10,888 research outputs found
Forward Drell-Yan plus backward jet as a test of BFKL evolution
We study Drell-Yan plus jet events where the gauge boson is produced in the
forward direction of one of the colliding protons and a jet is produced in the
forward direction of the second proton. The resulting large rapidity difference
between the final states then opens up the phase space for BFKL evolution.
First numerical results on partonic level are provided.Comment: 4 pages, 2 figures, proceedings of the XX Workshop on Deep-Inelastic
Scattering and Related Subjects, 26-30 March, University of Bonn (2012
Local stability analysis for a planar shock wave
A procedure to study the local stability of planar shock waves is presented. The procedure is applied to a Rankine-Hugoniot shock in a divergent/convergent nozzle, to an isentropic shock in a divergent/convergent nozzle, and to Rankine-Hugoniot shocks attached to wedges and cones. It is shown that for each case, the equation governing the shock motion is equivalent to the damped harmonic oscillator equation
Three-dimensional simulation of vortex breakdown
The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state
Using the BFKL resummation to fit DIS data: collinear and running coupling effects
The proton structure function F2 is studied in the low x regime using BFKL
evolution. The next to leading logarithmic (NLL) analysis requires the
inclusion of running coupling effects which lead to off-diagonal terms in the
evolution kernel. An all-orders resummation is used to improve the collinear
behavior of the NLL BFKL result. We emphasize the theoretical uncertainties
that appear throughout the analysis and give a comparison to the combined HERA
data.Comment: 4 pages, 5 figures, proceedings of the XX Workshop on Deep-Inelastic
Scattering and Related Subjects, 26-30 March, University of Bonn (2012
Spectral methods for inviscid, compressible flows
Report developments in the application of spectral methods to two dimensional compressible flows are reviewed. A brief introduction to spectral methods -- their history and especially their implementation -- is provided. The stress is on those techniques relevant to transonic flow computation. The spectral multigrid iterative methods are discussed with application to the transonic full potential equation. Discontinuous solutions of the Euler equations are considered. The key element is the shock fitting technique which is briefly explained
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