arXiv subjects

Danning Dong

Publications and source records attributed to Danning Dong.

2 recordsLinked to original sources

arXiv1999

An Improved Measurement of the b Quark Fragmentation Function in Z0 Decays

We present a new preliminary measurement of the b quark fragmentation function in Z0 decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 150,000 hadronic Z0 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 scaled B hadron energy distribution with several functional forms of the B hadron energy distribution and 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 XB = 0.719 +/- 0.005 (stat) +/- 0.007 (syst) +/- 0.001 (model) (preliminary).

hep-ex↗

arXiv1999

Tests of QCD using Heavy Flavors at SLD

We present preliminary results on three SLD analyses: the gluon energy spectrum in 3-jet bbg events, the rate of g->bb, and the b fragmentation function in Z0 decays. The gluon energy spectrum, measured over the full kinematic range, is compared with perturbative QCD predictions. We set new 95% C.L. limits on the anomalous chromomagnetic coupling of the b quark: -0.09 bb is measured to be (3.07 +/- 0.71(stat) +/- 0.66(syst)) X 10^-3. The inclusive B hadron energy distribution in Z0 decays is measured for the first time over the full kinematic range, using a novel B hadron energy reconstruction technique. Several models of b fragmentation including JETSET + Peterson are excluded by the data. The average scaled B hadron energy of the weakly decaying B hadron is measured to be XB = 0.713 +/- 0.005(stat) +/- 0.007(syst) +/- 0.002 (model). All three measurements take advantage of the small and stable SLC interaction point as well as the excellent vertexing and tracking capabilities of the upgraded CCD-pixel vertex detector.

hep-ex↗