Mr: A C++ library for the matching and running of the Standard Model parameters

Abstract

We present the C++ program library mr that allows us to reliably calculate the values of the running parameters in the Standard Model at high energy scales. The initial conditions are obtained by relating the running parameters in the MS¯ renormalization scheme to observables at lower energies with full two-loop precision. The evolution is then performed in accordance with the renormalization group equations with full three-loop precision. Pure QCD corrections to the matching and running are included through four loops. We also provide a Mathematica interface for this program library. Program summaryProgram title:mrCatalogue identifier: AFAI_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AFAI_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: GNU General Public License, version 3No. of lines in distributed program, including test data, etc.: 517613No. of bytes in distributed program, including test data, etc.: 2358729Distribution format: tar.gzProgramming language: C++.Computer: IBM PC.Operating system: Linux, Mac OS X.RAM: 1 GBClassification: 11.1.External routines: TSIL [1], OdeInt [2], boost [3]Nature of problem: The running parameters of the Standard Model renormalized in the MS¯ scheme at some high renormalization scale, which is chosen by the user, are evaluated in perturbation theory as precisely as possible in two steps. First, the initial conditions at the electroweak energy scale are evaluated from the Fermi constant GF and the pole masses of the W, Z, and Higgs bosons and the bottom and top quarks including the full two-loop threshold corrections. Second, the evolution to the high energy scale is performed by numerically solving the renormalization group evolution equations through three loops. Pure QCD corrections to the matching and running are included through four loops.Solution method: Numerical integration of analytic expressionsAdditional comments: Available for download from URL: http://apik.github.io/mr/. The MathLink interface is tested to work with Mathematica 7–9 and, with an additional flag, also with Mathematica 10 under Linux and with Mathematica 10 under Mac OS X.Running time: less than 1 second