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