Markovian Monte Carlo program EvolFMC v.2 for solving QCD evolution equations

We present the program EvolFMC v.2 that solves the evolution equations in QCD for the parton momentum distributions by means of the Monte Carlo technique based on the Markovian process. The program solves the DGLAP-type evolution as well as modified-DGLAP ones. In both cases the evolution can be performed in the LO or NLO approximation. The quarks are treated as massless. The overall technical precision of the code has been established at 5×10−45×10−4. This way, for the first time ever, we demonstrate that with the Monte Carlo method one can solve the evolution equations with precision comparable to the other numerical methods.New version program summaryProgram title: EvolFMC v.2Catalogue identifier: AEFN_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFN_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including binary test data, etc.: 66 456 (7407 lines of C++ code)No. of bytes in distributed program, including test data, etc.: 412 752Distribution format: tar.gzProgramming language: C++Computer: PC, MacOperating system: Linux, Mac OS XRAM: Less than 256 MBClassification: 11.5External routines: ROOT (http://root.cern.ch/drupal/)Nature of problem: Solution of the QCD evolution equations for the parton momentum distributions of the DGLAP- and modified-DGLAP-type in the LO and NLO approximations.Solution method: Monte Carlo simulation of the Markovian process of a multiple emission of partons.Restrictions:1.Limited to the case of massless partons.2.Implemented in the LO and NLO approximations only.3.Weighted events only.Unusual features: Modified-DGLAP evolutions included up to the NLO level.Additional comments:   Technical precision established at 5×10−45×10−4.Running time: For the 106 events at 100 GeV: DGLAP NLO: 27s; C′C′-type modified DGLAP NLO: 150s (MacBook Pro with Mac OS X v.10.5.5, 2.4 GHz Intel Core 2 Duo, gcc 4.2.4, single thread).