889 research outputs found

    Phylogenetic relationships within Orobanche and Phelipanche (Orobanchaceae) from Central Europe, focused on problematic aggregates, taxonomy, and host ranges

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    Holoparasitic genera within the family Orobanchaceae are characterized by greatly reduced vegetative organs; therefore, molecular analysis has proved to be a useful tool in solving taxonomic problems in this family. For this purpose, we studied all species of the genera Orobanche and Phelipanche occurring in Central Europe, specifically in Poland, the Czech Republic, Slovakia, and Austria, supplemented by samples mainly from Spain, France, Germany, and Ukraine. They were investigated using nuclear sequences (ITS region) and a plastid trnL- trnF region. The aim of this study was to examine phylogenetic relationships within Orobanche and Phelipanche from Central Europe; we focused on problematic species and aggregates, recent taxonomic changes in these (rank and secondary ranks), and host ranges. The most interesting results concern the exlusion of O. mayeri from O. alsatica aggr. Additionally, following the rules of traditional taxonomy, the correct names and types of some secondary ranks are given and, as a result of this, a new combination below the Phelipanche genus is made ( P . sect. Trionychon ). The host ranges of the investigated species in Central Europe include 102 species from 12 families, most often from Asteraceae. For this purpose, ca. 400 localities were examined in the field. Moreover, data acquired from the literature and European and Asian herbaria were use

    Search for the radiative transitions ψ(3770)γηc\psi(3770)\to\gamma\eta_c and γηc(2S)\gamma\eta_c(2S)

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    By using a 2.92 fb1^{-1} data sample taken at s=3.773\sqrt{s} = 3.773 GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions ψ(3770)γηc\psi(3770)\to\gamma\eta_c and γηc(2S)\gamma\eta_c(2S) through the hadronic decays ηc(ηc(2S))KS0K±π\eta_c(\eta_c(2S))\to K^0_SK^\pm\pi^\mp. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be B(ψ(3770)γηc)×B(ηcKS0K±π)<1.6×105\mathcal{B}(\psi(3770)\to\gamma\eta_c)\times \mathcal{B}(\eta_c\to K^0_SK^\pm\pi^\mp) < 1.6\times10^{-5} and B(ψ(3770)γηc(2S))×B(ηc(2S)KS0K±π)<5.6×106\mathcal{B}(\psi(3770)\to\gamma\eta_c(2S))\times \mathcal{B}(\eta_c(2S)\to K^0_SK^\pm\pi^\mp) < 5.6\times10^{-6}. Combining our result with world-average values of B(ηc(ηc(2S))KS0K±π)\mathcal{B}(\eta_c(\eta_c(2S))\to K^0_SK^\pm\pi^\mp), we find the branching fractions B(ψ(3770)γηc)<6.8×104\mathcal{B}(\psi(3770)\to\gamma\eta_c) < 6.8\times10^{-4} and B(ψ(3770)γηc(2S))<2.0×103\mathcal{B}(\psi(3770)\to\gamma\eta_c(2S)) < 2.0\times10^{-3} at a 90% confidence level.Comment: 10 pages, 4 figure

    Measurement of azimuthal asymmetries in inclusive charged dipion production in e+ee^+e^- annihilations at s\sqrt{s} = 3.65 GeV

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    We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process e+eππXe^+e^-\rightarrow \pi\pi X based on a data set of 62 pb1\rm{pb}^{-1} at the center-of-mass energy s=3.65\sqrt{s}=3.65 GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.Comment: 7 pages, 5 figure

    Measurement of the e+eπ+π\mathrm e^+\mathrm e^-\rightarrow\mathrm\pi^+\mathrm\pi^- Cross Section between 600 and 900 MeV Using Initial State Radiation

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    We extract the e+eπ+πe^+e^-\rightarrow \pi^+\pi^- cross section in the energy range between 600 and 900 MeV, exploiting the method of initial state radiation. A data set with an integrated luminosity of 2.93 fb1^{-1} taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider is used. The cross section is measured with a systematic uncertainty of 0.9%. We extract the pion form factor Fπ2|F_\pi|^2 as well as the contribution of the measured cross section to the leading order hadronic vacuum polarization contribution to (g2)μ(g-2)_\mu. We find this value to be aμππ,LO(600900  MeV)=(368.2±2.5stat±3.3sys)1010a_\mu^{\pi\pi,\rm LO}(600-900\;\rm MeV) = (368.2 \pm 2.5_{\rm stat} \pm 3.3_{\rm sys})\cdot 10^{-10}.Comment: 14 pages, 7 figures, accepted by PL

    Study of D+Kπ+e+νeD^{+} \to K^{-} \pi^+ e^+ \nu_e

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    We present an analysis of the decay D+Kπ+e+νeD^{+} \to K^{-} \pi^+ e^+ \nu_e based on data collected by the BESIII experiment at the ψ(3770)\psi(3770) resonance. Using a nearly background-free sample of 18262 events, we measure the branching fraction B(D+Kπ+e+νe)=(3.71±0.03±0.08)%\mathcal{B}(D^{+} \to K^{-} \pi^+ e^+ \nu_e) = (3.71 \pm 0.03 \pm 0.08)\%. For 0.8<mKπ<1.00.8<m_{K\pi}<1.0 GeV/c2c^{2} the partial branching fraction is B(D+Kπ+e+νe)[0.8,1]=(3.33±0.03±0.07)%\mathcal{B}(D^{+} \to K^{-} \pi^+ e^+ \nu_e)_{[0.8,1]} = (3.33 \pm 0.03 \pm 0.07)\%. A partial wave analysis shows that the dominant Kˉ(892)0\bar K^{*}(892)^{0} component is accompanied by an \emph{S}-wave contribution accounting for (6.05±0.22±0.18)%(6.05\pm0.22\pm0.18)\% of the total rate and that other components are negligible. The parameters of the Kˉ(892)0\bar K^{*}(892)^{0} resonance and of the form factors based on the spectroscopic pole dominance predictions are also measured. We also present a measurement of the Kˉ(892)0\bar K^{*}(892)^{0} helicity basis form factors in a model-independent way.Comment: 17 pages, 6 figure

    Observation of J/ψppˉa0(980)J/\psi \rightarrow p\bar{p}a_{0}(980) at BESIII

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    Using 2.25×1082.25\times10^{8} J/ψJ/\psi events collected with the BESIII detector at the BEPCII storage rings, we observe for the first time the process J/ψppˉa0(980)J/\psi\rightarrow p\bar{p}a_{0}(980), a0(980)π0ηa_{0}(980)\rightarrow \pi^{0}\eta with a significance of 6.5σ6.5\sigma (3.2σ3.2\sigma including systematic uncertainties). The product branching fraction of J/ψppˉa0(980)ppˉπ0ηJ/\psi\rightarrow p\bar{p}a_{0}(980)\rightarrow p\bar{p}\pi^{0}\eta is measured to be (6.8±1.2±1.3)×105(6.8\pm1.2\pm1.3)\times 10^{-5}, where the first error is statistical and the second is systematic. This measurement provides information on the a0a_{0} production near threshold coupling to ppˉp\bar{p} and improves the understanding of the dynamics of J/ψJ/\psi decays to four body processes.Comment: 8 pages, 7 figure

    Observation of Ds+pnˉD^+_s\rightarrow p\bar{n} and confirmation of its large branching fraction

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    The baryonic decay Ds+pnˉD^+_s\rightarrow p\bar{n} is observed, and the corresponding branching fraction is measured to be (1.21±0.10±0.05)×103(1.21\pm0.10\pm0.05)\times10^{-3}, where the first uncertainty is statistical and second systematic. The data sample used in this analysis was collected with the BESIII detector operating at the BEPCII e+ee^+e^- double-ring collider with a center-of-mass energy of 4.178~GeV and an integrated luminosity of 3.19~fb1^{-1}. The result confirms the previous measurement by the CLEO Collaboration and is of greatly improved precision, which may deepen our understanding of the dynamical enhancement of the W-annihilation topology in the charmed meson decays

    Search for C-parity violation in J/ψγγJ/ \psi \to \gamma\gamma and γϕ \gamma \phi

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    Using 1.06×1081.06\times10^8 ψ(3686)\psi(3686) events recorded in e+ee^{+}e^{-} collisions at s=\sqrt{s}= 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in J/ψγγJ/\psi \to \gamma\gamma and γϕ \gamma \phi decays via ψ(3686)J/ψπ+π\psi(3686) \to J/\psi \pi^+\pi^-. No significant signals are observed in either channel. Upper limits on the branching fractions are set to be B(J/ψγγ)<2.7×107\mathcal{B}(J/\psi \to \gamma\gamma) < 2.7 \times 10^{-7} and B(J/ψγϕ)<1.4×106\mathcal{B}(J/\psi \to \gamma\phi) < 1.4 \times 10^{-6} at the 90\% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.Comment: 7 pages, 2 figure

    Observation and study of the decay J/ψϕηηJ/\psi\rightarrow\phi\eta\eta'

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    We report the observation and study of the decay J/ψϕηηJ/\psi\rightarrow\phi\eta\eta' using 1.3×1091.3\times{10^9} J/ψJ/\psi events collected with the BESIII detector. Its branching fraction, including all possible intermediate states, is measured to be (2.32±0.06±0.16)×104(2.32\pm0.06\pm0.16)\times{10^{-4}}. We also report evidence for a structure, denoted as XX, in the ϕη\phi\eta' mass spectrum in the 2.02.12.0-2.1 GeV/c2c^2 region. Using two decay modes of the η\eta' meson (γπ+π\gamma\pi^+\pi^- and ηπ+π\eta\pi^+\pi^-), a simultaneous fit to the ϕη\phi\eta' mass spectra is performed. Assuming the quantum numbers of the XX to be JP=1J^P = 1^-, its significance is found to be 4.4σ\sigma, with a mass and width of (2002.1±27.5±21.4)(2002.1 \pm 27.5 \pm 21.4) MeV/c2c^2 and (129±17±9)(129 \pm 17 \pm 9) MeV, respectively, and a product branching fraction B(J/ψηX)×B(Xϕη)=(9.8±1.2±1.7)×105\mathcal{B}(J/\psi\rightarrow\eta{}X)\times{}\mathcal{B}(X\rightarrow\phi\eta')=(9.8 \pm 1.2 \pm 1.7)\times10^{-5}. Alternatively, assuming JP=1+J^P = 1^+, the significance is 3.8σ\sigma, with a mass and width of (2062.8±13.1±7.2)(2062.8 \pm 13.1 \pm 7.2) MeV/c2c^2 and (177±36±35)(177 \pm 36 \pm 35) MeV, respectively, and a product branching fraction B(J/ψηX)×B(Xϕη)=(9.6±1.4±2.0)×105\mathcal{B}(J/\psi\rightarrow\eta{}X)\times{}\mathcal{B}(X\rightarrow\phi\eta')=(9.6 \pm 1.4 \pm 2.0)\times10^{-5}. The angular distribution of J/ψηXJ/\psi\rightarrow\eta{}X is studied and the two JPJ^P assumptions of the XX cannot be clearly distinguished due to the limited statistics. In all measurements the first uncertainties are statistical and the second systematic.Comment: 10 pages, 6 figures and 4 table
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