150 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

    The Full Event Interpretation -- An exclusive tagging algorithm for the Belle II experiment

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    The Full Event Interpretation is presented: a new exclusive tagging algorithm used by the high-energy physics experiment Belle II. The experimental setup of Belle II allows the precise measurement of otherwise inaccessible BB meson decay-modes. The Full Event Interpretation algorithm enables many of these measurements. The algorithm relies on machine learning to automatically identify plausible BB meson decay chains based on the data recorded by the detector. Compared to similar algorithms employed by previous experiments, the Full Event Interpretation provides a greater efficiency, yielding a larger effective sample size usable in the measurement.Comment: 11 pages, 7 figures, 1 tabl

    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

    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

    Invariant-mass and fractional-energy dependence of inclusive production of di-hadrons in e+ee^+e^- annihilation at s=\sqrt{s}= 10.58 GeV

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    The inclusive cross sections for di-hadrons of charged pions and kaons (e+ehhXe^+e^- \rightarrow hhX) in electron-positron annihilation are reported. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere di-hadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-dependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a 655fb1655\,{\rm fb}^{-1} data sample collected at or near the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+ e^- collider.Comment: 21 pages, 18 figures plus 25 figures in supplemental material, submitted to PR

    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

    Search for CPCP violation in the D+π+π0D^{+}\to\pi^{+}\pi^{0} decay at Belle

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    We search for CPCP violation in the charged charm meson decay D+π+π0D^{+}\to\pi^{+}\pi^{0}, based on a data sample corresponding to an integrated luminosity of 921 fb1\rm 921~fb^{-1} collected by the Belle experiment at the KEKB e+ee^{+}e^{-} asymmetric-energy collider. The measured CPCP violating asymmetry is [+2.31±1.24(stat)±0.23(syst)]%[+2.31\pm1.24({\rm stat})\pm0.23({\rm syst})]\%, which is consistent with the standard model prediction and has a significantly improved precision compared to previous results.Comment: 8 pages, 3 figure

    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
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