QCD evolution equations: numerical algorithms from the Laguerre expansion. C. Coriano, C. Savkli.

PROGRAM SUMMARY
Title of program: QCD EVOLUTION EQUATIONS
Catalogue identifier: ADJS
Ref. in CPC: 118(1999)236
Distribution format: uuencoded compressed tar file
Operating system: Unix
Number of lines in distributed program, including test data, etc: 4438
Programming language used: Fortran
Computer: Sun 19

Nature of physical problem:
The programs provided here solve the DGLAP evolution equations, with next-to-leading order alphas effects taken to account, for unpolarized, longitudinally polarized and transversely polarized parton distributions.

Method of solution
The method developed by Furmanski and Pertonzio is used. The kernel P(x) of the DGLAP integrodifferential equations and the evolution operators E(t,x) are expanded in Laguerre polynomials.

Typical running time
About 5 seconds for the transverse polarization case and 20 minutes for the longitudinal polarization and for the unpolarized.