32,873 research outputs found
SU(3) Flavor Breaking in Hadronic Matrix Elements for Oscillations
We present an analysis, using quenched configurations at 5.7, 5.85,
6.0, and 6.3 of the matrix element \MP\equiv\langle \bar P_{hl}|\bar h
\gamma_\mu (1-\gamma_5)l \bar h \gamma_\mu(1-\gamma_5)l|P_{hl}\rangle for
heavy-light pseudoscalar mesons. The results are extrapolated to the physical
meson states, \Bd and \Bs. We directly compute the ratio \MS/\MB, and
obtain the preliminary result \MS/\MB=1.54(13)(32). A precise value of this
SU(3) breaking ratio is important for determining once the mixing
parameter for \Bs-\bar\Bs is measured experimentally. We also determine
values for the corresponding B parameters, , which we cannot distinguish in the present analysis.Comment: Poster presented at LATTICE96(heavy quarks). LaTeX, uses espcrc2.sty
and epsf, 4 pages, 4 postscript figures include
Mass storage system experiences and future needs at the National Center for Atmospheric Research
A summary and viewgraphs of a discussion presented at the National Space Science Data Center (NSSDC) Mass Storage Workshop is included. Some of the experiences of the Scientific Computing Division at the National Center for Atmospheric Research (NCAR) dealing the the 'data problem' are discussed. A brief history and a development of some basic mass storage system (MSS) principles are given. An attempt is made to show how these principles apply to the integration of various components into NCAR's MSS. Future MSS needs for future computing environments is discussed
Mass storage system experiences and future needs at the National Center for Atmospheric Research
This presentation is designed to relate some of the experiences of the Scientific Computing Division at NCAR dealing with the 'data problem'. A brief history and a development of some basic Mass Storage System (MSS) principles are given. An attempt is made to show how these principles apply to the integration of various components into NCAR's MSS. There is discussion of future MSS needs for future computing environments
Light hadron properties with improved staggered quarks
Preliminary results from simulations with 2+1 dynamical quark flavors at a
lattice spacing of 0.09 fm are combined with earlier results at a=0.13 fm. We
examine the approach to the continuum limit and investigate the dependence of
the pseudoscalar masses and decay constants as the sea and valence quark masses
are separately varied.Comment: Lattice2002(spectrum
Finite-Temperature Phase Structure of Lattice QCD with the Wilson Quark Action for Two and Four Flavors
We present further analyses of the finite-temperature phase structure of
lattice QCD with the Wilson quark action based on spontaneous breakdown of
parity-flavor symmetry. Results are reported on (i) an explicit demonstration
of spontaneous breakdown of parity-flavor symmetry beyond the critical line,
(ii) phase structure and order of chiral transition for the case of
flavors, and (iii) approach toward the continuum limit.Comment: Poster presented at LATTICE96(finite temperature); 4 pages, Latex,
uses espcrc2 and epsf, seven ps figures include
Modular Invariant of Quantum Tori II: The Golden Mean
In our first article in this series ("Modular Invariant of Quantum Tori I:
Definitions Nonstandard and Standard" arXiv:0909.0143) a modular invariant of
quantum tori was defined. In this paper, we consider the case of the quantum
torus associated to the golden mean. We show that the modular invariant is
approximately 9538.249655644 by producing an explicit formula for it involving
weighted versions of the Rogers-Ramanujan functions
Oil-in-oil emulsions stabilised solely by solid particles
A brief review of the stabilisation of emulsions of two immiscible oils is given. We then describe the use of fumed silica particles coated with either hydrocarbon or fluorocarbon groups in acting as sole stabilisers of emulsions of various vegetable oils with linear silicone oils (PDMS) of different viscosity. Transitional phase inversion of emulsions, containing equal volumes of the two oils, from silicone-invegetable (S/V) to vegetable-in-silicone (V/S) occurs upon increasing the hydrophobicity of the particles. Close to inversion, emulsions are stable to coalescence and gravity-induced separation for at least one year. Increasing the viscosity of the silicone oil enables stable S/V emulsions to be prepared even with relatively hydrophilic particles. Predictions of emulsion type from calculated contact angles of a silica particle at the oil–oil interface are in agreement with experiment provided a small polar contribution to the surface energy of the oils is included. We also show that stable multiple emulsions of V/S/V can be prepared in a two-step procedure using two particle types of different hydrophobicity. At fixed particle concentration, catastrophic phase inversion of emulsions from V/S to S/V can be effected by increasing the volume fraction of vegetable oil. Finally, in the case of sunflower oil + 20 cS PDMS, the study is extended to particles other than silica which differ in chemical type, particle size and particle shape. Consistent with the above findings, we find that only sufficiently hydrophobic particles (clay, zinc oxide, silicone, calcium carbonate) can act as efficient V/S emulsion stabilisers
Modulational instability of nonlinear polarization mode coupling in microresonators
We investigate frequency comb generation in the presence of polarization
effects induced by nonlinear mode coupling in microresonator devices. A set of
coupled temporal Lugiato-Lefever equations are derived to model the propagation
dynamics, and an in-depth study is made of the modulational instability of
their multistable homogeneous steady-state solutions. It is shown that new
kinds of instabilities can occur for co-propagating fields that interact
through nonlinear cross-phase modulation. These instabilities display
properties that differ from their scalar counterpart, and are shown to result
in the generation of new types of incoherently coupled frequency comb states.Comment: 8 pages, 7 figure
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