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Heavy flavor properties of jets produced in pp̄ interactions at √s = 1.8 TeV

Physical Review D 69:7 (2004)

Authors:

D Acosta, D Ambrose, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, F Azfar, P Azzi-Bacchetta, N Bacchetta, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Behari, S Belforte, WH Bell, G Bellettini, J Bellinger, A Beretvas, A Bhatti, D Bisello, C Blocker, B Blumenfeld, A Bocci, G Bolla, A Bolshov, D Bortoletto, J Budagov, HS Budd, K Burkett, G Busetto, S Cabrera, W Carithers, D Carlsmith, R Carosi, A Castro, D Cauz, A Cerri, C Chen, YC Chen, G Chiarelli, G Chlachidze, ML Chu, WH Chung, YS Chung, AG Clark, M Coca, M Convery, M Cordelli, J Cranshaw, D Dagenhart, S D'Auria, S Dell'Agnello, P de Barbaro, S de Cecco, M Dell'Orso, L Demortier, M Deninno, D de Pedis, C Dionisi, S Donati, M D'Onofrio, T Dorigo, R Eusebi, S Farrington, JP Fernandez, RD Field, I Fiori, A Foland, LR Flores-Castillo, M Franklin, J Friedman, I Furic, M Gallinaro, AF Garfinkel, E Gerstein, S Giagu, P Giannetti, K Giolo, M Giordani, P Giromini, V Glagolev, G Gomez, I Gorelov, AT Goshaw, K Goulianos, A Gresele, M Guenther, J Guimaraes da Costa, E Halkiadakis, C Hall, R Handler, F Happacher, K Hara, F Hartmann, K Hatakeyama, J Hauser, J Heinrich

Abstract:

We present a detailed examination of the heavy flavor properties of jets produced at the Fermilab Tevatron collider. The data set, collected with the Collider Detector at Fermilab, consists of events with two or more jets with transverse energy ET≥15 GeV and pseudorapidity |η|≤1.5. The heavy flavor content of the data set is enriched by requiring that at least one of the jets (lepton-jet) contains a lepton with a transverse momentum larger than 8 GeV/c. Jets containing hadrons with heavy flavor are selected via the identification of secondary vertices. The parton-level cross sections predicted by the HERWIG Monte Carlo generator program are tuned within theoretical and experimental uncertainties to reproduce the secondary-vertex rates in the data. The tuned simulation provides new information on the origin of the discrepancy between the bb̄ cross section measurements at the Tevatron and the next-to-leading order QCD prediction. We also compare the rate of away-jets (jets recoiling against the lepton-jet) containing a soft lepton (p T≥2 GeV/c) in the data to that in the tuned simulation. We find that this rate is larger than what is expected for the conventional production and semileptonic decay of pairs of hadrons with heavy flavor. © 2004 The American Physical Society.

Measurement of the B-meson inclusive semileptonic branching fraction and electron-energy moments

Physical Review D Particles Fields Gravitation and Cosmology 70:3 (2004)

Authors:

AH Mahmood, SE Csorna, G Bonvicini, D Cinabro, M Dubrovin, A Bornheim, E Lipeles, SP Pappas, A Shapiro, AJ Weinstein, RA Briere, GP Chen, T Ferguson, G Tatishvili, H Vogel, ME Watkins, NE Adam, JP Alexander, K Berkelman, V Boisvert, DG Cassel, JE Duboscq, KM Ecklund, R Ehrlich, RS Galik, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, L Hsu, CD Jones, J Kandaswamy, DL Kreinick, VE Kuznetsov, A Magerkurth, H Mahlke-Krüger, TO Meyer, JR Patterson, TK Pedlar, D Peterson, J Pivarski, D Riley, AJ Sadoff, H Schwarthoff, MR Shepherd, WM Sun, JG Thayer, D Urner, T Wilksen, M Weinberger, SB Athar, P Avery, L Breva-Newell, V Potlia, H Stoeck, J Yelton, BI Eisenstein, GD Gollin, I Karliner, N Lowrey, P Naik, C Sedlack, M Selen, JJ Thaler, J Williams, KW Edwards, D Besson, KY Gao, DT Gong, Y Kubota, SZ Li, R Poling, AW Scott, A Smith, CJ Stepaniak, J Urheim, Z Metreveli, KK Seth, A Tomaradze, P Zweber, J Ernst, K Arms, E Eckhart, KK Gan, C Gwon, H Severini, P Skubic, DM Asner, SA Dytman, S Mehrabyan, JA Mueller, S Nam, V Savinov, GS Huang, DH Miller, V Pavlunin, B Sanghi, EI Shibata, IPJ Shipsey

Abstract:

We report a new measurement of the B-meson semileptonic decay momentum spectrum that has been made with a sample of 9.4 [Formula Presented] of [Formula Presented] data collected with the CLEO II detector at the [Formula Presented] resonance. Electrons from primary semileptonic decays and secondary charm decays were separated by using charge and angular correlations in [Formula Presented] events with a high-momentum lepton and an additional electron. We determined the semileptonic branching fraction to be [Formula Presented] from the normalization of the electron-energy spectrum. We also measured the moments of the electron-energy spectrum with minimum energies from 0.6 to 1.5 GeV. © 2004 The American Physical Society.

Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Fermilab Tevatron

Physical Review D - Particles, Fields, Gravitation and Cosmology 69:1 (2004)

Authors:

D Acosta, T Affolder, H Akimoto, MG Albrow, D Ambrose, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, S Bailey, P Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Behari, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, J Berryhill, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, G Bolla, A Bolshov, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, C Bromberg, M Brozovic, E Brubaker, N Bruner, J Budagov, HS Budd, K Burkett, G Busetto, KL Byrum, S Cabrera, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, A Castro, D Cauz, A Cerri, L Cerrito, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, M Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, JY Chung, W Chung, YS Chung, CI Ciobanu, AG Clark, M Coca, A Connolly, M Convery, J Conway, M Cordelli, J Cranshaw, R Culbertson, D Dagenhart

Abstract:

We have measured the number of like-sign (LS) and opposite-sign (OS) lepton pairs arising from double semileptonic decays of b and [Formula Presented] hadrons, pair produced at the Fermilab Tevatron collider. The data samples were collected with the Collider Detector at Fermilab during the 1992–1995 collider run by triggering on the existence of [Formula Presented] or [Formula Presented] candidates in an event. The observed ratio of LS to OS dileptons leads to a measurement of the average time-integrated mixing probability of all produced b-flavored hadrons which decay weakly, [Formula Presented] that is significantly larger than the world average [Formula Presented] © 2004 The American Physical Society.

Moments of the B meson inclusive semileptonic decay rate using neutrino reconstruction

Physical Review D - Particles, Fields, Gravitation and Cosmology 70:3 (2004)

Authors:

SE Csorna, G Bonvicini, D Cinabro, M Dubrovin, A Bornheim, E Lipeles, SP Pappas, A Shapiro, AJ Weinstein, RA Briere, GP Chen, T Ferguson, G Tatishvili, H Vogel, ME Watkins, NE Adam, JP Alexander, K Berkelman, V Boisvert, DG Cassel, JE Duboscq, KM Ecklund, R Ehrlich, RS Galik, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, L Hsu, CD Jones, J Kandaswamy, DL Kreinick, VE Kuznetsov, A Magerkurth, H Mahlke-Krüger, TO Meyer, JR Patterson, TK Pedlar, D Peterson, J Pivarski, D Riley, AJ Sadoff, H Schwarthoff, MR Shepherd, WM Sun, JG Thayer, D Urner, T Wilksen, M Weinberger, SB Athar, P Avery, L Breva-Newell, V Potlia, H Stoeck, J Yelton, BI Eisenstein, GD Gollin, I Karliner, N Lowrey, P Naik, C Sedlack, M Selen, JJ Thaler, J Williams, KW Edwards, D Besson, KY Gao, DT Gong, Y Kubota, SZ Li, R Poling, AW Scott, A Smith, CJ Stepaniak, J Urheim, Z Metreveli, KK Seth, A Tomaradze, P Zweber, J Ernst, K Arms, E Eckhart, KK Gan, C Gwon, H Severini, P Skubic, DM Asner, SA Dytman, S Mehrabyan, JA Mueller, S Nam, V Savinov, GS Huang, DH Miller, V Pavlunin, B Sanghi, EI Shibata, IPJ Shipsey, GS Adams

Abstract:

We present a measurement of the composition of B meson inclusive semileptonic decays using 9.4 [Formula Presented] of [Formula Presented] data taken with the CLEO detector at the [Formula Presented] resonance. In addition to measuring the charged lepton kinematics, the neutrino four-vector is inferred using the hermiticity of the detector. We perform a maximum likelihood fit over the full three-dimensional differential decay distribution for the fractional contributions from the [Formula Presented] processes with [Formula Presented] [Formula Presented] [Formula Presented] and nonresonant [Formula Presented] and the process [Formula Presented] From the fit results we extract the first and second moments of the [Formula Presented] and [Formula Presented] distributions with minimum lepton-energy requirements of 1.0 GeV and 1.5 GeV. We find [Formula Presented] with a minimum lepton energy of 1.0 GeV and [Formula Presented] with minimum lepton energy of 1.5 GeV. The uncertainties are from statistics, detector systematic effects, and model dependence, respectively. As a test of the HQET and OPE calculations, the results for the [Formula Presented] moment as a function of the minimum lepton energy requirement are compared to the predictions. © 2004 The American Physical Society.

New measurements of Y(1S) decays to charmonium final states

Physical Review D - Particles, Fields, Gravitation and Cosmology 70:7 (2004)

Authors:

RA Briere, GP Chen, T Ferguson, G Tatishvili, H Vogel, ME Watkins, NE Adam, JP Alexander, K Berkelman, DG Cassel, JE Duboscq, KM Ecklund, R Ehrlich, L Fields, RS Galik, L Gibbons, B Gittelman, R Gray, SW Gray, DL Hartill, BK Heltsley, D Hertz, L Hsu, CD Jones, J Kandaswamy, DL Kreinick, VE Kuznetsov, H Mahlke-Krüger, TO Meyer, PUE Onyisi, JR Patterson, D Peterson, J Pivarski, D Riley, JL Rosner, A Ryd, AJ Sadoff, H Schwarthoff, MR Shepherd, WM Sun, JG Thayer, D Urner, T Wilksen, M Weinberger, SB Athar, P Avery, L Breva-Newell, R Patel, V Potlia, H Stoeck, J Yelton, P Rubin, BI Eisenstein, GD Gollin, I Karliner, D Kim, N Lowrey, P Naik, C Sedlack, M Selen, JJ Thaler, J Williams, J Wiss, KW Edwards, D Besson, KY Gao, DT Gong, Y Kubota, SZ Li, R Poling, AW Scott, A Smith, CJ Stepaniak, J Urheim, Z Metreveli, KK Seth, A Tomaradze, P Zweber, J Ernst, K Arms, KK Gan, H Severini, P Skubic, DM Asner, SA Dytman, S Mehrabyan, JA Mueller, V Savinov, Z Li, A Lopez, H Mendez, J Ramirez, GS Huang, DH Miller, V Pavlunin, B Sanghi, EI Shibata, IPJ Shipsey, GS Adams, M Chasse

Abstract:

Using data collected by the CLEO III detector at CESR, we report on measurements of Y(1S) decays to charmonium final states. The data sample used for this analysis consists of 21.2 × 106 Y(1S) decays, representing about 35 times more data than previous CLEO Y(1S) data samples. We present substantially improved measurements of the branching fraction B(Y(1S) → J/ψ + X) using J/ψ → μ+ μ- and J/ψ → e+ e- decays. The branching fractions for these two modes are averaged, thereby obtaining: B(Y(1S) → J/ψ + X) = (6.4 ± 0.4(stat) ± 0.6(syst)) × 10-4. A greatly improved measurement of the J/ø momentum distribution is presented and indicates a spectrum which is much softer than predicted by the color-octet model and somewhat softer than the color-singlet model. First measurements of the J/ψ polarization and production angle are also presented. In addition, we report on the first observation of Y(1S) → ψA(2S) + X and evidence for Y(1S) → χcJ + X. Their branching fractions are measured relative to B(Y(1S) → J/ψ + X) and are found to be {[B(Y(1S) → ψ(2S) + X)]/[B(Y(1S) → J/ψ + X)]} = 0.41 ± 0.11(stat) ± 0.08(syst), {[B(Y(1S) → χc1 + X)]/[B(Y(1S) → J/ψ + X)]} = 0.35 ± 0.08(stat) ± 0.06(syst), {[B(Y(1S) → χc2 + X)]/[B(Y(1S) → J/ψ + X)]} = 0.52 ± 0.12(stat) ± 0.09(syst), and {[B(Y(1S) → χc0 + X)]/[B(Y(1S) → J/ψ + X)]} < 7.4 at 90% confidence level. The resulting feed-down contributions to J/ψ are [24 ± 6(stat) ± 5(syst)]% for ψ(2S), [11 ± 3(stat) ± 2(syst)]% for χc1, [10 ± 2(stat) ± 2(syst)]% for χc2, and <8.2% at 90% confidence level for ψc0. These measurements (apart from χc0) are about a factor of 2 larger than expected based on the coloroctet model.