//********************************************************************
// Example (very naive for the moment) of the data analysis
// using the ESD classes
-// It demonstrates the idea of the "combined PID".
-// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
+// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
//********************************************************************
#if !defined( __CINT__) || defined(__MAKECINT__)
#include <Riostream.h>
- #include "TKey.h"
+ #include <TTree.h>
#include "TFile.h"
#include "TH1F.h"
- #include "TH2F.h"
#include "TCanvas.h"
+ #include "TStyle.h"
#include "TStopwatch.h"
- #include "TParticle.h"
- #include "AliRun.h"
- #include "AliStack.h"
- #include "AliRunLoader.h"
- #include "AliLoader.h"
-
- #include "AliESD.h"
+ #include "AliESDEvent.h"
#endif
-extern AliRun *gAlice;
-
-Int_t AliESDanalysis(Int_t nev=1) {
- TH2F *tpcHist=
- new TH2F("tpcHist","TPC dE/dX vs momentum",100,0.,4.,100,0.,500.);
- tpcHist->SetXTitle("p (GeV/c)"); tpcHist->SetYTitle("dE/dx (Arb. Units)");
- tpcHist->SetMarkerStyle(8);
- tpcHist->SetMarkerSize(0.3);
-
- TH1F *piG=new TH1F("piG","",20,0.,4.);
- TH1F *piR=new TH1F("piR","",20,0.,4.);
- TH1F *piF=new TH1F("piF","",20,0.,4.);
- TH1F *piGood=new TH1F("piGood","Combined PID for pions",20,0.,4.);
- piGood->SetLineColor(4); piGood->SetXTitle("p (GeV/c)");
- TH1F *piFake=new TH1F("piFake","",20,0.,4.); piFake->SetLineColor(2);
-
- TH1F *kaG=new TH1F("kaG","",20,0.,4.);
- TH1F *kaR=new TH1F("kaR","",20,0.,4.);
- TH1F *kaF=new TH1F("kaF","",20,0.,4.);
- TH1F *kaGood=new TH1F("kaGood","Combined PID for kaons",20,0.,4.);
- kaGood->SetLineColor(4); kaGood->SetXTitle("p (GeV/c)");
- TH1F *kaFake=new TH1F("kaFake","",20,0.,4.); kaFake->SetLineColor(2);
-
- TH1F *prG=new TH1F("prG","",20,0.,4.);
- TH1F *prR=new TH1F("prR","",20,0.,4.);
- TH1F *prF=new TH1F("prF","",20,0.,4.);
- TH1F *prGood=new TH1F("prGood","Combined PID for protons",20,0.,4.);
- prGood->SetLineColor(4); prGood->SetXTitle("p (GeV/c)");
- TH1F *prFake=new TH1F("prFake","",20,0.,4.); prFake->SetLineColor(2);
-
- if (gAlice) {
- delete gAlice->GetRunLoader();
- delete gAlice;
- gAlice=0;
- }
- AliRunLoader *rl = AliRunLoader::Open("galice.root");
- if (rl == 0x0) {
- cerr<<"Can not open session"<<endl;
- return 1;
- }
- if (rl->LoadgAlice()) {
- cerr<<"LoadgAlice returned error"<<endl;
- delete rl;
- return 1;
- }
- if (rl->LoadHeader()) {
- cerr<<"LoadHeader returned error"<<endl;
- delete rl;
- return 1;
- }
- rl->LoadKinematics();
- AliStack* stack = rl->Stack();
-
- TFile *ef=TFile::Open("AliESDs.root");
- if (!ef->IsOpen()) {cerr<<"Can't AliESDs.root !\n"; return 1;}
+extern TStyle *gStyle;
+Int_t AliESDanalysis() {
TStopwatch timer;
- Int_t rc=0,n=0;
- TKey *key=0;
- TIter next(ef->GetListOfKeys());
- //****** Tentative particle type "concentrations"
- Double_t c[5]={0.01, 0.01, 0.85, 0.10, 0.05};
+ gStyle->SetOptStat(111110);
+ gStyle->SetOptFit(1);
- //******* The loop over events
- while ((key=(TKey*)next())!=0) {
- rl->GetEvent(n);
+ Double_t V0mass=0.497672, V0width=0.020, V0window=0.05;
+ Double_t mmin=V0mass-V0window, mmax=V0mass+V0window;
+ TH1F *hm =new TH1F("hm","K0s",40, mmin, mmax);
+ hm->SetXTitle("Mass (GeV/c**2)"); hm->SetLineColor(2);
+ TH1F *hp =new TH1F("hp","Momentum of the positive daughter",40, 0, 2);
+ hp->SetXTitle("P (GeV/c)"); hp->SetLineColor(4);
- cerr<<"Processing event number : "<<n++<<endl;
+//****** File with the ESD
+ TFile *ef=TFile::Open("AliESDs.root");
+ if (!ef || !ef->IsOpen()) {cerr<<"Can't AliESDs.root !\n"; return 1;}
+ AliESDEvent* event = new AliESDEvent();
+ TTree* tree = (TTree*) ef->Get("esdTree");
+ if (!tree) {cerr<<"no ESD tree found\n"; return 1;};
+ event->ReadFromTree(tree);
- AliESD *event=(AliESD*)key->ReadObj();
+ Int_t n=0;
- Int_t ntrk=event->GetNumberOfTracks();
- cerr<<"Number of ESD tracks : "<<ntrk<<endl;
- //****** The loop over tracks
+//******* The loop over events
+ while (tree->GetEvent(n)) {
+ cout<<endl<<"Processing event number : "<<n++<<endl;
- Int_t pisel=0,kasel=0,prsel=0,nsel=0;
+ Int_t ntrk=event->GetNumberOfTracks();
+ cout<<"Number of ESD tracks : "<<ntrk<<endl;
+ Int_t nv0=event->GetNumberOfV0s();
+ cout<<"Number of ESD V0s : "<<nv0<<endl;
+ Int_t ncas=event->GetNumberOfCascades();
+ cout<<"Number of ESD cascades : "<<ncas<<endl;
+ //****** The loop over tracks
+ Int_t nk=0;
while (ntrk--) {
- AliESDtrack *t=event->GetTrack(ntrk);
-
- Double_t p=t->GetP();
-
- if (t->GetStatus()&AliESDtrack::kTPCin) {
- Double_t dedx=t->GetTPCsignal();
- tpcHist->Fill(p,dedx,1);
- }
-
- UInt_t status=AliESDtrack::kESDpid;
- status|=AliESDtrack::kTPCpid;
- status|=AliESDtrack::kTOFpid;
-
- if ((t->GetStatus()&status) == status) {
- nsel++;
-
- Int_t lab=TMath::Abs(t->GetLabel());
- TParticle *part=stack->Particle(lab);
- Int_t code=part->GetPdgCode();
-
- Double_t r[10]; t->GetESDpid(r);
-
- Double_t rcc=0.;
- Int_t i;
- for (i=0; i<AliESDtrack::kSPECIES; i++) rcc+=(c[i]*r[i]);
- if (rcc==0.) continue;
-
- //Here we apply Bayes' formula
- Double_t w[10];
- for (i=0; i<AliESDtrack::kSPECIES; i++) w[i]=c[i]*r[i]/rcc;
-
- if (w[4]>w[3] && w[4]>w[2] && w[4]>w[1] && w[4]>w[0]) {//proton
- prsel++;
- prG->Fill(p);
- if (TMath::Abs(code)==2212) prR->Fill(p);
- else prF->Fill(p);
- }
-
- if (w[3]>w[4] && w[3]>w[2] && w[3]>w[1] && w[3]>w[0]) {//kaon
- kasel++;
- kaG->Fill(p);
- if (TMath::Abs(code)==321) kaR->Fill(p);
- else kaF->Fill(p);
- }
-
- if (w[2]>w[3] && w[2]>w[4] && w[2]>w[1] && w[2]>w[0]) {//pion
- pisel++;
- piG->Fill(p);
- if (TMath::Abs(code)==211) piR->Fill(p);
- else piF->Fill(p);
- }
-
- }
-
- }
- delete event;
- cerr<<"Number of selected ESD tracks : "<<nsel<<endl;
- cerr<<"Number of selected pion ESD tracks : "<<pisel<<endl;
- cerr<<"Number of selected kaon ESD tracks : "<<kasel<<endl;
- cerr<<"Number of selected proton ESD tracks : "<<prsel<<endl;
+ AliESDtrack *track=event->GetTrack(ntrk);
+ UInt_t status=track->GetStatus();
+
+ //select only tracks with the "combined PID"
+ if ((status&AliESDtrack::kESDpid)==0) continue;
+
+ Double_t w[10]; track->GetESDpid(w);
+ //count only "Kaon-like" tracks
+ if (w[3]>w[4] && w[3]>w[2] && w[3]>w[1] && w[3]>w[0]) nk++;
+ }
+ cout<<"Number of \"Kaon-like\" tracks : "<<nk<<endl;
+
+ //****** The loop over V0s
+ while (nv0--) {
+ AliESDv0 *v0=event->GetV0(nv0);
+ v0->ChangeMassHypothesis(310); // K0s
+ Double_t mass=v0->GetEffMass();
+ hm->Fill(mass);
+
+ Int_t pidx=v0->GetPindex(); // now let's get an access
+ AliESDtrack *track=event->GetTrack(pidx); // to the positive daughter
+ Double_t p=track->GetP();
+ hp->Fill(p);
+ }
+
+ //****** The loop over cascades
+ while (ncas--) {
+ AliESDcascade *cas=event->GetCascade(ncas);
+ Double_t q; //"quality" of the associated Lambda
+ cas->ChangeMassHypothesis(q,3312); // Xi-
+ // Here you do something with your Xis
+ // ...
+ // You can get the access to the daughters
+ }
+
}
+ delete event;
+ ef->Close();
+
timer.Stop(); timer.Print();
TCanvas *c1=new TCanvas("c1","",0,0,600,1200);
- c1->Divide(1,4);
+ c1->Divide(1,2);
c1->cd(1);
- tpcHist->Draw();
+ hm->Fit("gaus","","",V0mass-V0width,V0mass+V0width);
c1->cd(2);
- piG->Sumw2(); piF->Sumw2(); piR->Sumw2();
- piGood->Divide(piR,piG,1,1,"b");
- piFake->Divide(piF,piG,1,1,"b");
- piGood->Draw("hist");
- piFake->Draw("same");
-
- c1->cd(3);
- kaG->Sumw2(); kaF->Sumw2(); kaR->Sumw2();
- kaGood->Divide(kaR,kaG,1,1,"b");
- kaFake->Divide(kaF,kaG,1,1,"b");
- kaGood->Draw("hist");
- kaFake->Draw("same");
-
- c1->cd(4);
- prG->Sumw2(); prF->Sumw2(); prR->Sumw2();
- prGood->Divide(prR,prG,1,1,"b");
- prFake->Divide(prF,prG,1,1,"b");
- prGood->Draw("hist");
- prFake->Draw("same");
-
- ef->Close();
-
- delete rl;
+ hp->Fit("expo","","",0.3,2);
- return rc;
+ return 0;
}