The helicity structure of the diffractive electroproducti on of mesons, e+ p ! e+ + Y , is studied in a previously unexplored region of large four-m omentum transfer squared at the proton vertex,t: 0 < t < 3 G eV , wheret = jtj jtjm in . The data used are collected with the H1 detector at HERA in the kinematic domai n 2:5 < Q 2 < 60 G eV , 40 < W < 120 GeV. Notdependence of the r 00 spin density matrix element is found. A significanttdependent helicity non-conservation from the virtual phot on to the meson is observed for the spin density matrix element combination s r 00 + 2r 11 andr 00 + 2r 11 . Thesetdependences are consistently described by a perturbative Q CD model based on the exchange of two gluons. C. Adloff, V. Andreev, B. Andrieu, T. Anthonis, V. Arkadov, A. Astvatsatourov , A. Babaev, J. Bähr , P. Baranov , E. Barrelet , W. Bartel, J. Becker , A. Beglarian, O. Behnke, C. Beier, A. Belousov, Ch. Berger , T. Berndt, J.C. Bizot , J. Böhme, V. Boudry, W. Braunschweig , V. Brisson, H.-B. Bröker, D.P. Brown, W. Brückner , D. Bruncko, J. Bürger , F.W. Büsser , A. Bunyatyan, A. Burrage, G. Buschhorn , L. Bystritskaya, A.J. Campbell , J. Cao, S. Caron, F. Cassol-Brunner , D. Clarke, B. Clerbaux, C. Collard, J.G. Contreras , Y.R. Coppens , J.A. Coughlan, M.-C. Cousinou, B.E. Cox, G. Cozzika, J. Cvach, J.B. Dainton, W.D. Dau, K. Daum, M. Davidsson, B. Delcourt, N. Delerue, R. Demirchyan, A. De Roeck, E.A. De Wolf, C. Diaconu, J. Dingfelder , P. Dixon, V. Dodonov, J.D. Dowell, A. Droutskoi, A. Dubak, C. Duprel , G. Eckerlin, D. Eckstein, V. Efremenko, S. Egli, R. Eichler, F. Eisele, E. Eisenhandler , M. Ellerbrock, E. Elsen, M. Erdmann, W. Erdmann, P.J.W. Faulkner , L. Favart, A. Fedotov, R. Felst , J. Ferencei , S. Ferron, M. Fleischer , Y.H. Fleming, G. Flügge, A. Fomenko, I. Foresti , J. Formánek , G. Franke, E. Gabathuler , K. Gabathuler , J. Garvey, J. Gassner , J. Gayler , R. Gerhards , C. Gerlich, S. Ghazaryan , L. Goerlich, N. Gogitidze, C. Grab, V. Grabski , H. Grässler , T. Greenshaw, G. Grindhammer , T. Hadig, D. Haidt, L. Hajduk, J. Haller, W.J. Haynes , B. Heinemann, G. Heinzelmann , R.C.W. Henderson , S. Hengstmann , H. Henschel , R. Heremans , G. Herrera, I. Herynek, M. Hildebrandt , M. Hilgers, K.H. Hiller, J. Hladký, P. Höting, D. Hoffmann, R. Horisberger , A. Hovhannisyan , S. Hurling, M. Ibbotson, Ç. İşsever , M. Jacquet , M. Jaffre, L. Janauschek , X. Janssen , V. Jemanov, L. Jönsson , C. Johnson , D.P. Johnson , M.A.S. Jones , H. Jung, D. Kant, M. Kapichine, M. Karlsson, O. Karschnick, F. Keil, N. Keller, J. Kennedy, I.R. Kenyon, S. Kermiche, C. Kiesling, P. Kjellberg, M. Klein, C. Kleinwort, T. Kluge, G. Knies, B. Koblitz, S.D. Kolya, V. Korbel, P. Kostka, S.K. Kotelnikov, R. Koutouev, A. Koutov, H. Krehbiel , J. Kroseberg , K. Krüger, A. Küpper, T. Kuhr, T. Kurča, D. Lamb, M.P.J. Landon , W. Lange, T. Laštovička, P. Laycock, E. Lebailly, A. Lebedev, B. Leißner , R. Lemrani , V. Lendermann, S. Levonian, M. Lindstroem, B. List, E. Lobodzinska , B. Lobodzinski , A. Loginov, N. Loktionova, V. Lubimov, S. Lüders, D. Lüke, L. Lytkin, H. Mahlke-Krüger , N. Malden, E. Malinovski, I. Malinovski, R. Maraček, P. Marage, J. Marks, R. Marshall , H.-U. Martyn, J. Martyniak, S.J. Maxfield, D. Meer, A. Mehta, K. Meier, A.B. Meyer, H. Meyer, J. Meyer , P.-O. Meyer , S. Mikocki, D. Milstead, T. Mkrtchyan, R. Mohr, S. Mohrdieck, M.N. Mondragon, F. Moreau, A. Morozov, J.V. Morris, K. Müller, P. Murı́n, V. Nagovizin, B. Naroska, J. Naumann , Th. Naumann , G. Nellen, P.R. Newman , F. Niebergall , C. Niebuhr , O. Nix, G. Nowak, J.E. Olsson , D. Ozerov, V. Panassik , C. Pascaud , G.D. Patel , M. Peez, E. Perez , J.P. Phillips, D. Pitzl, R. Pöschl , I. Potachnikova, B. Povh, G. Rädel , J. Rauschenberger , P. Reimer , B. Reisert , D. Reyna, C. Risler, E. Rizvi, P. Robmann , R. Roosen, A. Rostovtsev , S. Rusakov , K. Rybicki, D.P.C. Sankey , S. Schätzel , J. Scheins , F.-P. Schilling, P. Schleper , D. Schmidt , D. Schmidt , S. Schmidt , S. Schmitt , M. Schneider , L. Schoeffel , A. Schöning, T. Schörner , V. Schröder , H.-C. Schultz-Coulon , C. Schwanenberger , K. Sedlák, F. Sefkow, V. Shekelyan, I. Sheviakov, L.N. Shtarkov, Y. Sirois, T. Sloan, P. Smirnov, Y. Soloviev, D. South, V. Spaskov, A. Specka, H. Spitzer ,

This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.

The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton-proton collision data with a centre-of-mass energy of [Formula: see text] TeV corresponding to an integrated luminosity of [Formula: see text][Formula: see text]. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti-[Formula: see text] algorithm with distance parameters [Formula: see text] or [Formula: see text], and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a reference object such as a photon or a [Formula: see text] boson, for [Formula: see text] and pseudorapidities [Formula: see text]. The effect of multiple proton-proton interactions is corrected for, and an uncertainty is evaluated using in situ techniques. The smallest JES uncertainty of less than 1 % is found in the central calorimeter region ([Formula: see text]) for jets with [Formula: see text]. For central jets at lower [Formula: see text], the uncertainty is about 3 %. A consistent JES estimate is found using measurements of the calorimeter response of single hadrons in proton-proton collisions and test-beam data, which also provide the estimate for [Formula: see text] TeV. The calibration of forward jets is derived from dijet [Formula: see text] balance measurements. The resulting uncertainty reaches its largest value of 6 % for low-[Formula: see text] jets at [Formula: see text]. Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.5-3 %.

Jet production in charged and neutral current events in the kinematic range of from 640 to 35 000 GeV is studied in deep-inelastic positron-proton scattering at HERA. The measured rate of multi-jet events and distributions of jet polar angle, transverse energy, dijet mass, and other dijet variables are presented. Using parton densities derived from inclusive DIS cross sections, perturbative QCD calculations in NLO are found to give a consistent description of both the neutral and charged current dijet production. A direct, model independent comparison of the jet distributions in charged and neutral current events confirms that the QCD dynamics of the hadronic final state is independent of the underlying electroweak scattering process. submitted to Eur. Phys. J. C C. Adloff , V. Andreev , B. Andrieu , V. Arkadov , A. Astvatsatourov , I. Ayyaz , A. Babaev , J. Bähr , P. Baranov , E. Barrelet , W. Bartel , U. Bassler , P. Bate , A. Beglarian , O. Behnke , C. Beier , A. Belousov , T. Benisch , Ch. Berger , G. Bernardi , T. Berndt , J.C. Bizot , K. Borras , V. Boudry , W. Braunschweig , V. Brisson , H.-B. Bröker , D.P. Brown , W. Brückner , P. Bruel , D. Bruncko , J. Bürger , F.W. Büsser , A. Bunyatyan , H. Burkhardt , A. Burrage , G. Buschhorn , A.J. Campbell , J. Cao , T. Carli , S. Caron , E. Chabert , D. Clarke , B. Clerbaux , C. Collard , J.G. Contreras , J.A. Coughlan , M.-C. Cousinou , B.E. Cox , G. Cozzika , J. Cvach , J.B. Dainton , W.D. Dau , K. Daum , M. David , M. Davidsson , B. Delcourt , N. Delerue , R. Demirchyan , A. De Roeck , E.A. De Wolf , C. Diaconu , P. Dixon , V. Dodonov , J.D. Dowell , A. Droutskoi , C. Duprel , G. Eckerlin , D. Eckstein , V. Efremenko , S. Egli , R. Eichler , F. Eisele , E. Eisenhandler , M. Ellerbrock , E. Elsen , M. Erdmann , W. Erdmann , P.J.W. Faulkner , L. Favart , A. Fedotov , R. Felst , J. Ferencei , S. Ferron , M. Fleischer , G. Flügge , A. Fomenko , I. Foresti , J. Formánek , J.M. Foster , G. Franke , E. Gabathuler , K. Gabathuler , J. Garvey , J. Gassner , J. Gayler , R. Gerhards , S. Ghazaryan , L. Goerlich , N. Gogitidze , M. Goldberg , C. Goodwin , C. Grab , H. Grässler , T. Greenshaw , G. Grindhammer , T. Hadig , D. Haidt , L. Hajduk , W.J. Haynes , B. Heinemann , G. Heinzelmann , R.C.W. Henderson , S. Hengstmann , H. Henschel , R. Heremans , G. Herrera , I. Herynek , M. Hilgers , K.H. Hiller , J. Hladký , P. Höting , D. Hoffmann , W. Hoprich , R. Horisberger , S. Hurling , M. Ibbotson , Ç. İşsever , M. Jacquet , M. Jaffre , L. Janauschek , D.M. Jansen , X. Janssen , V. Jemanov , L. Jönsson , D.P. Johnson , M.A.S. Jones , H. Jung , H.K. Kästli , D. Kant , M. Kapichine , M. Karlsson , O. Karschnick , O. Kaufmann , M. Kausch , F. Keil , N. Keller , J. Kennedy , I.R. Kenyon , S. Kermiche , C. Kiesling , M. Klein , C. Kleinwort , G. Knies , B. Koblitz , S.D. Kolya , V. Korbel , P. Kostka , S.K. Kotelnikov , M.W. Krasny , H. Krehbiel , J. Kroseberg , D. Krücker , K. Krüger , A. Küpper , T. Kuhr , T. Kurča , R. Kutuev , W. Lachnit , R. Lahmann , D. Lamb , M.P.J. Landon , W. Lange , T. Laštovička , A. Lebedev , B. Leißner , R. Lemrani , V. Lendermann , S. Levonian , M. Lindstroem , B. List , E. Lobodzinska , B. Lobodzinski , N. Loktionova , V. Lubimov , S. Lüders , D. Lüke , L. Lytkin , N. Magnussen , H. Mahlke-Krüger , N. Malden , E. Malinovski , I. Malinovski , R. Maraček , P. Marage , J. Marks , R. Marshall , H.-U. Martyn , J. Martyniak , S.J. Maxfield , A. Mehta , K. Meier , P. Merkel , F. Metlica , H. Meyer , J. Meyer , P.-O. Meyer , S. Mikocki , D. Milstead , T. Mkrtchyan , R. Mohr , S. Mohrdieck , M.N. Mondragon , F. Moreau , A. Morozov , J.V. Morris , K. Müller , P. Murı́n , V. Nagovizin , B. Naroska , J. Naumann , Th. Naumann , G. Nellen , P.R. Newman , T.C. Nicholls , F. Niebergall , C. Niebuhr , O. Nix , G. Nowak , T. Nunnemann , J.E. Olsson , D. Ozerov , V. Panassik , C. Pascaud , G.D. Patel , E. Perez , J.P. Phillips , D. Pitzl , R. Pöschl , I. Potachnikova , B. Povh , K. Rabbertz , G. Rädel , J. Rauschenberger , P. Reimer , B. Reisert , D. Reyna , S. Riess , E. Rizvi , P. Robmann , R. Roosen , A. Rostovtsev , C. Royon , S. Rusakov , K. Rybicki , D.P.C. Sankey , J. Scheins , F.-P. Schilling , P. Schleper , D. Schmidt , D. Schmidt , L. Schoeffel , A. Schöning , T. Schörner , V. Schröder , H.-C. Schultz-Coulon , K. Sedlák , F. Sefkow , V. Shekelyan , I. Sheviakov , L.N. Shtarkov , G. Siegmon , P. Sievers , Y. Sirois , T. Sloan , P. Smirnov , V. Solochenko , Y. Soloviev ,

A search for doubly charged Higgs bosons decaying to pairs of electrons and/or muons is presented. The search is performed using a data sample corresponding to an integrated luminosity of 4.7 fb−1 of pp collisions at \(\sqrt{s}\) = 7 TeV collected by the ATLAS detector at the LHC. Pairs of prompt, isolated, high-p T leptons with the same electric charge (e ± e ±, e ± μ ±, μ ± μ ±) are selected, and their invariant mass distribution is searched for a narrow resonance. No significant excess over Standard Model background expectations is observed, and limits are placed on the cross section times branching ratio for pair production of doubly charged Higgs bosons. The masses of doubly charged Higgs bosons are constrained depending on the branching ratio into these leptonic final states. Assuming pair production, coupling to left-handed fermions, and a branching ratio of 100 % for each final state, masses below 409 GeV, 375 GeV, and 398 GeV are excluded for e ± e ±, e ± μ ±, and μ ± μ ±, respectively.