA

Author

Kniehl, Bernd A., Kohrs, H. G., and Kramer, G.

Subjects
structure function: pomeron, pomeron: exchange, jet: photoproduction, effective Lagrangian, interpretation of experiments: DESY HERA Stor, electron p: inclusive reaction, diffraction, one-photon: exchange, (2jet): final state, (quark pomeron): coupling, model: parton, electroproduction: jet, final state: (2jet), jet: electroproduction, exchange: pomeron, rapidity spectrum, coupling: (quark pomeron), photoproduction: jet, transverse momentum: spectrum, spectrum: transverse momentum, photon p: inclusive reaction, numerical calculations, exchange: one-photon
Abstract

We investigate in detail the effect of a direct pomeron coupling to quarks on the production of jets in $ep$ scattering with almost real photons. Jet production via a direct pomeron coupling is compared with the resolved--pomeron mechanism. We consider both direct and resolved photoproduction. Rapidity and transverse momentum distributions are calculated and compared with preliminary H1 and ZEUS data.

Published
1995
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17. Observation of events with a large rapidity gap in deep inelastic scattering at HERA

Author

Derrick, M., Krakauer, D., Magill, S., Musgrave, B., Repond, J., Repond, S., Stanek, R., Talaga, R. L., Thron, J., Arzarello, F., Ayad, R., Bari, G., Basile, M., Bellagamba, L., Boscherini, D., Bruni, A., Bruni, G., Bruni, P., Cara Romeo, G., Castellini, G., Chiarini, M., Cifarelli, L., Cindolo, F., Ciralli, F., Contin, A., D'Auria, S., Del Papa, C., Frasconi, F., Giusti, P., Iacobucci, G., Laurenti, G., Levi, G., Lin, Q., Lisowski, B., Maccarrone, G., Margotti, A., Massam, T., Nania, R., Nemoz, C., Palmonari, F., Sartorelli, G., Timellini, R., Zamora Garcia, Y., Zichichi, A., Bargende, A., Crittenden, J., Desch, K., Diekmann, B., Doeker, T., Frey, A., Geerts, M., Geitz, G., Hartmann, H., Haun, D., Heinloth, K., Hilger, E., Jakob, H.-P., Kramarczyk, S., Kückes, M., Mass, A., Mengel, S., Mollen, J., Monaldi, D., Müsch, H., Paul, E., Schattevoy, R., Schneider, J.-L., Schramm, D., Wedemeyer, R., Cassidy, A., Cussans, D. G., Dyce, N., Foster, B., Gilmore, R., Heath, G. P., Heath, H. F., Lancaster, M., Llewellyn, T. J., Malos, J., Morgado, C. J. S., Tapper, R. J., Wilson, S. S., Yoshida, R., Rau, R. R., Arneodo, M., Schioppa, M., Susinno, G., Bernstein, A., Caldwell, A., Gialas, I., Parsons, J. A., Ritz, S., Sciulli, F., Straub, P. B., Wai, L., Yang, S., Borzemski, P., Chwastowski, J., Dwuraźny, A., Eskreys, A., Jakubowski, Z., Niziol, B., Piotrzkowski, K., Zachara, M., Zawiejski, L., Adamczyk, L., Bednarek, B., Eskreys, K., Jeleń, K., Kisielewska, D., Kowalski, T., Rulikowska-Zarȩbska, E., Suszycki, L., Zaja̧c, J., Kȩdzieski, T., Kotański, A., Przybycień, M., Bauerdick, L. A. T., Behrens, U., Bienlein, J. K., Böttcher, S., Coldewey, C., Dannemann, A., Drews, G., Erhard, P., Flasiński, M., Fleck, I., Gläser, R., Göttlicher, P., Gutjahr, B., Haas, T., Hagge, L., Hain, W., Hasell, D., Hultschig, H., Jahnen, G., Joos, P., Kasemann, M., Klanner, R., Koch, W., Köpke, L., Kötz, U., Kowalski, H., Kröger, W., Krüger, J., Labs, J., Ladage, A., Löhr, B., Löwe, M., Lüke, D., Mainusch, J., Manczak, O., Momayezi, M., Ng, J. S. T., Nickel, S., Notz, D., Pösnecker, K.-U., Rohde, M., Roldán, J., Ros, E., Schneekloth, U., Schroeder, J., Schulz, W., Selonke, F., Stiliaris, E., Tscheslog, E., Tsurugai, T., Vogel, W., Wolf, G., Youngman, C., Grabosch, H. J., Leich, A., Meyer, A., Rethfeldt, C., Schlenstedt, S., Barbagli, G., Francescato, A., Nuti, M., Pelfer, P., Anzivino, G., Casaccia, R., De Pasquale, S., Qian, S., Votano, L., Bamberger, A., Freidhof, A., Poser, T., Söldner-Rembold, S., Theisen, G., Trefzger, T., Brook, N. H., Bussey, P. J., Doyle, A. T., Forbes, J. R., Jamieson, V. A., Raine, C., Saxon, D. H., Brückmann, H., Gloth, G., Holm, U., Kammerlocher, H., Krebs, B., Neumann, T., Wick, K., Fürtjes, A., Lohrmann, E., Milewski, J., Nakahata, M., Pavel, N., Poelz, G., Schott, W., Terron, J., Zetsche, F., Bacon, T. C., Beuselinck, R., Butterworth, I., Gallo, E., Harris, V. L., Miller, D. B., Prinias, A., Sedgbeer, J. K., Vorvolakos, A., Whitfield, A., Bienz, T., Kreutzmann, H., Mallik, U., McCliment, E., Roco, M., Wang, M. Z., Cloth, P., Filges, D., An, S. H., Hong, S. M., Kim, C. O., Kim, T. Y., Nam, S. W., Park, S. K., Suh, M. H., Yon, S. H., Imlay, R., Kartik, S., Kim, H.-J., McNeil, R. R., Metcalf, W., Nadendla, V. K., Barreiro, F., Cases, G., Hervás, L., Labarga, L., del Peso, J., de Trocóniz, J. F., Ikraiam, F., Mayer, J. K., Smith, G. R., Corriveau, F., Gilkinson, D. J., Hanna, D. S., Hartmann, J., Hung, L. W., Lim, J. N., Meijer Drees, R., Mitchell, J. W., Patel, P. M., Sinclair, L. E., Stairs, D. G., St. Laurent, M., Ullmann, R., Bashindzhagyan, G. L., Ermolov, P. F., Gladilin, L. K., Golubkov, Y. A., Kuzmin, V. A., Kuznetsov, E. N., Savin, A. A., Voronin, A. G., Zotov, N. P., Bentvelsen, S., Botje, M., Dake, A., Engelen, J., de Jong, P., de Kamps, M., Kooijman, P., Kruse, A., van der Lugt, H., O'Dell, V., Tenner, A., Tiecke, H., Uijterwaal, H., Vreeswijk, M., Wiggers, L., de Wolf, E., van Woudenberg, R., Bylsma, B., Durkin, L. S., Honscheid, K., Li, C., Ling, T. Y., McLean, K. W., Murray, W. N., Park, I. H., Romanowski, T. A., Seidlein, R., Blair, G. A., Byrne, A., Cashmore, R. J., Cooper-Sarkar, A. M., Devenish, R. C. E., Gingrich, D. M., Hallam-Baker, P. M., Harnew, N., Khatri, T., Long, K. R., Luffman, P., McArthur, I., Morawitz, P., Nash, J., Smith, S. J. P., Roocroft, N. C., Wilson, F. F., Abbiendi, G., Brugnera, R., Carlin, R., Dal Corso, F., De Giorgi, M., Dosselli, U., Gasparini, F., Limentani, S., Morandin, M., Posocco, M., Stanco, L., Stroili, R., Voci, C., Butterworth, J. M., Bulmahn, J., Feild, G., Oh, B. Y., Whitmore, J., Contino, U., D'Agostini, G., Guida, M., Iori, M., Mari, S. M., Marini, G., Mattioli, M., Nigro, A., Hart, J. C., McCubbin, N. A., Prytz, K., Shah, T. P., Short, T. L., Barberis, E., Cartiglia, N., Heusch, C., Hubbard, B., Leslie, J., Lockman, W., O'Shaughnessy, K., Sadrozinski, H. F., Seiden, A., Zer-Zion, D., Badura, E., Biltzinger, J., Seifert, R. J., Walenta, A. H., Zech, G., Dagan, S., Levy, A., Hasegawa, T., Hazumi, M., Ishii, T., Kasai, S., Kuze, M., Mine, S., Nagasawa, Y., Nagira, T., Nakao, M., Okuno, H., Suzuki, I., Tokushuku, K., Yamada, S., Yamazaki, Y., Chiba, M., Hamatsu, R., Hirose, T., Kitamura, S., Nagayama, S., Nakamitsu, Y., Cirio, R., Costa, M., Ferrero, M. I., Lamberti, L., Maselli, S., Peroni, C., Solano, A., Staiano, A., Dardo, M., Bailey, D. C., Bandyopadhyay, D., Bernard, F., Bhadra, S., Brkic, M., Burow, B. D., Chlebana, F. S., Crombie, M. B., Hartner, G. F., Levman, G. M., Martin, J. F., Orr, R. S., Prentice, J. D., Sampson, C. R., Stairs, G. G., Teuscher, R. J., Yoon, T.-S., Bullock, F. W., Catterall, C. D., Giddings, J. C., Jones, T. W., Khan, A. M., Lane, J. B., Makkar, P. L., Shaw, D., Shulman, J., Blankenship, K., Kochocki, J., Lu, B., Mo, L. W., Charchuła, K., Ciborowski, J., Gajewski, J., Grzelak, G., Kasprzak, M., Krzyżanowski, M., Muchorowski, K., Nowak, R. J., Pawlak, J. M., Stopczyński, A., Tymieniecka, T., Walczak, R., Wróblewski, A. K., Zakrzewski, J. A., Żarnecki, A. F., Adamus, M., Abramowicz, H., Eisenberg, Y., Glasman, C., Karshon, U., Montag, A., Revel, D., Shapira, A., Foudas, C., Fordham, C., Loveless, R. J., Goussiou, A., Ali, I., Behrens, B., Dasu, S., Reeder, D. D., Smith, W. H., Silverstein, S., Frisken, W. R., Furutani, K. M., Iga, Y., and ZEUS Collaboration

Subjects
electron p: deep inelastic scattering, gap [rapidity spectrum], electron p [deep inelastic scattering], diffraction: dissociation, 296 GeV, hadron [electroproduction], momentum transfer [dependence], hadron: electroproduction, electroproduction [hadron], deep inelastic scattering: electron p, ddc:530, exchange [one-photon], pomeron: exchange, DESY DESY HERA Stor Stor, electroproduction: hadron, one-photon: exchange, ZEUS, exchange: pomeron, dependence: momentum transfer, rapidity spectrum: gap, deep inelastic scattering [electron p], one-photon [exchange], exchange [pomeron], dissociation [diffraction], pomeron [exchange], exchange: one-photon, experimental results
Abstract

13 pp. (1993)., In deep inelastic, neutral current scattering of electrons and protons at s=296GeV, we observe in the ZEUS detector events with a large rapidity gap in the hadronic final state. They occur in the region of small Bjorken x and are observed up to Q2 of 100 GeV2. They account for about 5% of the events with Q2⩾10 GeV2. Their general properties are inconsistent with the dominant mechanism of deep inelastic scattering, where color is transferred between the scattered quark and the proton remnant, and suggest that the underlying production mechanism is the diffractive dissociation of the virtual photon.

Published
1993

18. Diffractive W and Z production at p$\overline p$ colliders and the pomeron parton content

Author

Bruni, P. and Ingelman, G.

Subjects
structure function: pomeron, momentum spectrum [quark], inclusive reaction [anti-p p], +W+anti-p+anything%22">anti-p p --> W anti-p anything, hadroproduction: Z0, W [hadroproduction], transverse momentum [differential cross section], Z0 [hadroproduction], differential cross section [transverse momentum], W: hadroproduction, production [diffraction], momentum spectrum [gluon], anti-p p: inclusive reaction, hadroproduction [Z0], transverse momentum: differential cross section, ddc:530, production: diffraction, pomeron: exchange, gluon: momentum spectrum, Z0: hadroproduction, pomeron [structure function], quark: momentum spectrum, hadroproduction [W], diffraction [production], hadroproduction: W, exchange: pomeron, differential cross section: transverse momentum, exchange [pomeron], 1800 GeV-cms, diffraction: production, pomeron [exchange]
Abstract

8 pp. (1993)., High-$p⊥$ jets in diffractive pp events have revealed a parton structure in the exchanged pomeron. Based on a model using a pomeron structure function dominated by either quarks or gluons we calculate diffractive W/Z production and find observably large cross-sections at the Tevatron energy. The relative quark and gluon content may here be experimentally investigated and the x-shape of their density functions obtained to give new insights on the nature of the pomeron

Published
1993

19. Transverse momentum distributions for exclusive $\varrho^{0}$ muoproduction

Author

M. van der Heijden, H. Peschel, M. Treichel, Ralf Kaiser, D. Nowotny, A. Sandacz, U. Krüner, W. Brückner, Chiara Mariotti, P. Amaudruz, M. Botje, Geoffrey Taylor, E. Rondio, F. Zetsche, Amedeo Staiano, L. Fluri, J. Domingo, B. Badelek, R. A. Schumacher, A. Simon, A. Brüll, G. van Middelkoop, J. Nassalski, H. Engelien, M.I. Ferrero, I. G. Bird, Ulrich Landgraf, Michele Arneodo, C. Scholz, J. Beaufays, L. Ropelewski, J. Drinkard, T. Lindqvist, P. Grafström, Q. Ingram, G. Baum, D. von Harrach, K. Röhrich, J. Ciborowski, N. Pavel, H. Döbbeling, M. Siebler, Thomas Walcher, R. van Dantzig, R. Rieger, Y. Mizuno, U. Sennhauser, F. Klein, M. de Jong, B. Povh, K. Janson, S. Kullander, C. Broggini, Cristiana Peroni, Roland Windmolders, A. Arvidson, G. K. Mallot, W. J. Burger, Tjeerd Ketel, B. Korzen, F. Lettenström, T.-A. Shibata, Klaus Rith, F. Sever, J.-L. Vuilleumier, E. M. Kabuß, and C. A. Heusch

Subjects
forward spectrometer: experimental results, Physics and Astronomy (miscellaneous), Nuclear Theory, muon nucleus: nuclear reaction, chemistry.chemical_element, Elementary particle, muon deuteron: nuclear reaction, Nuclear physics, mass spectrum: two-pion, momentum transfer: slope, spectrum: transverse momentum, Field theory (psychology), Quantum field theory, Nuclear Experiment, rho(770)0: electroproduction, Engineering (miscellaneous), muon p: exclusive reaction, Physics, pomeron: exchange, calcium, two-pion: mass spectrum, background, electroproduction: rho(770)0, carbon, 200 GeV, CERN SPS, Deep inelastic scattering, Particle acceleration, exchange: pomeron, chemistry, transverse momentum: spectrum, Quantum electrodynamics, Transverse momentum, High Energy Physics::Experiment, Carbon, Particle Physics - Experiment, +rho%28770%290+nucleon%22">muon p --> rho(770)0 nucleon
Abstract

We have studied transverse momentum distributions for exclusive rho(0) muoproduction on protons and heavier nuclei at 2 < Q2 < 25 GeV2. The Q2 dependence of the slopes of the p(t)2 and t' distributions is discussed. The influence of the non-exclusive background is investigated. The p(t)2-slope for exclusive events is 4.3 +/- 0.6 +/- 0.7 GeV-2 at large Q2. The p(t)2 spectra are much softer than inclusive p(t)2 spectra of leading hadrons produced in deep inelastic scattering.

Published
1991

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