Laser-plasma accelerator group: publications

Measurement of total and partial photon proton cross sections at 180 GeV center of mass energy

Zeitschrift Fur Physik C Particles and Fields 63:3 (1994) 391-408

Authors:

M Derrick, D Krakauer, S Magill, B Musgrave, J Repond, J Schlereth, R Stanek, RL Talaga, J Thron, F Arzarello, R Ayad, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, GC Romeo, G Castellini, M Chiarini, L Cifarelli, F Cindolo, F Ciralli, A Contin, S D'Auria, C Del Papa, F Frasconi, P Giusti, G Iacobucci, G Laurenti, G Levi, G Maccarrone, A Margotti, T Massam, R Nania, C Nemoz, F Palmonari, G Sartorelli, R Timellini, Y Zamora Garcia, A Zichichi, A Bargende, J Crittenden, K Desch, B Diekmann, T Doeker, L Feld, A Frey, M Geerts, G Geitz, H Hartmann, D Haun, K Heinloth, E Hilger, HP Jakob, UF Katz, S Kramarczyk, A Mass, S Mengel, J Mollen, E Paul, C Rembser, R Schattevoy, JL Schneider, D Schramm, R Wedemeyer, A Cassidy, DG Cussans, N Dyce, B Foster, S George, R Gilmore, GP Heath, HF Heath, M Lancaster, TJ Llewellyn, CJS Morgado, JA O'Mara, RJ Tapper, SS Wilson, R Yoshida, RR Rau, M Arneodo, M Schioppa, G Susinno, A Bernstein, A Caldwell, I Gialas, JA Parsons, S Ritz, F Sciulli, PB Straub, L Wai, S Yang, P Borzemski, J Chwastowski, A Eskreys, K Piotrzkowski, M Zachara

Abstract:

Photon proton cross sections for elastic light vector meson production, σel^ν��, inelastic diffractive production, σnd^ν��, non-diffractive production, σd^ν��, as well as the total cross section, σtot^ν��, have been measured at an average υp center of mass energy of 180 GeV with the ZEUS detector at HERA. The resulting values are σel^ν�� = 18 ± 7 μb, σd^ν�� = 33 ± 8 μb, σnd^ν�� = 91 ± 11 μb, and σtot^ν�� 143 ± 17 μb, where the errors include statistical and systematic errors added in quadrature. © 1994 Springer-Verlag.

Observation of jet production in deep inelastic scattering with a large rapidity gap at HERA

Physics Letters B 332:1-2 (1994) 228-243

Authors:

M Derrick, D Krakauer, S Magill, B Musgrave, J Repond, J Schlereth, R Stanek, RL Talaga, J Thron, F Arzarello, R Ayad, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, GC Romeo, G Castellini, M Chiarini, L Cifarelli, F Cindolo, F Ciralli, A Contin, S D'Auria, C Del Papa, F Frasconi, P Giusti, G Iacobucci, G Laurenti, G Levi, G Maccarrone, A Margotti, T Massam, R Nania, C Nemoz, F Palmonari, G Sartorelli, R Timellini, YZ Garcia, A Zichichi, A Bargende, J Crittenden, K Desch, B Diekmann, T Doeker, L Feld, A Frey, M Geerts, G Geitz, H Hartmann, D Haun, K Heinloth, E Hilger, HP Jakob, UF Katz, S Kramarczyk, A Mass, S Mengel, J Mollen, E Paul, C Rembser, R Schattevoy, JL Schneider, D Schramm, J Stamm, R Wedemeyer, S Campbell-Robson, A Cassidy, N Dyce, B Foster, S George, R Gilmore, GP Heath, HF Heath, TJ Llewellyn, CJS Morgado, DJP Norman, JA O'Mara, RJ Tapper, SS Wilson, R Yoshida, RR Rau, M Arneodo, M Schioppa, G Susinno, A Bernstein, A Caldwell, I Gialas, JA Parsons, S Ritz, F Sciulli, PB Straub, L Wai, S Yang, P Borzemski, J Chwastowski, A Eskreys, K Piotrzkowski

Abstract:

Events with a large rapidity gap in deep inelastic scattering with Q2 ≥ 10 GeV2 have been studied in the ZEUS detector. The properties of these events with W > 140 GeV are consistent with a leading twist diffractive production mechanism. In the laboratory frame, with ETjet ≥ 4 GeV, 15% of the events are of the 1-jet type with negligible 2-jet production. The single jet is back-to-back in azimuth with the scattered electron. No energy flow is observed between the jet and the proton direction. With a lower jet transverse energy cut 2-jet production is observed both in the laboratory and the γ* p centre-of-mass systems, demonstrating the presence of hard scattering in the virtual photon proton interactions that give rise to large rapidity gap events. © 1994.

Observation of direct processes in photoproduction at HERA

Physics Letters B 322:3 (1994) 287-300

Authors:

M Derrick, D Krakauer, S Magill, B Musgrave, J Repond, S Repond, R Stanek, RL Talaga, J Thron, F Arzarello, R Ayad, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, G Cara Romeo, G Castellini, M Chiarini, L Cifarelli, F Cindolo, F Ciralli, A Contin, C Del Papa, S D'Auria, F Frasconi, P Giusti, G Iacobucci, G Laurenti, G Levi, Q Lin, G Maccarrone, A Margotti, T Massam, R Nania, C Nemoz, F Palmonari, G Sartorelli, R Timellini, Y Zamora Garcia, A Zichichi, A Bargende, J Crittenden, K Desch, B Diekmann, T Doeker, L Feld, A Frey, M Geerts, G Geitz, H Hartmann, D Haun, K Heinloth, E Hilger, HP Jakob, UF Katz, S Kramarczyk, M Kückes, A Mass, S Mengel, J Mollen, H Müsch, E Paul, R Schattevoy, JL Schneider, D Schramm, R Wedemeyer, A Cassidy, DG Cussans, N Dyce, B Foster, S George, R Gilmore, GP Heath, HF Heath, M Lancaster, TJ Llewellyn, CJS Morgado, JA O'Mara, RJ Tapper, SS Wilson, R Yoshida, RR Rau, M Arneodo, M Schioppa, G Susinno, A Bernstein, A Caldwell, I Gialas, JA Parsons, S Ritz, F Sciulli, PB Straub, L Wai, S Yang, P Borzemski, J Chwastowski, A Eskreys

Abstract:

Jets in photoproduction events have been studied with the ZEUS detector for γp centre-of-mass energies ranging from 130 to 250 GeV. The inclusive jet distributions give evidence for the dominance of resolved photon interactions. In the di-jet sample the direct processes are for the first time clearly isolated. Di-jet cross sections for the resolved and direct processes are given in a restricted kinematic range. © 1994.

Progress in vacuum ultraviolet lasers

Progress in Quantum Electronics 18:3 (1994) 227-274

Authors:

SM Hooker, CE Webb

MEASUREMENTS OF TRANSIENT GAIN AND LOSS IN SOLID STATE VUV LASER MATERIALS

(1994) 295-296

Authors:

SM HOOKER, JS CASHMORE, CE WEBB

51��