ITS/AliCascadeComparison.C

   1 /****************************************************************************
   2  *           Very important, delicate and rather obscure macro.             *
   3  *                                                                          *
   4  *               Creates list of "findable" cascades,                       *
   5  *             calculates efficiency, resolutions etc.                      *
   6  *                                                                          *
   7  *  Origin: Christian Kuhn, IReS, Strasbourg, christian.kuhn@ires.in2p3.fr  *
   8  ****************************************************************************/
   9
  10 #if !defined(__CINT__) || defined(__MAKECINT__)
  11   #include <Riostream.h>
  12   #include <fstream.h>
  13
  14   #include "AliRun.h"
  15   #include "AliMC.h"
  16   #include "AliHeader.h"
  17   #include "AliRunLoader.h"
  18   #include "AliITSLoader.h"
  19
  20   #include "TH1.h"
  21   #include "TFile.h"
  22   #include "TKey.h"
  23   #include "TObjArray.h"
  24   #include "TStyle.h"
  25   #include "TCanvas.h"
  26   #include "TLine.h"
  27   #include "TText.h"
  28   #include "TParticle.h"
  29   #include "TStopwatch.h"
  30   #include "TPDGCode.h"
  31
  32   #include "AliRun.h"
  33   #include "AliESD.h"
  34   #include "AliCascadeVertex.h"
  35 #endif
  36
  37 struct GoodCascade {
  38   Int_t nlab,plab;   // V0's daughter labels
  39   Int_t blab;        // Bachelor label
  40   Int_t code;
  41   Float_t px,py,pz;
  42   Float_t x,y,z;
  43 };
  44 Int_t good_cascades(GoodCascade *gt, Int_t max);
  45
  46 extern AliRun *gAlice;
  47
  48 Int_t AliCascadeComparison(Int_t code=3312) {
  49   //code= 3312; //kXiMinus
  50   //code=-3312; //kXiPlusBar
  51   //code= 3334; //kOmegaMinus
  52   //code=-3334; //kOmegaPlusBar
  53    cerr<<"Doing comparison...\n";
  54    TStopwatch timer;
  55
  56    /*** Check if the file with the "good" cascades exists ***/
  57    GoodCascade gc[100];
  58    Int_t ngood=0;
  59    ifstream in("good_cascades");
  60    if (in) {
  61       cerr<<"Reading good cascades...\n";
  62       while (in>>gc[ngood].nlab>>gc[ngood].plab>>
  63                  gc[ngood].blab>>gc[ngood].code>>
  64                  gc[ngood].px>>gc[ngood].py>>gc[ngood].pz>>
  65                  gc[ngood].x >>gc[ngood].y >>gc[ngood].z) {
  66          ngood++;
  67          cerr<<ngood<<'\r';
  68          if (ngood==100) {
  69             cerr<<"Too many good cascades !\n";
  70             break;
  71          }
  72       }
  73       if (!in.eof()) cerr<<"Read error (good_cascades) !\n";
  74    } else {
  75      /*** generate a file with the "good" cascades ***/
  76       cerr<<"Marking good cascades (this will take a while)...\n";
  77       ngood=good_cascades(gc,100);
  78       ofstream out("good_cascades");
  79       if (out) {
  80          for (Int_t ngd=0; ngd<ngood; ngd++)
  81             out<<gc[ngd].nlab<<' '<<gc[ngd].plab<<' '<<
  82                  gc[ngd].blab<<' '<<gc[ngd].code<<' '<<
  83                  gc[ngd].px<<' '<<gc[ngd].py<<' '<<gc[ngd].pz<<' '<<
  84                  gc[ngd].x <<' '<<gc[ngd].y <<' '<<gc[ngd].z <<endl;
  85       } else cerr<<"Can not open file (good_cascades) !\n";
  86       out.close();
  87    }
  88
  89    AliESD *event=0;
  90    { /*** Load reconstructed vertices ***/
  91    TFile *ef=TFile::Open("AliESDcas.root");
  92    if ((!ef)||(!ef->IsOpen())) {
  93      cerr<<"AliCascadeComparison.C: Can't open AliESDcas.root !\n";
  94      return 1;
  95    }
  96    TKey *key=0;
  97    TIter next(ef->GetListOfKeys());
  98    if ((key=(TKey*)next())!=0) event=(AliESD*)key->ReadObj();
  99    ef->Close();
 100    }
 101    Int_t nentr=event->GetNumberOfCascades();
 102
 103
 104    const Double_t cascadeWindow=0.05, cascadeWidth=0.015;
 105    Double_t ptncut=0.12, ptpcut=0.33, kine0cut=0.003;
 106    Double_t ptbcut=0.11, kinecut=0.002;
 107    Double_t cascadeMass=1.32131;
 108    switch (code) {
 109    case kXiMinus:
 110         break;
 111    case kXiPlusBar:
 112         ptncut=0.33; ptpcut=0.12;
 113         break;
 114    case kOmegaMinus:
 115         cascadeMass=1.67245;
 116         kine0cut=0.001;
 117         ptbcut=0.22; kinecut=0.006;
 118         break;
 119    case kOmegaPlusBar:
 120         cascadeMass=1.67245;
 121         kine0cut=0.001;
 122         ptncut=0.33; ptpcut=0.12;
 123         ptbcut=0.22; kinecut=0.006;
 124         break;
 125    default: cerr<<"Invalid PDG code !\n"; return 1;
 126    }
 127
 128    /*** create some histograms ***/
 129    TH1F *hp=new TH1F("hp","Angular Resolution",30,-30.,30.); //phi resolution
 130    hp->SetXTitle("(mrad)"); hp->SetFillColor(2);
 131    TH1F *hl=new TH1F("hl","Lambda Resolution",30,-30,30);
 132    hl->SetXTitle("(mrad)"); hl->SetFillColor(1); hl->SetFillStyle(3013);
 133    TH1F *hpt=new TH1F("hpt","Relative Pt Resolution",30,-10.,10.);
 134    hpt->SetXTitle("(%)"); hpt->SetFillColor(2);
 135
 136    TH1F *hx=new TH1F("hx","Position Resolution (X,Y)",30,-3.,3.); //x res.
 137    hx->SetXTitle("(mm)"); hx->SetFillColor(6);
 138    TH1F *hy=new TH1F("hy","Position Resolution (Y)",30,-3.,3.);   //y res
 139    hy->SetXTitle("(mm)"); hy->SetFillColor(1); hy->SetFillStyle(3013);
 140    TH1F *hz=new TH1F("hz","Position Resolution (Z)",30,-3.,3.);   //z res.
 141    hz->SetXTitle("(mm)"); hz->SetFillColor(6);
 142
 143    Double_t pmin=0.2, pmax=4.2; Int_t nchan=20;
 144    TH1F *hgood=new TH1F("hgood","Good Cascades",nchan,pmin,pmax);
 145    TH1F *hfound=new TH1F("hfound","Found Cascades",nchan,pmin,pmax);
 146    TH1F *hfake=new TH1F("hfake","Fake Cascades",nchan,pmin,pmax);
 147    TH1F *hg=new TH1F("hg","Efficiency for Good Cascades",nchan,pmin,pmax);
 148    hg->SetLineColor(4); hg->SetLineWidth(2);
 149    TH1F *hf=new TH1F("hf","Probability of Fake Cascades",nchan,pmin,pmax);
 150    hf->SetFillColor(1); hf->SetFillStyle(3013); hf->SetLineWidth(2);
 151
 152    Double_t mmin=cascadeMass-cascadeWindow, mmax=cascadeMass+cascadeWindow;
 153    TH1F *cs =new TH1F("cs","Cascade Effective Mass",40, mmin, mmax);
 154    cs->SetXTitle("(GeV)");
 155    cs->SetLineColor(4); cs->SetLineWidth(4);
 156    TH1F *csf =new TH1F("csf","Fake Cascade Effective Mass",40, mmin, mmax);
 157    csf->SetXTitle("(GeV)"); csf->SetFillColor(6);
 158
 159    Double_t pxg=0.,pyg=0.,ptg=0.;
 160    Int_t nlab=-1, plab=-1, blab=-1;
 161    Int_t i;
 162    for (i=0; i<nentr; i++) {
 163        AliESDcascade *cascade=event->GetCascade(i);
 164
 165        Int_t nidx=TMath::Abs(cascade->GetNindex());
 166        Int_t pidx=TMath::Abs(cascade->GetPindex());
 167        Int_t bidx=TMath::Abs(cascade->GetBindex());
 168
 169        AliESDtrack *ntrack=event->GetTrack(nidx);
 170        AliESDtrack *ptrack=event->GetTrack(pidx);
 171        AliESDtrack *btrack=event->GetTrack(bidx);
 172
 173        nlab=TMath::Abs(ntrack->GetLabel());
 174        plab=TMath::Abs(ptrack->GetLabel());
 175        blab=TMath::Abs(btrack->GetLabel());
 176
 177        /** Kinematical cuts **/
 178        Double_t pxn,pyn,pzn; cascade->GetNPxPyPz(pxn,pyn,pzn);
 179        Double_t ptn=TMath::Sqrt(pxn*pxn + pyn*pyn);
 180        if (ptn < ptncut) continue;
 181        Double_t pxp,pyp,pzp; cascade->GetPPxPyPz(pxp,pyp,pzp);
 182        Double_t ptp=TMath::Sqrt(pxp*pxp + pyp*pyp);
 183        if (ptp < ptpcut) continue;
 184        Double_t pxb,pyb,pzb; cascade->GetBPxPyPz(pxb,pyb,pzb);
 185        Double_t ptb=TMath::Sqrt(pxb*pxb + pyb*pyb);
 186        if (ptb < ptbcut) continue;
 187        Double_t kine0;
 188        Double_t kine=cascade->ChangeMassHypothesis(kine0,code);
 189        if (TMath::Abs(kine0)>kine0cut) continue;
 190        //if (TMath::Abs(kine)>kinecut) continue;
 191
 192        Double_t mass=cascade->GetEffMass();
 193        cs->Fill(mass);
 194        csf->Fill(mass);
 195
 196        if (TMath::Abs(mass-cascadeMass)>cascadeWidth) continue;
 197
 198        Int_t j;
 199        for (j=0; j<ngood; j++) {
 200           if (gc[j].code != cascade->GetPdgCode()) continue;
 201           if (gc[j].nlab == nlab)
 202           if (gc[j].plab == plab)
 203           if (gc[j].blab == blab) break;
 204        }
 205
 206        Double_t px,py,pz; cascade->GetPxPyPz(px,py,pz);
 207        Double_t pt=TMath::Sqrt(px*px+py*py);
 208
 209        if (j==ngood) {
 210           hfake->Fill(pt);
 211           cerr<<"Fake cascade: ("<<nlab<<","<<plab<<","<<blab<<")\n";
 212           continue;
 213        }
 214        csf->Fill(mass,-1);
 215
 216        pxg=gc[j].px; pyg=gc[j].py; ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
 217        Double_t phig=TMath::ATan2(pyg,pxg), phi=TMath::ATan2(py,px);
 218        Double_t lamg=TMath::ATan2(gc[j].pz,ptg), lam=TMath::ATan2(pz,pt);
 219        hp->Fill((phi - phig)*1000.);
 220        hl->Fill((lam - lamg)*1000.);
 221        hpt->Fill((1/pt - 1/ptg)/(1/ptg)*100.);
 222
 223        Double_t x,y,z; cascade->GetXYZ(x,y,z);
 224        hx->Fill((x-gc[j].x)*10);
 225        hy->Fill((y-gc[j].y)*10);
 226        hz->Fill((z-gc[j].z)*10);
 227
 228        hfound->Fill(ptg);
 229        gc[j].nlab=-1;
 230
 231    }
 232    for (i=0; i<ngood; i++) {
 233       if (gc[i].code != code) continue;
 234       pxg=gc[i].px; pyg=gc[i].py; ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
 235       hgood->Fill(ptg);
 236       nlab=gc[i].nlab; plab=gc[i].plab; blab=gc[i].blab;
 237       if (nlab < 0) continue;
 238      cerr<<"Cascade ("<<nlab<<','<<plab<<","<<blab<<") has not been found !\n";
 239    }
 240
 241    delete event;
 242
 243    Stat_t ng=hgood->GetEntries();
 244    Stat_t nf=hfound->GetEntries();
 245
 246    cerr<<"Number of found cascades: "<<nentr<<" ("<<nf<<" in the peak)\n";
 247    cerr<<"Number of good cascades: "<<ng<<endl;
 248
 249    if (ng!=0)
 250       cerr<<"Integral efficiency is about "<<nf/ng*100.<<" %\n";
 251
 252    gStyle->SetOptStat(111110);
 253    gStyle->SetOptFit(1);
 254
 255    TCanvas *c1=new TCanvas("c1","",0,0,580,610);
 256    c1->Divide(2,2);
 257
 258    c1->cd(1);
 259    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 260    //hp->Fit("gaus");
 261    hp->Draw();
 262    hl->Draw("same"); c1->cd();
 263
 264    c1->cd(2);
 265    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 266    //hpt->Fit("gaus"); c1->cd();
 267    hpt->Draw(); c1->cd();
 268
 269    c1->cd(3);
 270    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 271    //hx->Fit("gaus");
 272    hx->Draw();
 273    hy->Draw("same"); c1->cd();
 274
 275    c1->cd(4);
 276    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 277    //hz->Fit("gaus");
 278    hz->Draw();
 279
 280
 281    TCanvas *c2=new TCanvas("c2","",600,0,580,610);
 282    c2->Divide(1,2);
 283
 284    c2->cd(1);
 285    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 286    hfound->Sumw2(); hgood->Sumw2(); hfake->Sumw2();
 287    hg->Divide(hfound,hgood,1,1.,"b");
 288    hf->Divide(hfake,hgood,1,1.,"b");
 289    hg->SetMaximum(1.4);
 290    hg->SetYTitle("Cascade reconstruction efficiency");
 291    hg->SetXTitle("Pt (GeV/c)");
 292    hg->Draw();
 293
 294    TLine *line1 = new TLine(pmin,1.0,pmax,1.0); line1->SetLineStyle(4);
 295    line1->Draw("same");
 296    TLine *line2 = new TLine(pmin,0.9,pmax,0.9); line2->SetLineStyle(4);
 297    line2->Draw("same");
 298
 299    hf->SetFillColor(1);
 300    hf->SetFillStyle(3013);
 301    hf->SetLineColor(2);
 302    hf->SetLineWidth(2);
 303    hf->Draw("histsame");
 304    TText *text = new TText(0.461176,0.248448,"Fake cascades");
 305    text->SetTextSize(0.05);
 306    text->Draw();
 307    text = new TText(0.453919,1.11408,"Good cascades");
 308    text->SetTextSize(0.05);
 309    text->Draw();
 310
 311
 312    c2->cd(2);
 313    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 314    //cs->Fit("gaus","","",cascadeMass-cascadeWidth,cascadeMass+cascadeWidth);
 315    cs->Draw();
 316    csf->Draw("same");
 317    Double_t max=cs->GetMaximum();
 318    TLine *line3 =
 319       new TLine(cascadeMass-cascadeWidth,0.,cascadeMass-cascadeWidth,max);
 320    line3->Draw("same");
 321    TLine *line4 =
 322       new TLine(cascadeMass+cascadeWidth,0.,cascadeMass+cascadeWidth,max);
 323    line4->Draw("same");
 324
 325    timer.Stop(); timer.Print();
 326
 327    return 0;
 328 }
 329
 330
 331 Int_t good_cascades(GoodCascade *gc, Int_t max) {
 332    Int_t nc=0;
 333    /*** Get information about the cuts ***/
 334    Double_t r2min=0.9*0.9;
 335    Double_t r2max=2.9*2.9;
 336
 337    /*** Get labels of the "good" tracks ***/
 338    Double_t dd; Int_t id, label[15000], ngt=0;
 339    ifstream in("good_tracks_its");
 340    if (!in) {
 341      cerr<<"Can't open the file good_tracks_its \n";
 342      return nc;
 343    }
 344    while (in>>label[ngt]>>id>>dd>>dd>>dd>>dd>>dd>>dd) {
 345      ngt++;
 346      if (ngt>=15000) {
 347        cerr<<"Too many good ITS tracks !\n";
 348        return nc;
 349      }
 350    }
 351    if (!in.eof()) {
 352       cerr<<"Read error (good_tracks_its) !\n";
 353       return nc;
 354    }
 355
 356    /*** Get an access to the kinematics ***/
 357    if (gAlice) {
 358       delete gAlice->GetRunLoader();
 359       delete gAlice;
 360       gAlice=0;
 361    }
 362    AliRunLoader *rl = AliRunLoader::Open("galice.root");
 363    if (!rl) {
 364        cerr<<"AliCascadeComparison.C, good_cascades :Can't start session !\n";
 365        return 1;
 366    }
 367
 368    rl->LoadgAlice();
 369    rl->LoadHeader();
 370    rl->LoadKinematics();
 371    Int_t np = rl->GetHeader()->GetNtrack();
 372
 373    while (np--) {
 374       cerr<<np<<'\r';
 375       TParticle *cp=gAlice->GetMCApp()->Particle(np);
 376
 377       /*** only these cascades are "good" ***/
 378       Int_t code=cp->GetPdgCode();
 379       if (code!=kXiMinus)    if (code!=kXiPlusBar)
 380       if (code!=kOmegaMinus) if (code!=kOmegaPlusBar) continue;
 381
 382       /*** daughter tracks must be "good" ***/
 383       Int_t v0lab=cp->GetFirstDaughter(), blab=cp->GetLastDaughter();
 384       if (v0lab==blab) continue;
 385       if (v0lab<0) continue;
 386       if (blab<0) continue;
 387
 388       TParticle *p0=gAlice->GetMCApp()->Particle(v0lab);
 389       TParticle *bp=gAlice->GetMCApp()->Particle(blab);
 390       if ((p0->GetPdgCode()!=kLambda0) && (p0->GetPdgCode()!=kLambda0Bar)) {
 391          TParticle *p=p0; p0=bp; bp=p;
 392          Int_t i=v0lab; v0lab=blab; blab=i;
 393          if ((p0->GetPdgCode()!=kLambda0) && (p0->GetPdgCode()!=kLambda0Bar))
 394                                                                    continue;
 395       }
 396
 397       /** is the bachelor "good" ? **/
 398       Int_t i;
 399       for (i=0; i<ngt; i++) if (label[i]==blab) break;
 400       if (i==ngt) continue;
 401
 402       /** is the V0 "good" ? **/
 403       Int_t plab=p0->GetFirstDaughter(), nlab=p0->GetLastDaughter();
 404       if (nlab==plab) continue;
 405       if (nlab<0) continue;
 406       if (plab<0) continue;
 407
 408       for (i=0; i<ngt; i++) if (label[i]==nlab) break;
 409       if (i==ngt) continue;
 410       for (i=0; i<ngt; i++) if (label[i]==plab) break;
 411       if (i==ngt) continue;
 412
 413       /*** fiducial volume ***/
 414       Double_t x=bp->Vx(), y=bp->Vy(), r2=x*x+y*y; //bachelor
 415       if (r2<r2min) continue;
 416       if (r2>r2max) continue;
 417       TParticle *pp=gAlice->GetMCApp()->Particle(plab);
 418       x=pp->Vx(); y=pp->Vy(); r2=x*x+y*y;                      //V0
 419       if (r2<r2min) continue;
 420       if (r2>r2max) continue;
 421
 422       if (gAlice->GetMCApp()->Particle(plab)->GetPDG()->Charge() < 0.) {
 423          i=plab; plab=nlab; nlab=i;
 424       }
 425
 426       gc[nc].code=code;
 427       gc[nc].plab=plab;   gc[nc].nlab=nlab; gc[nc].blab=blab;
 428       gc[nc].px=cp->Px(); gc[nc].py=cp->Py(); gc[nc].pz=cp->Pz();
 429       gc[nc].x=bp->Vx(); gc[nc].y=bp->Vy(); gc[nc].z=bp->Vz();
 430       nc++;
 431
 432    }
 433
 434    delete rl;
 435
 436    return nc;
 437 }