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Using data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.178 to 4.600 GeV, we study the process eþe− → π0Xð3872Þγ and search for Zcð4020Þ0 → Xð3872Þγ. We find no significant signal and set upper limits on σðeþe− → π0Xð3872ÞγÞ · BðXð3872Þ → πþπ−J=ψÞ and σðeþe− → π0Zcð4020Þ0Þ · BðZcð4020Þ0 → Xð3872ÞγÞ · BðXð3872Þ → πþπ−J=ψÞ for each energy point at 90% confidence level, which is of the order of several tenths pb.
By analyzing 6.32 fb − 1 of e+ e− annihilation data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we determine the branching fraction of the leptonic decay D + s → τ + ντ, with τ+ → π + π0¯ντ, to be B D + s → τ + ν τ = (5.29 ± 0.25 stat ± 0.20 syst) %. We estimate the product of the Cabibbo-Kobayashi-Maskawa matrix element |Vcs|and the D + s decay constant f D + s to be f D + s|Vcs| = (244.8 ± 5.8 stat ± 4.8syst) MeV, using the known values of the τ + and D + s masses as well as the D + s lifetime, together with our branching fraction measurement. Combining the value of |Vcs| obtained from a global fit in the standard model and f D + s from lattice quantum chromodynamics, we obtain f D + s = (251.6 ± 5.9 stat ± 4.9syst) MeV and |Vcs| = 0.980 ± 0.023 stat ± 0.019 syst. Using the branching fraction of B D + s → μ + νμ = (5.35±0.21)×10−3, we obtain the ratio of the branching fractions B D + s → τ + ντ/B D +s → μ+νμ = 9.89±0.71, which is consistent with the standard model prediction of lepton flavor universality.
We present the first experimental search for the rare charm decay D0→π0ν¯ν. It is based on an e+e− collision sample consisting of 10.6×10^6 pairs of D0¯D0 mesons collected by the BESIII detector at √s=3.773 GeV, corresponding to an integrated luminosity of 2.93 fb^−1. A data-driven method is used to ensure the reliability of the background modeling. No significant D0→π0ν¯ν signal is observed in data and an upper limit of the branching fraction is set to be 2.1×10^-4 at the 90% confidence level. This is the first experimental constraint on charmed-hadron decays into dineutrino final states.
We measure the inclusive semielectronic decay branching fraction of the D+s meson. A double-tag technique is applied to e+e− annihilation data collected by the BESIII experiment at the BEPCII collider, operating in the center-of-mass energy range 4.178–4.230 GeV. We select positrons fromD+s→Xe+νe with momenta greater than 200 MeV/c and determine the laboratory momentum spectrum, accounting for the effects of detector efficiency and resolution. The total positron yield and semielectronic branching fraction are determined by extrapolating this spectrum below the momentum cutoff. We measure the D+s semielectronic branching fraction to be(6.30±0.13(stat.)±0.09(syst.)±0.04(ext.))%, showing no evidence for unobserved exclusive semielectronic modes. We combine this result with external data taken from literature to determine the ratio of the D+s and D0 semielectronic widths, Γ(D+s→Xe+νe)Γ(D0→Xe+νe)=0.790±0.016(stat.)±0.011(syst.)±0.016(ext.). Our results are consistent with and more precise than previous measurements.
The Born cross sections of the e+e− → D*+D*− and e+e− → D*+D− processes are measured using e+e− collision data collected with the BESIII experiment at center-of-mass energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of 15.7 fb−1. The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.
By using 6.32 fb−1 of data collected with the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, we perform an amplitude analysis of the decay D+s ! K0S + 0 and determine the relative fractions and phase differences of different intermediate processes, which include K0S (770)+, K0S (1450)+, K (892)0 +, K (892)+ 0, and K (1410)0 +. With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be B(D+s ! K0S + 0) = (5.43 ± 0.30stat ± 0.15syst) × 10−3.
Using a sample of (10.09±0.04)×109 J/ψ events collected with the BESIII detector, a partial wave analysis of J/ψ→γη′η′ is performed.The masses and widths of the observed resonances and their branching fractions are reported. The main contribution is from J/ψ→γf0(2020) with f0(2020)→η′η′, which is found with a significance of greater than 25σ. The product branching fraction B(J/ψ → γf0(2020))⋅B(f0(2020) → η′η′ is measured to be (2.63±0.06(stat.) + 0.31−0.46(syst.))×10−4.
The electromagnetic process is studied with the initial-state-radiation technique using 7.5 fb−1 of data collected by the BESIII experiment at seven energy points from 3.773 to 4.600 GeV. The Born cross section and the effective form factor of the proton are measured from the production threshold to 3.0 GeV/ using the invariant-mass spectrum. The ratio of electric and magnetic form factors of the proton is determined from the analysis of the proton-helicity angular distribution.
Diese Diplomarbeit beschäftigt sich sowohl mit der Akquisition, der Verwaltung und der winkelabhängigen, spektralen Reflexionsfunktion BRDF (Bidirectional Reflectance Distribution Function) und BTFs (Bidirection Texture Functions) von einigen ausgewählten realistischen Materialoberflächen bei fester Beleuchtung, als auch der Generierung der BTFs aus vorhandenen BRDFs und BTFs und der Anwendung der Beschreibung von Oberflächen mittels BRDFs und BTFs bei Erzeugungen von 3D-Szenen. Im Rahmen dieser Diplomarbeit werden Konzepte für eine effektivere Nutzung von BTFs in der photorealistischen Bilderzeugung entwickelt und prototypisch umgesetzt. Der Fokus liegt dabei auf einer vereinfachten Synthese von BTFs aus vorhandenen BRDF- und BTF-Daten, sowie in einer effizienten Nutzbarmachung dieser Informationen für Rendering-Prozesse.
Analyses of whole genomic shotgun datasets, COI barcodes, morphology, and historical literature suggest that the following 13 butterfly species from the family Hesperiidae (Lepidoptera: Papilionoidea) in Texas, USA are distinct from their closest named relatives and therefore are described as new (type localities are given in parenthesis): Spicauda atelis Grishin, new species (Hidalgo Co., Mission), Urbanus (Urbanus) rickardi Grishin, new species (Hidalgo Co., nr. Madero), Urbanus (Urbanus) oplerorum Grishin, new species (Hidalgo Co., Mission/Madero), Telegonus tsongae Grishin, new species (Starr Co., Roma), Autochton caballo Grishin, new species (Hidalgo Co., 6 mi W of Hidalgo), Epargyreus fractigutta Grishin, new species (Hidalgo Co., McAllen), Aguna mcguirei Grishin, new species (Cameron Co., Brownsville), Polygonus pardus Grishin, new species (Hidalgo Co., McAllen), Arteurotia artistella Grishin, new species (Hidalgo Co., Mission), Heliopetes elonmuski Grishin, new species (Cameron Co., Boca Chica), Hesperia balcones Grishin, new species (Travis Co., Volente), Troyus fabulosus Grishin, new species (Hidalgo Co., Peñitas), and Lerema ochrius Grishin, new species (Hidalgo Co., nr. Relampago). Most of these species are known in the US almost exclusively from the Lower Rio Grande Valley in Texas. Nine of the holotypes were collected in 1971-1975, a banner period for butterfly species newly recorded from the Rio Grande Valley of Texas; five of them collected by William W. McGuire, and one by Nadine M. McGuire. At the time, these new species have been recorded under the names of their close relatives. A Neotype is designated for Papilio fulminator Sepp, [1841] (Suriname). Lectotypes are designated for Goniurus teleus Hübner, 1821 (unknown, likely in South America), Goniloba azul Reakirt, [1867] (Mexico: Veracruz) and Eudamus misitra Plötz, 1881 (Mexico). Several taxonomic changes are proposed. The following taxa are species (not subspecies): Spicauda zalanthus (Plötz, 1880), reinstated status (not Spicauda teleus (Hübner, 1821)), Telegonus fulminator (Sepp, [1841]), reinstated status (not Telegonus fulgerator (Walch, 1775), Telegonus misitra (Plötz, 1881), reinstated status (not Telegonus azul (Reakirt, [1867])), Autochton reducta (Mabille and Boullet, 1919), new status (not Autochton potrillo (Lucas, 1857)), Epargyreus gaumeri Godman and Salvin, 1893, reinstated status (not Epargyreus clavicornis (Herrich-Schäffer, 1869)), and Polygonus punctus E. Bell and W. Comstock, 1948, new status (not Polygonus savigny (Latreille, [1824])). Urbanus ehakernae Burns, 2014 and Epargyreus socus chota Evans, 1952 are junior subjective synonyms of Urbanus alva Evans, 1952 and Epargyreus clavicornis (Herrich-Schäffer, 1869), respectively, and Epargyreus gaumeri tenda Evans, 1955, new combination is not a subspecies of E. clavicornis.
ZooBank registration. https://zoobank.org/D5462F9E-E08D-46C6-898D-76EE7466DD19
