Computer Physics Communications Program LibraryPrograms in Physics & Physical Chemistry |

[Licence| Download | New Version Template] adhf_v1_0.tar.gz(13 Kbytes) | ||
---|---|---|

Manuscript Title: Numerical solution of Q**2 evolution equations for polarized
structure functions. | ||

Authors: M. Hirai, S. Kumano, M. Miyama | ||

Program title: BFP1 | ||

Catalogue identifier: ADHF_v1_0Distribution format: tar.gz | ||

Journal reference: Comput. Phys. Commun. 108(1998)38 | ||

Programming language: Fortran. | ||

Computer: AlphaServer 2100 4/200. | ||

Operating system: OpenVMS V6.1. | ||

Keywords: Particle physics, Elementary, Qcd, Structure function, Polarized parton, Distribution, Q**2 evolution, Numerical solution. | ||

Classification: 11.5. | ||

Nature of problem:This program solves DGLAP Q**2 evolution equations with or without next- to-leading-order alphas effects for longitudinally polarized parton distributions. The evolved distributions could be convoluted with coefficient functions for calculating the structure function g1. Both flavor-nonsinglet and singlet cases are provided, so that the distributions, xDeltaqNS, xDeltaqs, xDeltaqi+ equivalent to xDeltaqi + xDeltaqibar (i=quark flavor), xDeltag, xg1NS, xg1S, and xg(1,i)+ can be obtained. | ||

Solution method:The DGLAP integrodifferential equations are simply solved by a brute- force method. We divide the variables x and Q**2 into very small steps, and the integrodifferential equations are solved step by step. | ||

Restrictions:This program is used for calculating Q**2 evolution of a longitudinally polarized flavor-nonsinglet-quark, singlet-quark, Deltaqi+, and gluon distributions in the leading order or in the next-to-leading order of alphas. Q**2 evolution equations are the DGLAP equations. The double precision arithmetic is used. The renormalization scheme is the modified minimal subtraction scheme (MSbar). A user provides the initial distribution as a subroutine or as a data file. Examples are explained in section 4. Then, the user inputs fifteen parameters in section 4. | ||

Running time:Approximately seven minutes on AlphaServer 2100 4/200 in the nonsinglet case, sixty minutes in the singlet-quark evolution. |

Disclaimer | ScienceDirect | CPC Journal | CPC | QUB |