Accelerator Neutrinos

Research group

Research theme

Sub department

About

Related research groups

Measurement of the average lifetime of b-hadrons in Z decays

Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 416:1-2 (1998) 220-232

Authors:

M Acciarri, O Adriani, M Aguilar-Benitez, S Ahlen, J Alcaraz, G Alemanni, J Allaby, A Aloisio, G Alverson, MG Alviggi, G Ambrosi, H Anderhub, VP Andreev, T Angelescu, F Anselmo, A Arefiev, T Azemoon, T Aziz, P Bagnaia, L Baksay, RC Ball, S Banerjee, S Banerjee, K Banicz, A Barczyk, R Barillère, L Barone, P Bartalini, A Baschirotto, M Basile, R Battiston, A Bay, F Becattini, U Becker, F Behner, J Berdugo, P Berges, B Bertucci, BL Betev, S Bhattacharya, M Biasini, A Biland, GM Bilei, JJ Blaising, SC Blyth, GJ Bobbink, R Bock, A Böhm, L Boldizsar, B Borgia, D Bourilkov, M Bourquin, D Boutigny, S Braccini, JG Branson, V Brigljevic, IC Brock, A Buffini, A Buijs, JD Burger, WJ Burger, J Busenitz, XD Cai, M Campanelli, M Capell, G Cara Romeo, G Carlino, AM Cartacci, J Casaus, G Castellini, F Cavallari, N Cavallo, C Cecchi, M Cerrada, F Cesaroni, M Chamizo, YH Chang, UK Chaturvedi, SV Chekanov, M Chemarin, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chen, G Chiefari, CY Chien, L Cifarelli, F Cindolo, C Civinini, I Clare, R Clare, HO Cohn, G Coignet, AP Colijn, N Colino, S Costantini, F Cotorobai, B de la Cruz

Abstract:

We present a measurement of the average b-hadron lifetime τb at the e+e collider LEP. Using hadronic Z decays collected in the period from 1991 to 1994, two independent analyses have been performed. In the first one, the b-decay position is reconstructed as a secondary vertex of hadronic b-decay particles. The second analysis is an updated measurement of Tb using the impact parameter of leptons with high momentum and high transverse momentum. The combined result is τb = [1549 ± 9 (stat) ± 15 (syst)] fs. In addition, we measure the average charged b-decay multiplicity 〈nb〉 and the normalized average b-energy 〈xE〉b at LEP to be 〈nb〉 = 4.90 ± 0.04 (stat) ± 0.11 (syst), 〈xE〉b = 0.709 ± 0.004 (stat + syst). © 1998 Published by Elsevier Science B.V.
More details from the publisher
More details

Measurement of the shape of the transverse momentum distribution of W bosons produced in pp¯ collisions at √s = 1.8 TeV

Physical Review Letters 80:25 (1998) 5498-5503

Authors:

B Abbott, M Abolins, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, GA Alves, N Amos, EW Anderson, R Astur, MM Baarmand, L Babukhadia, A Baden, V Balamurali, J Balderston, B Baldin, S Banerjee, J Bantly, E Barberis, JF Bartlett, A Belyaev, SB Beri, I Bertram, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, N Biswas, G Blazey, S Blessing, P Bloom, A Boehnlein, NI Bojko, F Borcherding, C Boswell, A Brandt, R Brock, A Bross, D Buchholz, VS Burtovoi, JM Butler, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, SM Chang, SV Chekulaev, LP Chen, W Chen, S Choi, S Chopra, BC Choudhary, JH Christenson, M Chung, D Claes, AR Clark, WG Cobau, J Cochran, L Coney, WE Cooper, C Cretsinger, D Cullen-Vidal, MAC Cummings, D Cutts, OI Dahl, K Davis, K De, K Del Signore, M Demarteau, D Denisov, SP Denisov, HT Diehl, M Diesburg, G Di Loreto, P Draper, Y Ducros, LV Dudko, SR Dugad, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, VN Evdokimov, T Fahland, MK Fatyga, S Feher, D Fein, T Ferbel, G Finocchiaro, HE Fisk, Y Fisyak, E Flattum, GE Forden

Abstract:

The shape of the transverse momentum distribution of W bosons (pW T) produced in pp¯ collisions at √s = 1.8 TeV is measured with the D0 detector at Fermilab. The result is compared with QCD perturbative and resummation calculations over the pW T range from 0 to 200 GeV/c. The shape of the distribution is consistent with the theoretical prediction. © 1998 The American Physical Society.
More details from the publisher

Measurement of the top quark mass using dilepton events

Physical Review Letters 80:10 (1998) 2063-2068

Authors:

B Abbott, M Abolins, BS Acharya, I Adam, DL Adams, M Adams, S Ahn, H Aihara, GA Alves, E Amidi, N Amos, EW Anderson, R Astur, MM Baarmand, A Baden, V Balamurali, J Balderston, B Baldin, S Banerjee, J Bantly, E Barberis, JF Bartlett, K Bazizi, A Belyaev, SB Beri, I Bertram, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, N Biswas, G Blazey, S Blessing, P Bloom, A Boehnlein, NI Bojko, F Borcherding, J Borders, C Boswell, A Brandt, R Brock, A Bross, D Buchholz, VS Burtovoi, JM Butler, W Carvalho, D Casey, Z Casilum, H Castilla-Valdez, D Chakraborty, SM Chang, SV Chekulaev, LP Chen, W Chen, S Choi, S Chopra, BC Choudhary, JH Christenson, M Chung, D Claes, AR Clark, WG Cobau, J Cochran, WE Cooper, C Cretsinger, D Cullen-Vidal, MAC Cummings, D Cutts, OI Dahl, K Davis, K De, K Del Signore, M Demarteau, D Denisov, SP Denisov, HT Diehl, M Diesburg, G Di Loreto, P Draper, Y Ducros, LV Dudko, SR Dugad, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, VN Evdokimov, T Fahland, M Fatyga, MK Fatyga, J Featherly, S Feher, D Fein, T Ferbel, G Finocchiaro, HE Fisk

Abstract:

The D0 Collaboration has performed a measurement of the top quark mass mt based on six candidate events for the process tt- → bW+bW-, where the W bosons decay to eν or μν. This sample was collected during an exposure of the D0 detector to an integrated luminosity of 125pb-1 of √ s = 1.8 TeV pp collisions. We obtain mt = 168.4 ± 12.3(stat) ± 3.6(syst) GeV/c2, consistent with the measurement obtained using single-lepton events. Combination of the single-lepton and dilepton results yields mt = 172.0 ± 7.5 GeV/c2. © 1998 The American Physical Society.
More details from the publisher

Measurement of ℬ (D0 → K-π+) Using Partial Reconstruction of Using Partial Reconstruction of ¯ B → D*+ Xℓ- ¯v

Physical Review Letters 80:15 (1998) 3193-3197

Authors:

M Artuso, F Azfar, A Efimov, M Goldberg, D He, S Kopp, GC Moneti, R Mountain, S Schuh, T Skwarnicki, S Stone, G Viehhauser, X Xing, J Bartelt, SE Csorna, V Jain, KW McLean, S Marka, R Godang, K Kinoshita, IC Lai, P Pomianowski, S Schrenk, G Bonvicini, D Cinabro, R Greene, LP Perera, GJ Zhou, M Chadha, S Chan, G Eigen, JS Miller, C O’grady, M Schmidtler, J Urheim, AJ Weinstein, F Würthwein, DM Asner, J Gronberg, TS Hill, DJ Lange, RJ Morrison, HN Nelson, TK Nelson, D Roberts, A Ryd, R Balest, BH Behrens, WT Ford, H Park, J Roy, JG Smith, JP Alexander, R Baker, C Bebek, BE Berger, K Berkelman, K Bloom, V Boisvert, DG Cassel, DS Crowcroft, M Dickson, S Von Dombrowski, PS Drell, KM Ecklund, R Ehrlich, AD Foland, P Gaidarev, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, PI Hopman, J Kandaswamy, PC Kim, DL Kreinick, T Lee, Y Liu, NB Mistry, CR Ng, E Nordberg, M Ogg, JR Patterson, D Peterson, D Riley, A Soffer, B Valant Spaight, C Ward, M Athanas, P Avery, CD Jones, M Lohner, S Patton, C Prescott, J Yelton, J Zheng, G Brandenburg, RA Briere, A Ershov

Abstract:

We present a measurement of the absolute branching fraction for D0 → K-π+ using the reconstruction of the decay chain ¯ B → D*+ Xℓ- ¯v where only the lepton and the low-momentum pion from the D*+ are detected. With data collected by the CLEO II detector at the Cornell Electron Storage Ring, we have determined B(D0 → K-π+)=[3.81±0.15(stat)±0.16(syst)]%. © 1998 The American Physical Society.
More details from the publisher

New limits for neutrinoless tau decays

Physical Review D - Particles, Fields, Gravitation and Cosmology 57:9 (1998) 5903-5907

Authors:

DW Bliss, G Masek, HP Paar, S Prell, V Sharma, HN Nelson, TK Nelson, D Roberts, A Ryd, M Dickson, S von Dombrowski, PS Drell, KM Ecklund, R Ehrlich, AD Foland, P Gaidarev, RS Galik, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, PI Hopman, J Kandaswamy, PC Kim, DL Kreinick, T Lee, Y Liu, NB Mistry, CR Ng, E Nordberg, M Ogg, JR Patterson, D Peterson, D Riley, A Soffer, B Valant-Spaight, C Ward

Abstract:

Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using (Formula presented) of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis represents an update of a previous study and the addition of six decay channels. In all channels the numbers of events found are compatible with background estimates and branching fraction upper limits are set for 28 different decay modes. These limits are either more stringent than those set previously or represent the first attempt to find these decays. © 1998 The American Physical Society.
More details from the publisher