Top++: A program for the calculation of the top-pair cross-section at hadron colliders

Abstract

We present the program Top++ for the numerical evaluation of the total inclusive cross-section for producing top quark pairs at hadron colliders. The program calculates the cross-section in (a) fixed order approach with exact next-to-next-to leading order (NNLO) accuracy and (b) by including soft-gluon resummation for the hadronic cross-section in Mellin space with full next-to-next-to-leading logarithmic (NNLL) accuracy. The program offers the user significant flexibility through the large number (29) of available options. Top++ is written in C++. It has a very simple to use interface that is intuitive and directly reflects the physics. The running of the program requires no programming experience from the user. Program summaryProgram title: Top++ (ver. 2.0)Catalogue identifier: AETR_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETR_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: GNU General Public LicenseNo. of lines in distributed program, including test data, etc.: 15896No. of bytes in distributed program, including test data, etc.: 695919Distribution format: tar.gzProgramming language: C++.Computer: any running a unix operating system. Program was developed and tested with GNU Compiler Collection, C++ compiler.Operating system: Linux; Mac OS X; can be adapted for other unix systems.RAM: typically less than 200 MB.Classification: 11.1.External routines: GNU Scientific Library (GSL); the Les Houches Accord pdf Interface (LHAPDF).Nature of problem:computation of the total cross-section in perturbative QCD.Solution method:numerical integration of the product of hard partonic cross-section (with or without soft gluon resummation) with two parton distribution functions.Additional comments:sub per-mill accuracy achievable in realistic time (program does not employ Monte Carlo methods).Running time:depending on the options. The program is optimized for speed.