4,291 research outputs found
The Semileptonic Decay Fraction of B Mesons in the Light of Interfering Amplitudes
Consequences of the interference between spectator amplitudes for the
lifetimes and semileptonic decay fractions of B^0 and B^+ mesons are discussed.
Assuming duality and constructive interference between spectator amplitudes we
are able to explain the low experimental value for the semileptonic decay
fraction of mesons. Extracting these amplitudes from a fit to 11 exclusive
hadronic B decay fractions we find
a_1 = 1.05 +/- 0.03 +/- 0.10,
a_2 =+0.227 +/ 0.012 +/- 0.022,
an inclusive semileptonic decay fraction of
(11.2 +/- 0.5 +/- 1.7),
and a lifetime ratio
tau(B^+) / tau(B^0) = 0.83 +/- 0.01 +/- 0.01.Comment: 9 page
The ARGUS Vertex Trigger
A fast second level trigger has been developed for the ARGUS experiment which
recognizes tracks originating from the interaction region. The processor
compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks
stored in random access memories. The masks which are fully defined in three
dimensions are able to reject tracks originating in the wall of the narrow
beampipe of 10.5\,mm radius.Comment: gzipped Postscript, 27 page
Forward-backward and CP-violating asymmetries in rare B_{d,s}\to (V,\gamma) l^+l^- decays
We study the forward-backward and the CP-violating asymmetries (both
time-independent and time-dependent) in rare semileptonic , , and radiative leptonic
decays and investigate the sensitivity of these asymmetries to the extensions
of the Standard model.Comment: Revised version: plots for A_CP corrected, discussion of B_d\to
\rho^0 l^+l^- adde
Pengaruh Latihan Loncat Tali Terhadap Daya Tahan Dalam Permainan Badminton Pada Club Riau Televisi Pekanbaru
The research problem is the Effect of jump rope exercises against resistance in the game of badminton at the club RTV pekanbaru. His goal to find out how much influence the relationship jump rope and endurance capabilities of individuals and groups. This research technique using total sampling with a sample of 10 athletes badminton RTV Pekanbaru. This study uses correlation techniques. Then, the test data using the normality test, the test product moment correlation, significant test α = 0:05. Normality test variable X, L0maks (0.2064) <Ltabel (0.258), and the normality test variable Y, L0maks (0.2015) <Ltabel (0.258) in other words 95% confidence level of normal data and conclusions of research shows: where there is a significant relationship between the effect of jump rope and endurance capabilities, Similarly, Ho is rejected and Ha accepted
Penghilangan Mikroorganisme Dalam Air Minum Dengan Dielectric Barrier Discharge
Microorganisms such as Escherichia coli in water are a component that is difficult to remove in conventional water treatment systems. Several systems have been implemented to reduce levels of microorganisms is the use of disinfectants, the membrane filtration and activated carbon absorption. These systems have several weaknesses, so that not all microorganisms can be removed from drinking water. The plasma system is an applicable technology for removing organic compounds and microorganisms in drinking water. By creating plasma in water will produce several of active species such as OH-, H+, O3 and H2O2 that has a high oxidation potential, decompose organic compounds and kill microorganisms in the water significantly. This paper will describe the removal of microorganisms in drinking water using a plasma system by the method of dielectric barrier discharge (DBD ). The results howed that the pH of drinking water produced in the range 6.5 to 7.3. The higher voltage causes the higher the conductivity, temperature and ORP water. Removal efficiency for the content of microorganisms Coli Fecal and Coliform in the range 99.2 to 100% after water was injected voltage of 13-17 kV for 10 minutes
Measurement of exclusive production of scalar meson in proton-(anti)proton collisions via decay
We consider a measurement of exclusive production of scalar
meson in the proton-proton collisions at LHC and RHIC and in
the proton-antiproton collisions at the Tevatron via decay. The corresponding amplitude for exclusive
double-diffractive meson production was obtained within the
-factorization approach including virtualities of active gluons and the
corresponding cross section is calculated with unintegrated gluon distribution
functions (UGDFs) known from the literature. The four-body reaction constitutes an irreducible background to the exclusive
meson production. We calculate several differential distributions
for process including absorptive
corrections. The influence of kinematical cuts on the signal-to-background
ratio is investigated. Corresponding experimental consequences are discussed.Comment: 16 pages, 10 figures, 2 table
Determination of the Michel Parameters rho, xi, and delta in tau-Lepton Decays with tau --> rho nu Tags
Using the ARGUS detector at the storage ring DORIS II, we have
measured the Michel parameters , , and for
decays in -pair events produced at
center of mass energies in the region of the resonances. Using
as spin analyzing tags, we find , , , , and . In addition, we report
the combined ARGUS results on , , and using this work
und previous measurements.Comment: 10 pages, well formatted postscript can be found at
http://pktw06.phy.tu-dresden.de/iktp/pub/desy97-194.p
Application of Al-Cu-W-Ta graded density impactors in dynamic ramp compression experiments
Graded density impactors (GDIs) are used to dynamically compress materials to extreme conditions. Two modifications to a previously developed Mg-Cu-W GDI are made in this work before using it in a dynamic compression experiment: Mg is replaced with Al and a Ta disk is glued to the back. The Mg phase is replaced by Al because FCC Al remains solid to higher pressure along its Hugoniot compared to Mg. The addition of the Ta disk creates a constant particle velocity regime and facilitates a definition of peak pressure states. Microstructure analysis, profilometry, and ultrasonic C-scans of the Al-Cu-W GDI all confirm excellent uniformity. We evaluated signal variation in the radial direction of a dynamically compressed Al-LiF bilayer target to evaluate the contribution of spatial nonuniformity to errors. Velocity traces from five photon Doppler velocimetry (PDV) probes located at different radial distances from the center of the target varied at most by 1.1% with a root mean square of 0.3% during the compression ramp, demonstrating low PDV measurement error over a relatively large experimental area. The experimental PDV data also agrees well with 1D simulations that use inputs from predictive characterization models developed for the material properties resulting from tape casting, laminating, and powder consolidation processes. Low measurement error during quasi-isentropic compression, leading to better precision, ensures a robust platform to reach extreme compression and low-temperature recovery states and facilitates discovery via synthesis, quenching, and preservation of new high-pressure phases
Application of Al-Cu-W-Ta graded density impactors in dynamic ramp compression experiments
Graded density impactors (GDIs) are used to dynamically compress materials to extreme conditions. Two modifications to a previously developed Mg-Cu-W GDI are made in this work before using it in a dynamic compression experiment: Mg is replaced with Al and a Ta disk is glued to the back. The Mg phase is replaced by Al because FCC Al remains solid to higher pressure along its Hugoniot compared to Mg. The addition of the Ta disk creates a constant particle velocity regime and facilitates a definition of peak pressure states. Microstructure analysis, profilometry, and ultrasonic C-scans of the Al-Cu-W GDI all confirm excellent uniformity. We evaluated signal variation in the radial direction of a dynamically compressed Al-LiF bilayer target to evaluate the contribution of spatial nonuniformity to errors. Velocity traces from five photon Doppler velocimetry (PDV) probes located at different radial distances from the center of the target varied at most by 1.1% with a root mean square of 0.3% during the compression ramp, demonstrating low PDV measurement error over a relatively large experimental area. The experimental PDV data also agrees well with 1D simulations that use inputs from predictive characterization models developed for the material properties resulting from tape casting, laminating, and powder consolidation processes. Low measurement error during quasi-isentropic compression, leading to better precision, ensures a robust platform to reach extreme compression and low-temperature recovery states and facilitates discovery via synthesis, quenching, and preservation of new high-pressure phases
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