Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

Manuscript Title: Direct solution of renormalization group equations of QCD in x-space: NLO implementations at leading twist
Authors: Alessandro Cafarella, Claudio Corianò
Program title: evolution.c
Catalogue identifier: ADUB
Journal reference: Comput. Phys. Commun. 160(2004)213
Programming language: C.
Computer: Athlon 1800 plus.
Operating system: Linux.
Peripherals: Laser printer.
Keywords: Polarized and unpolarized parton distribution, Numerical solutions of renormalization group equation, Quantum chromodynamics.
Classification: 11.5.

Nature of problem:
The program provided here solves the DGLAP evolution equations to next-to-leading order αs, for unpolarized, longitudinally polarized and transversely polarized parton distributions.

Solution method:
We use a recursive method based on an expansion of the solution in powers of log(αs(Q)/αs(Q0)).

Running time:
About 1 minute and 30 seconds for the unpolarized and longitudinally polarized cases and 1 minute for the transversely polarized case.