A Measurement of Psi(2S) Resonance Parameters

Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) total width; partial widths to hadrons, pi+pi- J/Psi, muons; and corresponding branching fractions have been determined to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)= (2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)= (97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%, respectively.Comment: 8 pages, 6 figure

Partial Wave Analysis of J/ψ→γ(K+K−π+π−)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

BES data on $J/\psi \to \gamma (K^+K^-\pi^+\pi^-)$ are presented. The $K^*\bar K^*$ contribution peaks strongly near threshold. It is fitted with a broad $0^{-+}$ resonance with mass $M = 1800 \pm 100$ MeV, width $\Gamma = 500 \pm 200$ MeV. A broad $2^{++}$ resonance peaking at 2020 MeV is also required with width $\sim 500$ MeV. There is further evidence for a $2^{-+}$ component peaking at 2.55 GeV. The non-$K^*\bar K^*$ contribution is close to phase space; it peaks at 2.6 GeV and is very different from $K^{*}\bar{K^{*}}$.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

New hydrogen distribution in a-si:h: An nmr study

Hot-filament-assisted CVD deposited a-Si:H with low H concentration and low defect density has been examined by 1H NMR. It is demonstrated for the first time that H microstructures can be altered significantly in device quality a-Si:H films. In the present films, large H clusters account for 90% of the 2-3 at. % H atoms, with the remaining H more dispersed, but still aggregated in a small volume fraction of the material. These results suggest that an ideal a-Si:H network with low defect density and high structural stability may not necessarily be homogeneous

Varying Contents of Sources Affect Tectonic-Setting Discrimination of Sediments: A Case Study from Permian Sandstones in the Eastern Tianshan, Northwestern China

This article reports new geochemical data from Permian sandstones, most probably deposited during a period of postcollisional extension, from the Yamansu, Shaquanzi, and Xingxingxia areas in the Eastern Tianshan, northwestern China, to determine and characterize their provenance and source nature. The medium- to coarse-grained sandstones are composed mainly of angular to subangular quartz and volcanic fragments, with minor plagioclase and/or microcline, suggesting proximal deposition. Although the samples show relatively large variations in SiO2 (59.7–70.8 wt%), Al2O3 (9.0–14.9 wt%), and Fe2O3T + MgO (2.3–5.2 wt%) contents, they yield low chemical index of alteration values (41–55) but high index of compositional variability values (1.06–1.78), suggestive of their derivation mainly from compositionally immature sources with weak chemical weathering. Their relatively low Zr concentrations (99–225 ppm) and GdN/YbN ratios (1.20–1.53) manifest insignificant zircon and monazite enrichments. Most of the samples are characterized by upper continental crust–like rare earth element (REE) patterns with δEu values of 0.63–0.99, reflecting dominant contributions from intermediate to felsic rocks. In particular, the Xingxingxia and Shaquanzi samples have relatively low SiO2/Al2O3 (4.51–5.82) and Th/U (2.67–3.77) ratios but high ∑REE (total REE) contents (71.8–141.1 ppm), indicative of a low degree of sedimentary sorting/recycling, whereas the Yamansu samples have higher SiO2/Al2O3 (6.30–6.57) and Th/U (3.93–5.16) ratios but low ∑REE contents (77.1–86.8 ppm), probably indicative of a higher degree of sedimentary recycling or more involvement of recycled materials. Tectonic-setting discrimination using geochemical data from the samples yielded inconsistent results, with the Xingxingxia and Shaquanzi samples dominantly plotted in or adjacent to the active continental margin or continental island arc field, while the Yamansu samples mostly plotted in or adjacent to the passive margin field. Combining our findings with those of previous detrital zircon studies, we suggest that the inconsistent tectonic discriminations of the Permian sandstones most likely resulted from their receiving different proportions of source rocks that have distinct geochemical compositions. This study provides ample evidence that the geochemical compositions of sedimentary rocks within a continuous sequence or in the same depositional tectonic setting can vary significantly as a result of changes in contents of different source materials and thus that the use of tectonic-setting discrimination diagrams requires great caution

Modern temporal network theory: A colloquium

The power of any kind of network approach lies in the ability to simplify a complex system so that one can better understand its function as a whole. Sometimes it is beneficial, however, to include more information than in a simple graph of only nodes and links. Adding information about times of interactions can make predictions and mechanistic understanding more accurate. The drawback, however, is that there are not so many methods available, partly because temporal networks is a relatively young field, partly because it more difficult to develop such methods compared to for static networks. In this colloquium, we review the methods to analyze and model temporal networks and processes taking place on them, focusing mainly on the last three years. This includes the spreading of infectious disease, opinions, rumors, in social networks; information packets in computer networks; various types of signaling in biology, and more. We also discuss future directions.Comment: Final accepted versio

Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-

Evidence of $\psi(3770)$ decays to a non-${D \bar D}$ final state is observed. A total of $11.8 \pm 4.8 \pm 1.3$ \psi(3770) \to \PPJP events are obtained from a data sample of 27.7 $\rm {pb^{-1}}$ taken at center-of-mass energies around 3.773 GeV using the BES-II detector at the BEPC. The branching fraction is determined to be BF(\psi(3770) \to \PPJP)=(0.34\pm 0.14 \pm 0.09)%, corresponding to the partial width of \Gamma(\psi(3770) \to \PPJP) = (80 \pm 33 \pm 23) keV.Comment: 8 pages, 7 figures, Submitted to Physics Letters

A Study of J/psi-->gamma gamma V(rho,phi) Decays with the BESII Detector

Using a sample of $58\times 10^6$ $J/\psi$ events collected with the BESII detector, radiative decays $J/\psi\to\gamma\gamma V$, where $V=\rho$ or $\phi$, are studied. A resonance around 1420 MeV/c$^2$ (X(1424)) is observed in the $\gamma\rho$ mass spectrum. Its mass and width are measured to be $1424\pm 10(stat)\pm 11(sys)$ MeV/c$^2$ and $101.0\pm 8.8 \pm 8.8$ MeV/c$^2$, respectively, and its branching ratio $B(J/\psi\to \gamma X(1424)\to \gamma \gamma \rho)$ is determined to be $(1.07\pm0.17 \pm 0.11)\times 10^{-4}$. A search for $X(1424)\to \gamma\phi$ yields a 95% C.L. upper limit $B(J/\psi\to \gamma X(1424)\to \gamma\gamma \phi) < 0.82 \times 10^{-4}$.Comment: 10 pages, 5 figures, submitted to PL

Improved measurement of the branching ratio of J/psi-->K_S K_L

The branching ratio of J/psi-->K_S K_L is measured with improved precision to be B(J/psi-->K_S K_L) = (1.82\pm 0.04\pm 0.13)\times 10^{-4}. using J/psi data collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider. This result is used to test the perturbative QCD ``12%'' rule between psi(2S) and J/psi decays and to investigate the relative phase between the three-gluon and one-photon annihilation amplitudes in J/psi decays.Comment: 10 pages, 14 figures, 2 tables, submitted to Phys. Rev.