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Search for Heavy, Long-Lived Particles that Decay to Photons at CDF II

ArXiv 0704.0760 (2007)
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Search for single production of scalar leptoquarks in p over(p, ̄) collisions decaying into muons and quarks with the D0 detector

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 647:2-3 (2007) 74-81

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, 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, I Blackler, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, 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 on a search for second generation leptoquarks (LQ2) which decay into a muon plus quark in p over(p, ̄) collisions at a center-of-mass energy of sqrt(s) = 1.96   TeV in the D0 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 β into a quark and a muon was determined for second generation scalar leptoquarks as a function of the leptoquark mass. This result has been combined with a previously published D0 search for leptoquark pair production to obtain leptoquark mass limits as a function of the leptoquark-muon-quark coupling, λ. Assuming λ = 1, lower limits on the mass of a second generation scalar leptoquark coupling to a u quark and a muon are mLQ2 > 274   GeV and mLQ2 > 226   GeV for β = 1 and β = 1 / 2, respectively. © 2007 Elsevier B.V. All rights reserved.
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Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV

ArXiv 0704.0638 (2007)
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Measurement of the top-quark mass in all-hadronic decays in pp̄ collisions at CDF II

Physical Review Letters 98:14 (2007)

Authors:

T Aaltonen, A Abulencia, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Budroni, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, S Carillo, D Carlsmith, R Carosi, 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, I Cho, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, M Ciljak, CI Ciobanu, MA Ciocci

Abstract:

We present a measurement of the top-quark mass Mtop in the all-hadronic decay channel tt̄→W+bW-b̄→q1q̄2bq3q̄4b̄. The analysis is performed using 310pb-1 of s=1.96TeV pp̄ collisions collected with the CDF II detector using a multijet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of Mtop=177.1±4.9(stat)±4.7(syst)GeV/c2. © 2007 The American Physical Society.
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Event shapes in deep inelastic scattering at HERA

Nuclear Physics B 767:1-2 (2007) 1-28

Authors:

S Chekanov, M Derrick, S Magill, S Miglioranzi, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, N Pavel, AG Yagües Molina, S Antonelli, P Antonioli, G Bari, M Basile, L Bellagamba, M Bindi, D Boscherini, A Bruni, G Bruni, L Cifarelli, F Cindolo, A Contin, M Corradi, S De Pasquale, G Iacobucci, A Margotti, R Nania, A Polini, L Rinaldi, G Sartorelli, A Zichichi, G Aghuzumtsyan, D Bartsch, I Brock, S Goers, H Hartmann, E Hilger, HP Jakob, M Jüngst, OM Kind, E Paul, J Rautenberg, R Renner, U Samson, V Schönberg, M Wang, M Wlasenko, NH Brook, GP Heath, JD Morris, T Namsoo, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, KJ Ma, ZA Ibrahim, B Kamaluddin, WAT Wan Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, M Gil, K Olkiewicz, P Stopa, L Zawiejski, L Adamczyk, T Bołd, I Grabowska-Bołd, D Kisielewska, J Łukasik, M Przybycień, L Suszycki, A Kotański, W Słomiński, V Adler, U Behrens, I Bloch, A Bonato, K Borras, N Coppola, J Fourletova, A Geiser, D Gladkov, P Göttlicher, I Gregor, O Gutsche, T Haas, W Hain, C Horn, B Kahle, U Kötz

Abstract:

Mean values and differential distributions of event-shape variables have been studied in neutral current deep inelastic scattering using an integrated luminosity of 82.2 pb-1 collected with the ZEUS detector at HERA. The kinematic range is 80 < Q2 < 20 480 GeV2 and 0.0024 < x < 0.6, where Q2 is the virtuality of the exchanged boson and x is the Bjorken variable. The data are compared with a model based on a combination of next-to-leading-order QCD calculations with next-to-leading-logarithm corrections and the Dokshitzer-Webber non-perturbative power corrections. The power-correction method provides a reasonable description of the data for all event-shape variables studied. Nevertheless, the lack of consistency of the determination of αs and of the non-perturbative parameter of the model, over(α0, -), suggests the importance of higher-order processes that are not yet included in the model. © 2006 Elsevier B.V. All rights reserved.
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