what is the value that Particle_Mother1 return?

[Huanian Zhang]

Hello,

Right now I am trying to identity B_jet from Higgs. So first I need to choose B_jets, then to check whether the B_jet comes from Higgs or not. Here is my code:

   std::vector<double> B_Jet_PT;
   std::vector<double> B_Jet_Eta;
   std::vector<double> B_Jet_Phi;
   std::vector<double> B_Jet_Mass;

   for(int i = 0; i < Particle_size; i++){

      if (abs(Particle_PID[i]) == 5) {

         //std::cout << Particle_PT[i] << std::endl;
         B_Jet_PT.push_back(Particle_PT[i]);
         B_Jet_Eta.push_back(Particle_Eta[i]);
         B_Jet_Phi.push_back(Particle_Phi[i]);
         B_Jet_Mass.push_back(Particle_M[i]);
      }
   }

         std::vector<double> B_Higgs_PT;
         std::vector<double> B_Higgs_Eta;
         std::vector<double> B_Higgs_Phi;
         std::vector<double> B_Higgs_Mass;

         for(int i = 0; i < B_Jet_PT.size(); i++){

            int a = Particle_Mother1[i];
            std::cout << a << std::endl;
            std::cout << Particle_PID[a] << std::endl;

         if (Particle_PID[a] == 25) {

               B_Higgs_PT.push_back(B_Jet_PT.at(i));
               B_Higgs_Eta.push_back(B_Jet_Eta.at(i));
               B_Higgs_Phi.push_back(B_Jet_Phi.at(i));
               B_Higgs_Mass.push_back(B_Jet_Mass.at(i));
               PT_Bjet->Fill(B_Jet_PT.at(i));

            }
         }

But there are some wired things. First the value of a is 0 0 2 3, I do not know what exactly that means. Then the value of Particle_PID[a] is 21 21 21 1000023, it is not Higgs. Could you tell me HOW I can modify the code. Thank you very much. Have a nice night.

[Olivier Mattelaer (olivier-mattelaer)]

Convert this to a question since this is clearly not a bug of MG5.