15 research outputs found
Measurement of the Branching Fraction for B->eta' K and Search for B->eta'pi+
We report measurements for two-body charmless B decays with an eta' meson in
the final state. Using 11.1X10^6 BBbar pairs collected with the Belle detector,
we find BF(B^+ ->eta'K^+)=(79^+12_-11 +-9)x10^-6 and BF(B^0 ->
eta'K^0)=(55^+19_-16 +-8)x10^-6, where the first and second errors are
statistical and systematic, respectively. No signal is observed in the mode B^+
-> eta' pi^+, and we set a 90% confidence level upper limit of BF(B^+->
eta'pi^+) eta'K^+- decays is
investigated and a limit at 90% confidence level of -0.20<Acp<0.32 is obtained.Comment: Submitted to Physics Letters
Observation of Cabibbo-suppressed and W-exchange Lambda_c^+ baryon decays
We present measurements of the Cabibbo-suppressed decays Lambda_c^+ -->
Lambda0 K+ and Lambda_c^+ --> Sigma0 K+ (both first observations), Lambda_c^+
--> Sigma+ K+ pi- (seen with large statistics for the first time), Lambda_c^+
--> p K+ K- and Lambda_c^+ --> p phi (measured with improved accuracy).
Improved branching ratio measurements for the decays Lambda_c^+ --> Sigma+ K+
K- and Lambda_c^+ --> Sigma+ phi, which are attributed to W-exchange diagrams,
are shown. We also present the first evidence for Lambda_c^+ --> Xi(1690)^0 K+
and set an upper limit on the non-resonant decay Lambda_c^+ --> Sigma+ K+ K-.
This analysis was performed using 32.6 fb^{-1} of data collected by the Belle
detector at the asymmetric e+ e- collider KEKB.Comment: Submitted to Phys. Lett. B. v2: A small correction to the Authorlist
was made. An earlier version of this analysis was released as
BELLE-CONF-0130, hep-ex/010800
Measurements of Branching Fractions and Decay Amplitudes in B-> J/\psi K^* decays
The branching fractions and the decay amplitudes of B -> J/psi K^* decays are
measured in a 29.4/fb data sample collected with the Belle detector at the KEKB
electron-positron collider. The decay amplitudes of helicity states of the
J/psi K^* system are determined from the full angular distribution of the final
state particles in the transversity basis. The branching fractions are measured
to be (1.29\pm0.05\pm0.13) \times 10^{-3} for neutral mesons and
(1.28\pm0.07\pm0.14) \times 10^{-3} for charged mesons. The measured
longitudinal and transverse (perpendicular to the transversity plane)
amplitudes are |A_0|^2 = 0.62\pm0.02\pm0.03 and |A_{\perp}|^2 =
0.19\pm0.02\pm0.03, respectively. The value of |A_{\perp}|^2 shows that the CP
even component dominates in the B^0 \to J/\psi K^{*0}(K_S\pi^0) decay.Comment: 17 pages, 3 figures, 5 tables, to appear in Phys. Lett.
Measurement of the inclusive semileptonic branching fraction of B mesons and |Vcb|
We present a measurement of the electron spectrum from inclusive semileptonic
{\it B} decay, using 5.1 fb of data collected with the
Belle detector. A high-momentum lepton tag was used to separate the
semileptonic {\it B} decay electrons from secondary decay electrons. We
obtained the branching fraction, , with minimal model dependence.
From this measurement, we derive a value for the Cabibbo-Kobayashi-Maskawa
matrix element .Comment: 16 pages, 3 figures, 3 table
Determination of |Vcb| using the semileptonic decay \bar{B}^0 --> D^{*+}e^-\bar{\nu}
We present a measurement of the Cabibbo-Kobayashi-Maskawa (CKM) matrix
element |Vcb| using a 10.2 fb^{-1} data sample recorded at the \Upsilon(4S)
resonance with the Belle detector at the KEKB asymmetric e^+e^- storage ring.
By extrapolating the differential decay width of the \bar{B}^0 -->
D^{*+}e^-\bar{\nu} decay to the kinematic limit at which the D^{*+} is at rest
with respect to the \bar{B}^0, we extract the product of |Vcb| with the
normalization of the decay form factor F(1), |Vcb |F(1)=
(3.54+/-0.19+/-0.18)x10^{-2}, where the first error is statistical and the
second is systematic. A value of |Vcb| = (3.88+/-0.21+/-0.20+/-0.19)x10^{-2} is
obtained using a theoretical calculation of F(1), where the third error is due
to the theoretical uncertainty in the value of F(1). The branching fraction
B(\bar{B}^0 --> D^{*+}e^-\bar{\nu}) is measured to be
(4.59+/-0.23+/-0.40)x10^{-2}.Comment: 20 pages, 6 figures, elsart.cls, submitted to PL
Measurement of \chi_{c2} Production in Two-Photon Collisions
The production of the \chi_{c2} charmonium state in two-photon collisions has
been measured with the Belle detector at the KEKB e^+e^- collider. A clear
signal for \chi_{c2} --> \gamma J/\psi, J/\psi --> l^+l^- is observed in a
32.6fb^{-1} data sample accumulated at center-of-mass energies near 10.6GeV,
and the product of its two-photon decay width and branching fraction is
determined to be \Gamma_{\gamma\gamma}(\chi_{c2})B(\chi_{c2} --> \gamma J/\psi)
B(J/\psi --> l^+l^-)= 13.5 +/- 1.3(stat.) +/- 1.1(syst.)eV.Comment: 16 pages, 5 figures, to be submitted to Phys. Lett.
Not Available
Not AvailableThe present work evaluates the bacteriocidal and algicidal efficacy of nanosilver particles (AgNPs) synthesized through a green pathway by using the cyanobacterium Synechococcus elongatus. Further, the synergistic effects of the conjugates of selected antibiotics and biogenic silver nanoparticle were evaluated against three Gram-negative fish pathogens, viz. Aeromonas hydrophila ATCC-7966, Vibrio parahaemolyticus ATCC BAA-238 and Edwardsiella tarda ATCC-15947. The biogenic silver nanoparticles were polydispersed and showed a size range 71–201 nm with a zeta potential of −9.11 mV. The antibacterial activities of ampicillin, gentamicin, ofloxacin and ciprofloxacin exhibited a significant (P < 0.05) increase when conjugated with AgNPs against the selected bacterial strains. The highest synergistic effect of conjugates of AgNPs with gentamicin and ampicillin was observed against E. tarda. The biogenic silver nanoparticles exhibited a considerable inhibition of growth and decrease in photosynthetic pigments in a bloom-forming alga (Microcystis aeruginosa) and biofouling alga (Phormidium sp). This report aims to establish that biogenic silver nanoparticles are effective against water-borne fish pathogens and their efficacy is comparable with silver nanoparticles synthesized through chemical-based pathways.Not Availabl
Not Available
Not AvailableRice straw is a useful bio-resource with worldwide annual production of approximately 731 million tons. However, this valuable biomass is unfortunately burnt on field as waste that causes air pollution, global warming, plant nutrient losses and environment menace. About 60% of rice straw produced in Asia in general and India in particular is burnt in field. As for the basic requirement to predict their suitability for best alternative industrial uses biochemical, morphological and chemical (functional group) characterization of straws of 18 most widely grown rice cultivars from eastern region of India was carried out. Biochemical characterization was done on the basis of cellulose, hemicellulose, lignin and silica content. The surface morphology of straws was observed through Scanning Electron Microscopy (SEM), while, presence of functional groups were analyzed through Fourier Transform Infrared (FTIR) spectroscopy. Primarily, quantified biochemical profiles were used to
group cultivars for best alternate uses of straw like bio-ethanol, biochar, compost and mushroom production. Morphological feature (from SEM) of straw and functional group (through FTIR) were used to support the grouping. Cultivars with higher hemicelluloses and cellulose with low to medium lignin and Si were better suited for bio-ethanol production while, straw having higher lignin and low to medium cellulose and hemicelluloses were selected for biochar. Therefore, considering all the three characterization methods (chemical composition, morphological features, presence or absence of functional groups), we found straws of rice cultivars, Tapaswini and IR 64 were best suited for bio-ethanol and biochar production, respectively. There are overlapping as well as contradictory observations found during grouping, when the three approaches were followed together. This indicate that the grouping of straw for better alternative uses could be done by biochemical and morphological characterization but this should be validated in small scale at farm or factory level for final recommendation.ICA