A Higher Order Perturbative Parton Evolution Toolkit (HOPPET)

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract This document describes a Fortran 95 package for carrying out DGLAP evolution and other common manipulations of parton distribution functions (PDFs). The PDFs are represented on a grid in x-space so as to avoid limitations on the functional form of input distributions. Good speed and accuracy are obtained through the representation of splitting functions in terms of their convolution with a set of piecewise polynomial basis functions, and Runge–Kutta techniques are used for the evolution in Q... Title of program: HOPPET Catalogue Id: AECA_v1_0 Nature of problem Solution of the DGLAP evolution equations up to NNLO (NLO) for unpolarised (longitudinally polarised) PDFs, and provision of tools to facilitate manipulation (convolutions, etc.) of PDFs with user-defined coefficient and splitting functions. Versions of this program held in the CPC repository in Mendeley Data AECA_v1_0; HOPPET; 10.1016/j.cpc.2008.08.010本程序源自贝尔法斯特女王大学馆藏的CPC程序库（1969-2018年）。 摘要 本文档介绍一款用于执行DGLAP演化以及对部分子分布函数（Parton Distribution Functions, PDFs）开展常见操作的Fortran 95软件包。为避免对输入分布的函数形式施加限制，该软件包将部分子分布函数在x空间的网格上进行表征。通过将分裂函数表示为其与一组分段多项式基函数的卷积形式，可获得优异的计算速度与精度；并采用龙格-库塔（Runge-Kutta）技术实现Q标度下的演化。 程序名称：HOPPET 目录编号：AECA_v1_0 问题本质 针对非极化（纵向极化）部分子分布函数，求解至次次领头阶（NNLO）、次领头阶（NLO）的DGLAP演化方程，并提供工具以支持用户自定义系数函数与分裂函数参与的部分子分布函数操作（如卷积等）。 本程序在Mendeley数据的CPC存储库中的版本：AECA_v1_0; HOPPET; 10.1016/j.cpc.2008.08.010