[u/mrichter/AliRoot.git] / PWG2 / UNICOR / AliUnicorAnalCorrel.cxx

/************************************************************************* 
* Copyright(c) 1998-2048, ALICE Experiment at CERN, All rights reserved. * 
*                                                                        * 
* Author: The ALICE Off-line Project.                                    * 
* Contributors are mentioned in the code where appropriate.              * 
*                                                                        * 
* Permission to use, copy, modify and distribute this software and its   * 
* documentation strictly for non-commercial purposes is hereby granted   * 
* without fee, provided that the above copyright notice appears in all   * 
* copies and that both the copyright notice and this permission notice   * 
* appear in the supporting documentation. The authors make no claims     * 
* about the suitability of this software for any purpose. It is          * 
* provided "as is" without express or implied warranty.                  * 
**************************************************************************/

// Author: Dariusz Miskowiec <mailto:d.miskowiec@gsi.de> 2005

//=============================================================================
// two-particle correlation analyzer
// Loop over pairs and fill pair histograms. The first particle is always 
// taken from ev0 and the second from ev1 so for ev0=ev1 one is getting true 
// pairs, otherwise mixed ones. 
//=============================================================================

#include <TROOT.h>
#include <TMath.h>
#include <TRandom2.h>
#include "AliUnicorEvent.h"
#include "AliUnicorHN.h"
#include "AliUnicorAnalCorrel.h"

ClassImp(AliUnicorAnalCorrel)
 
//=============================================================================
AliUnicorAnalCorrel::AliUnicorAnalCorrel(Char_t *nam, Double_t emi, Double_t ema, 
			 Int_t pid0, Int_t pid1): 
  AliUnicorAnal(nam), fPid0(pid0), fPid1(pid1), fMass0(0), fMass1(0), fPa()
{
  // constructor
  // emi and ema define the rapidity range for histogram

  TParticlePDG *part0 = AliUnicorAnal::fgPDG.GetParticle(fPid0);
  TParticlePDG *part1 = AliUnicorAnal::fgPDG.GetParticle(fPid1);
  fMass0 = part0? part0->Mass() : 0;
  fMass1 = part1? part1->Mass() : 0;

  double pi = TMath::Pi();
  TAxis *ax[8];
  ax[0] = new TAxis(3,-0.5,2.5);ax[0]->SetTitle("trumixrot");
  ax[1] = new TAxis(5,0,0.5);   ax[1]->SetTitle("centrality");
  ax[2] = new TAxis(3,emi,ema); ax[2]->SetTitle("pair y");
  //ax[3] = new TAxis(8,-pi,pi);  ax[3]->SetTitle("pair phi"); // wrt event plane
  ax[3] = new TAxis(1,-pi,pi);  ax[3]->SetTitle("pair phi"); // wrt event plane
  double a0[]={0,0.1,0.2,0.3,0.4,0.5,0.7,1.0};
  ax[4] = new TAxis(7,a0);      ax[4]->SetTitle("(pair pt)/2 (GeV)");
  ax[5] = new TAxis(8,0,pi);    ax[5]->SetTitle("q-theta");
  ax[6] = new TAxis(16,-pi,pi); ax[6]->SetTitle("q-phi");
  double a1[100];
  for (int i=0;i<20;i++) a1[i]=i*0.005;
  for (int i=0;i<45;i++) a1[20+i]=0.1+i*0.02;
  ax[7] = new TAxis(64,a1);     ax[7]->SetTitle("q (GeV/c)");
  AliUnicorHN *pair = new AliUnicorHN("pair",8,ax);
  for (int i=0; i<8; i++) delete ax[i];
  fHistos.Add(pair);
  gROOT->cd();
  printf("%s object named %s created\n",ClassName(),GetName());
}
//=============================================================================
void AliUnicorAnalCorrel::Process(Int_t tmr, AliUnicorEvent *ev0, AliUnicorEvent *ev1, Double_t phirot) 
{
  // process pairs from one or two (if mixing) events
  // tmr tells which histogram (bins) to fill: tru,mix,rot

  // Could be possibly accelerated by checking the "good particle" only once 
  // and caching the result. (Maybe the optimizer does it already.)

  static TRandom2 ran;
  AliUnicorHN *pair = (AliUnicorHN*) fHistos.At(0);

  // mixing-and-rotating-proof centrality and reaction plane angle
  // (but not rotation-proof for rotation angles much different from 0 and 180)
  // true and rotated pairs are within the triangle (j<i), mixed - all
  // thus, proper rotation is either by 180, or by 170 AND 190, etc. 

  double cent = (ev0->Centrality()+ev1->Centrality())/2.0;
  double q0x,q0y,q1x,q1y;
  ev0->RP(q0x,q0y);
  ev1->RP(q1x,q1y); 
  double rpphi = atan2(q0y+q1y,q0x+q1x);

  // loop over pairs 

  for (int i=0; i<ev0->NParticles(); i++) {
    if (!ev0->ParticleGood(i,fPid0)) continue;
    for (int j=0; j<ev1->NParticles(); j++) {
      if (ev0==ev1 && j<i && fPid0==fPid1 ) continue; 
      if (ev0==ev1 && j==i) continue; // beware, not even when rotated or non-identical
      if (!ev1->ParticleGood(j,fPid1)) continue;
      if (!ev0->PairGood(ev0->ParticleP(i),ev0->ParticleTheta(i),ev0->ParticlePhi(i),
			 ev1->ParticleP(j),ev1->ParticleTheta(j),ev1->ParticlePhi(j)+phirot)) continue;
      fPa.Set0(fMass0,ev0->ParticleP(i),ev0->ParticleTheta(i),ev0->ParticlePhi(i));
      fPa.Set1(fMass1,ev1->ParticleP(j),ev1->ParticleTheta(j),ev1->ParticlePhi(j)+phirot);
      if (ev0==ev1 && fPid0==fPid1 && ran.Rndm()>=0.5) fPa.Swap();
      fPa.CalcLAB();
      fPa.CalcPairCM();
      if (fPa.QCM()==0) return; // should not be too frequent
      double phi = TVector2::Phi_mpi_pi(fPa.Phi()-rpphi);
      pair->Fill(tmr,                    // 0 for tru, 1 for mix, 2 for rot
		 cent,                   // centrality
		 fPa.Rapidity(),         // pair rapidity
		 phi,                    // pair phi wrt reaction plane
		 fPa.Pt()/2.0,           // half of pair pt
		 fPa.QCMTheta(),         // polar angle of Q
		 fPa.QCMPhiOut(),        // azimuthal angle of Q w.r.t. out
		 fPa.QCM(),              // |p2-p1| in c.m.s.
		 1.0);                   // weigth
    }
  }
}
//=============================================================================
Commit	Line	Data
621688e4	1	/*************************************************************************
	2	* Copyright(c) 1998-2048, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
	15
	16	// Author: Dariusz Miskowiec <mailto:d.miskowiec@gsi.de> 2005
	17
	18	//=============================================================================
	19	// two-particle correlation analyzer
	20	// Loop over pairs and fill pair histograms. The first particle is always
	21	// taken from ev0 and the second from ev1 so for ev0=ev1 one is getting true
	22	// pairs, otherwise mixed ones.
	23	//=============================================================================
	24
	25	#include <TROOT.h>
	26	#include <TMath.h>
	27	#include <TRandom2.h>
	28	#include "AliUnicorEvent.h"
	29	#include "AliUnicorHN.h"
	30	#include "AliUnicorAnalCorrel.h"
	31
	32	ClassImp(AliUnicorAnalCorrel)
	33
	34	//=============================================================================
	35	AliUnicorAnalCorrel::AliUnicorAnalCorrel(Char_t *nam, Double_t emi, Double_t ema,
	36	Int_t pid0, Int_t pid1):
	37	AliUnicorAnal(nam), fPid0(pid0), fPid1(pid1), fMass0(0), fMass1(0), fPa()
	38	{
	39	// constructor
	40	// emi and ema define the rapidity range for histogram
	41
	42	TParticlePDG *part0 = AliUnicorAnal::fgPDG.GetParticle(fPid0);
	43	TParticlePDG *part1 = AliUnicorAnal::fgPDG.GetParticle(fPid1);
	44	fMass0 = part0? part0->Mass() : 0;
	45	fMass1 = part1? part1->Mass() : 0;
	46
	47	double pi = TMath::Pi();
	48	TAxis *ax[8];
	49	ax[0] = new TAxis(3,-0.5,2.5);ax[0]->SetTitle("trumixrot");
	50	ax[1] = new TAxis(5,0,0.5); ax[1]->SetTitle("centrality");
	51	ax[2] = new TAxis(3,emi,ema); ax[2]->SetTitle("pair y");
	52	//ax[3] = new TAxis(8,-pi,pi); ax[3]->SetTitle("pair phi"); // wrt event plane
	53	ax[3] = new TAxis(1,-pi,pi); ax[3]->SetTitle("pair phi"); // wrt event plane
	54	double a0[]={0,0.1,0.2,0.3,0.4,0.5,0.7,1.0};
	55	ax[4] = new TAxis(7,a0); ax[4]->SetTitle("(pair pt)/2 (GeV)");
	56	ax[5] = new TAxis(8,0,pi); ax[5]->SetTitle("q-theta");
	57	ax[6] = new TAxis(16,-pi,pi); ax[6]->SetTitle("q-phi");
	58	double a1[100];
	59	for (int i=0;i<20;i++) a1[i]=i*0.005;
	60	for (int i=0;i<45;i++) a1[20+i]=0.1+i*0.02;
	61	ax[7] = new TAxis(64,a1); ax[7]->SetTitle("q (GeV/c)");
	62	AliUnicorHN *pair = new AliUnicorHN("pair",8,ax);
	63	for (int i=0; i<8; i++) delete ax[i];
	64	fHistos.Add(pair);
65	gROOT->cd();
66	printf("%s object named %s created\n",ClassName(),GetName());
67	}
68	//=============================================================================
69	void AliUnicorAnalCorrel::Process(Int_t tmr, AliUnicorEvent ev0, AliUnicorEvent ev1, Double_t phirot)
70	{
71	// process pairs from one or two (if mixing) events
72	// tmr tells which histogram (bins) to fill: tru,mix,rot
73
74	// Could be possibly accelerated by checking the "good particle" only once
75	// and caching the result. (Maybe the optimizer does it already.)
76
77	static TRandom2 ran;
78	AliUnicorHN pair = (AliUnicorHN) fHistos.At(0);
79
80	// mixing-and-rotating-proof centrality and reaction plane angle
81	// (but not rotation-proof for rotation angles much different from 0 and 180)
82	// true and rotated pairs are within the triangle (j<i), mixed - all
83	// thus, proper rotation is either by 180, or by 170 AND 190, etc.
84
85	double cent = (ev0->Centrality()+ev1->Centrality())/2.0;
86	double q0x,q0y,q1x,q1y;
87	ev0->RP(q0x,q0y);
88	ev1->RP(q1x,q1y);
89	double rpphi = atan2(q0y+q1y,q0x+q1x);
90
91	// loop over pairs
92
93	for (int i=0; i<ev0->NParticles(); i++) {
94	if (!ev0->ParticleGood(i,fPid0)) continue;
95	for (int j=0; j<ev1->NParticles(); j++) {
96	if (ev0==ev1 && j<i && fPid0==fPid1 ) continue;
97	if (ev0==ev1 && j==i) continue; // beware, not even when rotated or non-identical
98	if (!ev1->ParticleGood(j,fPid1)) continue;
99	if (!ev0->PairGood(ev0->ParticleP(i),ev0->ParticleTheta(i),ev0->ParticlePhi(i),
100	ev1->ParticleP(j),ev1->ParticleTheta(j),ev1->ParticlePhi(j)+phirot)) continue;
101	fPa.Set0(fMass0,ev0->ParticleP(i),ev0->ParticleTheta(i),ev0->ParticlePhi(i));
102	fPa.Set1(fMass1,ev1->ParticleP(j),ev1->ParticleTheta(j),ev1->ParticlePhi(j)+phirot);
103	if (ev0==ev1 && fPid0==fPid1 && ran.Rndm()>=0.5) fPa.Swap();
104	fPa.CalcLAB();
105	fPa.CalcPairCM();
106	if (fPa.QCM()==0) return; // should not be too frequent
107	double phi = TVector2::Phi_mpi_pi(fPa.Phi()-rpphi);
108	pair->Fill(tmr, // 0 for tru, 1 for mix, 2 for rot
109	cent, // centrality
110	fPa.Rapidity(), // pair rapidity
111	phi, // pair phi wrt reaction plane
112	fPa.Pt()/2.0, // half of pair pt
113	fPa.QCMTheta(), // polar angle of Q
114	fPa.QCMPhiOut(), // azimuthal angle of Q w.r.t. out
115	fPa.QCM(), // \|p2-p1\| in c.m.s.
116	1.0); // weigth
117	}
118	}
119	}
120	//=============================================================================