472 research outputs found

    A Scaling-up Synthesis From Laboratory Scale to Pilot Scale and to Near Commercial Scale for Paste-Glue Production

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    This paper concerns on developing a synthesis method of paste-glue production for gummed tape using a corn-based starch as an alternative feedstock from laboratory-scale to pilot-scale and to near commercial scale. Basically, two methods of synthesis were developed to produce paste-glue in laboratory scale. Based on the two methods, we then scale-up the earlier laboratory scale data to pilot-scale and near commercial-scale for developing a large scale process production of paste-glue. Scaling up production from 1,000 ml reactor to 500 L pilot-scale reactor and 1,500 L near commercial scale reactor, we monitored pathway of temperature increase during reaction as well as adjustment of operating condition conducted for laboratory experimental data in order to produce a good quality of paste-glue. Some scaling up parameters have been found as well as critical parameters for a good product quality such as viscosity and ceiling temperature of the reaction which are very crucial in order to give optimum operating condition. We have selected synthesis method of paste-glue production and found the range of the parameters in order to produce a very good quality of paste-glue in pilot scale and near commercial scale

    Search for D0D^{0} decays to invisible final states at Belle

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    We report the result from the first search for D0D^0 decays to invisible final states. The analysis is performed on a data sample of 924 fb1\rm{fb}^{-1} collected at and near the Υ(4S)\Upsilon(4S) and Υ(5S)\Upsilon(5S) resonances with the Belle detector at the KEKB asymmetric-energy e+ee^{+}e^{-} collider. The absolute branching fraction is determined using an inclusive D0D^0 sample, obtained by fully reconstructing the rest of the particle system including the other charmed particle. No significant signal yield is observed and an upper limit of 9.4×1059.4\times 10^{-5} is set on the branching fraction of D0D^0 to invisible final states at 90\% confidence level.Comment: 17 pages, 4 figures, submitted to PRD(RC

    Search for a dark vector gauge boson decaying to π+π\pi^+ \pi^- using ηπ+πγ\eta \rightarrow \pi^+\pi^- \gamma decays

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    We report a search for a dark vector gauge boson UU^\prime that couples to quarks in the decay chain D+D0π+,D0KS0η,ηUγD^{*+} \to D^0 \pi^+, D^0 \to K^0_S \eta, \eta \to U^\prime \gamma, Uπ+πU^\prime \to \pi^+ \pi^-. No signal is found and we set a mass-dependent limit on the baryonic fine structure constant of 10310210^{-3} - 10^{-2} in the UU^\prime mass range of 290 to 520 MeV/c2c^2. This analysis is based on a data sample of 976 fb1^{-1} collected by the Belle experiment at the KEKB asymmetric-energy e+ee^+e^- collider.Comment: 6 pages, 4 figure

    Observation of D0Dˉ0D^0-\bar{D}^0 Mixing in e+ee^+e^- Collisions

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    We observe D0Dˉ0D^0-\bar{D}^0 mixing in the decay D0K+πD^0\rightarrow K^+\pi^- using a data sample of integrated luminosity 976 fb1^{-1} collected with the Belle detector at the KEKB e+ee^+e^- asymmetric-energy collider. We measure the mixing parameters x2=(0.09±0.22)×103{x'}^2 = (0.09\pm0.22)\times 10^{-3} and y=(4.6±3.4)×103y' = (4.6\pm3.4)\times 10^{-3} and the ratio of doubly Cabibbo-suppressed to Cabibbo-favored decay rates RD=(3.53±0.13)×103R_D = (3.53\pm0.13)\times 10^{-3}, where the uncertainties are statistical and systematic combined. Our measurement excludes the no-mixing hypothesis at the 5.1 standard deviation level.Comment: 6 pages, 4 figure

    Semi-inclusive studies of semileptonic BsB_s decays at Belle

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    We present an analysis of the semi-inclusive decays BsDsX+νB_s \to D_s^- X \ell^+ \nu and BsDsX+νB_s \to D_s^{*-} X \ell^+ \nu, where XX denotes a final state that may consist of additional hadrons or photons and \ell is an electron or muon. The studied BsB_s decays are contained in the 121.4 fb1121.4~{\rm fb}^{-1} Υ(5S)\Upsilon(5S) data sample collected by the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. The branching fractions of the decays are measured to be B(BsDsX+ν)=[8.2±0.2(stat)±0.6(syst)±1.4(ext)]%\mathcal{B}(B_s \to D_s^- X \ell^+ \nu) = [8.2 \pm 0.2 (\text{stat}) \pm 0.6 (\text{syst}) \pm 1.4 (\text{ext})]\% and B(BsDsX+ν)=[5.4±0.4(stat)±0.4(syst)±0.9(ext)]%\mathcal{B}(B_s \to D_s^{*-} X \ell^+ \nu) = [5.4 \pm 0.4 (\text{stat}) \pm 0.4 (\text{syst}) \pm 0.9 (\text{ext})]\%, where the first two uncertainties are statistical and systematic and the last is due to external parameters. The measurement also provides an estimate of the Bs()Bˉs()B_s^{(*)}\bar{B}_s^{(*)} production cross-section, σ(e+eBs()Bˉs())=(53.8±1.4(stat)±4.0(syst)±3.4(ext))pb\sigma(e^+e^- \to B_s^{(*)}\bar{B}_s^{(*)}) = (53.8 \pm 1.4 (\text{stat}) \pm 4.0 (\text{syst}) \pm 3.4 (\text{ext}))\,{\rm pb}, at the center-of-mass energy s=10.86GeV\sqrt{s} = 10.86\,{\rm GeV}.Comment: 13 pages, 2 figures, submitted to Phys. Rev.

    Measurement of e+eγχcJe^+e^- \to \gamma\chi_{cJ} via initial state radiation at Belle

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    The process e+eγχcJe^+e^- \to \gamma\chi_{cJ} (JJ=1, 2) is studied via initial state radiation using 980 fb1^{-1} of data at and around the Υ(nS)\Upsilon(nS) (nn=1, 2, 3, 4, 5) resonances collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. No significant signal is observed except from ψ(2S)\psi(2S) decays. Upper limits on the cross sections between s=3.80\sqrt{s}=3.80 and 5.56 GeV5.56~{\rm GeV} are determined at the 90% credibility level, which range from few pb to a few tens of pb. We also set upper limits on the decay rate of the vector charmonium [ψ(4040\psi(4040), ψ(4160)\psi(4160), and ψ(4415)\psi(4415)] and charmoniumlike [Y(4260)Y(4260), Y(4360)Y(4360), and Y(4660)Y(4660)] states to γχcJ\gamma\chi_{cJ}.Comment: Accepted by PR
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