ATLAS

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Introduction

Chapter in , (2009) 3-7

Authors:

M Dittmar, S Forte, A Glazov, S Moch, G Altarelli, J Anderson, RD Ball, G Beuf, M Boonekamp, H Burkhardt, F Caola, M Ciafaloni, D Colferai, A Cooper-Sarkar, A De Roeck, L Del Debbio, J Feltesse, F Gelis, J Grebenyuk, A Guffanti, V Halyol, J I. Latorre, V Lendermann, G Li, L Motyka, T Petersen, A Piccione, V Radescu, M Rogal, J Rojo, C Royon, GP Salam, D Sálek, AM Stásto, RS Thorne, M Ubiali, JAM Vermaseren, A Vogt, G Watt, CD White

Abstract:

We provide an assessment of the state of the art in various issues related to experimental measurements, phenomenological methods and theoretical results relevant for the determination of parton distribution functions (PDFs) and their uncertainties, with the specific aim of providing benchmarks of different existing approaches and results in view of their application to physics at the LHC. We discuss higher order corrections, we review and compare different approaches to small x resummation, and we assess the possible relevance of parton saturation in the determination of PDFS at HERA and its possible study in LHC processes. We provide various benchmarks of PDF fits, with the specific aim of studying issues of error propagation, non-gaussian uncertainties, choice of functional forms of PDFs, and combination of data from different experiments and different processes. We study the impact of combined HERA (ZEUS-H1) structure function data, their impact on PDF uncertainties, and their implications for the computation of standard candle processes, and we review the recent F L determination at HERA. Finally, we compare and assess methods for luminosity measurements at the LHC and the impact of PDFs on them.

Introduction

Proceedings of the Workshop - HERA and the LHC: Workshop Series on the Implications of HERA for LHC Physics, HERA-LHC 2006 - 2008 (2009) 567-581

Authors:

A Bunyatyan, A Cooper-Sarkar, C Diaconu, R Engel, C Kiesling, K Kutak, S Ostapchenko, T Pierog, TC Rogers, MI Strikman, T Sako

Abstract:

When particle physic started, cosmic ray were used as source of new particles. Nowadays particle physic is a fundamental key to understand the nature of the very high energy cosmic rays. Above 1014 eV, primary cosmic rays are detected via air showers whose development strongly rely on the physic of the forward region of hadronic interactions as tested in the HERA and LHC experiments. After an introduction on air shower phenomenology, we will review how HERA and LHC can constrain the physic used both in hadronic interaction model, or for photon or neutrino primaries.

Jet cross sections and αs in deep inelastic scattering and photoproduction at hera

DIS 2009 - Proceedings of the 17th International Workshop on Deep-Inelastic Scattering and Related Topics (2009)

Abstract:

Recent ZEUS measurements of inclusive-jet and dijet cross sections in neutral current deep inelastic ep scattering at HERA are presented. The data correspond to more than a two-fold increase in statistics compared to previous studies. The cross sections are measured in the Breit frame, for boson virtualities of Q2 > 125 GeV2, as functions of various kinematic and jet observables. The data are found to be well described by NLO QCD and have the potential to constrain the gluon density in the proton. Two new extractions of the strong coupling, αs, are also presented: the first is determined from the inclusive-jet neutral current DIS measurement presented here, while the second is from a re-analysis of previously published data on inclusive jet photoproduction. Both measurements are of competitive precision and in agreement with the world average.

Jet cross sections and α s in deep inelastic scattering and photoproduction at HERA

ScienceWise Publishing (2009)

Leading proton production in deep inelastic scattering at HERA

Journal of High Energy Physics 2009:6 (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, G Cara Romeo, F Cindolo, M Corradi, P Giusti, 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, L Ianotti, 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 Lukasik, M Przybycień, L Suszycki, A Kotański, W Slomiński, 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

Abstract:

The semi-inclusive reaction e+p→e+Xp was studied with the ZEUS detector at HERA with an integrated luminosity of 12.8 pb -1. The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, xL > 0.32, and its transverse momentum squared satisfied p 2T < 0.5GeV2; the exchanged photon virtuality, Q2, was greater than 3GeV2 and the range of the masses of the photon-proton system was 45 < W < 225GeV. The leading proton production cross section and rates are presented as a function of xL, p2 T , Q2 and the Bjorken scaling variable, x. © SISSA 2009.