ManeParse : A Mathematica reader for Parton Distribution Functions

Abstract

Parton Distribution Functions (PDFs) are essential non-perturbative inputs for calculation of any observable with hadronic initial states. These PDFs are released by individual groups as discrete grids as a function of the Bjorken-x and energy scale Q. The LHAPDF project maintains a repository of PDFs from various groups in a new standardized LHAPDF6 format, additionally older formats such as the CTEQ PDS grid format are still in use. ManeParse is a package that provides access to PDFs within Mathematica to facilitate calculation and plotting. The program is self-contained so there are no external links to any FORTRAN, C or C++ programs. The package includes the option to use the built-in Mathematica interpolation or a custom cubic Lagrange interpolation routine which allows for flexibility in the extrapolation (particularly at small x-values). ManeParse is fast enough to enable simple calculations (involving even one or two integrations) in the Mathematica framework. Program summaryProgram Title:ManeParseProgram Files doi:http://dx.doi.org/10.17632/knbsccggg4.1Licensing provisions: MITProgramming language:MathematicaNature of problem: PDFs are currently read and interpolated via a FORTRAN or C++ interface. No method exist to read the LHAPDF6 or CTEQ PDFs directly in Mathematica.Solution method: A Mathematica package reads in LHAPDF6 and CTEQ PDF files. The PDFs are parsed into a three-dimensional array in Bjorken-x, scattering energy Q, and parton flavor, and are stored in memory. Provided functions give access to the PDF, the PDF uncertainty, the PDF correlations, and the parton–parton Luminosities. The LHAPDF6 info files are converted from YAML format into Mathematica rules.