154 research outputs found

    Strict Forest Reserve Research in the Margin of the Carpathians, the Vár-hegy Case-Study

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    Sixteen forest reserves are situated in the northern part of Hungary which belongs to the Carpathian region according to EURAC delimitation (Ruffini et al. 2006). These Hungarian forest reserves expand the natural forest remnant/forest reserve net of the Carpathians towards the lower hilly region, representing the deciduous beech and oak forest belts near their lower (xeric) distribution limits. This paper outlines the Hungarian forest reserves belonging to the Carpathian region and the preliminary results of current projects in the Vár-hegy Forest Reserve (Bükk Mts., Hungary) as a case study. The alteration of tree species composition was investigated here based on the reconstruction of forest history in the previous 130 years (management period) and analyses of forest stand inventory. In another project CO2 sequestration changes of these forest stands were modeled since the clear-cutting in the 1880th and carbon stored in the forest ecosystem compartments was estimated. Our results show that the forest reserve stands are presently in a transition state from the managed forest towards a more natural mixed forest with several age-classes

    Study of Excited Ξc\Xi_c States Decaying into Ξc0\Xi_c^0 and Ξc+\Xi_c^+ Baryons

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    Using a data sample of 980 fb1{\rm fb}^{-1} of e+ee^+e^- annihilation data taken with the Belle detector operating at the KEKB asymmetric-energy e+ee^+e^- collider, we report the results of a study of excited Ξc\Xi_c states that decay, via the emission of photons and/or charged pions, into Ξc0\Xi_c^0 or Ξc+\Xi_c^+ ground state charmed-strange baryons. We present new measurements of the masses of all members of the Ξc\Xi_c^{\prime}, Ξc(2645)\Xi_c(2645), Ξc(2790)\Xi_c(2790), Ξc(2815)\Xi_c(2815), and Ξc(2980)\Xi_c(2980) isodoublets, measurements of the intrinsic widths of those that decay strongly, and evidence of previously unknown transitions.Comment: Submitted to PR

    Energy scan of the e+ehb(nP)π+πe^+e^- \to h_b(nP)\pi^+\pi^- (n=1,2)(n=1,2) cross sections and evidence for Υ(11020)\Upsilon(11020) decays into charged bottomonium-like states

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    Using data collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider, we measure the energy dependence of the e+ehb(nP)π+πe^+e^- \to h_b(nP)\pi^+\pi^- (n=1,2)(n=1,2) cross sections from thresholds up to 11.0211.02\,GeV. We find clear Υ(10860)\Upsilon(10860) and Υ(11020)\Upsilon(11020) peaks with little or no continuum contribution. We study the resonant substructure of the Υ(11020)hb(nP)π+π\Upsilon(11020) \to h_b(nP)\pi^+\pi^- transitions and find evidence that they proceed entirely via the intermediate isovector states Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650). The relative fraction of these states is loosely constrained by the current data: the hypothesis that only Zb(10610)Z_b(10610) is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only Zb(10650)Z_b(10650) is produced is not excluded at a significant level.Comment: 8 pages, 4 figures, submitted to Physical Review Letter

    Study of e+e- => B(*) B(*)-bar pi+- at sqrt(s)=10.866 GeV

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    We report the analysis of the three-body e+e- => B B-bar pi, B B*-bar pi, and B* B*-bar pi processes, including the first observation of the Zb+-(10610) =>[B B*-bar+c.c.]+- and Zb+-(10650) => [B*B*-bar]+- transitions. We measure visible cross sections for the three-body production of sigma_vis(e+e- => [B B*-bar+c.c.]+-pi-+=(11.2+-1.0(stat.)+-1.2(syst.)) pb and sigma_vis(e+e- => [B*B*-bar]+-pi-+)=(5.61+-0.73(stat.)+-0.66(syst.)) pb and set a 90% C.L. upper limit of sigma_vis(e+e- => [BB-bar]+-pi-+)<2.1 pb. The results are based on a 121.4 1/fb data sample collected with the Belle detector at a center-of-mass energy near the Y(5S) peak.Comment: 8 pages, 2 figure

    Observation of D0ρ0γD^0\to \rho^0\gamma and search for CPCP violation in radiative charm decays

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    We report the first observation of the radiative charm decay D0ρ0γD^0 \to \rho^0 \gamma and the first search for CPCP violation in decays D0ρ0γD^0 \to \rho^0 \gamma, ϕγ\phi\gamma, and K0γ\overline{K}{}^{*0} \gamma, using a data sample of 943 fb1^{-1} collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. The branching fraction is measured to be B(D0ρ0γ)=(1.77±0.30±0.07)×105\mathcal{B}(D^0 \to \rho^0 \gamma)=(1.77 \pm 0.30 \pm 0.07) \times 10^{-5}, where the first uncertainty is statistical and the second is systematic. The obtained CPCP asymmetries, ACP(D0ρ0γ)=+0.056±0.152±0.006\mathcal{A}_{CP}(D^0 \to \rho^0 \gamma)=+0.056 \pm 0.152 \pm 0.006, ACP(D0ϕγ)=0.094±0.066±0.001\mathcal{A}_{CP}(D^0 \to \phi \gamma)=-0.094 \pm 0.066 \pm 0.001, and ACP(D0K0γ)=0.003±0.020±0.000\mathcal{A}_{CP}(D^0 \to \overline{K}{}^{*0} \gamma)=-0.003 \pm 0.020 \pm 0.000, are consistent with no CPCP violation. We also present an improved measurement of the branching fractions B(D0ϕγ)=(2.76±0.19±0.10)×105\mathcal{B}(D^0 \to \phi \gamma)=(2.76 \pm 0.19 \pm 0.10) \times 10^{-5} and B(D0K0γ)=(4.66±0.21±0.21)×104\mathcal{B}(D^0 \to \overline{K}{}^{*0} \gamma)=(4.66 \pm 0.21 \pm 0.21) \times 10^{-4}

    Search for B+ -> l+ nu gamma decays with hadronic tagging using the full Belle data sample

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    We search for the decay B+ -> l+ nu gamma with l+ = e+ or mu+ using the full Belle data set of 772 x 10^6 BBbar pairs, collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct one B meson in a hadronic decay mode and search for the B+ -> l+ nu gamma decay in the remainder of the event. We observe no significant signal within the phase space of E_gamma^sig > 1 GeV and obtain upper limits of BR(B+ -> e+ nu gamma) mu+ nu gamma) l+ nu gamma) < 3.5 x 10^-6 at 90 % credibility level.Comment: Submitted to Phys. Rev.

    Search for a massive invisible particle X0X^0 in B+e+X0B^{+}\to e^{+}X^{0} and B+μ+X0B^{+}\to \mu^{+}X^{0} decays

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    We present a search for a non-Standard-Model invisible particle X0X^0 in the mass range 0.1-1.8GeV/c20.1\textrm{-}1.8 \,{\rm GeV}/{c^2} in B+e+X0B^{+}\to e^{+} X^{0} and B+μ+X0B^{+}\to \mu^{+} X^{0} decays. The results are obtained from a 711 fb1711~{\rm fb}^{-1} data sample that corresponds to 772×106BBˉ772 \times 10^{6} B\bar{B} pairs, collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB e+ee^+ e^- collider. One BB meson is fully reconstructed in a hadronic mode to determine the momentum of the lepton of the signal decay in the rest frame of the recoiling partner BB meson. We find no evidence of a signal and set upper limits on the order of 10610^{-6}.Comment: 8 pages, 4 figures, 3 table

    Studies of charmed strange baryons in the ΛD\Lambda D final state at Belle

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    We report the discovery of Ξc(3055)0\Xi_{c}(3055)^{0}, observed by its decay into the final state ΛD0\Lambda D^{0}, and present the first observation and evidence of the decays of Ξc(3055)+\Xi_c(3055)^{+} and Ξc(3080)+\Xi_c(3080)^{+} into ΛD+\Lambda D^{+}. We also perform a combined analysis of the ΛD+\Lambda D^{+} with the Σc++K\Sigma_{c}^{++}K^{-} and Σc++K\Sigma_{c}^{\ast ++}K^{-} decay modes to measure the ratios of branching fractions, masses and widths with improved accuracy. We measure the ratios of branching fractions B(Ξc(3055)+ΛD+)/B(Ξc(3055)+Σc++K)=5.09±1.01±0.76{\cal B}(\Xi_{c}(3055)^{+} \to \Lambda D^{+})/{\cal B}(\Xi_{c}(3055)^{+} \to \Sigma_{c}^{++}K^{-})=5.09\pm1.01\pm0.76, B(Ξc(3080)+ΛD+)/B(Ξc(3080)+Σc++K)=1.29±0.30±0.15{\cal B}(\Xi_{c}(3080)^{+} \to \Lambda D^{+})/{\cal B}(\Xi_{c}(3080)^{+} \to \Sigma_{c}^{++}K^{-})=1.29\pm0.30\pm0.15, and B(Ξc(3080)+Σc++K)/B(Ξc(3080)+Σc++K)=1.07±0.27±0.01{\cal B}(\Xi_{c}(3080)^{+} \to \Sigma_{c}^{\ast ++}K^{-})/{\cal B}(\Xi_{c}(3080)^{+} \to \Sigma_{c}^{++}K^{-})=1.07\pm0.27\pm0.01, where the uncertainties are statistical and systematic. The analysis is performed using a 980 fb1^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e+ee^{+}e^{-} collider.Comment: Submitted to PR

    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
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