75 research outputs found
eta - eta' - glueball mixing
We have revisited glueball mixing with the pseudoscalar mesons in the MIT bag
model scheme. The calculation has been performed in the spherical cavity
approximation to the bag using two different fermion propagators, the cavity
and the free propagators. We obtain a very small probability of mixing for the
eta at the level of $0.04-0.1% and a bigger for the eta' at the level of 4-12%.
Our results differ from previous calculations in the same scheme but seem to
agree with the experimental analysis. We discuss the origin of our difference
which stems from the treatment of our time integrations.Comment: 21 pages, 7 figure
The Stochastic Toolbox User's Guide -- xSPDE3: extensible software for stochastic ordinary and partial differential equations
The xSPDE toolbox treats stochastic partial and ordinary differential
equations, with applications in biology, chemistry, engineering, medicine,
physics and quantum technologies. It computes statistical averages, including
time-step and/or sampling error estimation. xSPDE can provide higher order
convergence, Fourier spectra and probability densities. The toolbox has
graphical output and statistics, as well as weighted, projected, or
forward-backward equations. It can generate input-output quantum spectra. All
equations may have independent periodic, Dirichlet, and Neumann or Robin
boundary conditions in any dimension, for any vector field component, and at
either end of any interval.Comment: User manual for xSPDE software on Github, at
https://github.com/peterddrummond/xspde_matlab. Total of 160 pages with
examples. This is a replacement with minor corrections and an updated
reference list. Accepted, and will appear in Scipos
Designed Guanidinium-Rich Amphipathic Oligocarbonate Molecular Transporters Complex, Deliver and Release siRNA in Cells
The polyanionic nature of oligonucleotides and their enzymatic degradation present challenges for the use of siRNA in research and therapy; among the most notable of these is clinically relevant delivery into cells. To address this problem, we designed and synthesized the first members of a new class of guanidinium-rich amphipathic oligocarbonates that noncovalently complex, deliver, and release siRNA in cells, resulting in robust knockdown of target protein synthesis in vitro as determined using a dual-reporter system. The organocatalytic oligomerization used to synthesize these co-oligomers is step-economical and broadly tunable, affording an exceptionally quick strategy to explore chemical space for optimal siRNA delivery in varied applications. The speed and versatility of this approach and the biodegradability of the designed agents make this an attractive strategy for biological tool development, imaging, diagnostics, and therapeutic applications
Comparing Notes: Recording and Criticism
This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edison’s Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice
The 2020 report of The Lancet Countdown on health and climate change: responding to converging crises
The Lancet Countdown is an international collaboration, established to provide an independent, global monitoring system dedicated to tracking the emerging health profile of the changing climate. The 2020 report presents 43 indicators across five sections: climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; economics and finance; and public and political engagement. This report represents the findings and consensus of the 35 leading academic institutions and UN agencies that make up the Lancet Countdown, and draws on the expertise of climate scientists, geographers, and engineers; of energy, food, and transport experts; and of economists, social and political scientists, data scientists, public health professionals, and doctors
Wider Still and Wider: British Music Criticism since the Second World War
This chapter provides the first historical examination of music criticism in Britain since the Second World War. In the process, it also challenges the simplistic prevailing view of this being a period of decline from a golden age in music criticism
Numerical Simulation and Calculation of Resistance of Laminated Paper-Impregnated Insulation of Power Cables
Numerical simulation of polypropylene laminated paper insulation is a serious challenge, as it must take into account the layered structure and presence of longitudinal and radial gaps in the coils of the winded tape for cables with sector-shape conductive cores. Thus far, it has been performed only with serious simplifications. We propose a technique for numerical modeling of electric parameters in this type of insulation by reducing a complex 3D problem to a simplified 2D model that takes into account the main influencing factors. The results of modeling the distribution of electric field strength and current density in insulation are presented, and the influence of the location of gaps between the edges of winded tape on the conductivity of cable insulation is estimated. Analytical expressions are obtained for estimating the electrical resistance of insulation while taking into account the parameters of the butt gap between the insulating tapes. The results of calculations, numerical modeling, and experimentally measured values of electrical resistance are compared, showing that there is a good match. The main effects affecting the properties of polypropylene laminated paper insulation are described
xSPDE: Extensible software for stochastic equations
We introduce an extensible software toolbox, xSPDE, for solving ordinary and partial stochastic differential equations. The toolbox makes extensive use of vector and parallel methods. Inputs are exceptionally simple, to reduce the learning curve, with default options for all of the many input parameters. The code calculates functional means, correlations and spectra, checks for errors in both time-step and sampling, and provides several choices of algorithm. Most aspects of the code, including the numerical algorithm, have a modular functional design to allow user modifications. Keywords: Stochastic software code-generato
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