57 research outputs found

    Aquacultural Potential of Derelict Waterbodies – A Case Study

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    Derelict waterbodies could be an important source to boost fish production for meeting the future fish demand of the country. The study has shown that fish yield from these waterbodies could be as high as 4.6 t/ha. Overall, net income per hectare through scientific management of derelict waterbodies has been found to be Rs 104443, with maximum and minimum net incomes per hectare being Rs 207416 and Rs 64033, respectively. Benefit–cost analysis has indicated that all waterbodies are favourable for aquaculture. Overall B-C ratio under the project has been found to be 3.82 and interestingly, scientific management of waterbodies could yield good income even from low level of investment. Such an activity can provide enormous income and employment opportunities in the rural areas. To encourage large-scale utilization of available derelict waterbodies for aquaculture, a prudent and well-conceived policy for leasing out derelict waterbodies and transfer of relevant technologies to the needy and interested farmers should be evolved. These steps would not only boost fish production in the rural areas, but would also provide much needed impetus to the growth and diversification of rural economy.Resource /Energy Economics and Policy,

    Precise measurement of hadronic tau-decays with an eta meson

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    We have studied hadronic tau decay modes involving an eta meson using 490 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The following branching fractions have been measured: B(tau- -> K- eta nu)=(1.58 +- 0.05 +- 0.09)x 10^{-4}, B(tau- -> K- pi0 eta nu)=(4.6 +- 1.1 +- 0.4)x 10^{-5}, B(tau- -> pi- pi0 eta nu)=(1.35 +- 0.03 +- 0.07)x 10^{-3}, B(tau- -> pi- KS eta nu)=(4.4 +- 0.7 +- 0.2)x 10^{-5}, and B(tau- -> K^{*-} eta nu)=(1.34 +- 0.12 +- 0.09)x 10^{-4}. These results are substantially more precise than previous measurements. The new measurements are compared with theoretical calculations based on the CVC hypothesis or the chiral perturbation theory. We also set upper limits on branching fractions for tau decays into K- KS eta nu, pi- KS pi0 eta nu, K- eta eta nu, pi- eta eta nu and non-resonant K- pi^0 eta nu final states.Comment: 24 pages, 7 figure

    Search for Lepton-Flavor-Violating tau Decays into a Lepton and an f0(980) Meson

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    We search for lepton-flavor-violating tau decays into a lepton (electron or muon) and an f0(980) meson using 671 fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. No events are observed and we set the following 90% C.L. upper limits on the branching fraction products: B(tau- -> e-f0(980))*B(f0(980)->pi+pi-) mu-f0(980))*B(f0(980) -> pi+pi-)<3.4x10^-8. This is the first search performed for these modes.Comment: 10 pages, 4 figures, submitted to Phys. Lett.

    Search for B+ -> D*+ pi0 decay

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    We report on a search for the doubly Cabibbo suppressed decay B+ -> D*+ pi0, based on a data sample of 657 million BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider. We find no significant signal and set an upper limit of Br(B+ -> D*+ pi0) < 3.6 x 10^-6 at the 90% confidence level. This limit can be used to constrain the ratio between suppressed and favored B -> D* pi decay amplitudes, r < 0.051, at the 90% confidence level.Comment: 5pages, 2figures, submitted to PRL (v1); PRL published version (v2: minor corrections in the text

    Observation of the ϕ(1680)\phi(1680) and the Y(2175) in e+eϕπ+πe^+ e^- \to \phi\pi^+\pi^-

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    The cross sections for e+eϕπ+πe^+ e^- \to \phi\pi^+\pi^- and e^+ e^- \to \phi \fzero are measured from threshold to s=3.0\sqrt{s}=3.0 GeV\hbox{GeV} using initial state radiation. The analysis is based on a data sample of 673 fb1^{-1} collected on and below the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. First measurements are reported for the resonance parameters of the ϕ(1680)\phi(1680) in the ϕπ+π\phi\pi^+\pi^- mode: m=(1689±7±10)m=(1689\pm 7\pm 10) MeV/c2c^2 and Γ=(211±14±19)\Gamma=(211\pm 14\pm 19) MeV/c2c^2. A structure at s=2.1GeV/c2\sqrt{s}=2.1 \hbox{GeV}/c^2, corresponding to the so called Y(2175), is observed; its mass and width are determined to be 2079±1328+792079\pm13^{+79}_{-28} MeV/c2c^2 and 192±2361+25MeV/c2192\pm23^{+25}_{-61} \hbox{MeV}/c^2, respectively.Comment: 11 pages, 6 figures. Add one plot. Accepted by Phys.Rev.D(RC

    Measurement of CP asymmetry in Cabibbo suppressed D0 decays

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    We measure the CP-violating asymmetries in decays to the D0 -> K+K- and D0 -> pi+pi- CP eigenstates using 540 fb^{-1} of data collected with the Belle detector at or near the Upsilon(4S) resonance. Cabibbo-favored D0 -> K-pi+ decays are used to correct for systematic detector effects. The results, A_{CP}^{KK} = (-0.43 +- 0.30 +- 0.11)% and A_{CP}^{pipi} = (+0.43 +- 0.52 +- 0.12)%, are consistent with no CP violation.Comment: Submitted to Phys. Lett.

    Study of \Omega_c^0 and \Omega_c^{*0} Baryons at Belle

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    We report results from a study of the charmed double strange baryons \Omega_c^0 and \Omega_c^{*0} at Belle. The \Omega_c^0 is reconstructed using the \Omega_c^0 --> \Omega^- \pi^+ decay mode, and its mass is measured to be (2693.6 \pm 0.3 {+1.8 \atop -1.5}) MeV/c^2. The \Omega_c^{*0} baryon is reconstructed in the \Omega_c^0 \gamma mode. The mass difference M_{\Omega_c^{*0}} - M_{\Omega_c^0} is measured to be (70.7 \pm 0.9 {+0.1 \atop -0.9}) MeV/c^2. The analysis is performed using 673 fb^{-1} of data on and near the \Upsilon(4S) collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider.Comment: 11 pages, 5 figures, prepared for 34th International Conference on High Energy Physics (ICHEP 08), Philadelphia, PA, 29 Jul - 5 Aug 200

    Measurement of cross sections of exclusive e+eVPe^+ e^- \to VP processes at s=10.58\sqrt{s}=10.58 GeV

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    The cross sections for the reactions e+eϕη,ϕη,ρη,ρηe^+e^- \to \phi\eta, \quad \phi\eta', \quad \rho\eta, \quad \rho\eta' have been measured using a data sample of 516 fb1^{-1} collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. The corresponding values of the cross sections are: 1.4±0.4±0.11.4 \pm 0.4 \pm 0.1 fb (ϕη)(\phi\eta), 5.3±1.1±0.45.3 \pm 1.1 \pm 0.4 fb (ϕη)(\phi\eta'), 3.1±0.5±0.13.1 \pm 0.5 \pm 0.1 fb (ρη)(\rho\eta) and 3.3±0.6±0.23.3 \pm 0.6 \pm 0.2 fb (ρη)(\rho\eta'). The energy dependence of the cross sections is presented using Belle measurements together with those of CLEO and BaBar.Comment: 8 pages, 8 figure

    Observation of B_s0->D_s*- pi+, B_s0->D_s(*)- rho+ Decays and Measurement of B_s0->D_s*- rho+ Polarization

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    First observations of the B_s0->D_s*- pi+, B_s0->D_s- rho+ and B_s0->D_s*- rho+ decays are reported together with measurements of their branching fractions: B(B_s0->D_s*- pi+)=(2.4 +0.5-0.4(stat.) +-0.3(syst.) +-0.4(fs))x10^(-3), B(Bs->D_s- rho+)=(8.5 +1.3-1.2(stat.) +-1.1(syst.) +-1.3(fs))x10^(-3) and B(Bs->D_s*- rho+)=(11.8 +2.2-2.0(stat.) +-1.7(syst.) +-1.8(fs))x10^(-3) (f_s=N(B_s(*)B_s(*)-bar)/N(b b-bar)). From helicity-angle distributions, we measured the longitudinal polarization fraction in B_s0->D_s*- rho+ decays to be f_L(Bs->D_s*- rho+)=1.05 +0.08-0.10(stat.) +0.03-0.04(syst.). These results are based on a 23.6 /fb data sample collected at the Y(5S) resonance with the Belle detector at the KEKB e+e- collider.Comment: 6 pages, 2 figures; submitted to Phys. Rev. Lett

    Measurement of the Decay B_s^0 -> D_s^- pi^+ and Evidence for B_s^0 -> D_s^{+/-} K^{-/+} in e+e- Annihilation at sqrt(s)~10.87 GeV

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    We have studied Bs0 -> Ds- pi+ and Bs0 -> Ds^(-/+) K^(+/-) decays using 23.6 /fb of data collected at the Upsilon(5S) resonance with the Belle detector at the KEKB e+e- collider. This highly pure Bs0 -> Ds- pi+ sample is used to measure the branching fraction, BR(Bs0 -> Ds- pi+)=[3.67 +0.35,-0.33}(stat.) +0.43,-0.42(syst.) +-0.49(f_s)] x 10^{-3} (f_s=N(Bs(*) Bs(*)bar)/N(b\bar b)) and the fractions of Bs0 event types at the Upsilon(5S) energy, {in particular N(Bs* Bs*bar}/N(N(Bs(*) Bs(*)bar)=(90.1 +3.8,-4.0 +-0.2)%. We also determine the masses M(Bs0)=(5364.4 +-1.3 +-0.7) MeV/c^2 and M(Bs*)=(5416.4 +-0.4 +-0.5) MeV/c^2. In addition, we observe Bs0 -> Ds^(-/+) K^(+/-) decays with a significance of 3.5\sigma and measure BR(Bs0 -> Ds^(-/+) K^(+/-))=[2.4 +1.2,-1.0(stat.) +-0.3(syst.) +-0.3(f_s)] x 10^{-4}.Comment: 5 pages, 4 figures, accepted by PR
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