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Searching the inclusive l γe T+b-quark signature for radiative top quark decay and non-standard-model processes

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:1 (2009)

Authors:

T Aaltonen, J Adelman, T Akimoto, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, J Beringer, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Burke, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, C Calancha, M Campanelli, M Campbell, F Canelli, A Canepa, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark, D Clark

Abstract:

We compare the inclusive production of events containing a lepton (á), a photon (γ), significant transverse momentum imbalance (E T), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at s=1.96TeV corresponding to 1.9fb-1 of integrated luminosity taken with the CDF detector. We find 28 áγbET events versus an expectation of 31.0-3.5+4.1 events. If we further require events to contain at least three jets and large total transverse energy, the largest SM source is radiative top-quark pair production, tt̄+γ. In the data we observe 16 tt̄γ candidate events versus an expectation from SM sources of 11.2-2.1+2.3. Assuming the difference between the observed number and the predicted non-top-quark total of 6.8-2.0+2.2 is due to SM top-quark production, we estimate the tt̄γ cross section to be 0.15±0.08pb. © 2009 The American Physical Society.
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Measurement of high-Q 2 neutral current deep inelastic e - P scattering cross sections with a longitudinally polarised electron beam at HERA

European Physical Journal C 62:4 (2009) 625-658

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 neutral current cross sections for deep inelastic scattering in e - p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential cross-sections d σ/dQ 2, d σ/dx and d σ/dy and the double-differential cross sections in Q 2 and x are measured in the kinematic region y<0.9 and Q 2>185∈GeV 2 for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9∈pb -1 taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318∈GeV. The structure functions F3 and xF 3γ Z are determined by combining the e - p results presented in this paper with previously measured e + p neutral current data. The asymmetry parameter A - is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model. © 2009 Springer-Verlag / Società Italiana di Fisica.
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Search for excited quarks in ep collisions at HERA

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 678:4 (2009) 335-343

Authors:

FD Aaron, C Alexa, K Alimujiang, V Andreev, B Antunovic, A Asmone, S Backovic, A Baghdasaryan, E Barrelet, W Bartel, K Begzsuren, A Belousov, JC Bizot, V Boudry, I Bozovic-Jelisavcic, J Bracinik, G Brandt, M Brinkmann, V Brisson, D Bruncko, A Bunyatyan, G Buschhorn, L Bystritskaya, AJ Campbell, KBC Avila, F Cassol-Brunner, K Cerny, V Cerny, V Chekelian, A Cholewa, JG Contreras, JA Coughlan, G Cozzika, J Cvach, JB Dainton, K Daum, M Deák, Y de Boer, B Delcourt, M Del Degan, J Delvax, A De Roeck, EA De Wolf, C Diaconu, V Dodonov, A Dossanov, A Dubak, G Eckerlin, V Efremenko, S Egli, A Eliseev, E Elsen, A Falkiewicz, PJW Faulkner, L Favart, A Fedotov, R Felst, J Feltesse, J Ferencei, DJ Fischer, M Fleischer, A Fomenko, E Gabathuler, J Gayler, S Ghazaryan, A Glazov, I Glushkov, L Goerlich, N Gogitidze, M Gouzevitch, C Grab, T Greenshaw, BR Grell, G Grindhammer, S Habib, D Haidt, C Helebrant, RCW Henderson, E Hennekemper, H Henschel, M Herbst, G Herrera, M Hildebrandt, KH Hiller, D Hoffmann, R Horisberger, T Hreus, M Jacquet, ME Janssen, X Janssen, V Jemanov, L Jönsson, AW Jung, H Jung, M Kapichine, J Katzy, IR Kenyon, C Kiesling, M Klein, C Kleinwort

Abstract:

A search for excited quarks is performed using the full e ± p data sample collected by the H1 experiment at HERA, corresponding to a total integrated luminosity of 475   pb - 1. The electroweak decays of excited quarks q * → q γ, q * → q Z and q * → q W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for first generation excited quark production is found. Mass dependent exclusion limits on q * production cross sections and on the ratio f / Λ of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited quark searches. © 2009 Elsevier B.V.
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Search for the production of narrow tb[over] resonances in 1.9 fb;{-1} of pp[over] collisions at sqrt[s] = 1.96 TeV.

Phys Rev Lett 103:4 (2009) 041801

Authors:

T Aaltonen, J Adelman, T Akimoto, B Alvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, V Bartsch, G Bauer, P-H Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, J Beringer, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Burke, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, C Calancha, M Campanelli, M Campbell, F Canelli, A Canepa, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark, D Clark, G Compostella, ME Convery, J Conway, M Cordelli, G Cortiana, CA Cox, DJ Cox, F Crescioli, C Cuenca Almenar, J Cuevas, R Culbertson, JC Cully, D Dagenhart, M Datta, T Davies, P de Barbaro, S De Cecco, A Deisher, G De Lorenzo, M Dell'orso, C Deluca, L Demortier, J Deng, M Deninno, PF Derwent, A Di Canto, GP di Giovanni, C Dionisi, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, P Dong, J Donini, T Dorigo, S Dube, J Efron, A Elagin, R Erbacher, D Errede, S Errede, R Eusebi, HC Fang, S Farrington, WT Fedorko, RG Feild, M Feindt, JP Fernandez, C Ferrazza, R Field, G Flanagan, R Forrest, MJ Frank, M Franklin, JC Freeman, I Furic, M Gallinaro, J Galyardt, F Garberson, JE Garcia, AF Garfinkel, P Garosi, K Genser, H Gerberich, D Gerdes, A Gessler, S Giagu, V Giakoumopoulou, P Giannetti, K Gibson, JL Gimmell, CM Ginsburg, N Giokaris, M Giordani, P Giromini, M Giunta, G Giurgiu, V Glagolev, D Glenzinski, M Gold, N Goldschmidt, A Golossanov, G Gomez, G Gomez-Ceballos, M Goncharov, O González, I Gorelov, AT Goshaw, K Goulianos, A Gresele, S Grinstein, C Grosso-Pilcher, U Grundler, J Guimaraes da Costa, Z Gunay-Unalan, C Haber, K Hahn, SR Hahn, E Halkiadakis, B-Y Han, JY Han, F Happacher, K Hara, D Hare, M Hare, S Harper, RF Harr, RM Harris, M Hartz, K Hatakeyama, C Hays, M Heck, A Heijboer, J Heinrich, C Henderson, M Herndon, J Heuser, S Hewamanage, D Hidas, CS Hill, D Hirschbuehl, A Hocker, S Hou, M Houlden, S-C Hsu, BT Huffman, RE Hughes, U Husemann, M Hussein, J Huston, J Incandela, G Introzzi, M Iori, A Ivanov, E James, D Jang, B Jayatilaka, EJ Jeon, MK Jha, S Jindariani, W Johnson, M Jones, KK Joo, SY Jun, JE Jung, TR Junk, T Kamon, D Kar, PE Karchin, Y Kato, R Kephart, W Ketchum, J Keung, V Khotilovich, B Kilminster, DH Kim, HS Kim, HW Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YK Kim, N Kimura, L Kirsch, S Klimenko, B Knuteson, BR Ko, K Kondo, DJ Kong, J Konigsberg, A Korytov, AV Kotwal, M Kreps, J Kroll, D Krop, N Krumnack, M Kruse, V Krutelyov, T Kubo, T Kuhr, NP Kulkarni, M Kurata, S Kwang, AT Laasanen, S Lami, S Lammel, M Lancaster, RL Lander, K Lannon, A Lath, G Latino, I Lazzizzera, T Lecompte, E Lee, HS Lee, SW Lee, S Leone, JD Lewis, C-S Lin, J Linacre, M Lindgren, E Lipeles, A Lister, DO Litvintsev, C Liu, T Liu, NS Lockyer, A Loginov, M Loreti, L Lovas, D Lucchesi, C Luci, J Lueck, P Lujan, P Lukens, G Lungu, L Lyons, J Lys, R Lysak, D Macqueen, R Madrak, K Maeshima, K Makhoul, T Maki, P Maksimovic, S Malde, S Malik, G Manca, A Manousakis-Katsikakis, F Margaroli, C Marino, CP Marino, A Martin, V Martin, M Martínez, R Martínez-Ballarín, T Maruyama, P Mastrandrea, T Masubuchi, M Mathis, ME Mattson, P Mazzanti, KS McFarland, P McIntyre, R McNulty, A Mehta, P Mehtala, A Menzione, P Merkel, C Mesropian, T Miao, N Miladinovic, R Miller, C Mills, M Milnik, A Mitra, G Mitselmakher, H Miyake, N Moggi, MN Mondragon, CS Moon, R Moore, MJ Morello, J Morlock, P Movilla Fernandez, J Mülmenstädt, A Mukherjee, Th Muller, R Mumford, P Murat, M Mussini, J Nachtman, Y Nagai, A Nagano, J Naganoma, K Nakamura, I Nakano, A Napier, V Necula, J Nett, C Neu, MS Neubauer, S Neubauer, J Nielsen, L Nodulman, M Norman, O Norniella, E Nurse, L Oakes, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Orava, K Osterberg, S Pagan Griso, C Pagliarone, E Palencia, V Papadimitriou, A Papaikonomou, AA Paramonov, B Parks, S Pashapour, J Patrick, G Pauletta, M Paulini, C Paus, T Peiffer, DE Pellett, A Penzo, TJ Phillips, G Piacentino, E Pianori, L Pinera, K Pitts, C Plager, L Pondrom, O Poukhov, N Pounder, F Prakoshyn, A Pronko, J Proudfoot, F Ptohos, E Pueschel, G Punzi, J Pursley, J Rademacker, A Rahaman, V Ramakrishnan, N Ranjan, I Redondo, P Renton, M Renz, M Rescigno, S Richter, F Rimondi, L Ristori, A Robson, T Rodrigo, T Rodriguez, E Rogers, S Rolli, R Roser, M Rossi, R Rossin, P Roy, A Ruiz, J Russ, V Rusu, B Rutherford, H Saarikko, A Safonov, WK Sakumoto, O Saltó, L Santi, S Sarkar, L Sartori, K Sato, A Savoy-Navarro, P Schlabach, A Schmidt, EE Schmidt, MA Schmidt, MP Schmidt, M Schmitt, T Schwarz, L Scodellaro, A Scribano, F Scuri, A Sedov, S Seidel, Y Seiya, A Semenov, L Sexton-Kennedy, F Sforza, A Sfyrla, SZ Shalhout, T Shears, PF Shepard, M Shimojima, S Shiraishi, M Shochet, Y Shon, I Shreyber, P Sinervo, A Sisakyan, AJ Slaughter, J Slaunwhite, K Sliwa, JR Smith, FD Snider, R Snihur, A Soha, S Somalwar, V Sorin, T Spreitzer, P Squillacioti, M Stanitzki, R St Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, GL Strycker, JS Suh, A Sukhanov, I Suslov, T Suzuki, A Taffard, R Takashima, Y Takeuchi, R Tanaka, M Tecchio, PK Teng, K Terashi, J Thom, AS Thompson, GA Thompson, E Thomson, P Tipton, P Ttito-Guzmán, S Tkaczyk, D Toback, S Tokar, K Tollefson, T Tomura, D Tonelli, S Torre, D Torretta, P Totaro, S Tourneur, M Trovato, S-Y Tsai, Y Tu, N Turini, F Ukegawa, S Vallecorsa, N van Remortel, A Varganov, E Vataga, F Vázquez, G Velev, C Vellidis, M Vidal, R Vidal, I Vila, R Vilar, T Vine, M Vogel, I Volobouev, G Volpi, P Wagner, RG Wagner, RL Wagner, W Wagner, J Wagner-Kuhr, T Wakisaka, R Wallny, SM Wang, A Warburton, D Waters, M Weinberger, J Weinelt, WC Wester, B Whitehouse, D Whiteson, AB Wicklund, E Wicklund, S Wilbur, G Williams, HH Williams, P Wilson, BL Winer, P Wittich, S Wolbers, C Wolfe, T Wright, X Wu, F Würthwein, S Xie, A Yagil, K Yamamoto, J Yamaoka, UK Yang, YC Yang, WM Yao, GP Yeh, K Yi, J Yoh, K Yorita, T Yoshida, GB Yu, I Yu, SS Yu, JC Yun, L Zanello, A Zanetti, X Zhang, Y Zheng, S Zucchelli, CDF Collaboration

Abstract:

We present new limits on resonant tb[over] production in pp[over] collisions at sqrt[s] = 1.96 TeV, using 1.9 fb;{-1} of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a candidate tb[over] mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb[over] production as modeled by W;{'} --> tb[over]. We set a new limit on a right-handed W;{'} with standard model-like coupling, excluding any mass below 800 GeV/c;{2} at 95% C.L. The cross section for any narrow, resonant tb[over] production between 750 and 950 GeV/c;{2} is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W;{'} coupling strength versus W;{'} mass over the range 300-950 GeV/c;{2}.
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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.
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