629 research outputs found

    The B_s and D_s decay constants in 3 flavor lattice QCD

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    Capitalizing on recent advances in lattice QCD, we present a calculation of the leptonic decay constants f_{B_s} and f_{D_s} that includes effects of one strange sea quark and two light sea quarks. The discretization errors of improved staggered fermion actions are small enough to simulate with 3 dynamical flavors on lattices with spacings around 0.1 fm using present computer resources. By shedding the quenched approximation and the associated lattice scale ambiguity, lattice QCD greatly increases its predictive power. NRQCD is used to simulate heavy quarks with masses between 1.5 m_c and m_b. We arrive at the following results: f_{B_s} = 260 \pm 7 \pm 26 \pm 8 \pm 5 MeV and f_{D_s} = 290 \pm 20 \pm 29 \pm 29 \pm 6 MeV. The first quoted error is the statistical uncertainty, and the rest estimate the sizes of higher order terms neglected in this calculation. All of these uncertainties are systematically improvable by including another order in the weak coupling expansion, the nonrelativistic expansion, or the Symanzik improvement program.Comment: 4 page

    Land Use Sector Involvement in Mitigation Policies Across Carbon Markets

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    Different local and international experiences show that the agroforestry sector can be fully included in the global warming mitigation strategies and in the market mechanisms that may have environmental and socioeconomic benefits. At present, however, the primary sector plays only a minor role in mitigation policies within the UNFCCC and under Kyoto’s Protocol, due to problems and difficulties related to emission/absorption accounting models andmonitoring and standardisation systems. If, on one hand, the progress in science has enabled to overcome accountingrelated problems, on the other, there are no adequate mechanisms to encourage and remunerate the primary sector’s efforts. More specifically, if the primary sector is considered as a source of emissions, it should also be recognised that it has beneficial impacts, notably in economic terms, as carbon sink. Therefore, the definition of clear and internationally shared rules might increase the carbon friendly initiatives and help reduce greenhouse gas emissions. This article is focused on the international experiences that have concerned the primary sector and is intended to supply researchers and policymakers with suggestions and recommendations for implementing local market practices related to carbon credits

    Heavy Quarkonium Physics

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    This report is the result of the collaboration and research effort of the Quarkonium Working Group over the last three years. It provides a comprehensive overview of the state of the art in heavy-quarkonium theory and experiment, covering quarkonium spectroscopy, decay, and production, the determination of QCD parameters from quarkonium observables, quarkonia in media, and the effects on quarkonia of physics beyond the Standard Model. An introduction to common theoretical and experimental tools is included. Future opportunities for research in quarkonium physics are also discussed.Comment: xviii + 487 pages, 260 figures. The full text is also available at the Quarkonium Working Group web page: http://www.qwg.to.infn.i

    Hadronic B Decays Involving Even Parity Charmed Mesons

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    Hadronic B decays containing an parity-even charmed meson in the final state are studied. Specifically we focus on the Cabibbo-allowed decays Bˉ→D∗∗π(ρ),D∗∗Dˉs(∗),Dˉs∗∗D(∗)\bar B\to D^{**} \pi(\rho), D^{**}\bar D_s^{(*)}, \bar D^{**}_sD^{(*)} and Bˉs→Ds∗∗π(ρ)\bar B_s\to D_s^{**}\pi(\rho), where D∗∗D^{**} denotes generically a p-wave charmed meson. The B→D∗∗B\to D^{**} transition form factors are studied in the improved version of the Isgur-Scora-Grinstein-Wise quark model. We apply heavy quark effective theory and chiral symmetry to study the strong decays of p-wave charmed mesons and determine the magnitude of the D11/2−D13/2D_1^{1/2}-D_1^{3/2} mixing angle. Except the decay to D1(2427)0π−D_1(2427)^0\pi^- the predictions for B−→D∗∗0π−B^-\to D^{**0}\pi^- agree with experiment. The sign of D11/2−D13/2D_1^{1/2}-D_1^{3/2} mixing angle is found to be positive in order to avoid a severe suppression on the production of D1(2427)0π−D_1(2427)^0\pi^-. The interference between color-allowed and color-suppressed tree amplitudes is expected to be destructive in the decay B−→D1(2427)0π−B^-\to D_1(2427)^0\pi^-. Hence, an observation of the ratio D1(2427)0π−/D1(2427)+π−D_1(2427)^0\pi^-/D_1(2427)^+\pi^- can be used to test the relative signs of various form factors as implied by heavy quark symmetry. Although the predicted B−→D1(2420)0ρ−B^-\to D_1(2420)^0\rho^- at the level of 3×10−33\times 10^{-3} exceeds the present upper limit, it leads to the ratio D1(2420)ρ−/D1(2420)π−≈2.6D_1(2420)\rho^-/D_1(2420)\pi^-\approx 2.6 as expected from the factorization approach and from the ratio fρ/fπ≈1.6f_\rho/f_\pi\approx 1.6 . Therefore, it is crucial to have a measurement of this mode to test the factorization hypothesis. For Bˉ→Dˉs∗∗D\bar B\to \bar D_s^{**}D decays, it is expected that \bar D_{s0}^*D\gsim \bar D_{s1}D as the decay constants of the multiplet (Ds0∗,Ds1)(D_{s0}^*,D_{s1}) become the same in the heavy quark limit.Comment: 27 pages, Belle's new data on DD_s^{**} productions in B decays and on the radiative decay D_{s1}-> D_s\gamma are updated and discussed. Add two reference

    From bowls to pots: the dairying revolution in Northwest Turkey, a view from Barcın HöyĂŒk, 6600 to 6000 BCE

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    Research has identified Northwest Turkey as a key region for the development of dairying inthe seventh millennium BCE, yet little is known about how this practice began or evolvedthere. This research studies Barcın Hošyuš k, a site located in Bursa’s YeniƟehir Valley, whichranges chronologically from 6600 BCE, when the first evidence of settled life appears in theMarmara Region, to 6000 BCE, when Neolithic habitation at the site ceases. Using potterysherds diagnostic by vessel category and type, this paper aims at identifying which onesmay have been primarily used to store, process, or consume dairy products. Organic residueanalysis of selected samples helped address the process of adoption and intensificationof milk processing in this region over time. The lipid residue data discussed in this paperderive from 143 isotopic results subsampled from 173 organic residues obtained from 805Neolithic potsherds and suggest that bowls and four-lugged pots may have been preferredcontainers for processing milk. The discovery of abundant milk residues even among theearliest ceramics indicates that the pioneer farmers arrived in the region already with theknowhow of dairying and milk processing. In fact, these skills and the reliance on secondaryproducts may have given them one of the necessary tools to successfully venture into theunfarmed lands of Northwest Anatolia in the first place.Middle Eastern Studie

    Observation of the Hadronic Transitions Chi_{b 1,2}(2P) -> omega Upsilon(1S)

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    The CLEO Collaboration has observed the first hadronic transition among bottomonium (b bbar) states other than the dipion transitions among vector states, Upsilon(nS) -> pi pi Upsilon(mS). In our study of Upsilon(3S) decays, we find a significant signal for Upsilon(3S) -> gamma omega Upsilon(1S) that is consistent with radiative decays Upsilon(3S) -> gamma chi_{b 1,2}(2P), followed by chi_{b 1,2} -> omega Upsilon(1S). The branching ratios we obtain are Br(chi_{b1} -> omega Upsilon(1S) = 1.63 (+0.35 -0.31) (+0.16 -0.15) % and Br(chi_{b2} -> omega Upsilon(1S) = 1.10 (+0.32 -0.28) (+0.11 - 0.10)%, in which the first error is statistical and the second is systematic.Comment: submitted to XXI Intern'l Symp on Lepton and Photon Interact'ns at High Energies, August 2003, Fermila

    Branching Fractions of tau Leptons to Three Charged Hadrons

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    From electron-positron collision data collected with the CLEO detector operating at CESR near \sqrt{s}=10.6 GeV, improved measurements of the branching fractions for tau decays into three explicitly identified hadrons and a neutrino are presented as {\cal B}(\tau^-\to\pi^-\pi^+\pi^-\nu_\tau)=(9.13\pm0.05\pm0.46)%, {\cal B}(\tau^-\to K^-\pi^+\pi^-\nu_\tau)=(3.84\pm0.14\pm0.38)\times10^{-3}, {\cal B}(\tau^-\to K^-K^+\pi^-\nu_\tau)=(1.55\pm0.06\pm0.09)\times10^{-3}, and {\cal B}(\tau^-\to K^-K^+K^-\nu_\tau)<3.7\times10^{-5} at 90% C.L., where the uncertainties are statistical and systematic, respectively.Comment: 10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, to appear in Phys. Rev. Let
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