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