0000000000510963
AUTHOR
Pd Dauncey
showing 8 related works from this author
B* production in Z decays
1995
The decay B*→Bγ has been observed with the DELPHI detector at LEP, where the B* meson is produced in Z boson decays. The combination of inclusively reconstructed B mesons with well-measured converted photons yields a measurement of the flavour-averaged B*-B mass difference of 45.5±0.3 (stat.) ±0.8 (syst.) MeV/c2. 95% confidence level upper limits at 6 MeV/c2 are placed on both the isospin (i.e. B+-B0) and the Bs-Bud splitting of the mass difference. The production ratio of B* to B mesons in Z decays is measured to be 0.72±0.03 (stat.) ±0.06 (syst.). Limits on the production cross-section of other hypothetical excited B hadron states decaying radiatively are established. The differential B* …
Measurement of Semileptonic B Decays into Orbitally Excited Charmed Mesons
2009
We present a study of B decays into semileptonic final states containing charged and neutral D-1(2420) and D-2*(2460). The analysis is based on a data sample of 208 fb(-1) collected at the Y(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. With a simultaneous fit to four different decay chains, the semileptonic branching fractions are extracted from measurements of the mass difference Delta m = m(D**) - m(D) distribution. Product branching fractions are determined to be B(B+ -> D(1)(0)l(+)nu(l)) x B(D-1(0) -> D*+pi(-)) = (2.97 +/- 0.17 +/- 0.17) x 10(-3), B(B+ -> D-2*l(+)nu(e)) x B(D-2*(0) -> D(*)+pi(-)) = (2.29 +/- 0.23 +/- 0.21) x 10(-3), B(B-0 -> D…
Rates, polarizations, and asymmetries in charmless vector-vector B meson decays
2003
With a sample of approximately 89 million BBbar pairs collected with the BABAR detector, we perform a search for B meson decays into pairs of charmless vector mesons (phi, rho, and K*). We measure the branching fractions, determine the degree of longitudinal polarization, and search for CP violation asymmetries in the processes B->phiK*+, B->phiK*0, B->rho0K*+, and B->rho0rho+. We also set an upper limit on the branching fraction for the decay B->rho0rho0.
Improved limits on the lepton-flavor violating decays tau(-) -> l(-)l(+)l(-)
2007
A search for the neutrinoless, lepton-flavor violating decay of the tau lepton into three charged leptons has been performed using 376fb-1 of data collected at an e+e- center-of-mass energy around 10.58 GeV with the BABAR detector at the SLAC PEP-II storage rings. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (4-8)×10-8 at 90% confidence level. © 2007 The American Physical Society.
Lifetime of Charged and Neutral B-hadrons Using Event Topology
1995
The lifetimes of charged and neutral B hadrons have been measured using data collected by the DELPHI experiment at LEP between 1991 and 1993. B hadrons are tagged as jets with a secondary vertex and the charge of the B candidate is taken to be the sum of the charges of the particles in the secondary vertex. Approximately 1,434,000 multihadronic \PZz decays yielded 1817 B hadron candidates. The B purity was estimated to be around 99.1\pm0.3\%, and 83\% (70\%) of the events measured as neutral (charged) came from neutral (charged) B's. The mean lifetimes of charged and neutral B hadrons were found to be \TAUBC\pm\ERRBC\;(stat.)\pm\SYSBC\;(syst.)~ps and \TAUBN\pm\ERRBN\;(stat.)\pm\SYSBN\;(syst…
Search for neutral and charged Higgs bosons in $e^+ e^-$ collisions at $\sqrt{s}$= 161 GeV and 172 GeV
1998
A search for neutral and charged Higgs bosons has been performed in the data collected by the {\sc DELPHI} detector at centre-of-mass energies of 161~GeV and 172~GeV. The analysis assumes either the pair-production of charged Higgs bosons, ${\mathrm H}^{\pm}$, or the production of the lightest neutral Higgs boson, h, with either a Z or a neutral pseudoscalar Higgs boson, A. All final state topologies expected from the decay of h and A %neutral Higgs particles into hadrons or a pair of $\tau$ leptons, and from the decay of ${\mathrm H}^{\pm}$ %charged Higgs bosons into a pair of quarks or a $\tau \nu_{\tau}$ pair have been considered. %In the case of the associated production with a Z boson,…
Measurement of the semileptonic branching fraction of the B_{s} meson
2012
We report a measurement of the inclusive semileptonic branching fraction of the B_s meson using data collected with the BaBar detector in the center-of-mass (CM) energy region above the Upsilon(4S) resonance. We use the inclusive yield of phi mesons and the phi yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B_s mesons relative to all B mesons as a function of CM energy. The inclusive semileptonic branching fraction of the B_s meson is determined to be B(B_s to l nu X)=9.5 (+2.5/-2.0)(stat)(+1.1/-1.9)(syst)%, where l indicates the average of e and mu.
Searches for B0 decays to combinations of charmless isoscalar mesons
2004
We search for B meson decays into two-body combinations of eta, eta', omega, and phi mesons from 89 million B B-bar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find the branching fraction BF(B0 -> eta omega) = (4.0^{+1.3}_{-1.2} +- 0.4) x 10^-6 with a significance of 4.3 sigma. For all the other decay modes we set the following 90% confidence level upper limits on the branching fractions, in units of 10^-6 : BF(B0 -> eta eta)<2.8, BF(B0 -> eta eta')<4.6, BF(B0 -> eta' eta')<10, BF(B0 -> eta'omega)<2.8, BF(B0 -> eta phi)<1.0, BF(B0 -> eta' phi)<4.5, BF(B0 -> phi phi)<1.5.