Measurements of Wγ and Zγ production in pp collisions at √s=7 TeV with the ATLAS detector at the LHC

Physical Review D - Particles, Fields, Gravitation and Cosmology 87:11 (2013)

Authors:

G Aad, T Abajyan, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, O Abdinov, R Aben, B Abi, M Abolins, OS Abouzeid, H Abramowicz, H Abreu, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Agustoni, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, TPA Åkesson, G Akimoto, AV Akimov, 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, BMM Allbrooke, LJ Allison, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, A Altheimer, B Alvarez Gonzalez, MG Alviggi, K Amako, C Amelung, VV Ammosov, SP Amor Dos Santos, A Amorim, S Amoroso, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, S Angelidakis, P Anger, A Angerami, F Anghinolfi, A Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, S Aoun, L Aperio Bella, R Apolle, G Arabidze, I Aracena

Abstract:

The integrated and differential fiducial cross sections for the production of a W or Z boson in association with a high-energy photon are measured using pp collisions at √s=7 TeV. The analyses use a data sample with an integrated luminosity of 4.6 fb-1 collected by the ATLAS detector during the 2011 LHC data-taking period. Events are selected using leptonic decays of the W and Z bosons [W(eν,μν) and Z(e+e-, μ+μ-,νν̄)] with the requirement of an associated isolated photon. The data are used to test the electroweak sector of the Standard Model and search for evidence for new phenomena. The measurements are used to probe the anomalous WWγ, ZZγ, and Zγγ triple-gauge-boson couplings and to search for the production of vector resonances decaying to Zγ and Wγ. No deviations from Standard Model predictions are observed and limits are placed on anomalous triple-gauge-boson couplings and on the production of new vector meson resonances. © 2013 CERN.

Performance of CMS 3D silicon pixel detectors before and after irradiation

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 730 (2013) 33-37

Authors:

M Obertino, A Solano, E Alagoz, J Andresen, K Arndt, G Bolla, D Bortoletto, M Boscardin, R Brosius, M Bubna, GF Dalla Betta, F Jensen, A Krzywda, A Kumar, S Kwan, CM Lei, D Menasce, L Moroni, J Ngadiuba, I Osipenkov, L Perera, M Povoli, A Prosser, R Rivera, I Shipsey, P Tan, S Terzo, L Uplegger, S Wagner, A Vilela Pereira, M Dinardo

Abstract:

Three-dimensional (3D) silicon detectors are emerging as one of the most promising technologies for the innermost layers of tracking devices for the foreseen upgrades of the LHC. 3D sensors compatible with the CMS readout, fabricated at FBK (Trento, Italy), were tested in the laboratory and with a 120 GeV/c proton beam at the FNAL test beam facility, before and after irradiation up to a fluence of 3.5×1015neq/cm2. Preliminary results of the data analysis are presented. © 2013 Elsevier B.V.

Measurement of R=B(t→Wb)/B(t→Wq) in top-quark-pair decays using lepton+jets events and the full CDF run II dataset

Physical Review D - Particles, Fields, Gravitation and Cosmology 87:11 (2013)

Authors:

T Aaltonen, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, T Bae, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, F Bedeschi, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, L Brigliadori, C Bromberg, E Brucken, J Budagov, HS Budd, K Burkett, G Busetto, P Bussey, P Butti, A Buzatu, A Calamba, S Camarda, M Campanelli, F Canelli, B Carls, D Carlsmith, R Carosi, S Carrillo, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, YC Chen, M Chertok, G Chiarelli, G Chlachidze, K Cho, D Chokheli, MA Ciocci, A Clark, C Clarke, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, M Cremonesi, D Cruz, J Cuevas, R Culbertson, N D'Ascenzo, M Datta, P De Barbaro, L Demortier, M Deninno, M D'Errico, F Devoto, A Di Canto, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, M Dorigo, A Driutti, K Ebina, R Edgar, A Elagin

Abstract:

We present a measurement of the ratio of the top-quark branching fractions R=B(t→Wb)/B(t→Wq), where q represents quarks of type b, s, or d, in the final state with a lepton and hadronic jets. The measurement uses √s=1.96 TeV proton-antiproton collision data from 8.7 fb-1 of integrated luminosity collected with the Collider Detector at Fermilab during Run II of the Tevatron. We simultaneously measure R=0.94±0.09 (stat+syst) and the tt̄ production cross section σtt̄=7. 5±1.0 (stat+syst) pb. The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element, |Vtb|=0.97±0.05 (stat+syst) is extracted assuming three generations of quarks, and a lower limit of |V tb|>0.89 at 95% credibility level is set. © 2013 American Physical Society.

Measurement of R=B(t→Wb)/B(t→Wq) in top-quark-pair decays using lepton+jets events and the full CDF run II dataset

Physical Review D American Physical Society (APS) 87:11 (2013) 111101

Authors:

T Aaltonen, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, T Bae, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, F Bedeschi, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, L Brigliadori, C Bromberg, E Brucken, J Budagov, HS Budd, K Burkett, G Busetto, P Bussey, P Butti, A Buzatu, A Calamba, S Camarda, M Campanelli, F Canelli, B Carls, D Carlsmith, R Carosi, S Carrillo, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, YC Chen, M Chertok, G Chiarelli, G Chlachidze, K Cho, D Chokheli, MA Ciocci, A Clark, C Clarke, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, M Cremonesi, D Cruz, J Cuevas, R Culbertson, N d’Ascenzo, M Datta, P De Barbaro, L Demortier, M Deninno, M d’Errico, F Devoto, A Di Canto, B Di Ruzza, JR Dittmann, M D’Onofrio, S Donati, M Dorigo, A Driutti, K Ebina, R Edgar, A Elagin, R Erbacher, S Errede, B Esham, R Eusebi, S Farrington, JP Fernández Ramos, R Field, G Flanagan, R Forrest, M Franklin, JC Freeman, H Frisch, Y Funakoshi, AF Garfinkel, P Garosi, H Gerberich, E Gerchtein, S Giagu, V Giakoumopoulou, K Gibson, CM Ginsburg, N Giokaris, P Giromini, G Giurgiu, V Glagolev, D Glenzinski, M Gold, D Goldin, A Golossanov, G Gomez, G Gomez-Ceballos, M Goncharov, O González López, I Gorelov, AT Goshaw, K Goulianos, E Gramellini, S Grinstein, C Grosso-Pilcher, RC Group, J Guimaraes da Costa, SR Hahn, JY Han, F Happacher, K Hara, M Hare, RF Harr, T Harrington-Taber, K Hatakeyama, C Hays, J Heinrich, M Herndon, A Hocker, Z Hong, W Hopkins, S Hou, RE Hughes, U Husemann, M Hussein, J Huston, G Introzzi, M Iori, A Ivanov, E James, D Jang, B Jayatilaka, EJ Jeon, S Jindariani, M Jones, KK Joo, SY Jun, TR Junk, M Kambeitz, T Kamon, PE Karchin, A Kasmi, Y Kato, W Ketchum, J Keung, B Kilminster, DH Kim, HS Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YJ Kim, YK Kim, N Kimura, M Kirby, K Knoepfel, K Kondo, DJ Kong, J Konigsberg, AV Kotwal, M Kreps, J Kroll, M Kruse, T Kuhr, M Kurata, AT Laasanen, S Lammel, M Lancaster, K Lannon, G Latino, HS Lee, JS Lee, S Leo, S Leone, JD Lewis, A Limosani, E Lipeles, A Lister, H Liu, Q Liu, T Liu, S Lockwitz, A Loginov, D Lucchesi, J Lueck, P Lujan, P Lukens, G Lungu, J Lys, R Lysak, R Madrak, P Maestro, S Malik, G Manca, A Manousakis-Katsikakis, F Margaroli, P Marino, M Martínez, K Matera, ME Mattson, A Mazzacane, P Mazzanti, R McNulty, A Mehta, P Mehtala, C Mesropian, T Miao, D Mietlicki, A Mitra, H Miyake, S Moed, N Moggi, CS Moon, R Moore, MJ Morello, A Mukherjee, Th Muller, P Murat, M Mussini, J Nachtman, Y Nagai, J Naganoma, I Nakano, A Napier, J Nett, C Neu, T Nigmanov, L Nodulman, SY Noh, O Norniella, L Oakes, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Orava, L Ortolan, C Pagliarone, E Palencia, P Palni, V Papadimitriou, W Parker, G Pauletta, M Paulini, C Paus, TJ Phillips, G Piacentino, E Pianori, J Pilot, K Pitts, C Plager, L Pondrom, S Poprocki, K Potamianos, A Pranko, F Prokoshin, F Ptohos, G Punzi, N Ranjan, I Redondo Fernández, P Renton, M Rescigno, F Rimondi, L Ristori, A Robson, T Rodriguez, S Rolli, M Ronzani, R Roser, JL Rosner, F Ruffini, A Ruiz, J Russ, V Rusu, WK Sakumoto, Y Sakurai, L Santi, K Sato, V Saveliev, A Savoy-Navarro, P Schlabach, EE Schmidt, T Schwarz, L Scodellaro, F Scuri, S Seidel, Y Seiya, A Semenov, F Sforza, SZ Shalhout, T Shears, PF Shepard, M Shimojima, M Shochet, I Shreyber-Tecker, A Simonenko, P Sinervo, K Sliwa, JR Smith, FD Snider, H Song, V Sorin, M Stancari, R St. Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, Y Sudo, A Sukhanov, I Suslov, K Takemasa, Y Takeuchi, J Tang, M Tecchio, PK Teng, J Thom, E Thomson, V Thukral, D Toback, S Tokar, K Tollefson, T Tomura, D Tonelli, S Torre, D Torretta, P Totaro, M Trovato, F Ukegawa, S Uozumi, F Vázquez, G Velev, C Vellidis, C Vernieri, M Vidal, R Vilar, J Vizán, M Vogel, G Volpi, P Wagner, R Wallny, SM Wang, A Warburton, D Waters, WC Wester, D Whiteson, AB Wicklund, S Wilbur, HH Williams, JS Wilson, P Wilson, BL Winer, P Wittich, S Wolbers, H Wolfe, T Wright, X Wu, Z Wu, K Yamamoto, D Yamato, T Yang, UK Yang, YC Yang, W-M Yao, GP Yeh, K Yi, J Yoh, K Yorita, T Yoshida, GB Yu, I Yu, AM Zanetti, Y Zeng, C Zhou, S Zucchelli

Measurement of the cross-section for W boson production in association with b-jets in pp collisions at √s=7 TeV with the ATLAS detector

Journal of High Energy Physics 2013:6 (2013)

Authors:

G Aad, T Abajyan, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, O Abdinov, R Aben, B Abi, M Abolins, OS Abouzeid, H Abramowicz, H Abreu, MI Ochoa, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Agustoni, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, TPA Åkesson, G Akimoto, AV Akimov, 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, BMM Allbrooke, LJ Allison, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, A Altheimer, B Alvarez Gonzalez, MG Alviggi, K Amako, C Amelung, VV Ammosov, SP Amor Dos Santos, A Amorim, S Amoroso, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, S Angelidakis, P Anger, A Angerami, F Anghinolfi, A Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, S Aoun, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, S Argyropoulos

Abstract:

This paper reports a measurement of the W +b-jets (W +b+ X and W+b̄b+X) production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC. These results are based on data corresponding to an integrated luminosity of 4.6 fb-1, collected with the ATLAS detector. Cross-sections are presented as a function of jet multiplicity and of the transverse momentum of the leading b-jet for both the muon and electron decay modes of the W boson. The W +b-jets cross-section, corrected for all known detector effects, is quoted in a limited kinematic range. Combining the muon and electron channels, the fiducial cross-section for W +b-jets is measured to be 7.1 ± 0.5 (stat) ± 1.4 (syst) pb, consistent with the next-to-leading order QCD prediction, corrected for non-perturbative and double-parton interactions (DPI) contributions, of 4.70 ± 0.09 (stat)-0.49+0.60 (scale) ±0.06 (PDF) ±0.16 (non-pert)-0.38+0.52 (DPI) pb. © 2013 CERN for the benefit of the ATLAS collaboration.