Measurement of the top quark pT distribution

Physical Review Letters 87:10 (2001)

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, J Cassada, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, YS Chung, CI Ciobanu, AG Clark, A Connolly, J Conway, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, S D'Auria

Abstract:

The first measurement of the true top quark PT distributon was carried out. An attempt was also made to compute a 95% confidence level upper limit on the fraction of top quarks that are produced with 225 > PT > 425 GeV/c. It was found that R4 > 0.16 at 95% C.L.

From factor ratio measurement in the decay Λc→Λ e+ ν

International Journal of Modern Physics A World Scientific Publishing 16:supp01b (2001) 511-513

Authors:

VICTOR PAVLUNIN, IAN SHIPSEY

Measurement of the Strong Coupling Constant from Inclusive Jet Production at the Tevatron $\bar pp$ Collider

ArXiv hep-ex/0108034 (2001)

Search for the supersymmetric partner of the top quark in pp̄ collisions at √s=1.8 TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 63:9 (2001) 911011-911016

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, J Cassada, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, YS Chung, CI Ciobanu, AG Clark, A Connolly, J Conway, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart

Abstract:

We report on a search for the supersymmetric partner of the top quark (top squark) produced in tt̄ events using 110 pb-1 of pp̄ collisions at √s = 1.8 TeV recorded with the Collider Detector at Fermilab. In the case of a light top squark, the decay of the top quark into a top squark plus the lightest supersymmetric particle (LSP) could have a significant branching ratio. The observed events are consistent with standard model tt̄ production and decay. Hence, we set limits on the branching ratio of the top quark decaying into a top squark plus LSP, excluding branching ratios above 45% for a LSP mass up to 40 GeV/c2.

Measurement of the decay asymmetry parameters in Ξ c0 → Ξ - π +

Physical Review D - Particles, Fields, Gravitation and Cosmology 63:11 (2001) 1111021-1111026

Authors:

M Bishai, J Fast, E Gerndt, JW Hinson, RL McIlwain, T Miao, DH Miller, M Modesitt, D Payne, EI Shibata, IPJ Shipsey, PN Wang, M Battle, J Ernst, L Gibbons, Y Kwon, S Roberts, EH Thorndike, CH Wang, J Dominick, M Lambrecht, S Sanghera, V Shelkov, T Skwarnicki, R Stroynowski, I Volobouev, G Wei, M Artuso, M Gao, M Goldberg, D He, N Horwitz, GC Moneti, R Mountain, F Muheim, Y Mukhin, S Playfer, Y Rozen, S Stone, X Xing, G Zhu, J Bartelt, SE Csorna, Z Egyed, V Jain, D Gibaut, K Kinoshita, P Pomianowski, B Barish, M Chadha, S Chan, DF Cowen, G Eigen, JS Miller, C O'Grady, J Urheim, AJ Weinstein, M Athanas, W Brower, G Masek, HP Paar, J Gronberg, CM Korte, R Kutschke, S Menary, RJ Morrison, S Nakanishi, HN Nelson, TK Nelson, C Qiao, JD Richman, A Ryd, D Sperka, H Tajima, MS Witherell, M Procario, R Balest, K Cho, WT Ford, DR Johnson, K Lingel, M Lohner, P Rankin, JG Smith, JP Alexander, C Bebek, K Berkelman, K Bloom, TE Browder, DG Cassel, HA Cho, DM Coffman, DS Crowcroft, PS Drell, DJ Dumas, R Ehrlich, P Gaidarev, M Garcia-Sciveres, B Geiser, B Gittelman

Abstract:

Using the CLEO II detector at the Cornell Electron Storage Ring we have measured the Ξ c0 decay asymmetry parameter in the decay Ξ 0c→ Ξ - π +. We find α Ξc0 = 0.26±0.18(stat) -0.04+0.05(syst); using the world average value of α Ξ = -0.456±0.014 we obtain α Ξc0 = -0.56±0.39(stat) -0.09+0.10(syst). The physically allowed range of a decay asymmetry parameter is -1 < α < + 1. Our result prefers a negative value: α Ξc0 is <0.1 at the 90% C.L. The central value occupies the middle of the theoretically expected range but is not yet precise enough to choose between models.