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Title: Measurement of the Probability for Gluon Splitting into b{bar b} in Z{sup 0} Decays

Abstract

We present a preliminary measurement of the rate of gluon splitting into bottom quarks, g {r_arrow} b{bar b}, in hadronic Z{sup 0} decays collected by SLD between 1996 and 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary flavor. 4-jet events were identified, and a topological vertex-mass technique was applied to each jet in order to identify b or {bar b} jets. The upgraded CCD based vertex detector gives very high B-tagging efficiency, especially for B hadrons of the low energies typical of this process. The two most nearly collinear b/{bar b} jets were tagged as originating from g {r_arrow} b{bar b}. We measured the rate of secondary b/{bar b} production per hadronic event, g{sub b{bar b}}, to be (3.07 {+-} 0.71(stat.) {+-} 0.66(syst.)) x 10{sup {minus}3} (preliminary).

Authors:
Publication Date:
Research Org.:
Stanford Linear Accelerator Center, Menlo Park, CA (US)
Sponsoring Org.:
USDOE Office of Energy Research (ER) (US)
OSTI Identifier:
10087
Report Number(s):
SLAC-PUB-8157
TRN: US0103349
DOE Contract Number:
AC03-76SF00515
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 9 Jul 1999
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; EFFICIENCY; GLUONS; HADRONIC PARTICLE DECAY; PROBABILITY; PARTICLE PRODUCTION; B QUARKS; Z NEUTRAL BOSONS; B MESONS

Citation Formats

Muller, David. Measurement of the Probability for Gluon Splitting into b{bar b} in Z{sup 0} Decays. United States: N. p., 1999. Web. doi:10.2172/10087.
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Muller, David. Measurement of the Probability for Gluon Splitting into b{bar b} in Z{sup 0} Decays. United States. doi:10.2172/10087.
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Muller, David. Fri . "Measurement of the Probability for Gluon Splitting into b{bar b} in Z{sup 0} Decays". United States. doi:10.2172/10087. https://www.osti.gov/servlets/purl/10087.
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@article{osti_10087,
title = {Measurement of the Probability for Gluon Splitting into b{bar b} in Z{sup 0} Decays},
author = {Muller, David},
abstractNote = {We present a preliminary measurement of the rate of gluon splitting into bottom quarks, g {r_arrow} b{bar b}, in hadronic Z{sup 0} decays collected by SLD between 1996 and 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary flavor. 4-jet events were identified, and a topological vertex-mass technique was applied to each jet in order to identify b or {bar b} jets. The upgraded CCD based vertex detector gives very high B-tagging efficiency, especially for B hadrons of the low energies typical of this process. The two most nearly collinear b/{bar b} jets were tagged as originating from g {r_arrow} b{bar b}. We measured the rate of secondary b/{bar b} production per hadronic event, g{sub b{bar b}}, to be (3.07 {+-} 0.71(stat.) {+-} 0.66(syst.)) x 10{sup {minus}3} (preliminary).},
doi = {10.2172/10087},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jul 09 00:00:00 EDT 1999},
month = {Fri Jul 09 00:00:00 EDT 1999}
}
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Technical Report:
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DOI:  10.2172/10087
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  • The authors present a preliminary measurement of the rate of gluon splitting into bottom quarks, g --> b anti-b, in hadronic Z{sup 0} decays collected by SLD between 1996 and 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary flavor. 4-jet events were identified, and a topological vertex-mass technique was applied to each jet in order to identify b or anti-b jets. The upgraded CCD based vertex detector gives very high B-tagging efficiency, especially for B hadrons of the low energies typical of this process. The two most nearly collinear b/anti-b jetsmore » were tagged as originating from g --> b anti-b. They measured the rate of secondary b/anti-b production per hadronic event, g{sub b/anti-b}, to be (2.84{+-}0.61(stat.){+-}0.59(syst.))xx 10{sup {minus}3} (preliminary).« less

  • The B{sup 0} meson decay modes B{sup 0} --> D*{sup -}p{bar p}{pi}{sup +}, D{sup -}p{bar p}{sup +}, {bar D}*{sup 0}p{bar p}, and B{sup 0} --> {bar D}{sup 0}p{bar p} are studied in a sample of 124 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II collider. The decay of B{sup 0} --> D{sup -}p{bar p}{pi}{sup +} is observed for the first time, with a measured branching fraction B(B{sup 0} --> D{sup -}p{bar p}{pi}{sup +}) = (3.80 {+-} 0.35 {+-} 0.46) x 10{sup -4}. The following branching fractions are also determined: B(B{sup 0} --> D*{sup -}p{barmore » p}{pi}{sup +}) = (5.61 {+-} 0.59 {+-} 0.73) x 10{sup -4}, B(B{sup 0} --> {bar D}*{sup 0} p{bar p}) = (0.67 {+-} 0.21 {+-} 0.09) x 10{sup -4}, and B(B{sup 0} --> {bar D}{sup 0}p{bar p}) = (1.24 {+-} 0.14 {+-} 0.12) x 10{sup -4}. In each decay mode the invariant mass spectra of the charmed mesons and the baryons are compared with a pure phase-space hypothesis in order to gain insight into the B meson decay dynamics. In particular, the Dalitz plots of {bar D}*{sup 0}p versus {bar D}*{sup 0}{bar p} for B{sup 0} --> {bar D}*{sup 0}p{bar p} and of {bar D}{sup 0}p versus {bar D}{sup 0}{bar p} for B{sup 0} --> {bar D}{sup 0}p{bar p} are presented. All results are preliminary.« less

  • The authors present a simultaneous measurement of the {bar B}{sup 0} lifetime {tau}(B{sup 0}) and mixing parameter {Delta}m{sub d}. They use a sample of about 50000 {bar B}{sup 0} --> D*{sup +} 1 {anti {nu}}(l) partially reconstructed decays identified with the BABAR detector at the PEP-II storage ring at SLAC, where the flavor of the other B meson is determined from the charge of another high momentum lepton in the same event. The preliminary results are: tau(B{sup 0}) = (1.50 {+-} 0.008(stat.) {+-} 0.030(syst.)) ps, {Delta}m{sub d} = (0.523 {+-} 0.004(stat.) {+-} 0.007(syst.)) p{sup s}(-1).

  • We present a measurement of the rate of gluon splitting into bottom quarks, g --> b anti-b, in hadronic Z 0 decays collected by SLD from 1996 to 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary avor. A topological vertex mass technique was used to tag the two jets with the smallest angle between them as b/anti-b. We obtained a rate of g --> b anti-b per hadronic event to be (3.07 ± 0.71(stat:) ± 0.66(syst:)) × 10³ (preliminary).

  • We present a measurement of the rate of gluon splitting into bottom quarks, g --> b anti-b, in hadronic Z 0 decays collected by SLD from 1996 to 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary avor. A topological vertex mass technique was used to tag the two jets with the smallest angle between them as b/anti-b. We obtained a rate of g --> b anti-b per hadronic event to be (3.07 0.71(stat:) 0.66(syst:)) 10 sup3; (preliminary).