A Measurement of the B Quark Fragmentation Function at (square Root)Q2
A Measurement of the B Quark Fragmentation Function at (square Root)Q2

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Published: 1996

Total Pages: 151

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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).

A Preliminary Measurement of the B Quark Fragmentation Function in Hadronic Z° Decays
A Preliminary Measurement of the B Quark Fragmentation Function in Hadronic Z° Decays

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Published: 1996

Total Pages: 32

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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).

A Measurement of B-quark Fragmentation Fractions in P¢p Collisions at [centre of Mass Energy]
A Measurement of B-quark Fragmentation Fractions in P¢p Collisions at [centre of Mass Energy]

Author: Wendy Jane Taylor

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Published: 1999

Total Pages: 0

ISBN-13:

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Fragmentation is the process by which quarks and gluons organize themselves into hadrons. The fragmentation properties of the bottom quark cannot be predicted from fundamental principles and hence must be determined empirically. We investigate one such property, namely the flavour dependence of the fragmentation process for bottom quarks produced in 1.8-TeV proton-antiproton collisions. This flavour dependence is investigated by determining the 'B'-hadron production ratios. We use a sample of pp data corresponding to an integrated luminosity of 110 pb-1 and reconstruct the following semileptonic 'B'-hadron decays into electrons and charmed hadrons: B+[right arrow]e+neD 0X,hsp sp="0.265"B0[right arrow]e+n eD*-X , B0[right arrow]e+neD- X,hsp sp="0.265"B0s[right arrow]e +neD-s X and L0b [right arrow]e+neL- cX . With these data, we measure the ratios of fragmentation fractions fd/fuvmk id="vm1"=88± 21%, fs/fu+fdvmkr rid="vm1"= 21.5±7.1%hsp sp="0.265"and fbaryon/fu+fd vmkr rid="vm1"=12.0±4.2%. Assuming that these four hadrons saturate production of weakly-decaying ' B' hadrons, that is, that fu+fd+fs+fbaryon 1 , we determine fuvmk id="vm1"=39.8±5.4 %, fdvmkr rid="vm1"=35.2±4.8 %, fsvmkr rid="vm1"=16.1±4.5 %hsp sp="0.265"and fbaryonvmkr rid="vm1"=9.0± 2.9%. These results represent the first measurement of all four 'b'-quark fragmentation fractions in a single experiment. These fractions are in agreement both with previous phenomenological interpretations and with other experimental measurements.

Measurement of the Doubly Inclusive B-bbar Quark Fragmentation Function in Z0 Decays and First Measurement of Angle Dependent B-Bbar Energy Correlation
Measurement of the Doubly Inclusive B-bbar Quark Fragmentation Function in Z0 Decays and First Measurement of Angle Dependent B-Bbar Energy Correlation

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Published: 2002

Total Pages: 5

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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.