Deep inelastic scattering with leading protons or large rapidity gaps at HERA

Nuclear Physics B 816:1-2 (2009) 1-61

Authors:

S Chekanov, M Derrick, S Magill, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, F Cindolo, M Corradi, G Iacobucci, A Margotti, T Massam, R Nania, A Polini, S Antonelli, M Basile, M Bindi, L Cifarelli, A Contin, F Palmonari, S De Pasquale, G Sartorelli, A Zichichi, D Bartsch, I Brock, H Hartmann, E Hilger, HP Jakob, M Jüngst, AE Nuncio-Quiroz, E Paul, U Samson, V Schönberg, R Shehzadi, M Wlasenko, NH Brook, GP Heath, JD Morris, M Kaur, P Kaur, I Singh, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, ZA Ibrahim, FM Idris, B Kamaluddin, WATW Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, K Olkiewicz, B Pawlik, P Stopa, L Zawiejski, L Adamczyk, T Bołd, I Grabowska-Bołd, D Kisielewska, J Łukasik, M Przybycień, L Suszycki, A Kotański, W Słomiński, O Behnke, U Behrens, C Blohm, A Bonato, K Borras, D Bot, R Ciesielski, N Coppola, S Fang, J Fourletova, A Geiser, P Göttlicher, J Grebenyuk, I Gregor, T Haas, W Hain, A Hüttmann, F Januschek, B Kahle, II Katkov

Abstract:

The dissociation of virtual photons, γ{star operator} p → X p, in events with a large rapidity gap between X and the outgoing proton, as well as in events in which the leading proton was directly measured, has been studied with the ZEUS detector at HERA. The data cover photon virtualities Q2 > 2   GeV2 and γ{star operator} p centre-of-mass energies 40 < W < 240   GeV, with MX > 2   GeV, where MX is the mass of the hadronic final state, X. Leading protons were detected in the ZEUS leading proton spectrometer. The cross section is presented as a function of t, the squared four-momentum transfer at the proton vertex and Φ, the azimuthal angle between the positron scattering plane and the proton scattering plane. It is also shown as a function of Q2 and xP, the fraction of the proton's momentum carried by the diffractive exchange, as well as β, the Bjorken variable defined with respect to the diffractive exchange. © 2009 Elsevier B.V.

Measurement of beauty production from dimuon events at HERA

Journal of High Energy Physics 2009:2 (2009)

Authors:

S Chekanov, M Derrick, S Magill, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, L Bellagamba, D Boscherini, A Bruni, G Bruni, F Cindolo, M Corradi, G Iacobucci, A Margotti, R Nania, A Polini, S Antonelli, M Basile, M Bindi, L Cifarelli, A Contin, S De Pasquale, G Sartorelli, A Zichichi, D Bartsch, I Brock, H Hartmann, E Hilger, HP Jakob, M Jungst, AE Nuncio-Quiroz, E Paul, U Samson, V Schonberg, R Shehzadi, M Wlasenko, NH Brook, GP Heath, JD Morris, M Kaur, P Kaur, I Singh, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, ZA Ibrahim, B Kamaluddin, WAT Wan Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, K Olkiewicz, P Stopa, L Zawiejski, L Adamczyk, T Bold, I Grabowska-Bold, D Kisielewska, J Lukasik, M Przybycien, L Suszycki, A Kotanski, WS Lominski, O Behnke, U Behrens, I Bloch, C Blohm, A Bonato, K Borras, D Bot, R Ciesielski, N Coppola, S Fang, J Fourletova, A Geiser, P Gottlicher, J Grebenyuk, I Gregor, O Gutsche, T Haas, W Hain, A Huttmann, F Januschek, B Kahle, II Katkov, U Klein, U Kotz, H Kowalski

Abstract:

Beauty production in events containing two muons in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb-1. A low transverse-momentum threshold for muon identification, in combination with the large rapidity coverage of the ZEUS muon system, gives access to almost the full phase space for beauty production. The total cross section for beauty production in ep collisions at (s)1/2 = 318 GeV has been measured to be σtot(ep bX) = 13.9 1.5(stat.)+4.0-4.3(syst.)nb. Differential cross sections and a measurement of b correlations are also obtained, and compared to other beauty cross-section measurements, Monte Carlo models and next-to-leading-order QCD predictions. © 2009 SISSA.

Measurement of charged current deep inelastic scattering cross sections with a longitudinally polarised electron beam at HERA

European Physical Journal C 61:2 (2009) 223-235

Authors:

S Chekanov, M Derrick, S Magill, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, L Bellagamba, D Boscherini, A Bruni, G Bruni, F Cindolo, M Corradi, G Iacobucci, A Margotti, R Nania, A Polini, S Antonelli, M Basile, M Bindi, L Cifarelli, A Contin, S De Pasquale, G Sartorelli, A Zichichi, D Bartsch, I Brock, H Hartmann, E Hilger, HP Jakob, M Jüngst, AE Nuncio-Quiroz, E Paul, U Samson, V Schönberg, R Shehzadi, M Wlasenko, NH Brook, GP Heath, JD Morris, M Kaur, P Kaur, I Singh, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, ZA Ibrahim, F Mohamad Idris, B Kamaluddin, WAT Wan Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, K Olkiewicz, B Pawlik, P Stopa, L Zawiejski, L Adamczyk, T Bołd, I Grabowska-Bołd, D Kisielewska, J Łukasik, M Przybycień, L Suszycki, A Kotański, W Słomiński, O Behnke, U Behrens, C Blohm, A Bonato, K Borras, D Bot, R Ciesielski, N Coppola, S Fang, J Fourletova, A Geiser, P Göttlicher, J Grebenyuk, I Gregor, T Haas, W Hain, A Hüttmann, F Januschek, B Kahle, II Katkov, U Klein, U Kötz, H Kowalski

Abstract:

Measurements of the cross sections for charged current deep inelastic scattering in e - p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb-1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections d σ/dQ 2, d σ/dx and d σ/dy are presented for Q 2>200 GeV2. The double-differential cross-section d 2 σ/dxdQ 2 is presented in the kinematic range 2802<30∈000 GeV2 and 0.015

Stable laser-driven electron beams from a steady-state-flow gas cell

AIP Conference Proceedings 1086 (2009) 125-130

Authors:

J Osterhoff, A Popp, Z Major, B Marx, TP Rowlands-Rees, M Fuchs, R Hörlein, F Grüner, D Habs, F Krausz, SM Hooker, S Karsch

Abstract:

Quasi-monoenergetic, laser-driven electron beams of up to ∼ 200 MeV in energy have been generated from steady-state-flow gas cells [1], These beams are emitted within a low-divergence cone of 2.1 ± 0.5 mrad FWHM and feature unparalleled shot-to-shot stability in energy (2.5% rms), pointing direction (1.4 mrad rms) and charge (16% rms) owing to a highly reproducible plasma-density profile within the laser-plasma-interaction volume. Laser-wakefield acceleration (LWFA) in gas cells of this type constitutes a simple and reliable source of relativistic electrons with well defined properties, which should allow for applications such as the production of extreme-ultraviolet undulator radiation in the near future. © 2009 American Institute of Physics.

Waveguides for high-intensity laser pulses

(2009) 79-100