Simultaneous measurement of the ratio R=B(t --> Wb)/B(t --> Wq) and the top-quark pair production cross section with the D0 detector at sqrt(s) = 1.96 TeV.

Phys Rev Lett 100:19 (2008) 192003

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, LS Ancu, T Andeen, S Anderson, B Andrieu, MS Anzelc, Y Arnoud, M Arov, M Arthaud, A Askew, B Asman, ACS Assis Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, S Banerjee, P Banerjee, E Barberis, A-F Barfuss, P Bargassa, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, S Beale, A Bean, M Begalli, M Begel, C Belanger-Champagne, L Bellantoni, A Bellavance, JA Benitez, SB Beri, G Bernardi, R Bernhard, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, C Biscarat, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, TA Bolton, G Borissov, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, V Bunichev, S Burdin, S Burke, TH Burnett, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, W Carvalho, BCK Casey, NM Cason, H Castilla-Valdez, S Chakrabarti, D Chakraborty, KM Chan, K Chan, A Chandra, F Charles, E Cheu, F Chevallier, DK Cho, S Choi, B Choudhary, L Christofek, T Christoudias, S Cihangir, D Claes, Y Coadou, M Cooke, WE Cooper, M Corcoran, F Couderc, M-C Cousinou, S Crépé-Renaudin, D Cutts, M Cwiok, H da Motta, A Das, G Davies, K De, SJ de Jong, E De La Cruz-Burelo, C De Oliveira Martins, JD Degenhardt, F Déliot, M Demarteau, R Demina, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, A Dominguez, H Dong, LV Dudko, L Duflot, SR Dugad, D Duggan, A Duperrin, J Dyer, A Dyshkant, M Eads, D Edmunds, J Ellison, VD Elvira, Y Enari, S Eno, P Ermolov, H Evans, A Evdokimov, VN Evdokimov, AV Ferapontov, T Ferbel, F Fiedler, F Filthaut, W Fisher, HE Fisk, M Ford, M Fortner, H Fox, S Fu, S Fuess, T Gadfort, CF Galea, E Gallas, E Galyaev, C Garcia, A Garcia-Bellido, V Gavrilov, P Gay, W Geist, D Gelé, CE Gerber, Y Gershtein, D Gillberg, G Ginther, N Gollub, B Gómez, A Goussiou, PD Grannis, H Greenlee, ZD Greenwood, EM Gregores, G Grenier, Ph Gris, J-F Grivaz, A Grohsjean, S Grünendahl, MW Grünewald, J Guo, F Guo, P Gutierrez, G Gutierrez, A Haas, NJ Hadley, P Haefner, S Hagopian, J Haley, I Hall, RE Hall, L Han, P Hansson, K Harder, A Harel, R Harrington, JM Hauptman, R Hauser, J Hays, T Hebbeker, D Hedin, JG Hegeman, JM Heinmiller, AP Heinson, U Heintz, C Hensel, K Herner, G Hesketh, MD Hildreth, R Hirosky, JD Hobbs, B Hoeneisen, H Hoeth, M Hohlfeld, SJ Hong, S Hossain, P Houben, Y Hu, Z Hubacek, V Hynek, I Iashvili, R Illingworth, AS Ito, S Jabeen, M Jaffré, S Jain, K Jakobs, C Jarvis, R Jesik, K Johns, C Johnson, M Johnson, A Jonckheere, P Jonsson, A Juste, E Kajfasz, AM Kalinin, JR Kalk, JM Kalk, S Kappler, D Karmanov, PA Kasper, I Katsanos, D Kau, R Kaur, V Kaushik, R Kehoe, S Kermiche, N Khalatyan, A Khanov, A Kharchilava, YM Kharzheev, D Khatidze, TJ Kim, MH Kirby, M Kirsch, B Klima, JM Kohli, J-P Konrath, VM Korablev, AV Kozelov, D Krop, T Kuhl, A Kumar, S Kunori, A Kupco, T Kurca, J Kvita, F Lacroix, D Lam, S Lammers, G Landsberg, P Lebrun, WM Lee, A Leflat, F Lehner, J Lellouch, J Leveque, J Li, QZ Li, L Li, SM Lietti, JGR Lima, D Lincoln, J Linnemann, VV Lipaev, R Lipton, Y Liu, Z Liu, A Lobodenko, M Lokajicek, P Love, HJ Lubatti, R Luna, AL Lyon, AKA Maciel, D Mackin, RJ Madaras, P Mättig, C Magass, A Magerkurth, PK Mal, HB Malbouisson, S Malik, VL Malyshev, HS Mao, Y Maravin, B Martin, R McCarthy, A Melnitchouk, L Mendoza, PG Mercadante, M Merkin, KW Merritt, J Meyer, A Meyer, T Millet, J Mitrevski, J Molina, RK Mommsen, NK Mondal, RW Moore, T Moulik, GS Muanza, M Mulders, M Mulhearn, O Mundal, L Mundim, E Nagy, M Naimuddin, M Narain, NA Naumann, HA Neal, JP Negret, P Neustroev, H Nilsen, H Nogima, SF Novaes, T Nunnemann, V O'Dell, DC O'Neil, G Obrant, C Ochando, D Onoprienko, N Oshima, J Osta, R Otec, GJ Otero Y Garzón, M Owen, P Padley, M Pangilinan, N Parashar, S-J Park, SK Park, J Parsons, R Partridge, N Parua, A Patwa, G Pawloski, B Penning, M Perfilov, K Peters, Y Peters, P Pétroff, M Petteni, R Piegaia, J Piper, M-A Pleier, PLM Podesta-Lerma, VM Podstavkov, Y Pogorelov, M-E Pol, P Polozov, BG Pope, AV Popov, C Potter, WL Prado da Silva, HB Prosper, S Protopopescu, J Qian, A Quadt, B Quinn, A Rakitine, MS Rangel, K Ranjan, PN Ratoff, P Renkel, S Reucroft, P Rich, J Rieger, M Rijssenbeek, I Ripp-Baudot, F Rizatdinova, S Robinson, RF Rodrigues, M Rominsky, C Royon, P Rubinov, R Ruchti, G Safronov, G Sajot, A Sánchez-Hernández, MP Sanders, A Santoro, G Savage, L Sawyer, T Scanlon, D Schaile, RD Schamberger, Y Scheglov, H Schellman, T Schliephake, C Schwanenberger, A Schwartzman, R Schwienhorst, J Sekaric, H Severini, E Shabalina, M Shamim, V Shary, AA Shchukin, RK Shivpuri, V Siccardi, V Simak, V Sirotenko, P Skubic, P Slattery, D Smirnov, J Snow, GR Snow, S Snyder, S Söldner-Rembold, L Sonnenschein, A Sopczak, M Sosebee, K Soustruznik, B Spurlock, J Stark, J Steele, V Stolin, DA Stoyanova, J Strandberg, S Strandberg, MA Strang, M Strauss, E Strauss, R Ströhmer, D Strom, L Stutte, S Sumowidagdo, P Svoisky, A Sznajder, M Talby, P Tamburello, A Tanasijczuk, W Taylor, J Temple, B Tiller, F Tissandier, M Titov, VV Tokmenin, T Toole, I Torchiani, T Trefzger, D Tsybychev, B Tuchming, C Tully, PM Tuts, R Unalan, S Uvarov, L Uvarov, S Uzunyan, B Vachon, PJ van den Berg, R Van Kooten, WM van Leeuwen, N Varelas, EW Varnes, IA Vasilyev, M Vaupel, P Verdier, LS Vertogradov, M Verzocchi, F Villeneuve-Seguier, P Vint, P Vokac, E Von Toerne, M Voutilainen, R Wagner, HD Wahl, L Wang, MHLS Wang, J Warchol, G Watts, M Wayne, M Weber, G Weber, L Welty-Rieger, A Wenger, N Wermes, M Wetstein, A White, D Wicke, GW Wilson, SJ Wimpenny, M Wobisch, DR Wood, TR Wyatt, Y Xie, S Yacoob, R Yamada, M Yan, T Yasuda, YA Yatsunenko, K Yip, HD Yoo, SW Youn, J Yu, A Zatserklyaniy, C Zeitnitz, T Zhao, B Zhou, J Zhu, M Zielinski, D Zieminska, A Zieminski, L Zivkovic, V Zutshi, EG Zverev

Abstract:

We present the first simultaneous measurement of the ratio of branching fractions, R=B(t --> Wb)/B(t --> Wq), with q being a d, s, or b quark, and the top-quark pair production cross section sigma(tt[over]) in the lepton plus jets channel using 0.9 fb(-1) of pp[over] collision data at sqrt(s)=1.96 TeV collected with the D0 detector. We extract R and sigma(tt[over]) by analyzing samples of events with 0, 1, and > or =2 identified b jets. We measure R=0.97(+0.09)/(-0.08)(stat+syst) and sigma(tt[over])=8.18(+0.09)(-0.84)(stat+syst) +/- 0.50(lumi) pb, in agreement with the standard model prediction.

Two-particle momentum correlations in jets produced in pp̄ collisions at s=1.96TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 77:9 (2008)

Authors:

T Aaltonen, J Adelman, T Akimoto, MG Albrow, BA González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, M Aoki, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, P Bednar, S Behari, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, 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, CI Ciobanu

Abstract:

We present the first measurement of two-particle momentum correlations in jets produced in pp̄ collisions at s=1.96TeV. Results are obtained for charged particles within a restricted cone with an opening angle of 0.5 radians around the jet axis and for events with dijet masses between 66 and 563GeV/c2. A comparison of the experimental data to theoretical predictions obtained for partons within the framework of resummed perturbative QCD in the next-to-leading log approximation shows that the parton momentum correlations survive the hadronization stage of jet fragmentation, giving further support to the hypothesis of local parton-hadron duality. The extracted value of the next-to-leading-log-approximation parton shower cutoff scale Qeff set equal to ΛQCD is found to be (1.4-0.7+0.9)×100MeV. © 2008 The American Physical Society.

A combined search for the standard model Higgs boson at sqrt(s) = 1.96   TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 663:1-2 (2008) 26-36

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, LS Ancu, T Andeen, S Anderson, B Andrieu, MS Anzelc, Y Arnoud, M Arov, M Arthaud, A Askew, B Åsman, ACSA Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, S Banerjee, P Banerjee, E Barberis, AF Barfuss, P Bargassa, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, S Beale, A Bean, M Begalli, M Begel, C Belanger-Champagne, L Bellantoni, A Bellavance, JA Benitez, SB Beri, G Bernardi, R Bernhard, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, C Biscarat, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, TA Bolton, G Borissov, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, V Bunichev, S Burdin, S Burke, TH Burnett, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, W Carvalho, BCK Casey, NM Cason, H Castilla-Valdez, S Chakrabarti, D Chakraborty, KM Chan, K Chan, A Chandra, F Charles

Abstract:

We present new results of the search for W H → ℓ ν b over(b, ̄) production in p over(p, ̄) collisions at a center-of-mass energy of sqrt(s) = 1.96   TeV, based on a dataset with integrated luminosity of 0.44   fb-1. We combine these new results with previously published searches by the D0 collaboration, for WH and ZH production analyzed in the E{combining long solidus overlay}T b over(b, ̄) final state, for ZH (→ ℓ+ ℓ- b over(b, ̄)) production, for WH (→ W W W) production, and for H (→ W W) direct production. No signal-like excess is observed either in the WH analysis or in the combination of all D0 Higgs boson analyses. We set 95% C.L. (expected) upper limits on σ (p over(p, ̄) → W H) × B (H → b over(b, ̄)) ranging from 1.6 (2.2) pb to 1.9 (3.3) pb for Higgs boson masses between 105 and 145 GeV, to be compared to the theoretical prediction of 0.13 pb for a Standard Model (SM) Higgs boson with mass mH = 115   GeV. After combination with the other D0 Higgs boson searches, we obtain for mH = 115   GeV an observed (expected) limit 8.5 (12.1) times higher than the SM predicted Higgs boson production cross section. For mH = 160   GeV, the corresponding observed (expected) ratio is 10.2 (9.0). © 2008 Elsevier B.V.

Large-angle production of charged pions with 3-12.9 GeV/c incident protons on nuclear targets

Physical Review C - Nuclear Physics 77:5 (2008)

Authors:

MG Catanesi, E Radicioni, R Edgecock, M Ellis, FJP Soler, C Gößling, S Bunyatov, A Krasnoperov, B Popov, V Serdiouk, V Tereschenko, E Di Capua, G Vidal-Sitjes, A Artamonov, S Giani, S Gilardoni, P Gorbunov, A Grant, A Grossheim, A Ivanchenko, V Ivanchenko, A Kayis-Topaksu, J Panman, I Papadopoulos, E Tcherniaev, I Tsukerman, R Veenhof, C Wiebusch, P Zucchelli, A Blondel, S Borghi, MC Morone, G Prior, R Schroeter, C Meurer, U Gastaldi, GB Mills, JS Graulich, G Grégoire, M Bonesini, F Ferri, M Kirsanov, A Bagulya, V Grichine, N Polukhina, V Palladino, L Coney, D Schmitz, G Barr, A De Santo, F Bobisut, D Gibin, A Guglielmi, M Mezzetto, J Dumarchez, U Dore, D Orestano, F Pastore, A Tonazzo, L Tortora, C Booth, L Howlett, G Skoro, M Bogomilov, M Chizhov, D Kolev, R Tsenov, S Piperov, P Temnikov, M Apollonio, P Chimenti, G Giannini, J Burguet-Castell, A Cervera-Villanueva, JJ Gómez-Cadenas, J Martín-Albo, P Novella, M Sorel, A Tornero

Abstract:

Measurements of the double-differential π± production cross section in the momentum range 100≤p≤800 MeV/c and angle range 0.35≤θ≤2.15 rad in proton-beryllium, proton-carbon, proton-aluminium, proton-copper, proton-tin, proton-tantalum, and proton-lead collisions are presented. The data were taken with the large-acceptance HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 to 12.9 GeV/c hitting a target with a thickness of 5% of a nuclear interaction length. Tracking and identification of the produced particles was performed by using a small-radius cylindrical Time Projection Chamber (TPC) placed inside a solenoidal magnet. Incident particles were identified by an elaborate system of beam detectors. Results are obtained for the double-differential cross sections d2σ/(dpdθ) at six incident proton beam momenta [3, 5, 8, and 8.9 GeV/c (Be only) and 12 and 12.9 GeV/c (Al only)]. They are based on a complete correction of static and dynamic distortions of tracks in the HARP TPC, which allows the complete statistics of the collected data set to be used. The results include and supersede our previously published results and are compatible with these. Results are compared with the GEANT4 and MARS Monte Carlo simulation. © 2008 The American Physical Society.

Measurement of the tt̄ production cross section in pp̄ collisions at s=1.96TeV

Physical Review Letters 100:19 (2008)

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, LS Ancu, T Andeen, S Anderson, B Andrieu, MS Anzelc, M Aoki, Y Arnoud, M Arov, M Arthaud, A Askew, B Asman, ACS Assis Jesus, O Atramentov, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, P Banerjee, S Banerjee, E Barberis, AF Barfuss, P Bargassa, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, S Beale, A Bean, M Begalli, M Begel, C Belanger-Champagne, L Bellantoni, A Bellavance, JA Benitez, SB Beri, G Bernardi, R Bernhard, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, C Biscarat, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, TA Bolton, G Borissov, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, V Bunichev, S Burdin, S Burke, TH Burnett, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, W Carvalho, BCK Casey, H Castilla-Valdez, S Chakrabarti, D Chakraborty, K Chan, KM Chan, A Chandra, F Charles

Abstract:

We measure the tt̄ production cross section in pp̄ collisions at s=1.96TeV in the lepton+jets channel. Two complementary methods discriminate between signal and background: b tagging and a kinematic likelihood discriminant. Based on 0.9fb-1 of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure σtt̄=7.62±0.85pb, assuming the current world average mt=172.6GeV. We compare our cross section measurement with theory predictions to determine a value for the top-quark mass of 170±7GeV. © 2008 The American Physical Society.