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Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed top-antitop Events with CDF II

ArXiv hep-ex/0612011 (2006)
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Measurement of the top quark mass in the lepton+jets final state with the matrix element method

Physical Review D Particles Fields Gravitation and Cosmology 74:9 (2006)

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, M Agelou, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, T Andeen, S Anderson, B Andrieu, MS Anzelc, Y Arnoud, M Arov, A Askew, B Åsman, ACS Assis Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, P Banerjee, S Banerjee, E Barberis, P Bargassa, P Baringer, C Barnes, 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, L Berntzon, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, M Binder, C Biscarat, KM Black, I Blackler, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, U Blumenschein, A Boehnlein, O Boeriu, TA Bolton, G Borissov, K Bos, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, S Burdin, S Burke, TH Burnett, E Busato, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, S Caron, W Carvalho, BCK Casey, NM Cason

Abstract:

We present a measurement of the top quark mass with the matrix element method in the lepton+jets final state. As the energy scale for calorimeter jets represents the dominant source of systematic uncertainty, the matrix element likelihood is extended by an additional parameter, which is defined as a global multiplicative factor applied to the standard energy scale. The top quark mass is obtained from a fit that yields the combined statistical and systematic jet energy scale uncertainty. Using a data set of 0.4fb-1 taken with the D0 experiment at Run II of the Fermilab Tevatron Collider, the mass of the top quark is measured using topological information to be: mtopℓ+jets(topo)=169. 2-7.4+5.0(stat+JES)-1.4+1.5(syst)GeV, and when information about identified b jets is included: mtopℓ+jets(b-tag)=170.3-4.5+4.1(stat+JES)-1.8+1.2(syst) GeV. The measurements yield a jet energy scale consistent with the reference scale. © 2006 The American Physical Society.
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Photoproduction of events with rapidity gaps between jets at HERA

ArXiv hep-ex/0612008 (2006)

Authors:

ZEUS Collaboration, S Chekanov
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Doubly-charged higgs bosons

Chapter in Search for the Higgs Boson, (2006) 1-25

Abstract:

The standard model includes a Higgs weak doublet whose vacuum expectation value results in the masses of the observed particles. A number of models also predict a Higgs weak triplet, which includes a doubly-charged Higgs boson (H±±). The existence of such a boson could be inferred indirectly by its exchange in measured processes, or observed directly through its production and decay. Measurements of Bhabha scattering, tau decay, muon decay, and (g - 2)μ provide indirect limits on H±± couplings to charged leptons. Direct H±± searches have been performed in e+e- collisions at the Large Electron Positron collider (LEP) and in pp collisions at the Fermilab Tevatron. The highest mass limits for exclusive H±± couplings to electrons and muons, and for long-lived H±±, are obtained by the Collider Detector at Fermilab (CDF), while the DELPHI detector at CERN obtains the highest mass limits for H±± couplings to taus. Future data at the Tevatron, Large Hadron Collider, and International Linear Collider will increase sensitivity to H±± mass and couplings by about an order of magnitude. © 2006 Nova Science Publishers, Inc. All rights reserved.

Measurement of the tt̄ production cross section in pp̄ collisions at s=1.96TeV using secondary vertex b tagging

Physical Review D - Particles, Fields, Gravitation and Cosmology 74:11 (2006)

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, A Askew, BA Asman, ACS Assis Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, P Banerjee, S Banerjee, E Barberis, P Bargassa, P Baringer, C Barnes, 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, L Berntzon, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, M Binder, C Biscarat, I Blackler, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, U Blumenschein, A Boehnlein, TA Bolton, G Borissov, K Bos, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, S Burdin, S Burke, TH Burnett, E Busato, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, S Caron, W Carvalho, BCK Casey, NM Cason, H Castilla-Valdez, S Chakrabarti

Abstract:

We report a new measurement of the tt̄ production cross section in pp̄ collisions at a center-of-mass energy of 1.96 TeV using events with one charged lepton (electron or muon), missing transverse energy, and jets. Using 425pb-1 of data collected using the D0 detector at the Fermilab Tevatron Collider, and enhancing the tt̄ content of the sample by tagging b jets with a secondary vertex tagging algorithm, the tt̄ production cross section is measured to be σpp̄→tt̄+X=6.6±0.9(stat+syst) ±0.4(lum)pb. This cross section is the most precise D0 measurement to date for tt̄ production and is in good agreement with standard model expectations. © 2006 The American Physical Society.
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