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Manuscript Title: QCDNUM: Fast QCD Evolution and Convolution - QCDNUM Version 17.00
Authors: M. Botje
Program title: QCDNUM version: 17.00
Catalogue identifier: AEHV_v1_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 182(2011)490
Programming language: Fortran-77.
Computer: All.
Operating system: All.
RAM: Typically 3 Mbytes
Keywords: QCD evolution, DGLAP evolution equations, Parton densities, Fragmentation functions, Structure functions.
PACS: 12.38.Bx.
Classification: 11.5.

Nature of problem:
Evolution of the strong coupling constant and parton densities, up to next-to-next-to-leading order in perturbative QCD. Computation of observable quantities by Mellin convolution of the evolved densities with partonic cross-sections.

Solution method:
Parameterisation of the parton densities as linear or quadratic splines on a discrete grid, and evolution of the spline coefficients by solving (coupled) triangular matrix equations with a forward substitution algorithm. Fast computation of convolution integrals as weighted sums of spline coefficients, with weights derived from user-given convolution kernels.

Accuracy and speed are determined by the density of the evolution grid.

Running time:
Less than 10 ms on a 2 GHz Intel Core 2 Duo processor to evolve the gluon density and 12 quark densities at next-to-next-to-leading order over a large kinematic range.