thermal_mult.C

Go to the documentation of this file.

{ 
    // test decay manager with thermal pi0 source in 2AGeV Ca+Ca collisions
    // R.H. 17/8/2000
    
    // Make funny use of the decay manager for a thermal macro
 
    PDecayManager *pdm = new PDecayManager;
    pdm->SetVerbose();
    //  pdm->SetDefault("pi0");       // use default pi0 decays
    //  pdm->SetDefault("dilepton");  // use default dilepton decays
 
    TH1F *h1 = new TH1F("Npart", "Npart", 100, 0., 100.);
    TH1F *h2 = new TH1F("b", "Impact Parameter", 100, 0., 20.);
    PFireball *source1 = new PFireball("pi0", 2., 0.07); // pure Boltzmann
    PFireball *source2 = new PFireball("pi0", 2., 0.07); // pure Boltzmann
    source2->setRandomB(40., 40., 0.1);                  // Ca + Ca, P(pi0) = 10%
 
    for(Int_t i=0; i<100000; i++) {
    float b = source2->sampleB();
    Int_t n = source2->sampleNProd(b);
    h1->Fill(n);
    h2->Fill(b);
    }
 
    Float_t sum = 0.;
    for(Int_t j=2; j<=5; j++) 
    sum += h1->GetBinContent(j);
    h1->Scale(1./sum);    // normalize multiplicity bins >0 to 1
    for(Int_t j=1; j <= 100; j++) printf("%d: %f\n", j, h1->GetBinContent(j)); 
 
    char *products[] = {
    "pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0",
    "pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0",
    "pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0",
    "pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0",
    "pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0","pi0"  };
 
    PDecayChannel *c = new PDecayChannel;  // set up decay of thermal source
    for(Int_t k=2; k<=5 && h1->GetBinContent(k)>0.01; k++) {
    printf("Mult=%d  Prob=%f\n", k-1, h1->GetBinContent(k));
    c->AddChannel(h1->GetBinContent(k), k-1, products);
    }
 
    pdm->InitReaction(source1, c);
    pdm->Print();
 
    pdm->loop(10000, 0, "fire", 0, 0, 0, 0);
}