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  • 1. Abazov, V. M.
    et al.
    Abbott, B.
    Abolins, M.
    Acharya, B. S.
    Adams, M.
    Adams, T.
    Aguilo, E.
    Ahsan, M.
    Alexeev, G. D.
    Alkhazov, G.
    Alton, A.
    Alverson, G.
    Alves, G. A.
    Anastasoaie, M.
    Ancu, L. S.
    Andeen, T.
    Andrieu, B.
    Anzelc, M. S.
    Aoki, M.
    Arnoud, Y.
    Arov, M.
    Arthaud, M.
    Askew, A.
    Asman, B.
    Jesus, A. C. S. Assis
    Atramentov, O.
    Avila, C.
    Badaud, F.
    Bagby, L.
    Baldin, B.
    Bandurin, D. V.
    Banerjee, P.
    Banerjee, S.
    Barberis, E.
    Barfuss, A. -F
    Bargassa, P.
    Baringer, P.
    Barreto, J.
    Bartlett, J. F.
    Bassler, U.
    Bauer, D.
    Beale, S.
    Bean, A.
    Begalli, M.
    Begel, M.
    Belanger-Champagne, C.
    Bellantoni, L.
    Bellavance, A.
    Benitez, J. A.
    Beri, S. B.
    Bernardi, G.
    Bernhard, R.
    Bertram, I.
    Besancon, M.
    Beuselinck, R.
    Bezzubov, V. A.
    Bhat, P. C.
    Bhatnagar, V.
    Biscarat, C.
    Blazey, G.
    Blekman, F.
    Blessing, S.
    Bloom, K.
    Boehnlein, A.
    Boline, D.
    Bolton, T. A.
    Boos, E. E.
    Borissov, G.
    Bose, T.
    Brandt, A.
    Brock, R.
    Brooijmans, G.
    Bross, A.
    Brown, D.
    Bu, X. B.
    Buchanan, Nj.
    Buchholz, D.
    Buehler, M.
    Buescher, V.
    Bunichev, V.
    Burdin, S.
    Burnett, T. H.
    Buszello, C. P.
    Butler, J. M.
    Calfayan, P.
    Calvet, S.
    Cammin, J.
    Carrera, E.
    Carvalho, W.
    Casey, B. C. K.
    Castilla-Valdez, H.
    Chakrabarti, S.
    Chakraborty, D.
    Chan, K. M.
    Chandra, A.
    Cheu, E.
    Chevallier, F.
    Cho, D. K.
    Choi, S.
    Choudhary, B.
    Christofek, L.
    Christoudias, T.
    Cihangir, S.
    Claes, D.
    Clutter, J.
    Cooke, M.
    Cooper, W. E.
    Corcoran, M.
    Couderc, F.
    Cousino, M. -C
    Crepe-Renaudin, S.
    Cuplov, V.
    Cutts, D.
    Cwiok, M.
    da Motta, H.
    Das, A.
    Davies, G.
    De, K.
    de Jong, S. J.
    De la Cruz-Burelo, E.
    Martins, C. De Oliveira
    DeVaughan, K.
    Degenhardt, J. D.
    Deliot, F.
    Demarteau, M.
    Demina, R.
    Denisov, D.
    Denisov, S. P.
    Desai, S.
    Diehl, H.
    Diesburg, M.
    Dominguez, A.
    Dong, H.
    Dorland, T.
    Dubey, A.
    Dudko, L. V.
    Duflot, L.
    Dugad, S. R.
    Duggan, D.
    Duperrin, A.
    Dyer, J.
    Dyshkant, A.
    Eads, M.
    Edmunds, D.
    Ellison, J.
    Elvira, V. D.
    Enari, Y.
    Eno, S.
    Ermolov, P.
    Evans, H.
    Evdokimov, A.
    Evdokimov, V. N.
    Ferapontov, An.
    Ferbel, T.
    Fiedler, F.
    Filthautl, F.
    Fisher, W.
    Fisk, H. E.
    Fortner, M.
    Fox, H.
    Fu, S.
    Fuess, S.
    Gadfort, T.
    Galea, C. F.
    Garcia, C.
    Garcia-Bellido, A.
    Gavrilov, V.
    Gay, P.
    Geist, W.
    Geng, W.
    Gerber, C. E.
    Gershtein, Y.
    Gillberg, D.
    Ginther, G.
    Gollub, Nils
    Gomez, B.
    Goussiou, A.
    Grannis, P. D.
    Greenlee, H.
    Greenwood, Z. D.
    Gregores, E. M.
    Grenier, G.
    Gris, Ph.
    Grivaz, J. -F
    Grohsjean, A.
    Gruenendahl, S.
    Gruenewald, M. W.
    Guo, F.
    Guo, J.
    Gutierrez, G.
    Gutierrez, P.
    Haas, A.
    Hadley, N. J.
    Haefner, P.
    Hagopian, S.
    Haley, J.
    Hall, I.
    Hall, R. E.
    Han, L.
    Harder, K.
    Harel, A.
    Hauptman, J. M.
    Hays, J.
    Hebbeker, T.
    Hedin, D.
    Hegeman, J. G.
    Heinson, A. P.
    Heintz, U.
    Hensel, C.
    Herner, K.
    Hesketh, G.
    Hildreth, M. D.
    Hirosky, R.
    Hobbs, J. D.
    Hoeneisen, B.
    Hoeth, H.
    Hohifeld, M.
    Hossain, S.
    Houben, P.
    Hu, Y.
    Hubacek, Z.
    Hynek, V.
    Iashvili, I.
    Illingworth, R.
    Ito, A. S.
    Jabeen, S.
    Jaffre, M.
    Jain, S.
    Jakobs, K.
    Jarvis, C.
    Jesik, R.
    Johns, K.
    Johnson, C.
    Johnson, M.
    Johnston, D.
    Jonckheere, A.
    Jonsson, P.
    Juste, A.
    Kajfasz, E.
    Kalk, J. M.
    Karmanov, D.
    Kasper, P. A.
    Katsanos, I.
    Kau, D.
    Kaushik, V.
    Kehoe, R.
    Kermiche, S.
    Khalatyan, N.
    Khanov, A.
    Kharchilava, A.
    Kharzheev, Y. M.
    Khatidze, D.
    Kim, T. J.
    Kirby, M. H.
    Kirsch, M.
    Klima, B.
    Kohli, J. M.
    Konrath, J. -P
    Kozelov, A. V.
    Kraus, J.
    Kuhl, T.
    Kumar, A.
    Kupco, A.
    Kurca, T.
    Kuzmin, V. A.
    Kvita, J.
    Lacroix, E.
    Lam, D.
    Lammers, S.
    Landsberg, G.
    Lebrun, P.
    Lee, W. M.
    Leflat, A.
    Lellouch, J.
    Li, J.
    Li, L.
    Li, Q. Z.
    Lietti, S. M.
    Lim, J. K.
    Lima, J. G. R.
    Lincoln, D.
    Linnemann, J.
    Lipaev, V. V.
    Lipton, R.
    Liu, Y.
    Liu, Z.
    Lobodenko, A.
    Lokajicek, M.
    Love, P.
    Lubatti, H. J.
    Luna, R.
    Lyon, A. L.
    Maciel, A. K. A.
    Mackin, D.
    Madaras, R. J.
    Maettig, P.
    Magass, C.
    Magerkurth, A.
    Mal, P. K.
    Malbouisson, H. B.
    Malik, S.
    Malyshev, V. L.
    Maravin, Y.
    Martin, B.
    McCarthy, R.
    Melnitchouk, A.
    Mendoza, L.
    Mercadante, P. G.
    Merkin, M.
    Merritt, K. W.
    Meyer, A.
    Meyer, J.
    Mitrevski, J.
    Mommsen, R. K.
    Mondal, N. K.
    Moore, R. W.
    Moulik, T.
    Muanza, G. S.
    Mulhearn, M.
    Mundal, O.
    Mundim, L.
    Nagy, E.
    Naimuddin, M.
    Narain, M.
    Naumann, N. A.
    Neal, H. A.
    Negret, J. P.
    Neustroev, P.
    Nilsen, H.
    Nogima, H.
    Novaes, S. F.
    Nunnemann, T.
    O'Dell, V.
    O'Neil, D. C.
    Obrant, G.
    Ochando, C.
    Onoprienko, D.
    Oshima, N.
    Osman, N.
    Osta, J.
    Otec, R.
    Otero y Garzon, G. J.
    Owen, M.
    Padley, P.
    Pangilinan, M.
    Parashar, N.
    Park, S. -J
    Park, S. K.
    Parsons, J.
    Partridge, R.
    Parua, N.
    Patwa, A.
    Pawlosk, G.
    Penning, B.
    Perfilov, M.
    Peters, K.
    Peters, Y.
    Petroff, P.
    Petteni, M.
    Piegaia, R.
    Piper, J.
    Pleier, M. -A
    Podesta-Lerma, P. L. M.
    Podstavkov, V. M.
    Pogorelo, Y.
    Pol, M. -E
    Polozov, P.
    Pope, B. G.
    Popov, A. V.
    Potter, C.
    da Silva, W. L. Prado
    Prosper, H. B.
    Protopopescu, S.
    Qian, J.
    Quadt, A.
    Quinn, B.
    Rakitine, A.
    Rangel, M. S.
    Ranjan, K.
    Ratoff, P. N.
    Renkel, P.
    Rich, P.
    Rieger, J.
    Rijssenbeek, M.
    Ripp-Baudot, I.
    Rizatdinova, F.
    Robinson, S.
    Rodrigues, R. F.
    Rominsky, M.
    Royon, C.
    Rubinov, P.
    Ruchti, R.
    Safronov, G.
    Sajot, G.
    Sanchez-Hernandezag, A.
    Sanders, M. P.
    Sanghi, B.
    Savage, G.
    Sawyer, L.
    Scanlon, T.
    Schaile, D.
    Schamberger, R. D.
    Scheglov, Y.
    Schellman, H.
    Schliephake, T.
    Schlobohm, S.
    Schwanenberger, C.
    Schwartzman, A.
    Schwienhorst, R.
    Sekaric, J.
    Severini, H.
    Shabalina, E.
    Shamim, M.
    Shary, V.
    Shchukin, A. A.
    Shivpuri, R. K.
    Siccardi, V.
    Simak, V.
    Sirotenko, V.
    Skubic, R.
    Slattery, P.
    Smirnov, D.
    Snow, G. R.
    Snow, J.
    Snyder, S.
    Soeldner-Rembold, S.
    Sonnenschein, L.
    Sopczak, A.
    Sosebee, M.
    Soustruznik, K.
    Spurlock, B.
    Stark, J.
    Steele, J.
    Stolin, V.
    Stoyanova, D. A.
    Strandberg, Jonas
    University of Chicago.
    Strandberg, S.
    Strang, M. A.
    Strauss, E.
    Strauss, M.
    Stroehmer, R.
    Strom, D.
    Stutte, L.
    Sumowidagdo, S.
    Svoisky, P.
    Sznajder, A.
    Tamburello, P.
    Tanasijczuk, A.
    Taylor, W.
    Tiller, B.
    Tissandier, F.
    Titov, M.
    Tokmenin, V. V.
    Torchiani, I.
    Tsybychev, D.
    Tuchming, B.
    Tully, C.
    Tuts, P. M.
    Unalan, R.
    Uvarov, L.
    Uvarov, S.
    Uzunyan, S.
    Vachon, B.
    van den Berg, P. J.
    Van Kooten, R.
    van Leeuwenah, W. M.
    Varelas, N.
    Varnes, E. W.
    Vasilyev, I. A.
    Verdier, P.
    Vertogradov, L. S.
    Verzocchi, M.
    Vilanova, D.
    Villeneuve-Seguier, F.
    Vint, P.
    Vokaci, P.
    Voultilainen, M.
    Wagner, R.
    Wahl, H. D.
    Wang, M. H. L. S.
    Warchol, J.
    Watts, G.
    Wayne, M.
    Weber, G.
    Weber, M.
    Welty-Rieger, L.
    Wenger, A.
    Wermes, N.
    Wetstein, M.
    White, A.
    Wicke, D.
    Williams, M.
    Wilson, G. W.
    Wimpenny, Sj.
    Wobisch, M.
    Wood, D. R.
    Wyatt, T. R.
    Xie, Y.
    Yacoob, S.
    Yamada, R.
    Yang, W. -C
    Yasuda, T.
    Yatsunenko, Y. A.
    Yin, H.
    Yip, K.
    Yoo, H. D.
    Youn, S. W.
    Yu, J.
    Zeitnitz, C.
    Zelitch, S.
    Zhao, T.
    Zhou, B.
    Zhu, J.
    Zielinski, M.
    Zieminska, D.
    Zieminski, A.
    Zivkovic, L.
    Zutshi, V.
    Zverev, E. G.
    Search for pair production of second generation scalar leptoquarks2009Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 671, nr 2, s. 224-232Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a search for the pair production of second generation scalar leptoquarks (LQ) in p (p) over bar collisions at the center of mass energy root s- = 1.96 TeV using a data set corresponding to an integrated luminosity of 1.0 fb(-1) collected with the D empty set experiment at the Fermilab Tevatron Collider. Topologies arising from the LQ (LQ) over bar -> mu q nu q and LQ (LQ) over bar -> mu q mu q decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction beta for the decay LQ -> mu q. These are interpreted as lower limits on the leptoquark mass as a function of beta. For beta = 1 (0.5), scalar second generation leptoquarks with masses up to 316 GeV (270 GeV) are excluded.

  • 2. Abazov, V. M.
    et al.
    Bélanger-Champagne, Camille
    Gollub, Nils
    Strandberg, Jonas
    Zverev, E.G.
    Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 100, nr 19, s. 192004-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We measure the t (t) over bar production cross section in p (p) over bar collisions at root s = 1.96 TeV in the lepton + jets channel. Two complementary methods discriminate between signal and background: b tagging and a kinematic likelihood discriminant. Based on 0.9 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure sigma(t (t) over bar) = 7.62 +/- 0.85 pb, assuming the current world average m(t) = 172.6 GeV. We compare our cross section measurement with theory predictions to determine a value for the top-quark mass of 170 +/- 7 GeV.

  • 3. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Evidence for production of single top quarks2008Inngår i: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 78, nr 1, s. 012005-Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p (p) over bar collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top-quark partner that is always produced from strong-coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top-quark production has been searched for in ever larger data sets. In this analysis, we select events from a 0.9 fb(-1) data set that have an electron or muon and missing transverse energy from the decay of a W boson from the top-quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W + jets and t (t) over bar events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix-element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top-quark production of sigma(p (p) over bar -> tb + X, tqb + X) = 4.7 +/- 1.3 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top-quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find vertical bar V(tb)f(1)(L)vertical bar = 1.31(-0.21)(+0.25), where f(1)(L) is a generic vector coupling. This model-independent measurement translates into 0.68 <vertical bar V(tb)vertical bar <= 1 at the 95% C.L. in the standard model.

  • 4. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Measurement of B(s)(0) Mixing Parameters from the Flavor-Tagged Decay B(s)(0)-> J/psi phi2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 24, s. 241801-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    From an analysis of the flavor-tagged decay B(s)(0)-> J/psi phi we obtain the width difference between the B(s)(0) light and heavy mass eigenstates, Delta Gamma(s)=0.19 +/- 0.07(stat)(-0.01)(+0.02)(syst) ps(-1), and the CP-violating phase, phi(s)=-0.57(-0.30)(+0.24)(stat)(-0.02)(+0.08)(syst). The allowed 90% CL intervals of Delta Gamma(s) and phi(s) are 0.06 <Delta Gamma(s)< 0.30 ps(-1) and -1.20 <phi(s)< 0.06, respectively. The data sample corresponds to an integrated luminosity of 2.8 fb(-1) accumulated with the D0 detector at the Fermilab Tevatron collider.

  • 5. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Measurement of differential Z/gamma* plus jet plus X cross sections in p(p)over-bar collisions at root S=1.96 TeV2008Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 669, nr 5, s. 278-286Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present new measurements of differential cross sections for Z/gamma* (-> mu mu) + jet + X production in a 1 fb(-1) data sample collected with the DO detector in p (p) over bar collisions at root s = 1.96 TeV. Results include the first measurements differential in the Z/gamma* transverse momentum and rapidity, as well as new measurements differential in the leading jet transverse momentum and rapidity. Next-to-leading order perturbative QCD predictions are compared to the measurements, and reasonable agreement is observed, except in the region of low Z/gamma* transverse momentum. Predictions from two event generators based on matrix elements and parton showers, and one pure parton shower event generator are also compared to the measurements. These show significant overall normalization differences to the data and have varied success in describing the shape of the distributions.

  • 6. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Measurement of the differential cross section for the production of an isolated photon with associated jet in p(p)over-bar collisions at root s=1.96 TeV2008Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 666, nr 5, s. 435-445Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The process p (p) over bar -> gamma + jet + X is studied using 1.0 fb(-1) of data collected by the DO detector at the Fermilab Tevatron p (p) over bar collider at a center-of-mass energy root s = 1.96 TeV. Photons are reconstructed in the central rapidity region vertical bar y(gamma)vertical bar < 1.0 with transverse momenta in the range 30 < p(T)(gamma) < 400 GeV while jets are reconstructed in either the central vertical bar y(jet)vertical bar < 0.8 or forward 1.5 < vertical bar y(jet)vertical bar < 2.5 rapidity intervals with P(T)(jet) > 15 GeV. The differential cross section d(3 sigma)/dp(T)(gamma) dy(gamma) dy(jet) is measured as a function of p(T)(gamma) in four regions, differing by the relative orientations of the photon and the jet in rapidity. Ratios between the differential cross sections in each region are also presented. Next-to-leading order QCD predictions using different parameterizations of parton distribution functions and theoretical scale choices are compared to the data. The predictions do not simultaneously describe the measured normalization and p(T)(gamma) dependence of the cross section in the four measured regions.

  • 7. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Measurement of the Electron Charge Asymmetry in p(p)over-bar -> W plus X -> e nu plus X Events at root s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 21, s. 211801-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a measurement of the electron charge asymmetry in p (p) over bar -> W + X -> e nu + X events at a center of mass energy of 1.96 TeV using 0.75 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider. The asymmetry is measured as a function of the electron transverse momentum and pseudorapidity in the interval (-3.2, 3.2) and is compared with expectations from next-to-leading order calculations in perturbative quantum chromodynamics. These measurements will allow more accurate determinations of the proton parton distribution functions.

  • 8. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Measurement of the inclusive jet cross section in p(p)over-bar collisions at root s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 6, s. 062001-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a measurement of the inclusive jet cross section in p (p) over bar collisions at a center-of-mass energy root s = 1.96 TeV using data collected by the D0 experiment at the Fermilab Tevatron Collider corresponding to an integrated luminosity of 0: 70 fb(-1). The data cover jet transverse momenta from 50 to 600 GeV and jet rapidities in the range -2.4 to 2.4. Detailed studies of correlations between systematic uncertainties in transverse momentum and rapidity are presented, and the cross section measurements are found to be in good agreement with next-to-leading order QCD calculations.

  • 9. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Measurement of the Polarization of the Upsilon(1S) and Upsilon(2S) States in pp Collisions at s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 18, s. 182004-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a study of the polarization of the Upsilon(1S) and Upsilon(2S) states using a 1.3 fb(-1) data sample collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron Collider. We measure the polarization parameter alpha=(sigma(T)-2 sigma(L))/(sigma(T)+2 sigma(L)), where sigma(T) and sigma(L) are the transversely and longitudinally polarized components of the production cross section, as a function of the transverse momentum (p(T)(Upsilon)) for the Upsilon(1S) and Upsilon(2S). Significant p(T)(Upsilon)-dependent longitudinal polarization is observed for the Upsilon(1S). A comparison with theoretical models is presented.

  • 10. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Measurement of the ratio of the p(p)over-bar -> W + c-jet cross section to the inclusive p(p)over-bar -> W + jets cross section2008Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 666, nr 1, s. 23-30Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a measurement of the fraction of inclusive W +jets events produced with net charm quantum number 11, denoted W + c-jet, in p collisions at root s = 1.96 TeV using approximately 1 fb(-1) of data collected by the DO detector at the Fermilab Tevatron Collider. We identify the W +jets events via the leptonic W boson decays. Candidate W + c-jet events are selected by requiring a jet containing a muon in association with a reconstructed W boson and exploiting the charge correlation between this muon and W boson decay lepton to perform a nearly model-independent background subtraction. We measure the fraction of W + c-jet events in the inclusive W +jets sample for jet PT > 20 GeV and pseudorapidity |eta| < 2.5 to be 0.074 +/- 0.019(stat.) +/-(0.012)(0.014) (syst.), in agreement with theoretical predictions. The probability that background fluctuations could produce the observed fraction of W + c-jet events is estimated to be 2.5 x 10(-4), which corresponds to a 3.5 sigma statistical significance.

  • 11. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Observation of the B(c) meson in the exclusive decay B(c)-> J/psi pi2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 1, s. 012001-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A fully reconstructed B(c)-> J/psi pi signal is observed with the D0 detector at the Fermilab Tevatron p (p) over bar collider using 1.3 fb(-1) of integrated luminosity. The signal consists of 54 +/- 12 candidates with a significance that exceeds 5 standard deviations, and confirms earlier observations of this decay. The measured mass of the B(c) meson is 6300 +/- 14(stat)+/- 5(syst) MeV/c(2).

  • 12. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Observation of the Doubly Strange b Baryon Omega(-)(b)2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 23, s. 232002-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report the observation of the doubly strange b baryon Omega(-)(b) in the decay channel Omega(-)(b) -> J/psi Omega(-), with J/psi -> mu(+)mu(-) and Omega(-) -> Lambda K(-) -> (p pi(-))K(-), in p (p) over bar collisions at root s = 1.96 TeV. Using approximately 1.3 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider, we observe 17.8 +/- 4.9(stat) +/- 0.8(syst) Omega(-)(b) signal events at a mass of 6.165 +/- 0.010(stat) +/- 0.013(syst) GeV. The significance of the observed signal is 5.4 sigma, corresponding to a probability of 6.7 x 10(-8) of it arising from a background fluctuation.

  • 13. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Observation of ZZ Production in p(p)over-bar Collisions at root s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 17, s. 171803-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present an observation for ZZ -> l(+) l(-) l'(+) l'(-) (l, l' =e or mu) production in p (p) over bar collisions at a center-of-mass energy of root s = 1.96 TeV. Using 1.7 fb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider, we observe three candidate events with an expected background of 0.14(-0.02)(+0.03) events. The significance of this observation is 5.3 standard deviations. The combination of D0 results in this channel, as well as in ZZ -> l(+) l(-) v (v) over bar yields a significance of 5.7 standard deviations and a combined cross section of sigma(ZZ) = 1.60 +/- 0.63(stat)(-0.17)(+0.16)(syst) pb.

  • 14. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Precise Measurement of the Top-Quark Mass from lepton plus jets Events2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 18, s. 182001-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We measure the mass of the top quark using top-quark pair candidate events in the lepton+jets channel from data corresponding to 1 fb(-1) of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron collider. We use a likelihood technique that reduces the jet energy scale uncertainty by combining an in situ jet energy calibration with the independent constraint on the jet energy scale (JES) from the calibration derived using photon+jets and dijet samples. We find the mass of the top quark to be 171.5 +/- 1.8(stat.+JES)+/- 1.1(syst.) GeV.

  • 15. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Relative rates of B meson decays into psi(2S) and J/psi mesons2009Inngår i: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 79, nr 11, s. 111102-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a study of the relative rates of B meson decays into psi(2S) and J/psi mesons using 1.3 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe the channels B(s)(0) -> psi(2S)phi, B(s)(0) -> J/psi phi, B(+/-) -> psi(2S)K(+/-), and B(+/-) -> J/psi K(+/-) and we measure the relative branching fractions for these channels to be B(B(s)(0) -> psi(2S)phi)/B(B(s)(0) -> J/psi phi)=0.53 +/- 0.10(stat)+/- 0.07(syst)+/- 0.06(B), B(B(+) -> psi(2S)K(+))/B(B(+) -> J/psi K(+))=0.63 +/- 0.05(stat)+/- 0.03(syst)+/- 0.07(B), where the final error corresponds to the uncertainty in the J/psi and psi(2S) branching ratio into two muons.

  • 16. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for Anomalous Wtb Couplings in Single Top Quark Production2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 22, s. 221801-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In 0.9 fb(-1) of pp collisions, the D0 Collaboration presented evidence for single top quark production in events with an isolated lepton, missing transverse momentum, and two to four jets. We examine these data to study the Lorentz structure of the Wtb coupling. The standard model predicts a left-handed vector coupling at the Wtb vertex. The most general lowest dimension, CP-conserving Lagrangian admits right-handed vector and left- or right-handed tensor couplings as well. We find that the data prefer the left-handed vector coupling and set upper limits on the anomalous couplings. These are the first direct constraints on a general Wtb interaction and the first direct limits on left- and right-handed tensor couplings.

  • 17. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et. al.,
    Search for Charged Higgs Bosons Decaying into Top and Bottom Quarks in pp Collisions2009Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 102, nr 19, s. 191802-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe a search for production of a charged Higgs boson, qq>-> H(+), reconstructed in the tb final state in the mass range 180 <= M(H)(+)<= 300 GeV. The search was undertaken at the Fermilab Tevatron collider with a center-of-mass energy s=1.96 TeV and uses 0.9 fb(-1) of data collected with the D0 detector. We find no evidence for charged Higgs boson production and set upper limits on the production cross section in the types I, II, and III two-Higgs-doublet models (2HDMs). An excluded region in the (M(H)(+), tan beta) plane for type I 2HDM is presented.

  • 18. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for decay of a fermiophobic Higgs boson h(f) -> gamma gamma with the D0 detector at root s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 5, s. 051801-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report the results of a search for a narrow resonance decaying into two photons in 1.1 fb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider during the period 2002-2006. We find no evidence for such a resonance and set a lower limit on the mass of a fermiophobic Higgs boson of m(hf) > 100 GeV at the 95% C.L. This exclusion limit exceeds those obtained in previous searches at the Fermilab Tevatron and covers a significant region of the parameter space B(h(f) -> gamma gamma) vs m(hf) which was not accessible at the CERN Large Electron-Positron Collider.

  • 19. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for Higgs bosons decaying to tau pairs in p(p)over-bar collisions with the D0 detector2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 7, s. 071804-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a search for the production of neutral Higgs bosons phi decaying into tau(+)tau(-) final states in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. The data, corresponding to an integrated luminosity of approximately 1 fb(-1), were collected by the D0 experiment at the Fermilab Tevatron Collider. Limits on the production cross section times branching ratio are set. The results are interpreted in the minimal supersymmetric standard model yielding limits that are the most stringent to date at hadron colliders.

  • 20. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for large extra dimensions via single photon plus missing energy final states at root s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 1, s. 011601-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a search for large extra dimensions in a data sample of approximately 1 fb(-1) of p (p) over bar collisions at root s=1.96 TeV. We investigate Kaluza-Klein graviton production with a photon and missing transverse energy in the final state. At the 95% C.L. we set limits on the fundamental mass scale M(D) from 884 to 778 GeV for two to eight extra dimensions.

  • 21. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for long-lived particles decaying into electron or photon pairs with the D0 detector2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 11, s. 111802-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, such as hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark.

  • 22. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for Neutral Higgs Bosons in Multi-b-Jet Events in pp Collisions at s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 22, s. 221802-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Data recorded by the D0 experiment at the Fermilab Tevatron Collider are analyzed to search for neutral Higgs bosons produced in association with b quarks. This production mode can be enhanced in the minimal supersymmetric standard model (MSSM). The search is performed in the three b quark channel using multijet triggered events corresponding to an integrated luminosity of 1 fb(-1). No statistically significant excess of events with respect to the predicted background is observed and limits are set in the MSSM parameter space.

  • 23. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for pair production of doubly charged Higgs bosons in the H(++)H(--)->mu(+)mu(+)mu(-)mu(-) final state2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 7, s. 071803-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report the results of a search for pair production of doubly charged Higgs bosons via p (p) over bar -> H(++)H(--)X ->mu(+)mu(+)mu(-)mu(-)X at root s=1.96 TeV. We use a data set corresponding to an integrated luminosity of 1.1 fb(-1) collected from 2002 to 2006 by the D0 detector at the Fermilab Tevatron Collider. In the absence of an excess above the standard model background, lower mass limits of M(H(L)(+/-+/-))> 150 GeV/c(2) and M(H(R)(+/-+/-))> 127 GeV/c(2) at 95% C.L. are set, respectively, for left-handed and right-handed doubly charged Higgs bosons assuming a 100% branching ratio into muons.

  • 24. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for scalar leptoquarks and T-odd quarks in the acoplanar jet topology using 2.5 fb(-1) of p(p)over-bar collision data at root s=1.96 TeV2008Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 668, nr 5, s. 357-363Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A search for new physics in the acoplanar jet topology has been performed in 2.5 fb(-1) of data from p (p) over bar collisions at root s = 1.96 TeV, recorded by the DO detector at the Fermilab Tevatron Collider. The numbers of events with exactly two acoplanar jets and missing transverse energy are in good agreement with the Standard Model expectations. The result of this search has been used to set a lower mass limit of 205 GeV at the 95% C.L. on the mass of a scalar leptoquark when this particle decays exclusively into a quark and a neutrino. In the framework of the Little Higgs model with T-parity, limits have also been obtained on the T-odd quark mass as a function of the T-odd photon mass.

  • 25. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for scalar top quarks in the acoplanar charm jets and missing transverse energy final state in p(p)over-bar collisions at root s=1.96 TeV2008Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 665, nr 1, s. 1-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a search for the pair production of scalar top quarks, (t) over tilde, using 995 pb(-1) of data collected in p (p) over bar collisions with the Dempty set detector at the Fermilab Tevatron Collider at root s = 1.96 TeV. Both scalar top quarks are assumed to decay into a charm quark and a neutralino ((chi) over tilde (0)(1)), where (chi) over tilde (0)(1) is the lightest supersymmetric particle. This leads to a final state with two acoplanar charm jets and missing transverse energy. We find the yield of such events to be consistent with the standard model expectation, and exclude sets of (t) over tilde and (chi) over tilde (0)(1) masses at the 95% C.L. that substantially extend the domain excluded by previous searches.

  • 26. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for the Standard Model Higgs Boson in the Missing Energy and Acoplanar b-Jet Topology at root s=1.96 TeV2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 25, s. 251802-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report a search for the standard model Higgs boson in the missing energy and acoplanar b-jet topology, using an integrated luminosity of 0.93 fb(-1) recorded by the D0 detector at the Fermilab Tevatron p (p) over bar Collider. The analysis includes signal contributions from p (p) over bar -> ZH -> v (v) over barb (b) over bar, as well as from WH production in which the charged lepton from the W boson decay is undetected. Neural networks are used to separate signal from background. In the absence of a signal, we set limits on sigma(p (p) over bar -> VH) x B(H -> b (b) over bar) at the 95% C.L. of 2.6-2.3 pb, for Higgs boson masses in the range 105-135 GeV, where V W, Z. The corresponding expected limits range from 2.8 to 2.0 pb.

  • 27. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for Third Generation Scalar Leptoquarks Decaying into tau b2008Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 24, s. 241802-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have searched for third generation leptoquarks (LQ(3)) using 1.05 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider operating at s=1.96 TeV. We set a 95% C.L. lower limit of 210 GeV on the mass of a scalar LQ(3) state decaying solely to a b quark and a tau lepton.

  • 28. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    Search for t(t)over-bar resonances in the lepton plus jets final state in p(p)over-bar collisions at root s=1.96 TeV2008Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 668, nr 2, s. 98-104Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a search for a narrow-width heavy resonance decaying into top quark pairs (X -> t (t) over bar) in p (p) over bar collisions at root s = 1.96 TeV using approximately 0.9 fb(-1) of data collected with the DO detector at the Fermilab Tevatron Collider. This analysis considers t (t) over bar candidate events in the lepton plus jets channel with at least one identified b jet and uses the t (t) over bar invariant mass distribution to search for evidence of resonant production. We find no evidence for a narrow resonance X decaying to t (t) over bar. Therefore, we set upper limits on sigma x center dot B(X -> t (t) over bar) for different hypothesized resonance masses using a Bayesian approach. For a Topcolor-assisted technicolor model, the existence of a leptophobic Z' boson with mass M(Z') < 700 GeV and width Gamma(Z') = 0.012M(Z') can be excluded at the 95% C.L.

  • 29. Abazov, V. M.
    et al.
    Gollub, Nils
    Strandberg, Jonas
    University of Chicago.
    Zverev, E.G.
    et al.,
    ZZ -> l(+)l(-)nu(nu)overbar production in p(p)overbar collisions at root s=1.96 TeV2008Inngår i: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 78, nr 7, s. 072002-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe a search for Z boson pair production in p(p)overbar collisions at root s=1.96 TeV with the D0 detector at the Fermilab Tevatron Collider using a data sample corresponding to an integrated luminosity of 2.7 fb(-1). Using the final state decay ZZ ->center dot(+)center dot(-)nu(nu)overbar (where center dot=e or mu) we find a signal with a 2.6 standard deviations significance (2.0 expected) corresponding to a cross section of sigma(p(p)overbar -> ZZ+X)=2.01 +/- 0.93(stat)+/- 0.29(sys) pb.

  • 30. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Combined D0 measurements constraining the CP-violating phase and width difference in the B-s(0) system2007Inngår i: PHYSICAL REVIEW D, ISSN 1550-7998, Vol. 76, nr 5, s. 057101-1-057101-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We combine the D0 measurement of the width difference between the light and heavy B-s(0) mass eigenstates and of the CP-violating mixing phase determined from the time-dependent angular distributions in the B-s(0)-> J/psi phi decays along with the charge asymmetry in semileptonic decays also measured with the D0 detector. With the additional constraint from the world average of the flavor-specific B-s(0) lifetime, we obtain Delta Gamma(s)equivalent to(Gamma(L)-Gamma(H))=0.13 +/- 0.09 ps(-1) and vertical bar phi(s)vertical bar=0.70(-0.47)(+0.39) or Delta Gamma(s)=-0.13 +/- 0.09 ps(-1) and vertical bar phi(s)vertical bar=2.44(-0.39)(+0.47). The data sample corresponds to an integrated luminosity of 1.1 fb(-1) accumulated with the D0 detector at the Fermilab Tevatron Collider.

  • 31. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Direct observation of the strange b baryon Xi(-)(b)2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 5, s. 052001-1-052001-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report the first direct observation of the strange b baryon Xi(-)(b)(Xi) over bar (+)(b)). We reconstruct the decay Xi(-)(b)-->J/psi Xi(-), with J/psi-->mu(+)mu(-), and Xi(-)-->Lambda pi(-)-->p pi(-)pi(-) in p (p) over bar collisions at root s = 1.96 TeV. Using 1.3 fb(-1) of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat)(-0.4)(+1.9)(syst) Xi(-)(b) candidates at a mass of 5.774 +/- 0.011(stat) +/- 0.015(syst) GeV. The significance of the observed signal is 5.5 sigma, equivalent to a probability of 3.3 x 10(-8) of it arising from a background fluctuation. Normalizing to the decay Lambda(b)-->J/psi Lambda, we measure the relative rate sigma(Xi(-)(b))xB(Xi(-)(b)-->J/psi Xi)/ sigma(Lambda(b))xB(Lambda(b)-->J/psi Lambda) = 0.28 +/- 0.09(stat)(-0.08)(+0.09)(syst).

  • 32. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Evidence for production of single top quarks and first direct measurement of vertical bar V-tb vertical bar2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 98, nr 18, s. 181802-1-181802-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The D0 Collaboration presents first evidence for the production of single top quarks at the Fermilab Tevatron < p(p)over bar > collider. Using a 0.9 fb(-1) dataset, we apply a multivariate analysis to separate signal from background and measure sigma(< p(p)over bar >-> tb+X,tqb+X)=4.9 +/- 1.4 pb. The probability to measure a cross section at this value or higher in the absence of a signal is 0.035%, corresponding to a 3.4 standard deviation significance. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa matrix element that describes the Wtb coupling and find 0.68 <vertical bar V-tb vertical bar <= 1 at 95% C.L. within the standard model.

  • 33. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Lifetime difference and CP-violating phase in the B-s(0) system2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 98, nr 12, s. 121801-1-121801-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    From an analysis of the decay B-s(0)-> J/psi phi, we obtain the width difference between the light and heavy mass eigenstates Delta Gamma equivalent to(Gamma(L)-Gamma(H))=0.17 +/- 0.09(stat)+/- 0.02(syst) ps(-1) and the CP-violating phase phi(s)=-0.79 +/- 0.56(stat)(-0.01)(+0.14)(syst). Under the hypothesis of no CP violation (phi(s)equivalent to 0), we obtain 1/Gamma=tau/(B-s(0))=1.52 +/- 0.08(stat)(-0.03)(+0.01)(syst) ps and Delta Gamma=0.12(-0.10)(+0.08)(stat)+/- 0.02(syst) ps(-1). The data sample corresponds to an integrated luminosity of about 1.1 fb(-1) accumulated with the D0 detector at the Fermilab Tevatron collider. This is the first direct measurement of the CP-violating mixing phase in the B-s(0) system.

  • 34. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the charge asymmetry in semileptonic B-s(0) decays2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 98, nr 15, s. 151801-1-151801-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have performed the first direct measurement of the time-integrated flavor untagged charge asymmetry in semileptonic B-s(0) decays A(SL)(s,unt) by comparing the decay rate of B-s(0) -> mu(+) D-s(-) nu X, where D-s(-) -> phi pi(-) and phi -> K+K-, with the charge-conjugate (B) over bar (0)(s) decay rate. This sample was selected from 1: 3 fb(-1) of data collected by the D0 experiment in run II of the Fermilab Tevatron collider. We obtain A(SL)(s,unt) = [1.23 +/- 0.97(stat) +/- 0.17(syst)] x 10(-2). Assuming that Delta m(s)/(Gamma) over bar (s) >> 1, this result can be translated into a measurement of the CP-violating phase in B-s(0) mixing: Delta Gamma(s)/Delta m(s) tan phi(s) = [2.45 +/- 1.93(stat) +/- 0.35(syst)] x 10(-2).

  • 35. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the Lambda(0)(b) lifetime using semileptonic decays2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 18, s. 182001-1-182001-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report a measurement of the Lambda(0)(b) lifetime using a sample corresponding to 1.3 fb(-1) of data collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. The Lambda(0)(b) baryon is reconstructed via the decay Lambda(0)(b)->mu(nu) over bar Lambda X-+(c). Using 4437 +/- 329 signal candidates, we measure the Lambda(0)(b) lifetime to be tau(Lambda(0)(b))=1.290(-0.110)(+0.119)(stat)(-0.091)(+0.087)(syst) ps, which is among the most precise measurements in semileptonic Lambda(0)(b) decays. This result is in good agreement with the world average value.

  • 36. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the Lambda(b) lifetime in the exclusive decay Lambda(b)-> J/psi Lambda2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 14, s. 142001-1-142001-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have measured the Lambda(b) lifetime using the exclusive decay Lambda(b)-> J/psi Lambda, based on 1.2 fb(-1) of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda(b) decays, where the J/psi and Lambda are identified via the decays J/psi ->mu(+)mu(-) and Lambda -> p pi, we measured the Lambda(b) lifetime to be tau(Lambda(b))=1.218(-0.115)(+0.130)(stat)+/- 0.042(syst) ps. We also measured the B-0 lifetime in the decay B-0 -> J/psi(mu(+)mu(-))K-S(0)(pi(+)pi(-)) to be tau(B-0)=1.501(-0.074)(+0.078)(stat)+/- 0.050(syst) ps, yielding a lifetime ratio of tau(Lambda(b))/tau(B-0)=0.811(-0.087)(+0.096)(stat)+/- 0.034(syst).

  • 37. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the p(p)over-bar -> t(t)over-bar + X production cross section at root s=1.96 TeV in the fully hadronic decay channel2007Inngår i: Physical Review D - Particles, Fields, Gravitation and Cosmology, ISSN 1550-7998, Vol. 76, nr 7, s. 072007-1-072007-11Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A measurement of the top quark pair production cross section in proton antiproton collisions at an interaction energy of root s=1.96 TeV is presented. This analysis uses 405 +/- 25 pb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider. Fully hadronic t (t) over bar decays with final states of six or more jets are separated from the multijet background using secondary vertex tagging and a neural network. The t (t) over bar cross section is measured as sigma(t (t) over bar)=4.5(-1.9)(+2.0)(stat)(-1.1)(+1.4)(syst)+/- 0.3(lumi) pb for a top quark mass of m(t)=175 GeV/c(2).

  • 38. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the shape of the boson rapidity distribution for p(p)over-bar -> Z/gamma(*)-> e(+)e(-)+X events produced at root s of 1.96 TeV2007Inngår i: PHYSICAL REVIEW D, ISSN 1550-7998, Vol. 76, nr 1, s. 012003-1-012003-10Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a measurement of the shape of the boson rapidity distribution for p (p) over bar -> Z/gamma(*)-> e(+)e(-)+X events at a center-of-mass energy of 1.96 TeV. The measurement is made for events with electron-positron mass 71 < M-ee < 111 GeV and uses 0.4 fb(-1) of data collected at the Fermilab Tevatron collider with the D0 detector. This measurement significantly reduces the uncertainties on the rapidity distribution in the forward region compared with previous measurements. Predictions of next-to-next-to-leading order (NNLO) QCD are found to agree well with the data over the full rapidity range.

  • 39. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the top quark mass in the lepton plus jets channel using the ideogram method2007Inngår i: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 75, nr 9, s. 092001-1-092001-21Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A measurement of the top quark mass using events with one charged lepton, missing transverse energy, and jets in the final state, collected by the D0 detector from p (p) over bar collisions at root s=1.96 TeV at the Fermilab Tevatron collider, is presented. A constrained fit is used to fully reconstruct the kinematics of the events. For every event a top quark mass likelihood is calculated taking into account all possible jet assignments and the probability that an event is signal or background. Lifetime-based identification of b jets is employed to enhance the separation between t (t) over bar signal and background from other physics processes and to improve the assignment of the observed jets to the quarks in the t (1) over bar hypothesis. We extract a multiplicative jet energy scale (JES) factor in situ, greatly reducing the systematic effect related to the jet energy measurement. In a data sample with an integrated luminosity of 425 pb(-1), we observe 230 candidate events, with an estimated background of 123 events, and measure m(t)=173.7 +/- 4.4(stat+JES)(-2.0)(+2.1)(syst) GeV. This result represents the first application of the ideogram technique to the measurement of the top quark mass in lepton+jets events.

  • 40. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using kinematic characteristics of lepton plus jets events2007Inngår i: PHYSICAL REVIEW D, ISSN 1550-7998, Vol. 76, nr 9, s. 092007-1-092007-22Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a measurement of the top quark pair production cross section in p (p) over bar collisions at root s=1.96 TeV utilizing 425 pb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-p(T) electron or muon and at least four jets. We exploit specific kinematic features of t (t) over bar events to extract the cross section. For a top quark mass of 175 GeV, we measure sigma(t (t) over bar)=6.4(-1.2)(+1.3)(stat)+/- 0.7(syst)+/- 0.4(lum) pb, in good agreement with the standard model prediction.

  • 41. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions using dilepton events2007Inngår i: Physical Review D - Particles, Fields, Gravitation and Cosmology, ISSN 1550-7998, Vol. 76, nr 5, s. 052006-1-052006-28Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a measurement of the t (t) over bar pair production cross section in p (p) over bar collisions at root s=1.96 TeV utilizing approximately 425 pb(-1) of data collected with the D0 detector. We consider decay channels containing two high p(T) charged leptons (either e or mu) from leptonic decays of both top-daughter W bosons. These were gathered using four sets of selection criteria, three of which required that a pair of fully identified leptons (i.e., e mu, ee, or mu mu) be found. The fourth approach imposed less restrictive criteria on one of the lepton candidates and required that at least one hadronic jet in each event be tagged as containing a b quark. For a top quark mass of 175 GeV, the measured cross section is 7.4 +/- 1.4(stat)+/- 1.0(syst) pb and for the current Tevatron average top quark mass of 170.9 GeV, the resulting value of the cross section is 7.8 +/- 1.8(stat+syst) pb.

  • 42. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Properties of l=1 B-1 and B*(2) Mesons2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 17, s. 172001-1-172001-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This Letter presents the first strong evidence for the resolution of the excited B mesons B-1 and B-2(*) as two separate states in fully reconstructed decays to B+(*())pi(-). The mass of B-1 is measured to be 5720.6 +/- 2.4 +/- 1.4 MeV/c(2) and the mass difference Delta M between B-2* and B-1 is 26.2 +/- 3.1 +/- 0: 9 MeV/c(2), giving the mass of the B-2* as 5746.8 +/- 2.4 +/- 1.7 MeV/c(2). The production rate for B-1 and B-2* mesons is determined to be a fraction (13.9 +/- 1.9 +/- 3.2)% of the production rate of the B+ meson.

  • 43. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Search for a Higgs boson produced in association with a Z boson in p(p)over-bar collisions2007Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 655, nr 5-6, s. 209-216Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe a search for the Standard Model Higgs boson with a mass of 105 GeV/c(2) to 145 GeV/c(2) in data corresponding to an integrated luminosity of approximately 450 pb(-1) collected with the D phi detector at the Fermilab Tevatron p (p) over bar collider at a center-of-mass energy of 1.96 TeV. The Higgs boson is required to be produced in association with a Z boson, and the Z boson is required to decay to either electrons or muons with the Higgs boson decaying to a b (b) over bar pair. The data are well described by the expected background, leading to 95% confidence level cross section upper limits sigma (p (p) over bar -> ZH) x B(H -> b (b) over bar) in the range of 3.1 pb to 4.4 pb.

  • 44. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Search for production of single top quarks via tcg and tug flavor-changing-neutral-current couplings2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 19, s. 191802-1-191802-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb(-1) of lepton+jets data from p (p) over tilde collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters kappa(c)(g)/Lambda and kappa(u)(g)/Lambda, where kappa(g) define the strength of tcg and tug couplings, and Lambda defines the scale of new physics. The limits at 95% C.L. are kappa(c)(g)/Lambda < 0.15 TeV-1 and kappa(u)(g)/Lambda < 0.037 TeV-1.

  • 45. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Search for single production of scalar leptoquarks in p(p)over-bar collisions decaying into muons and quarks with the D0 detector2007Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 647, nr 2-3, s. 74-81Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a search for second generation leptoquarks (LQ(2)) which decay into a muon plus quark in (p) over barp collisions at a center-of-mass energy of root s = 1.96 TeV in the DO detector using an integrated luminosity of about 300 pb(-1). No evidence for a leptoquark signal is observed and an upper bound on the product of the cross section for single leptoquark production times branching fraction into a quark and a muon was determined for second generation scalar leptoquaiks as a function of the leptoquark mass. This result has been combined with a previously published DO search for leptoquark pair production to obtain leptoquark mass limits as a function of the leptoquark-muon-quark coupling, lambda. Assuming lambda = 1, lower limits on the mass of a second generation scalar leptoquark coupling to a u quark and a muon are m(LQ2) > 274 GeV and m(LQ2) > 226 GeV for beta = 1 and beta = 1/2, respectively.

  • 46. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Search for stopped gluinos from p(p)over-bar collisions at root s=1.96 TeV2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 13, s. 131801-1-131801-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such "stopped gluinos" decaying into a gluon and a neutralino ((chi) over tilde (0)(1)). Limits are placed on the (gluino cross section) x (probability to stop) x [BR((g) over tilde -> g (chi) over tilde (0)(1))] as a function of the gluino and (chi) over tilde (0)(1) masses, for gluino lifetimes from 30 mu s-100 h.

  • 47. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Search for techniparticles in e plus jets events at D02007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 98, nr 22, s. 221801-1-221801-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We search for the technicolor process p(p) over bar ->rho(T)/omega(T)-> W pi(T) in events containing one electron and two jets, in data corresponding to an integrated luminosity of 390 pb(-1), recorded by the D0 experiment at the Fermilab Tevatron. Technicolor predicts that technipions pi(T) decay dominantly into b(b) over bar, b(c) over bar, or (b) over barc, depending on their charge. In these events b and c quarks are identified by their secondary decay vertices within jets. Two analysis methods based on topological variables are presented. Since no excess above the standard model prediction was found, the result is presented as an exclusion in the pi(T) vs rho(T) mass plane for a given set of model parameters.

  • 48. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Search for the pair production of scalar top quarks in the acoplanar charm jet final state in p(p)over-bar collisions at root s=1.96 TeV2007Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 645, nr 2-3, s. 119-127Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A search for the pair production of scalar top quarks, (t) over tilde, has been performed in 360 pb(-1) of data from pp collisions at a center-of-mass energy of 1.96 TeV, collected by the D phi detector at the Fermilab Tevatron collider. The (t) over tilde decay mode considered is (t) over tilde -> c (chi) over tilde (0)(1), where (chi) over tilde (0)(1) is the lightest supersymmetric particle. The topology analyzed therefore consists of a pair of acoplanar heavy-flavor jets with missing transverse energy. The data and standard model expectation are in agreement, anda 95% C.L. exclusion domain in the (m((t) over tilde), m((chi) over tilde1)(0)) plane has been determined, extending the domain excluded by previous experiments.

  • 49. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Search for third-generation scalar leptoquarks in p(p)over-bar collisions at root s=1.96 TeV2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 6, s. 061801-1-061801-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a search for charge-1/3 third-generation leptoquarks (LQ) produced in p (p) over bar collisions at root s =1.96 TeV using the D0 detector at Fermilab. Third-generation leptoquarks are assumed to be produced in pairs and to decay to a tau neutrino and a b quark with branching fraction B. We place upper limits on sigma(p (p) over bar -> LQ (LQ) over bar )B-2 as a function of the leptoquark mass M-LQ. Assuming B=1, we exclude at the 95% confidence level third-generation scalar leptoquarks with M-LQ < 229 GeV.

  • 50. Abazov, V. M.
    et al.
    Åsman, Barbro
    Bélanger-Champagne, Camille
    Clément, Christophe
    Gollub, Nils
    Hansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Strandberg, Jonas
    Strandberg, Sara
    Zverev, E. G.
    et al.,
    Study of the decay B-s(0)->(DsDs(*))-D-(*)2007Inngår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, nr 24, s. 241801-1-241801-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report a study of the decay B-s(0)->(DsDs(*))-D-(*) using a data sample corresponding to 1.3 fb(-1) of integrated luminosity collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. One D-s((*)) meson was partially reconstructed in the decay D-s ->phi mu nu, and the other D-s((*)) meson was identified using the decay D-s ->phi pi where no attempt was made to distinguish D-s and D-s(*) states. For the branching fraction Br(B-s(0)->(DsDs(*))-D-(*)) we obtain a 90% C.L. range [0.002,0.080] and central value 0.039(-0.017)(+0.019)(stat)(-0.015)(+0.016)(syst). This was subsequently used to make the most precise estimate of the width difference Delta Gamma(CP)(s) in the B-s(0)-(B)over bar(s)(0) system: Delta Gamma(CP)(s)/Gamma(s)=0.079(-0.035)(+0.038)(stat)(-0.030)(+0.031)(syst).

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