Combination of CDF and D0 measurements of the W boson helicity in top quark decays

ArXiv 1202.5272 (2012)

Authors:

CDF The, D0 Collaborations, T Aaltonen, VM Abazov, B Abbott, BS Acharya, M Adams, T Adams, GD Alexeev, G Alkhazov, A Alton, B Álvarez González, G Alverson, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, M Aoki, G Apollinari, JA Appel, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, A Askew, B Åsman, S Atkins, O Atramentov, B Auerbach, K Augsten, A Aurisano, C Avila, F Azfar, F Badaud, W Badgett, T Bae, L Bagby, B Baldin, DV Bandurin, S Banerjee, A Barbaro-Galtieri, E Barberis, P Baringer, VE Barnes, BA Barnett, J Barreto, P Barria, JF Bartlett, P Bartos, U Bassler, M Bauce, V Bazterra, A Bean, F Bedeschi, M Begalli, S Behari, C Belanger-Champagne, L Bellantoni, G Bellettini, J Bellinger, D Benjamin, A Beretvas, SB Beri, G Bernardi, R Bernhard, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, S Bhatia, V Bhatnagar, A Bhatti, PC Bhat, D Bisello, I Bizjak, KR Bland, G Blazey, S Blessing, K Bloom, B Blumenfeld, A Bocci, A Bodek, A Boehnlein, D Boline, EE Boos, G Borissov, D Bortoletto, T Bose, J Boudreau, A Boveia, A Brandt, O Brandt, L Brigliadori, R Brock, C Bromberg, G Brooijmans, A Bross, D Brown, J Brown, E Brucken, XB Bu, J Budagov, HS Budd, M Buehler, V Buescher, V Bunichev, S Burdin, K Burkett, P Bussey, CP Buszello, A Buzatu, A Calamba, C Calancha, E Camacho-Pérez, S Camarda, M Campanelli, M Campbell, F Canelli, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, BCK Casey, H Castilla-Valdez, A Castro, P Catastini, S Caughron, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, S Chakrabarti, D Chakraborty, KM Chan, A Chandra, E Chapon, YC Chen, G Chen, M Chertok, S Chevalier-Théry, G Chiarelli, G Chlachidze, F Chlebana, S Choi, D Chokheli, B Choudhary, DK Cho, K Cho, SW Cho, WH Chung, YS Chung, S Cihangir, MA Ciocci, D Claes, C Clarke, A Clark, J Clutter, G Compostella, ME Convery, J Conway, M Cooke, WE Cooper, M Corbo, M Corcoran, M Cordelli, F Couderc, M-C Cousinou, CA Cox, DJ Cox, F Crescioli, A Croc, J Cuevas, R Culbertson, D Cutts, N d'Ascenzo, M d'Errico, M D'Onofrio, D Dagenhart, A Das, M Datta, G Davies, F Déliot, M Dell'Orso, R Demina, L Demortier, M Deninno, D Denisov, SP Denisov, S Desai, C Deterre, K DeVaughan, F Devoto, P de Barbaro, SJ de Jong, E De La Cruz-Burelo, HT Diehl, M Diesburg, PF Ding, JR Dittmann, A Di Canto, B Di Ruzza, A Dominguez, S Donati, P Dong, M Dorigo, T Dorigo, T Dorland, A Dubey, LV Dudko, D Duggan, A Duperrin, S Dutt, A Dyshkant, M Eads, K Ebina, D Edmunds, A Elagin, J Ellison, VD Elvira, Y Enari, A Eppig, R Erbacher, S Errede, N Ershaidat, R Eusebi, H Evans, A Evdokimov, VN Evdokimov, G Facini, S Farrington, M Feindt, T Ferbel, L Feng, JP Fernandez, F Fiedler, R Field, F Filthaut, W Fisher, HE Fisk, G Flanagan, R Forrest, M Fortner, H Fox, M Franklin, MJ Frank, JC Freeman, S Fuess, Y Funakoshi, I Furic, M Gallinaro, JE Garcia, A Garcia-Bellido, GA García-Guerra, AF Garfinkel, P Garosi, V Gavrilov, P Gay, W Geng, D Gerbaudo, CE Gerber, H Gerberich, E Gerchtein, Y Gershtein, S Giagu, V Giakoumopoulou, P Giannetti, K Gibson, CM Ginsburg, G Ginther, N Giokaris, P Giromini, G Giurgiu, V Glagolev, D Glenzinski, D Goldin, M Gold, N Goldschmidt, A Golossanov, G Golovanov, G Gomez-Ceballos, G Gomez, M Goncharov, O González, I Gorelov, AT Goshaw, K Goulianos, A Goussiou, PD Grannis, S Greder, H Greenlee, G Grenier, S Grinstein, Ph Gris, J-F Grivaz, A Grohsjean, C Grosso-Pilcher, RC Group, S Grünendahl, MW Grünewald, T Guillemin, J Guimaraes da Costa, F Guo, G Gutierrez, P Gutierrez, A Haas, S Hagopian, SR Hahn, J Haley, E Halkiadakis, A Hamaguchi, JY Han, L Han, F Happacher, K Hara, K Harder, D Hare, M Hare, A Harel, RF Harr, K Hatakeyama, JM Hauptman, C Hays, J Hays, T Head, T Hebbeker, M Heck, D Hedin, H Hegab, J Heinrich, AP Heinson, U Heintz, C Hensel, I Heredia-De La Cruz, M Herndon, K Herner, G Hesketh, S Hewamanage, MD Hildreth, R Hirosky, T Hoang, JD Hobbs, A Hocker, B Hoeneisen, M Hohlfeld, W Hopkins, D Horn, S Hou, I Howley, Z Hubacek, RE Hughes, M Hurwitz, U Husemann, N Hussain, M Hussein, J Huston, V Hynek, I Iashvili, Y Ilchenko, R Illingworth, G Introzzi, M Iori, AS Ito, A Ivanov, S Jabeen, M Jaffré, E James, D Jamin, D Jang, A Jayasinghe, B Jayatilaka, EJ Jeon, R Jesik, S Jindariani, K Johns, M Johnson, A Jonckheere, M Jones, P Jonsson, KK Joo, J Joshi, SY Jun, AW Jung, TR Junk, A Juste, K Kaadze, E Kajfasz, T Kamon, PE Karchin, D Karmanov, A Kasmi, PA Kasper, Y Kato, I Katsanos, R Kehoe, S Kermiche, W Ketchum, J Keung, N Khalatyan, A Khanov, A Kharchilava, YN Kharzheev, V Khotilovich, B Kilminster, N Kimura, DH Kim, HS Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YJ Kim, YK Kim, S Klimenko, K Knoepfel, JM Kohli, K Kondo, DJ Kong, J Konigsberg, AV Kotwal, AV Kozelov, J Kraus, M Kreps, J Kroll, D Krop, M Kruse, V Krutelyov, T Kuhr, S Kulikov, A Kumar, A Kupco, M Kurata, T Kurča, VA Kuzmin, S Kwang, AT Laasanen, S Lami, S Lammel, S Lammers, M Lancaster, RL Lander, G Landsberg, K Lannon, A Lath, G Latino, P Lebrun, T LeCompte, E Lee, HS Lee, HS Lee, JS Lee, WM Lee, SW Lee, SW Lee, J Lellouch, S Leo, S Leone, JD Lewis, H Li, L Li, QZ Li, JK Lim, A Limosani, C-J Lin, D Lincoln, M Lindgren, J Linnemann, VV Lipaev, E Lipeles, R Lipton, A Lister, DO Litvintsev, C Liu, H Liu, H Liu, T Liu, Q Liu, Y Liu, A Lobodenko, S Lockwitz, A Loginov, M Lokajicek, R Lopes de Sa, HJ Lubatti, D Lucchesi, J Lueck, P Lujan, P Lukens, R Luna-Garcia, G Lungu, AL Lyon, R Lysak, J Lys, AKA Maciel, D Mackin, R Madar, R Madrak, K Maeshima, P Maestro, R Magaña-Villalba, S Malik, S Malik, VL Malyshev, G Manca, A Manousakis-Katsikakis, Y Maravin, F Margaroli, C Marino, M Martínez, J Martínez-Ortega, P Mastrandrea, K Matera, ME Mattson, A Mazzacane, P Mazzanti, R McCarthy, KS McFarland, CL McGivern, P McIntyre, R McNulty, A Mehta, P Mehtala, MM Meijer, A Melnitchouk, D Menezes, PG Mercadante, M Merkin, C Mesropian, A Meyer, J Meyer, T Miao, F Miconi, D Mietlicki, A Mitra, H Miyake, S Moed, N Moggi, NK Mondal, MN Mondragon, CS Moon, R Moore, MJ Morello, J Morlock, P Movilla Fernandez, A Mukherjee, M Mulhearn, Th Muller, P Murat, M Mussini, J Nachtman, Y Nagai, J Naganoma, E Nagy, M Naimuddin, I Nakano, A Napier, M Narain, R Nayyar, HA Neal, JP Negret, J Nett, MS Neubauer, P Neustroev, C Neu, J Nielsen, L Nodulman, SY Noh, O Norniella, T Nunnemann, L Oakes, G Obrant, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Orava, J Orduna, L Ortolan, N Osman, J Osta, M Padilla, S Pagan Griso, C Pagliarone, A Pal, E Palencia, V Papadimitriou, AA Paramonov, N Parashar, V Parihar, SK Park, R Partridge, N Parua, J Patrick, A Patwa, G Pauletta, M Paulini, C Paus, DE Pellett, B Penning, A Penzo, M Perfilov, Y Peters, K Petridis, G Petrillo, P Pétroff, TJ Phillips, G Piacentino, E Pianori, J Pilot, K Pitts, C Plager, M-A Pleier, PLM Podesta-Lerma, VM Podstavkov, P Polozov, L Pondrom, AV Popov, S Poprocki, K Potamianos, M Prewitt, D Price, N Prokopenko, F Prokoshin, A Pranko, F Ptohos, G Punzi, J Qian, A Quadt, B Quinn, A Rahaman, V Ramakrishnan, MS Rangel, K Ranjan, N Ranjan, PN Ratoff, I Razumov, I Redondo, P Renkel, P Renton, M Rescigno, T Riddick, F Rimondi, I Ripp-Baudot, L Ristori, F Rizatdinova, A Robson, T Rodrigo, T Rodriguez, E Rogers, S Rolli, M Rominsky, R Roser, A Ross, C Royon, P Rubinov, R Ruchti, F Ruffini, A Ruiz, J Russ, V Rusu, A Safonov, G Safronov, G Sajot, WK Sakumoto, Y Sakurai, P Salcido, A Sánchez-Hernández, MP Sanders, B Sanghi, L Santi, AS Santos, K Sato, G Savage, V Saveliev, A Savoy-Navarro, L Sawyer, T Scanlon, RD Schamberger, Y Scheglov, H Schellman, P Schlabach, S Schlobohm, A Schmidt, EE Schmidt, C Schwanenberger, T Schwarz, R Schwienhorst, L Scodellaro, A Scribano, F Scuri, S Seidel, Y Seiya, J Sekaric, A Semenov, H Severini, F Sforza, E Shabalina, SZ Shalhout, V Shary, S Shaw, AA Shchukin, T Shears, PF Shepard, M Shimojima, RK Shivpuri, M Shochet, I Shreyber-Tecker, V Simak, A Simonenko, P Sinervo, P Skubic, P Slattery, K Sliwa, D Smirnov, JR Smith, KJ Smith, FD Snider, GR Snow, J Snow, S Snyder, A Soha, S Söldner-Rembold, H Song, L Sonnenschein, V Sorin, K Soustruznik, P Squillacioti, R St Denis, M Stancari, J Stark, B Stelzer, O Stelzer-Chilton, D Stentz, V Stolin, DA Stoyanova, M Strauss, J Strologas, GL Strycker, L Stutte, Y Sudo, A Sukhanov, I Suslov, L Suter, P Svoisky, M Takahashi, K Takemasa, Y Takeuchi, J Tang, M Tecchio, PK Teng, J Thom, J Thome, GA Thompson, E Thomson, M Titov, D Toback, S Tokar, VV Tokmenin, K Tollefson, T Tomura, D Tonelli, D Torretta, S Torre, P Totaro, M Trovato, Y-T Tsai, K Tschann-Grimm, D Tsybychev, B Tuchming, C Tully, F Ukegawa, S Uozumi, L Uvarov, S Uvarov, S Uzunyan, R Van Kooten, WM van Leeuwen, N Varelas, A Varganov, EW Varnes, IA Vasilyev, F Vázquez, G Velev, C Vellidis, P Verdier, AY Verkheev, LS Vertogradov, M Verzocchi, M Vesterinen, M Vidal, I Vila, D Vilanova, R Vilar, J Vizán, M Vogel, P Vokac, G Volpi, P Wagner, RL Wagner, HD Wahl, T Wakisaka, R Wallny, MHLS Wang, SM Wang, A Warburton, J Warchol, D Waters, G Watts, M Wayne, J Weichert, L Welty-Rieger, WC Wester III, A White, D Whiteson, F Wick, D Wicke, AB Wicklund, E Wicklund, S Wilbur, HH Williams, MRJ Williams, GW Wilson, JS Wilson, P Wilson, BL Winer, P Wittich, M Wobisch, S Wolbers, H Wolfe, DR Wood, T Wright, X Wu, Z Wu, TR Wyatt, Y Xie, R Yamada, K Yamamoto, T Yang, UK Yang, W-C Yang, YC Yang, W-M Yao, T Yasuda, YA Yatsunenko, Z Ye, GP Yeh, K Yi, H Yin, K Yip, J Yoh, K Yorita, T Yoshida, SW Youn, I Yu, GB Yu, SS Yu, JC Yun, A Zanetti, Y Zeng, T Zhao, B Zhou, J Zhu, M Zielinski, D Zieminska, L Zivkovic, S Zucchelli

Abstract:

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7 - 5.4 fb^-1 of ppbar collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f0) and right-handed (f+) helicities, we find f0 = 0.722 \pm 0.081 [\pm 0.062 (stat.) \pm 0.052 (syst.)] and f+ = -0.033 \pm 0.046 [\pm 0.034 (stat.) \pm 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f0 = 0.682 \pm 0.057 [\pm 0.035 (stat.) \pm 0.046 (syst.)] and f+ = -0.015\pm0.035 [\pm 0.018 (stat.) \pm 0.030 (syst.)]. The results are consistent with standard model expectations.

Jet momentum dependence of jet quenching in PbPb collisions at sqrt(sNN)=2.76 TeV

ArXiv 1202.5022 (2012)

Observation of exclusive γγ production in pp̄ collisions at √s=1.96TeV

Physical Review Letters 108:8 (2012)

Authors:

T Aaltonen, MG Albrow, B Álvarez González, 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, D Bisello, I Bizjak, 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, A Buzatu, A Calamba, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, 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, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, WH Chung, YS Chung, MA Ciocci, A Clark, C Clarke, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli, J Cuevas, R Culbertson, D Dagenhart, N D'ascenzo, M Datta, P De Barbaro, M Dell'orso, L Demortier, M Deninno, F Devoto

Abstract:

We have observed exclusive γγ production in proton-antiproton collisions at √s=1.96TeV, using data from 1.11±0.07fb-1 integrated luminosity taken by the Run II Collider Detector at Fermilab. We selected events with two electromagnetic showers, each with transverse energy ET>2.5GeV and pseudorapidity |η|<1.0, with no other particles detected in -7.4<η<+7.4. The two showers have similar E T and azimuthal angle separation Δψ∼π; 34 events have two charged particle tracks, consistent with the QED process pp̄→p+e+e-+p̄ by two-photon exchange, while 43 events have no charged tracks. The number of these events that are exclusive π0π0 is consistent with zero and is <15 at 95% C.L. The cross section for pp̄→p+γγ+p̄ with |η(γ)|<1.0 and ET(γ)>2.5GeV is 2.48-0.35+0.40(stat)-0.51+0.40(syst)pb. © 2012 American Physical Society.

Search for Higgs bosons produced in association with b quarks

Physical Review D - Particles, Fields, Gravitation and Cosmology 85:3 (2012)

Authors:

T Aaltonen, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, A Apresyan, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, G Bauer, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, L Brigliadori, A Brisuda, C Bromberg, E Brucken, M Bucciantonio, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, 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, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, A Clark, C Clarke, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli, C Cuenca Almenar, J Cuevas, R Culbertson, D Dagenhart

Abstract:

We present a search for neutral Higgs bosons decaying into bb̄, produced in association with b quarks in pp̄ collisions. This process could be observable in supersymmetric models with high values of tanβ. The event sample corresponds to 2.6fb -1 of integrated luminosity collected with the CDF II detector at the Fermilab Tevatron collider. We search for an enhancement in the mass of the two leading jets in events with three jets identified as coming from b quarks using a displaced vertex algorithm. A data-driven procedure is used to estimate the dijet mass spectrum of the nonresonant multijet background. The contributions of backgrounds and a possible Higgs boson signal are determined by a two-dimensional fit of the data, using the dijet mass together with an additional variable which is sensitive to the flavor composition of the three tagged jets. We set mass-dependent limits on σ(pp̄→)×B(→bb̄) which are applicable for a narrow scalar particle produced in association with b quarks. We also set limits on tanβ in supersymmetric Higgs models including the effects of the Higgs boson width. © 2012 American Physical Society.

Inclusive b-jet production in pp collisions at sqrt(s)=7 TeV

ArXiv 1202.4617 (2012)