Observation of Bc mesons in pp̄ collisions at √s = 1.8 TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 58:11 (1998)

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, A Amadon, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, P Azzi-Bacchetta, N Bacchetta, S Bagdasarov, MW Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, S Bettelli, B Bevensee, A Bhatti, K Biery, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, S Blusk, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, R Brunetti, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, M Chertok, G Chiarelli, CN Chiou, F Chlebana, L Christofek, ML Chu, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, D Costanzo, C Couyoumtzelis, D Cronin-Hennessy, R Culbertson, D Dagenhart, T Daniels, F de Jongh, S dell'Agnello, M dell'Orso, R Demina, L Demortier

Abstract:

We report the observation of bottom-charmed mesons Bc ni 1.8 TeV pp̄ collisions using the CDF detector at the Fermilab Tevatron. The Bc mesons were found through their semileptonic decays, B±c → J/ψl± X. A fit to the J/ψl mass distribution yielded 20.4+6.2-5.5 events from Bc mesons. A test of the null hypothesis, i.e., an attempt to fit the data with background alone, was rejected at the level of 4.8 standard deviations. By studying the quality of the fit as a function of the assumed Bc mass, we determined M(Bc) = 6.40 ±0.39 (stat.)±0.13 (syst) GeV/c2. From the distribution of trilepton intersection points in the plane transverse to the beam direction we measure the Bc lifetime to be τ(Bc) = 0.46+0.18-0.16 (stat)±0.03 (syst) ps. We also measured the ratio of production cross section times branching fraction for B+c → J/ψl+ v relative to that for B+ → J/ψK+ to be σ(Bc)×B(B c→J/ψlv)/σ(B)×B(B→J/ψK) = 0.132+0.041-0.037 (stat)±0.031 (syst)+0.032-0.020(lifetime).

Search for a Technicolor omega_T Particle in Events with a Photon and a b-quark Jet at CDF

ArXiv hep-ex/9810031 (1998)

Authors:

The CDF Collaboration, F Abe

Measurement of the Top Quark Mass with the Collider Detector at Fermilab

ArXiv hep-ex/9810029 (1998)

Authors:

F Abe, CDF Collaboration

Search for second generation leptoquarks in the dimuon plus dijet channel of p-pbar collisions at sqrt{s}=1.8 TeV

ArXiv hep-ex/9810024 (1998)

Authors:

CDF collaboration, F Abe

Measurement of elastic Υ photoproduction at HERA

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 437:3-4 (1998) 432-444

Authors:

J Breitweg, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, R Yoshida, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, N Coppola, M Corradi, S De Pasquale, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, A Kappes, UF Katz, R Kerger, E Paul, M Pfeiffer, H Schnurbusch, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, GP Heath, HF Heath, JD McFall, D Piccioni, DG Roff, RJ Tapper, M Capua, L Iannotti, A Mastroberardino, M Schioppa, G Susinno, JY Kim, JH Lee, IT Lim, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, S Sampson, F Sciulli, PB Straub, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, J Figiel, K Klimek, MB Przybycień, L Zawiejski, L Adamczyk

Abstract:

The photoproduction reaction γp → μ+ μ-p has been studied in ep interactions using the ZEUS detector at HERA. The data sample corresponds to an integrated luminosity of 43.2pb-1. The Υ meson has been observed in photoproduction for the first time. The sum of the products of the elastic Υ(1S), Υ(2S),Υ(3S) photoproduction cross sections with their respective branching ratios is determined to be 13.3 ± 6.0(stat.)-2.3+2.7(syst.) pb at a mean photon-proton centre of mass energy of 120 GeV. The cross section is above the prediction of a perturbative QCD model. © 1998 Elsevier Science B.V. All rights reserved.