473 research outputs found

    THE GENUS TETRACERA (DILLENIACEAE) IN THE EASTERN OLD WORLD

    Get PDF
    1. An account of the genus Tetracera L. in the eastern Old World (Asia, Malaysia,Australia, New Caledonia) is given. The Malaysian species have already been in cluded in the revision of the Dilleniaceae in "Flora malesiana" (I 4: 141-149. 1951). 2. The main part of the present paper consists of a key to the species, followed by a systematic treatment of the 15 species admitted for the region. 3. Latin diagnoses are given for three new subspecies under Tetracera asiatiea (Lour.) Hoogl. and two new varieties under Tetracera nordtiana F. Muell. 4. A number of species are reduced either to the rank of variety or to synonymy. 5. Distribution-maps are provided for the species of which a relatively large number of specimens has been studied

    Amplitudes Fitted to Experimental Data and to Roy's Equations

    Full text link
    The scalar-isoscalar, scalar-isotensor and vector-isovector pi-pi amplitudes are fitted simultaneously to experimental data and to Roy's equations. The resulting amplitudes are compared with those fitted only to experimental data. No additional constraints for the pi-pi threshold behaviour of the amplitudes are imposed. Threshold parameters are calculated for the amplitudes in the three waves. Spectrum of scalar mesons below 1.8 GeV is found from the analysis of the analytical structure of the fitted amplitudes.Comment: 3 pages, 1 figure. Talk given at MESON 2004: 8th International Workshop on Meson Production, Properties and Interactions, Cracow, Poland, 4-8 Jun 2004. Submitted to Int.J.Mod.Phys.

    Monte Carlo Renormalization of the 3-D Ising model: Analyticity and Convergence

    Full text link
    We review the assumptions on which the Monte Carlo renormalization technique is based, in particular the analyticity of the block spin transformations. On this basis, we select an optimized Kadanoff blocking rule in combination with the simulation of a d=3 Ising model with reduced corrections to scaling. This is achieved by including interactions with second and third neighbors. As a consequence of the improved analyticity properties, this Monte Carlo renormalization method yields a fast convergence and a high accuracy. The results for the critical exponents are y_H=2.481(1) and y_T=1.585(3).Comment: RevTeX, 4 PostScript file

    New frog

    Get PDF
    6 p. : ill. ; 24 cm.Includes bibliographical references (p. 6)

    Broadband mid-IR frequency comb with CSP and AGS from a Er,Tm:Ho fiber laser

    Get PDF
    We report on the generation of a 2500 nm bandwidth frequency comb at 6.5 Όm central wavelength based on critically phase-matched parametric down-conversion in the nonlinear crystal CdSiP 2 CdSiP2 (CSP), driven by a compact Er,Tm:Ho fiber laser. The generated ultra-broadband pulses show a transform-limited duration of 2.3 optical cycles and carry up to 150 pJ of energy at a 100 MHz pulse repetition rate. For comparison, the spectrum generated in AgGaS 2 AgGaS2 (AGS) spans from 6.2 to 7.4 Όm at full-width at half-maximum (FWHM) with a pulse energy of 3 pJ. A full 3D nonlinear wave propagation code is used for optimization of the noncollinear angle, propagation direction, and crystal thickness.Peer ReviewedPostprint (author's final draft

    S-wave Meson-Meson Scattering from Unitarized U(3) Chiral Lagrangians

    Get PDF
    An investigation of the s-wave channels in meson-meson scattering is performed within a U(3) chiral unitary approach. Our calculations are based on a chiral effective Lagrangian which includes the eta' as an explicit degree of freedom and incorporates important features of the underlying QCD Lagrangian such as the axial U(1) anomaly. We employ a coupled channel Bethe-Salpeter equation to generate poles from composed states of two pseudoscalar mesons. Our results are compared with experimental phase shifts up to 1.5 GeV and effects of the eta' within this scheme are discussed.Comment: 18 pages, 6 figure

    On the precision of chiral-dispersive calculations of ππ\pi\pi scattering

    Get PDF
    We calculate the combination 2a0(0)−5a0(2)2a_0^{(0)}-5a_0^{(2)} (the Olsson sum rule) and the scattering lengths and effective ranges a1a_1, a2(I)a_2^{(I)} and b1b_1, b2(I)b_2^{(I)} dispersively (with the Froissart--Gribov representation) using, at low energy, the phase shifts for ππ\pi\pi scattering obtained by Colangelo, Gasser and Leutwyler (CGL) from the Roy equations and chiral perturbation theory, plus experiment and Regge behaviour at high energy, or directly, using the CGL parameters for aas and bbs. We find mismatch, both among the CGL phases themselves and with the results obtained from the pion form factor. This reaches the level of several (2 to 5) standard deviations, and is essentially independent of the details of the intermediate energy region (0.82≀E≀1.420.82\leq E\leq 1.42 GeV) and, in some cases, of the high energy behaviour assumed. We discuss possible reasons for this mismatch, in particular in connection with an alternate set of phase shifts.Comment: Version to appear in Phys. Rev. D. Graphs and sum rule added. Plain TeX fil

    Analysis of Bose-Einstein correlations in e+e- -> W+W- events including final state interactions

    Get PDF
    Recently DELPHI Collaboration reported new data on Bose-Einstein correlations (BEC) measured in e+e- -> W^+W^- events. Apparently no enhancement has been observed. We have analyzed these data including final state interactions (FSI) of both Coulomb and strong (s-wave) origin and found that there is enhancement in BEC but it is overshadowed by the FSI which are extremely important for those events. We have found the following values for the size of the interaction range beta and the degree of coherence lambda: beta=0.87 +/- 0.31fm and lambda=1.19 +/- 0.48, respectively.Comment: 7pages, 4 figure

    WW Cross-sections and Distributions

    Get PDF
    We present the results obtained by the "WW Cross-sections and Distributions" working group during the CERN Workshop "Physics at LEP2" (1994/1995)Comment: 61 pages, tar'ed gzip'ed uuencoded files, LaTeX, 4 Postscript figures. To appear in "Physics at LEP2", G.Altarelli and F.Zwirner eds., CERN Report 199
    • 

    corecore