Professor Claire Gwenlan: Publications

A search for ttbar resonances in lepton+jets events with highly boosted top quarks collected in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

JHEP (2012) 041

Authors:

S Livermore, ATLAS collaboration

Abstract:

A search for resonant production of high-mass top-quark pairs is performed on 2.05 fb^-1 of proton-proton collisions at sqrt(s) = 7 TeV collected in 2011 with the ATLAS experiment at the Large Hadron Collider. This analysis of the lepton+jets final state is specifically designed for the particular topology that arises from the decay of highly boosted top quarks. The observed ttbar invariant mass spectrum is found to be compatible with the Standard Model prediction and 95% credibility level upper limits are derived on the ttbar production rate through new massive states. An upper limit of 0.7 pb is set on the production cross section times branching fraction of a narrow 1 TeV resonance. A Kaluza-Klein gluon with a mass smaller than 1.5 TeV is excluded.

Measurement of high-Q2 neutral current deep inelastic e+p scattering cross sections with a longitudinally polarised positron beam at HERA

(2012)

Authors:

ZEUS Collaboration, 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 Bold, K Bondarenko, EG Boos, K Borras, D Boscherini, D Bot, I Brock, E Brownson, R Brugnera, N Brummer, 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, B Foster, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, A Gizhko, LK Gladilin, D Gladkov, C Glasman, O Gogota, Yu A Golubkov, P Gottlicher, I Grabowska-Bold, J Grebenyuk, I Gregor, G Grigorescu, G Grzelak, O Gueta, M Guzik, C Gwenlan, T Haas, W Hain, R Hamatsu, JC Hart, H Hartmann, G Hartner, E Hilger, D Hochman, R Hori, A Huttmann, ZA Ibrahim, Y Iga, R Ingbir, M Ishitsuka, H-P Jakob, F Januschek, TW Jones, M Jungst, I Kadenko, B Kahle, S Kananov, T Kanno, U Karshon, F Karstens, II Katkov, M Kaur, P Kaur, A Keramidas, LA Khein, JY Kim, D Kisielewska, S Kitamura, R Klanner, U Klein, E Koffeman, N Kondrashova, O Kononenko, P Kooijman, Ie Korol, IA Korzhavina, A Kotanski, U Kotz, H Kowalski, O Kuprash, M Kuze, A Lee, BB Levchenko, A Levy, V Libov, S Limentani, TY Ling, M Lisovyi, E Lobodzinska, W Lohmann, B Lohr, E Lohrmann, KR Long, A Longhin, D Lontkovskyi, O Yu Lukina, J Maeda, S Magill, I Makarenko, J Malka, R Mankel, A Margotti, G Marini, JF Martin, A Mastroberardino, MCK Mattingly, I-A Melzer-Pellmann, S Mergelmeyer, S Miglioranzi, F Mohamad Idris, V Monaco, A Montanari, JD Morris, K Mujkic, B Musgrave, K Nagano, T Namsoo, R Nania, A Nigro, Y Ning, T Nobe, D Notz, RJ Nowak, AE Nuncio-Quiroz, BY Oh, N Okazaki, K Olkiewicz, Yu Onishchuk, K Papageorgiu, A Parenti, E Paul, JM Pawlak, B Pawlik, PG Pelfer, A Pellegrino, W Perlanski, H Perrey, K Piotrzkowski, P Plucinski, NS Pokrovskiy, A Polini, AS Proskuryakov, M Przybycien, A Raval, DD Reeder, B Reisert, Z Ren, J Repond, YD Ri, A Robertson, P Roloff, I Rubinsky, M Ruspa, R Sacchi, U Samson, G Sartorelli, AA Savin, DH Saxon, M Schioppa, S Schlenstedt, P Schleper, WB Schmidke, U Schneekloth, V Schonberg, T Schorner-Sadenius, J Schwartz, F Sciulli, LM Shcheglova, R Shehzadi, S Shimizu, I Singh, IO Skillicorn, W Slominski, WH Smith, V Sola, A Solano, D Son, V Sosnovtsev, A Spiridonov, H Stadie, L Stanco, N Stefaniuk, A Stern, TP Stewart, A Stifutkin, P Stopa, S Suchkov, G Susinno, L Suszycki, J Sztuk-Dambietz, D Szuba, J Szuba, AD Tapper, E Tassi, J Terron, T Theedt, H Tiecke, K Tokushuku, J Tomaszewska, V Trusov, T Tsurugai, M Turcato, O Turkot, T Tymieniecka, M Vazquez, A Verbytskyi, O Viazlo, NN Vlasov, R Walczak, WAT Wan Abdullah, JJ Whitmore, K Wichmann, L Wiggers, M Wing, M Wlasenko, G Wolf, H Wolfe, K Wrona, AG Yagues-Molina, S Yamada, Y Yamazaki, R Yoshida, C Youngman, O Zabiegalov, AF Zarnecki, L Zawiejski, O Zenaiev, W Zeuner, BO Zhautykov, N Zhmak, A Zichichi, Z Zolkapli, DS Zotkin

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

Search for tb resonances in proton-proton collisions at √s=7TeV with the ATLAS detector

Physical Review Letters 109:8 (2012)

Authors:

G Aad, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, OS Abouzeid, H Abramowicz, H Abreu, E Acerbi, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, M Aderholz, S Adomeit, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, T Akdogan, TPA Åkesson, G Akimoto, AV Akimov, A Akiyama, MS Alam, MA Alam, J Albert, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, M Aliyev, BMM Allbrooke, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, B Alvarez Gonzalez, MG Alviggi, K Amako, P Amaral, C Amelung, VV Ammosov, A Amorim, G Amorós, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, A Angerami, F Anghinolfi, A Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, S Aoun, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, E Arik, M Arik, AJ Armbruster

Abstract:

This Letter presents a search for tb resonances in 1.04fb-1 of LHC proton-proton collision data collected by the ATLAS detector at a center-of-mass energy of 7 TeV. Events with a lepton, missing transverse momentum, and two jets are selected and the invariant mass of the corresponding final state is reconstructed. The search exploits the shape of the tb invariant mass distribution compared to the expected standard model backgrounds. The model of a right-handed WR′ with standard model-like couplings is chosen as the benchmark model for this search. No statistically significant excess of events is observed in the data, and upper limits on the cross section times the branching ratio of WR′ resonances at 95% C.L. lie in the range of 6.1-1.0 pb for WR′ masses ranging from 0.5 to 2.0 TeV. These limits are translated into a lower bound on the allowed right-handed WR′ mass, giving m WR′>1.13TeV at 95% C.L. © 2012 CERN.

Search for pair production of a new b′ quark that decays into a Z boson and a bottom quark with the ATLAS detector

Physical Review Letters 109:7 (2012)

Authors:

Abstract:

A search is reported for the pair production of a new quark b′ with at least one b′ decaying to a Z boson and a bottom quark. The data, corresponding to 2.0fb-1 of integrated luminosity, were collected from pp collisions at √s=7TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b′ candidates is tested for an enhancement. No evidence for a b′ signal is detected in the observed mass distribution, resulting in the exclusion at a 95% confidence level of b′ quarks with masses m b′<400GeV that decay entirely via b′→Z+b. In the case of a vectorlike singlet b′ mixing solely with the third standard model generation, masses mb′<358GeV are excluded. © 2012 CERN.

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