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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.

Tests of enhanced leading order QCD in W boson plus jets events from 1.8 TeV p̄p collisions

Physical Review D - Particles, Fields, Gravitation and Cosmology 63:7 (2001) 720031-7200329

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, 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, 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, J Cooper, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, S D'Auria

Abstract:

We present a study of events with W bosons and hadronic jets produced in p̄p collisions at a center of mass energy of 1.8 TeV. The data consist of 51400 W → e ν decay candidates from 108 pb-1 of integrated luminosity collected using the CDF detector at the Fermilab Tevatron collider. Cross sections and jet production properties have been measured for W + ≥ 1 to ≥ 4 jet events. The data compare well to predictions of leading-order QCD matrix element calculations with added gluon radiation and simulated parton fragmentation.

Rate measurement of D(0)-->K+pi(-)pi(0) and constraints on D(0) -- D(0) mixing.

Phys Rev Lett 87:7 (2001) 071802

Authors:

G Brandenburg, A Ershov, DY Kim, R Wilson, T Bergfeld, BI Eisenstein, J Ernst, GE Gladding, GD Gollin, RM Hans, E Johnson, I Karliner, MA Marsh, C Plager, C Sedlack, M Selen, JJ Thaler, J Williams, KW Edwards, AJ Sadoff, R Ammar, A Bean, D Besson, X Zhao, S Anderson, VV Frolov, Y Kubota, SJ Lee, R Poling, A Smith, CJ Stepaniak, J Urheim, S Ahmed, MS Alam, SB Athar, L Jian, L Ling, M Saleem, S Timm, F Wappler, A Anastassov, E Eckhart, KK Gan, C Gwon, T Hart, K Honscheid, D Hufnagel, H Kagan, R Kass, TK Pedlar, JB Thayer, E von Toerne, MM Zoeller, SJ Richichi, H Severini, P Skubic, A Undrus, V Savinov, S Chen, JW Hinson, J Lee, DH Miller, EI Shibata, IP Shipsey, V Pavlunin, D Cronin-Hennessy, AL Lyon, EH Thorndike, TE Coan, V Fadeyev, YS Gao, Y Maravin, I Narsky, R Stroynowski, J Ye, T Wlodek, M Artuso, K Benslama, C Boulahouache, K Bukin, E Dambasuren, G Majumder, R Mountain, T Skwarnicki, S Stone, JC Wang, A Wolf, S Kopp, M Kostin, AH Mahmood, SE Csorna, I Danko, KW McLean, Z Xu, R Godang, G Bonvicini, D Cinabro, M Dubrovin, S McGee, GJ Zhou, A Bornheim, E Lipeles, SP Pappas, A Shapiro, WM Sun, AJ Weinstein, DE Jaffe, R Mahapatra, G Masek, HP Paar, DM Asner, A Eppich, TS Hill, RJ Morrison, HN Nelson, RA Briere, GP Chen, T Ferguson, H Vogel, JP Alexander, C Bebek, BE Berger, K Berkelman, F Blanc, V Boisvert, DG Cassel, PS Drell, JE Duboscq, KM Ecklund, R Ehrlich, P Gaidarev, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, L Hsu, CD Jones, J Kandaswamy, DL Kreinick, M Lohner, A Magerkurth, TO Meyer, NB Mistry, E Nordberg, M Palmer, JR Patterson, D Peterson, D Riley, A Romano, H Schwarthoff, JG Thayer, D Urner, B Valant-Spaight, G Viehhauser, A Warburton, P Avery, C Prescott, AI Rubiera, H Stoeck, J Yelton, CLEO Collaboration

Abstract:

We present an observation and time-integrated rate measurement of the decay D(0)-->K(+)pi(-)pi(0) produced in 9 fb(-1) of e(+)e(-) collisions near the Upsilon(4S) resonance. The signal is inconsistent with an upward fluctuation of the background by 4.9 standard deviations. We measured the time-integrated rate of D(0)-->K(+)pi(-)pi(0) normalized to the rate of D(0)-->K(+)pi(-)pi(0) to be 0.0043(+0.0011)(-0.0010) (stat)+/-0.0007 (syst). This decay can be produced by doubly Cabibbo-suppressed decays or by the D(0) evolving into a D(0) through mixing, followed by a Cabibbo-favored decay to K(+)pi(-)pi(0). We also found the CP asymmetry A = (9(+25)(-22))% be consistent with zero.