Plasma-Wakefield Accelerator Group

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New results from the emma experiment

IPAC 2012 - International Particle Accelerator Conference 2012 (2012) 2134-2136

Authors:

B Muratori, J Jones, DJ Kelliher, S Machida, JM Garland, H Owen, CS Edmonds, K Hock, M Ibison, IW Kirkman, A Wolski, J Pasternak, R D'arcy

Abstract:

EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAGoperating at Daresbury Laboratory. After demonstrating serpentine channel acceleration andfast resonance crossing in 2011, studies continue of the beam dynamics to explore the largetransverse and longitudinal acceptance, the detailed effects of integer tune crossing atslow acceleration rates, comparison of measurements to detailed field measurements, and theexperimental mapping of the machine by relating the initial and final phase spacecoordinates. These recent results are reported in this paper, together with more practicalimprovements such as injection orbit matching with real-time monitoring of the bunchcoordinates in transverse phase space. Copyright © 2012 by IEEE.

Inclusive-jet photoproduction at HERA and determination of α s

Nuclear Physics B 864:1 (2012) 1-37

Authors:

H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, N Bartosik, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, V Bokhonov, T Bołd, K Bondarenko, EG Boos, K Borras, D Boscherini, D Bot, I Brock, E Brownson, R Brugnera, N Brümmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, F Dal Corso, J del Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, G Dolinska, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, A Gizhko, LK Gladilin, D Gladkov, C Glasman, O Gogota, YA Golubkov, P Göttlicher, I Grabowska-Bołd, J Grebenyuk, I Gregor

Abstract:

Inclusive-jet cross sections have been measured in the reaction ep→e+jet+X for photon virtuality Q 2<1 GeV 2 and γp centre-of-mass energies in the region 14217 GeV and -1< jet<2.5. In addition, measurements of double-differential inclusive-jet cross sections are presented as functions of ETjet in different regions of jet. Next-to-leading-order QCD calculations give a good description of the measurements, except for jets with low ETjet and high jet. The influence of non-perturbative effects not related to hadronisation was studied. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(αs2) terms. Values of α s(M Z) were extracted from the measurements and the energy-scale dependence of the coupling was determined. The value of α s(M Z) extracted from the measurements based on the k T jet algorithm is αs(MZ)=0.1206-0.0022+0.0023(exp.)-0.0035+0.0042(th.); the results from the anti-k T and SIScone algorithms are compatible with this value and have a similar precision. © 2012 Elsevier B.V.
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Measurement of isolated photons accompanied by jets in deep inelastic ep scattering

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 715:1-3 (2012) 88-97

Authors:

H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, O Arslan, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, N Bartosik, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, V Bokhonov, T Bołd, K Bondarenko, EG Boos, K Borras, D Boscherini, D Bot, I Brock, E Brownson, R Brugnera, N Brümmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, F Dal Corso, J del Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, G Dolinska, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, A Gizhko, LK Gladilin, D Gladkov, C Glasman, O Gogota, YA Golubkov, P Göttlicher, I Grabowska-Bołd, J Grebenyuk

Abstract:

The production of isolated high-energy photons accompanied by jets has been measured in deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 326pb -1. Measurements were made for exchanged photon virtualities, Q 2, in the range 10 to 350GeV 2. The photons were measured in the transverse-energy and pseudorapidity ranges 4
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Review of particle physics

Physical Review D - Particles, Fields, Gravitation and Cosmology 86:1 (2012)

Authors:

J Beringer, JF Arguin, RM Barnett, K Copic, O Dahl, DE Groom, CJ Lin, J Lys, H Murayama, CG Wohl, WM Yao, PA Zyla, C Amsler, M Antonelli, DM Asner, H Baer, HR Band, T Basaglia, CW Bauer, JJ Beatty, VI Belousov, E Bergren, G Bernardi, W Bertl, S Bethke, H Bichsel, O Biebel, E Blucher, S Blusk, G Brooijmans, O Buchmueller, RN Cahn, M Carena, A Ceccucci, D Chakraborty, MC Chen, RS Chivukula, G Cowan, G D'ambrosio, T Damour, D De Florian, A De Gouvêa, T Degrand, P De Jong, G Dissertori, B Dobrescu, M Doser, M Drees, DA Edwards, S Eidelman, J Erler, VV Ezhela, W Fetscher, BD Fields, B Foster, TK Gaisser, L Garren, HJ Gerber, G Gerbier, T Gherghetta, S Golwala, M Goodman, C Grab, AV Gritsan, JF Grivaz, M Grünewald, A Gurtu, T Gutsche, HE Haber, K Hagiwara, C Hagmann, C Hanhart, S Hashimoto, KG Hayes, M Heffner, B Heltsley, JJ Hernández-Rey, K Hikasa, A Höcker, J Holder, A Holtkamp, J Huston, JD Jackson, KF Johnson, T Junk, D Karlen, D Kirkby, SR Klein, E Klempt, RV Kowalewski

Abstract:

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2658 new measurements from 644 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 112 reviews are many that are new or heavily revised including those on Heavy-Quark and Soft-Collinear Effective Theory, Neutrino Cross Section Measurements, Monte Carlo Event Generators, Lattice QCD, Heavy Quarkonium Spectroscopy, Top Quark, Dark Matter, V cb & V ub, Quantum Chromodynamics, High-Energy Collider Parameters, Astrophysical Constants, Cosmological Parameters, and Dark Matter. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov/. The 2012 edition of Review of Particle Physics is published for the Particle Data Group as article 010001 in volume 86 of Physical Review D. This edition should be cited as: J. Beringer et al. (Particle Data Group), Phys. Rev. D 86, 010001 (2012). © 2012 Regents of the University of California.
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Search for first-generation leptoquarks at HERA

Physical Review D - Particles, Fields, Gravitation and Cosmology 86:1 (2012)

Authors:

H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, O Arslan, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, N Bartosik, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, V Bokhonov, T Bołd, K Bondarenko, EG Boos, K Borras, D Boscherini, D Bot, I Brock, E Brownson, R Brugnera, N Brümmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, F Dal Corso, J Del Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, G Dolinska, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, A Gizhko, LK Gladilin, D Gladkov, C Glasman, O Gogota, YA Golubkov, P Göttlicher, I Grabowska-Bołd, J Grebenyuk

Abstract:

A search for first-generation leptoquarks was performed in electron-proton and positron-proton collisions recorded with the ZEUS detector at HERA in 2003-2007 using an integrated luminosity of 366pb-1. Final states with an electron and jets or with missing transverse momentum and jets were analyzed, searching for resonances or other deviations from the standard model predictions. No evidence for any leptoquark signal was found. The data were combined with data previously taken at HERA, resulting in a total integrated luminosity of 498pb-1. Limits on the Yukawa coupling, λ, of leptoquarks were set as a function of the leptoquark mass for different leptoquark types within the Buchmüller-Rückl-Wyler model. Leptoquarks with a coupling λ=0.3 are excluded for masses up to 699 GeV. © 2012 American Physical Society.
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