533 research outputs found

    Improved Fixed Center Approximation of the Faddeev equations for the KˉNN\bar{K}NN system with S=0

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    We extend the Fixed Center Approximation (FCA) to the Faddeev Equations for the KˉNN\bar{K} NN system with S=0, including the charge exchange mechanisms in the Kˉ\bar{K} rescattering which have been ignored in former works within the FCA. We obtain similar results to those found before, but the binding is reduced by 6 MeV. At the same time we also evaluate the explicit contribution the πNΣ\pi N \Sigma intermediate state in the three body system and find that it produces and additional small decrease in the binding of about 3 MeV. The system appears bound by about 35 MeV and the width omitting two body absorption, is about 50 MeV.Comment: 12 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1102.285

    Semileptonic BqDqlνB_{q}\to D^{\ast}_{q}l\nu (q=s,d,u)(q=s, d, u) transitions in QCD

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    The form factors relevant to BqDq(JP=1)νB_{q}\to D^{\ast}_{q}(J^{P}=1^{-})\ell\nu (q=s,d,u)(q=s, d, u) decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors are obtained. The total decay width and branching ratio for these decays are also evaluated using the q2q^2 dependencies of these form factors.Comment: 4 pages, 4 figures and 3 tables. To be published in the proceedings of the 14th International QCD Conference (QCD 08), Montpellier, France, 7-12 July 200

    Double-Lepton Polarization Asymmetries and Polarized Forward Backward Asymmetries in the Rare b \to s \ell^+ \ell^- Decays in a Single Universal Extra Dimension Scenario

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    We study the double-lepton polarization asymmetries and single and double-lepton polarization forward backward asymmetries of the rare b \to s \ell^+ \ell^- mode within the Standard Model and in the Appelquist-Cheng-Dobrescu model, which is a new physics scenario with a single universal extra dimension. In particular, we examine the sensitivity of the observables to the radius R of the compactified extra-dimension, which is the new parameter in this new physics model.Comment: 20 Pages, 15 Figures and 1 Tabl

    Semileptonic BqDqlνB_{q}\to D^{\ast}_{q}l\nu (q=s,d,u)(q=s, d, u) Decays in QCD Sum Rules

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    The form factors relevant to BqDq(JP=1)ellνB_{q}\to D^{\ast}_{q}(J^{P}=1^{-}) ell\nu (q=s,d,u)(q=s, d, u) decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors as well as 1/mb1/m_{b} corrections to those form factors are obtained. A comparison of the results for the ratio of form factors at zero recoil limit and other values of q2q^{2} with the predictions of the subleading Isgur-Wise form factor application for BDνB\to D^{\ast}\ell\nu is presented. The total decay width and branching ratio for these decays are also evaluated using the q2q^2 dependencies of these form factors. The results are in good agreement with the constituent quark meson model and existing experimental data. The q=sq=s case can also be detected at LHC in the near future.Comment: 28 Pages, 6 Figures and 9 Table

    Flavor Changing Neutral Currents Transition of the ΣQ\Sigma_{Q} to Nucleon in Full QCD and Heavy Quark Effective Theory

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    The loop level flavor changing neutral currents transitions of the Σbnl+l\Sigma_{b}\to n l^+l^- and Σcpl+l\Sigma_{c}\to p l^+l^- are investigated in full QCD and heavy quark effective theory in the light cone QCD sum rules approach. Using the most general form of the interpolating current for ΣQ\Sigma_{Q}, Q=bQ=b or cc, as members of the recently discovered sextet heavy baryons with spin 1/2 and containing one heavy quark, the transition form factors are calculated using two sets of input parameters entering the nucleon distribution amplitudes, namely, QCD sum rules and lattice QCD inputs. The obtained results are used to estimate the decay rates of the corresponding transitions. Since such type transitions occurred at loop level in the standard model, they can be considered as good candidates to search for the new physics effects beyond the SM.Comment: 18 Pages and 13 Table

    Allelopathic and Antifungal potentials of endemic Salvia absconditiflora Greuter & Burdet collected from different locations in Turkey

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    We determined the antifungal and bioherbicidal properties of essential oils of Salvia absconditiflora. Its plant samples were collected from 10-locations in Kirsehir province, Turkey and dried in shade. Essential oils of dried plant samples were extracted by hydro-distillation method using a Schilcher device and the compounds identified in S. absconditiflora essential oils by GC-MS analysis were: Camphor (10.52-58.64%), Bicyclo [2.2.1] Heptane-2-One, 1.7.7 (21.94-30.16%) and viridiflorol (3.42-25.2%). S. absconditiflora essential oil (a dose of 10 mu l/petri dishes) inhibited the mycelium growth of Sclerotinia sclerotiorum and Alternaria solani pathogens by 9.3 and 54.40 %, respectively. At dose of 20 mu l/petri dish, the essential oil completely inhibited the mycelium growth of both pathogens. The S. absconditiflora essential oil at 20 mu l/petri dish. was 100 % phytotoxic to seed germination and seedling growth of Lepidum sativum and Amaranthus retroflexus. Thus S. absconditiflora essential oil can be used as an alternative to synthetic fungicide and herbicide to control the plant pathogenic fungi and weeds, respectively

    Description of ρ(1700)\rho (1700) as a ρKKˉ\rho K \bar{K} system with the fixed center approximation

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    We study the ρKKˉ\rho K\bar{K} system with an aim to describe the ρ(1700)\rho (1700) resonance. The chiral unitary approach has achieved success in a description of systems of the light hadron sector. With this method, the KKˉK \bar{K} system in the isospin sector I=0I=0, is found to be a dominant component of the f0(980)f_0 (980) resonance. Therefore, by regarding the KKˉK\bar{K} system as a cluster, the f0(980)f_0 (980) resonance, we evaluate the ρKKˉ\rho K\bar{K} system applying the fixed center approximation to the Faddeev equations. We construct the ρK\rho K unitarized amplitude using the chiral unitary approach. As a result, we find a peak in the three-body amplitude around 1739 MeV and a width of about 227 MeV. The effect of the width of ρ\rho and f0(980)f_0 (980) is also discussed. We associate this peak to the ρ(1700)\rho (1700) which has a mass of 1720±201720 \pm 20 MeV and a width of 250±100250 \pm 100 MeV
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