Download or read book Precise Measurement of the B quark Fragmentation Function in Z Boson Decays written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have developed a new technique for inclusive reconstruction of the energy of B hadrons. The excellent efficiency and resolution of this technique allow them to make the most precise determination of the b-quark fragmentation function, using ee− {r{underscore}arrow} Z° decays recorded in the SLD experiment at SLAC. The authors compared their measurement with the predictions of a number of fragmentation models. The authors excluded several of these models and measured the average scaled energy of weakly-decaying B hadrons to be (x{sub B}) = 0.714"0.005(stat)"0.007(syst)"0.002 (model-dependence).

Download or read book An Improved Measurement of the B Quark Fragmentation Function in Z Decays at SLD written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary results of a new measurement of the b quark fragmentation function in Z° decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 150,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1996 and 1997. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measure the B energy with good efficiency and resolution over the full kinematic range. We compare the scale B hadron energy distribution with several functional forms of the B hadron energy distribution and predictions of several models of b quark fragmentation. Several functions including JETSET + Peterson are excluded by the data. The average scaled energy of the weakly decaying B hadron is measured to be x{sub B} = 0.719 " 0.005 (stat) " 0.007 (syst) " 0.001 (model) (preliminary).

Download or read book Measurement of the B Quark Fragmentation Function in Z Decays written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present results of a new measurement of the inclusive b quark fragmentation function in Z decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 150,000 hadronic Z events recorded in the SLD experiment at SLAC between 1996 and 1997. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. The authors measure the B energy with good efficiency and resolution over the full kinematic range. While comparing the scaled B energy distribution with predictions of several models of b quark fragmentation, the authors also test several functional forms of the B energy distribution. Several fragmentation models and functional forms are excluded by the data. The mean of the scaled energy distribution of the weakly decaying B hadron is measured to be x{sub B} = 0.714"0.00(stat)"0.007(syst)"0.002 (model).

Download or read book Measurement of the B Quark Fragmentation Function in Z0 Decays written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the b-quark inclusive fragmentation function in Z° decays using a novel kinematic B-hadron energy reconstruction technique. The measurement was performed using 350,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1997 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector were used to reconstruct B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measured the B energy with good efficiency and resolution over the full kinematic range. We compared the scaled B-hadron energy distribution with models of b-quark fragmentation and with several ad hoc functional forms. A number of models and functions are excluded by the data. The average scaled energy of weakly-decaying B hadrons was measured to be x{sub b} = 0.709 " 0.003 (stat) " 0.003 (syst) " 0.002 (model).

Download or read book Improved Measurement of the B quark Fragmentation Function in Z0 Decays written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present preliminary results of an improved measurement of the inclusive b quark fragmentation function in Z0 decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 350,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1997 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. They measure the B energy with good efficiency and resolution over the full kinematic range. They compare the measured scaled B hadron energy distribution with predictions of several models of b quark fragmentation and several functional forms of the B hadron energy distribution. Many of these are excluded by the data. The average scaled energy of the weakly decaying B hadron is measured to be x{sub B} = 0.710 " 0.003 (stat) " 0.005 (syst) " 0.004 (model) (preliminary).

Download or read book Measurement of the B Quark Fragmentation Function in Z0 Decays written by Danning Dong and published by . This book was released on 2000 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of Bottom Quark Production in Z Boson Hadronic Decays written by J. Coller and published by . This book was released on 2003 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: A precise measurement of R{sub b}, the fraction of hadronic decays of the Z{sup 0} boson into bottom quark pairs, will test the Standard Model of particle physics. By measuring R{sub b}, the coupling between the Z{sup 0} boson and bottom quarks can be investigated. The strength of this coupling is sensitive to the top quark mass and to physics which lies outside the Standard Model. This thesis presents a measurement of R{sub b} made at the Stanford Linear Accelerator Center with the SLD experiment. Approximately 196,000 hadronic events are used in the measurement. The data set was obtained during the 1997-98 SLD physics run. The selection of B hadrons for identifying Z{sup 0} {yields} b{bar b} events is based on the invariant mass of topologically reconstructed vertices separated from the primary vertex for the event. This reconstruction method identifies B hadrons with a high efficiency (49.9%) and high purity (98.0%). Each candidate Z{sup 0} {yields} b{bar b} event is split into two separate hemispheres which are analyzed independently. The efficiency for tagging B hadrons is extracted from the data, reducing the dependence on the Monte Carlo simulation for B hadron and b quark systematic errors. A measured result of R{sub b} = 0.2185 {+-} 0.0013{sub (stat)} {+-} 0.0022{sub (syst.)} is reported. This value is consistent within measurement errors with the Standard Model prediction of 0.2158. The significant of this measurement is discussed.

Download or read book A Preliminary Measurement of the B Quark Fragmentation Function in Hadronic Z Decays written by and published by . This book was released on 1996 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the {ital b} quark fragmentation function from a sample of semi-leptonic {bold B} decays collected between 1993 and 1995 in the SLD experiment at SLAC. The energy of each tagged {bold B} hadron was reconstructed using information from the lepton and a partially reconstructed charm decay vertex. A comparison of the scaled energy distribution with several phenomenological models of heavy quark fragmentation was made, using the same model in each case to correct the data. The average scaled energy was found to be {l_angle}[chi]{sub E}{r_angle} = 0.697±0.012({ital stat}){sup +0. 028}{sub -0.024} ({ital syst})(preliminary).

Download or read book Measurement of the B Quark Fragmentation Function in Z0 Decays and First Measurement of B Bbar Energy Correlations written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary results of a new measurement of the inclusive b quark fragmentation function in Z° decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 350,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1997 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measure the B energy with good efficiency and resolution over the full kinematic range. We compare the measured scaled B hadron energy distribution with several functional forms of the B hadron energy distribution and predictions of several models of b quark fragmentation. Several functions are excluded by the data. The average scaled energy of the weakly decaying B hadron is measured to be x{sub B} = 0.710 " 0.003 (stat) " 0.005 (syst) " 0.004 (model) (preliminary). In addition, we reconstruct the decay vertices of both the leading B and hadrons in a large sample of events, and measure their energies. We present the first (preliminary) measurement of the correlation between the B and energies in Z° --> b{bar b} events, and compare with the leading order QCD prediction.

Download or read book A Preliminary Measurement of the B Quark Fragmentation Function in Hadronic Z sup 0 Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the[ital b] quark fragmentation function from a sample of semi-leptonic[bold B] decays collected between 1993 and 1995 in the SLD experiment at SLAC. The energy of each tagged[bold B] hadron was reconstructed using information from the lepton and a partially reconstructed charm decay vertex. A comparison of the scaled energy distribution with several phenomenological models of heavy quark fragmentation was made, using the same model in each case to correct the data. The average scaled energy was found to be[l-angle][chi][sub E][r-angle]= 0.697[+-]0.012([ital stat])[sup+0. 028][sub -0.024] ([ital syst])(preliminary).

Download or read book A Measurement of the Branching Ratio of the Z Boson to Bottom Quarks Using Precision Tracking written by Robert Gibbs Jacobsen and published by . This book was released on 1991 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of the B Quark Fragmentation Function at square Root Q2 written by and published by . This book was released on 1996 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented here is a measurement of the b quark fragmentation function D{sub b}(X), taken from a sample of 504 semi-leptonic B decays which were selected from the 150,000 Z° decays collected between 1993 and 1995 at the SLD at SLAC. The energy of each tagged B hadron is reconstructed using missing jet energy, based on the information from the lepton and a partially-reconstructed charm-decay vertex. Account is taken of the effect of primary orbitally excited mesons (B**s). An iterative unfolding procedure is used which serves to effectively extract the true fragmentation function from the reconstructed B energy spectrum. The final result is shown to be compatible with many theoretical models. A comparison is made with other b fragmentation function measurements at 45.6 GeV, and this measurement is shown to be consistent with those results. The average scaled energy is found to be (x{sub E}) = 0.697" 0.017(stat) " 0.034(sys).

Download or read book Measurement of the Doubly Inclusive B bbar Quark Fragmentation Function in Z0 Decays and First Measurement of Angle Dependent B Bbar Energy Correlation written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary results of a measurement of the double-inclusive b quark fragmentation function in Z° decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 350,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1996 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measure the B energy with good efficiency and resolution over the full kinematic range. We present a preliminary measurement of the angle dependent correlations between the B and {bar B} hadron energies in Z° b{bar b} events, and compare with the leading order QCD predictions.

Download or read book Measurement of the Z Boson Branching Fraction Into Hadrons Containing Bottom Quarks written by J. Frederic Kral and published by . This book was released on 1990 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Preliminary Improved Measurement of the B Hadron Energy Distribution in Z Decays written by and published by . This book was released on 1998 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured the B hadron energy distribution in Z° decays using a new technique applied to a sample of inclusive B decays recorded in the SLD experiment at SLAC between 1996 and 1997. The upgraded CCD vertex detector is used to reconstruct B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. For each reconstructed B-decay vertex, the part of the B energy missing from the vertex is derived from the kinematic quantities. B vertices with low missing mass are selected to provide a very high purity sample and to obtain good energy resolution. The authors compare the scaled B hadron energy distribution with the predictions of several QCD and phenomenological models of heavy quark fragmentation. The average scaled energy x{sub B} is measured to be 0.719"0.005 (stat.)"0.001 (unfolding) (preliminary).

Download or read book A Measurement of Bottom Quark Production in Z Boson Hadronic Decays written by John A. Coller and published by . This book was released on 2000 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Z boson Branching Fraction Into Hadrons Containing Bottom Quarks written by and published by . This book was released on 1990 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: We use the Mark II detector to study Z decays into bottom quark-anti-quark pairs, leading to the production of bottom hadrons. The Z bosons are formed in ee− annihilation at the SLC at center-of-mass energies between 89 and 93 GeV. We identify events containing semileptonic decays of bottom hadrons by detecting isolated leptons, i.e leptons with high transverse momenta relative to the nearest hadronic jet. Using isolated electrons and muons, we measure the B-hadron semileptonic branching ratio times the fraction of hadronic Z decays which contain bottom hadrons, B(B 2!Xl[nu]){center dot}[Gamma](Z 2!b{bar b})/[Gamma](Z 2!had) = 0.025 {sub -0.009}{sup +0.100} {plus minus} 0.005, where we have listed the statistical errors followed by the systematic error. Assuming B(B 2!X(ell)[nu]) = 11% {plus minus} 1%, we measure [Gamma](Z 2!b{bar b})/[Gamma](Z 2!had) = 0.23 {sub -0.09}{sup +0.11}, in good agreement with the standard-model prediction of 0.22. We find [Gamma](Z 2!b{bar b}) = 0.40 {sub -0.16}{sup +0.19} GeV. 83 refs., 34 figs., 19 tabs.