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HepMC Reference DocumentationHepMC |
00001 #ifndef HERWIG_HELPER_H 00002 #define HERWIG_HELPER_H 00004 // garren@fnal.gov, January 2010 00005 // 00006 // definitions needed by the Herwig examples 00007 // 00009 #include "HepMC/HerwigWrapper.h" 00010 #include "HepMC/GenCrossSection.h" 00011 00013 inline HepMC::GenCrossSection getHerwigCrossSection(int ngen) { 00014 00015 HepMC::GenCrossSection xsec; 00016 // set cross section information and convert to pb (HepMC convention) 00017 double xsecval = hwevnt.AVWGT * 1000.0; 00018 // statistical error 00019 // Herwig has a better calculation of the error, 00020 // but that information does not appear to be saved anywhere 00021 double xsecerr = xsecval / std::sqrt(ngen); 00022 // set and return cross section information 00023 xsec.set_cross_section(xsecval, xsecerr); 00024 return xsec; 00025 } 00026 00027 #endif // HERWIG_HELPER_H