105 research outputs found
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV
The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3
magnetic muon spectrometer for zenith angles ranging from 0 degree to 58
degree. Due to the large exposure of about 150 m2 sr d, and the excellent
momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in
the vertical direction is achieved.
The ratio of positive to negative muons is studied between 20 GeV and 500
GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003
(stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure
EuFeAs under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility and resistivity
measurements of EuFeAs under high pressure . By observing nearly
100% superconducting shielding and zero resistivity at = 28 kbar, we
establish that -induced superconductivity occurs at ~30 K in
EuFeAs. shows an anomalous nearly linear temperature dependence
from room temperature down to at the same . indicates that
an antiferromagnetic order of Eu moments with ~20 K persists
in the superconducting phase. The temperature dependence of the upper critical
field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.
Restructured fish product from white croacker (Micropogonias furnieri) mince using microbial transglutaminas
This study aimed at determining the influence of three concentrations of commercial transglutaminase enzyme in restructured fillet of minced fish from white croacker (Micropogonias furnieri), one of the four marine species with notability in Brazil. The restructured fillet developed had advantages when compared to traditional fillet, such as absence of spine and less flavour intensity (washes cycles). Washing process for white croacker mince was compared with five clarification agents: water (control), phosphoric acid (H3PO4), sodium chloride (NaCl), calcium carbonate (CaCO3) and sodium bicarbonate (NaHCO3). The higher quality product (whiteness) was obtained with calcium carbonate washes. Three concentrations (1.5, 1.0 and 0.5%) of microbial transglutaminase MGTase (Active TG-B %v/v and Active TG-BP %w/w) were compared, in order to produce fish restructured product (boneless fillet). The concentration of 1.5% (both enzymes), produced better results. The restructured products were compared by sensory analysis and showed better sensory parameters (appearance, odour, flavour and texture) samples treated with Active TG-B (solution form).<br>Este estudo teve como objetivo determinar a influência de três concentrações de enzima transglutaminase comercial em filés reestruturado a partir de polpa de corvina (Micropogonias furnieri), uma das quatro espécies marinhas notáveis no Brasil. O filé reestruturado desenvolvido tem vantagens quando comparado aos filés tradicionais, tais como, a ausência da espinhas e sabor menos intenso (ciclos de lavagens). O processo de lavagem da polpa de corvina foi comparado com cinco agentes clarificantes: água (controle), ácido fosfórico (H3PO4), cloreto de sódio (NaCl), carbonato de cálcio (CaCO3) e bicarbonato de sódio (NaHCO3). O produto de qualidade superior (mais branco) foi obtido com a lavagem com carbonato de cálcio. Três concentrações (1,5%, 1,0% e 0,5%) de transglutaminase microbiana (Activa TG-B % v/v e Activa TG-BP % p/p) foram comparadas a fim de produzir o produto reestruturado (filé sem espinha). A concentração de 1,5% (ambas as enzimas) produziu melhores resultados. Os produtos reestruturados foram comparados através de análise sensorial, e apresentaram melhores parâmetros sensoriais (aparência, odor, sabor e textura), as amostras tratadas com Activa TG-B (forma de solução)
The BaBar detector: Upgrades, operation and performance
Contains fulltext :
121729.pdf (preprint version ) (Open Access
First measurement of the double inclusive B / anti-B hadron energy distribution in e+ e- annihilations, and of angle dependent moments of the B and anti-B energies
We have made the first measurement of the double-inclusive B/Bbar energy
distribution in e+e- annihilations, using a sample of 400,000 hadronic Z0 decay
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 were used to
reconstruct B/Bbar decay vertices with high efficiency and purity, and to
provide measurements of the kinematic quantities used to calculate the B
energies in this novel technique. We measured the B/Bbar energies with good
efficiency and resolution over the full kinematic range. We measured moments of
the scaled energies of the B and Bbar hadrons vs. the opening angle between
them. By comparing these results with perturbative QCD predictions we tested
the ansatz of factorisation in heavy-quark production. A recent next-to-leading
order calculation reproduces the data.Comment: 17 pages, 6 figures; submitted to Physics Letters
Factorial and cumulant moments in e+ e- ---> hadrons at the Z0 resonance
We present the first experimental study of the ratio of cumulant to factorial
moments of the charged-particle multiplicity distribution in high-energy
particle interactions, using hadronic Z decays collected by the SLD
experiment at SLAC. We find that this ratio, as a function of the moment-rank
, decreases sharply to a negative minimum at , which is followed by
quasi-oscillations. These features are insensitive to experimental systematic
effects and are in qualitative agreement with expectations from
next-to-next-to-leading-order perturbative QCD.Comment: 13 pages, latex file, uuencoded eps figure
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