[u/mrichter/AliRoot.git] / PYTHIA6 / AliGenPythiaJets.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, 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.                  *
 **************************************************************************/

/* $Id$ */

//
// Generator using the TPythia interface (via AliPythia)
// to generate jets in pp collisions.
// Using SetNuclei() also nuclear modifications to the structure functions
// can be taken into account. 
// Using SetQuenchingFactor(f) quenched jets can be modelled by superimposing 
// two jets with energies e * f and e * (1-f)
//
// andreas.morsch@cern.ch
//


#include "AliGenPythiaJets.h"
#include "AliRun.h"
#include <TParticle.h>
#include <TClonesArray.h>

ClassImp(AliGenPythiaJets)

AliGenPythiaJets::AliGenPythiaJets()
                 :AliGenPythia()
{
// Default Constructor
}

AliGenPythiaJets::AliGenPythiaJets(Int_t npart)
                 :AliGenPythia(npart)
{
    fName = "PythiaJets";
    fTitle= "Jet Generator using PYTHIA";
}

AliGenPythiaJets::~AliGenPythiaJets()
{
// Destructor
}

void AliGenPythiaJets::Init()
{
// Initialization
//
    printf("AliGenPythiaJets::Init() \n");
    
    AliGenPythia::Init();
    
    if (fQuench > 0.) {
	 fEtMinJetQ[0]  = fEtMinJet  * fQuench;  
	 fEtMaxJetQ[0]  = fEtMaxJet  * fQuench;  
	 fEtMinJetQ[1]  = fEtMinJet  * (1. - fQuench);  
	 fEtMaxJetQ[1]  = fEtMaxJet  * (1. - fQuench);
	 fPtHardMinQ[0] = fPtHardMin * fQuench;  
	 fPtHardMaxQ[0] = fPtHardMax * fQuench;  
	 fPtHardMinQ[1] = fPtHardMin * (1. - fQuench);  
	 fPtHardMaxQ[1] = fPtHardMax * (1. - fQuench);  
    }
}

void AliGenPythiaJets::Generate()
{
// Generate one event
    fDecayer->ForceDecay();

    Float_t polar[3]   =   {0,0,0};
    Float_t origin[3]  =   {0,0,0};
    Float_t p[3];
//  converts from mm/c to s
    const Float_t kconv=0.001/2.999792458e8;
//
    Int_t nt  = 0;
    Int_t nc  = 0;
    Int_t jev = 0;
    Int_t j, kf, iparent;
    fTrials=0;
//
//  Set collision vertex position 
    if(fVertexSmear==kPerEvent) {
	fPythia->SetMSTP(151,1);
	for (j=0;j<3;j++) {
	    fPythia->SetPARP(151+j, fOsigma[j]*10.);
	}
    } else if (fVertexSmear==kPerTrack) {
	fPythia->SetMSTP(151,0);
    }
//  Event loop    
    while(1)
    {
	if (fQuench > 0.) {
	    fPythia->SetCKIN(3,fPtHardMinQ[jev]);
	    fPythia->SetCKIN(4,fPtHardMaxQ[jev]);
	    fEtMinJet = fEtMinJetQ[jev];
	    fEtMaxJet = fEtMaxJetQ[jev];	    
	}
	
	fPythia->Pyevnt();
	if (gAlice->GetEvNumber()>=fDebugEventFirst &&
	    gAlice->GetEvNumber()<=fDebugEventLast) fPythia->Pylist(1);
	fTrials++;
        //
	// Has this jet triggered
        //
	if ((fEtMinJet != -1) && ! CheckTrigger()) continue;
//
	fPythia->ImportParticles(fParticles,"All");
	Int_t i;
	Int_t np = fParticles->GetEntriesFast();
	if (np == 0 ) continue;
// Get event vertex and discard the event if the z coord. is too big	
	TParticle *iparticle = (TParticle *) fParticles->At(0);
	Float_t distz = iparticle->Vz()/10.;
	if(TMath::Abs(distz)>fCutVertexZ*fOsigma[2]) continue;
//
//
	fVertex[0] = iparticle->Vx()/10.+fOrigin.At(0);
	fVertex[1] = iparticle->Vy()/10.+fOrigin.At(1);
	fVertex[2] = iparticle->Vz()/10.+fOrigin.At(2);

	Int_t* pParent = new Int_t[np];
	for (i=0; i< np; i++) pParent[i] = -1;
	

	//
	for (i = 0; i<np; i++) {
	    Int_t trackIt = 0;
	    TParticle *  iparticle = (TParticle *) fParticles->At(i);
	    kf = CheckPDGCode(iparticle->GetPdgCode());
	    Int_t ks = iparticle->GetStatusCode();
	    Int_t km = iparticle->GetFirstMother();
	    if ((ks == 1  && kf !=0 && KinematicSelection(iparticle, 0)) ||
		(ks != 1) ||
		(fProcess == kPyJets && ks == 21 && km == 0 && i > 1)) {
		nc++;
		if (ks == 1) trackIt = 1;
		Int_t ipa = iparticle->GetFirstMother() - 1;
		iparent = (ipa > -1) ? pParent[ipa] : -1;
//
// Store track information
//
		p[0] = iparticle->Px();
		p[1] = iparticle->Py();
		p[2] = iparticle->Pz();
		origin[0] = fOrigin[0]+iparticle->Vx()/10.;
		origin[1] = fOrigin[1]+iparticle->Vy()/10.;
		origin[2] = fOrigin[2]+iparticle->Vz()/10.;
		Float_t tof=kconv*iparticle->T();
		PushTrack(fTrackIt*trackIt, iparent, kf, p, origin, polar,
			 tof, kPPrimary, nt, 1., ks);
		KeepTrack(nt);
		pParent[i] = nt;
	    } // select particle
	} // particle loop 
	
	if (pParent) delete[] pParent;
	printf("\n AliGenPythiaJets: I've put %i particles on the stack \n",nc);
	if (nc > 0) {
	    jev += 1;
	    if ((fQuench <= 0.) || (fQuench > 0. && jev == 2)) {
		fKineBias=Float_t(fNpart)/Float_t(fTrials);
		printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
		fNev++;
		MakeHeader();
		break;
	    }
	}
    }
    SetHighWaterMark(nt);
//  Get cross-section
    fXsection=fPythia->GetPARI(1);
}

Bool_t AliGenPythiaJets::CheckTrigger()
{
// Check the kinematic trigger condition
//
    Bool_t   triggered = kFALSE;
    Int_t njets = 0;
    Int_t ntrig = 0;
    Float_t jets[4][10];
//
// Use Pythia clustering on parton level to determine jet axis
//
    GetJets(njets, ntrig, jets);
    
    if (ntrig) {
	triggered = kTRUE;
	Float_t px   = jets[0][0];
	Float_t py   = jets[1][0];
	Float_t pz   = jets[2][0];
	Float_t e    = jets[3][0];
	Float_t beta = pz/e;
	Float_t phi  =  TMath::Pi()+TMath::ATan2(-py,-px);
	TransformEvent(beta, -2. * TMath::Pi() / 3. + phi);
    }
    return triggered;
}

void  AliGenPythiaJets::TransformEvent(Float_t beta, Float_t phi)
{
//
// Perform Lorentz Transformation and Rotation
//
    Float_t gamma = 1./TMath::Sqrt(1. - beta * beta);
    Int_t npart = (fPythia->GetPyjets())->N;

    for (Int_t part = 0; part < npart; part++) {
	Float_t px   = 	(fPythia->GetPyjets())->P[0][part];
	Float_t py   =  (fPythia->GetPyjets())->P[1][part];
	Float_t pz   =  (fPythia->GetPyjets())->P[2][part];
	Float_t e    =  (fPythia->GetPyjets())->P[3][part];
	//
	// Lorentz Transform
	//
	Float_t pzt =  gamma * pz        - gamma * beta * e;
	Float_t et  = -gamma * beta * pz + gamma        * e;
	//
	// Rotation
	//
	Float_t pxt =   TMath::Cos(phi) * px +  TMath::Sin(phi) * py;
	Float_t pyt = - TMath::Sin(phi) * px +  TMath::Cos(phi) * py;
	//
	//
	(fPythia->GetPyjets())->P[0][part] = pxt;
	(fPythia->GetPyjets())->P[1][part] = pyt;
	(fPythia->GetPyjets())->P[2][part] = pzt;
	(fPythia->GetPyjets())->P[3][part] = et;
    }
}
Commit	Line	Data
8d2cd130	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, 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
88cb7938	16	/* $Id$ */
8d2cd130	17
	18	//
	19	// Generator using the TPythia interface (via AliPythia)
	20	// to generate jets in pp collisions.
	21	// Using SetNuclei() also nuclear modifications to the structure functions
	22	// can be taken into account.
	23	// Using SetQuenchingFactor(f) quenched jets can be modelled by superimposing
	24	// two jets with energies e * f and e * (1-f)
	25	//
	26	// andreas.morsch@cern.ch
	27	//
	28
	29
	30	#include "AliGenPythiaJets.h"
	31	#include "AliRun.h"
	32	#include <TParticle.h>
37b09b91	33	#include <TClonesArray.h>
8d2cd130	34
	35	ClassImp(AliGenPythiaJets)
	36
	37	AliGenPythiaJets::AliGenPythiaJets()
	38	:AliGenPythia()
	39	{
	40	// Default Constructor
	41	}
	42
	43	AliGenPythiaJets::AliGenPythiaJets(Int_t npart)
	44	:AliGenPythia(npart)
	45	{
	46	fName = "PythiaJets";
	47	fTitle= "Jet Generator using PYTHIA";
	48	}
	49
8d2cd130	50	AliGenPythiaJets::~AliGenPythiaJets()
	51	{
	52	// Destructor
	53	}
	54
	55	void AliGenPythiaJets::Init()
	56	{
	57	// Initialization
	58	//
	59	printf("AliGenPythiaJets::Init() \n");
	60
	61	AliGenPythia::Init();
	62
	63	if (fQuench > 0.) {
	64	fEtMinJetQ[0] = fEtMinJet * fQuench;
	65	fEtMaxJetQ[0] = fEtMaxJet * fQuench;
	66	fEtMinJetQ[1] = fEtMinJet * (1. - fQuench);
	67	fEtMaxJetQ[1] = fEtMaxJet * (1. - fQuench);
	68	fPtHardMinQ[0] = fPtHardMin * fQuench;
	69	fPtHardMaxQ[0] = fPtHardMax * fQuench;
	70	fPtHardMinQ[1] = fPtHardMin * (1. - fQuench);
	71	fPtHardMaxQ[1] = fPtHardMax * (1. - fQuench);
	72	}
	73	}
	74
	75	void AliGenPythiaJets::Generate()
	76	{
	77	// Generate one event
	78	fDecayer->ForceDecay();
	79
	80	Float_t polar[3] = {0,0,0};
	81	Float_t origin[3] = {0,0,0};
	82	Float_t p[3];
	83	// converts from mm/c to s
	84	const Float_t kconv=0.001/2.999792458e8;
	85	//
	86	Int_t nt = 0;
	87	Int_t nc = 0;
	88	Int_t jev = 0;
	89	Int_t j, kf, iparent;
	90	fTrials=0;
	91	//
	92	// Set collision vertex position
	93	if(fVertexSmear==kPerEvent) {
	94	fPythia->SetMSTP(151,1);
	95	for (j=0;j<3;j++) {
	96	fPythia->SetPARP(151+j, fOsigma[j]*10.);
	97	}
	98	} else if (fVertexSmear==kPerTrack) {
	99	fPythia->SetMSTP(151,0);
	100	}
	101	// Event loop
	102	while(1)
	103	{
	104	if (fQuench > 0.) {
	105	fPythia->SetCKIN(3,fPtHardMinQ[jev]);
	106	fPythia->SetCKIN(4,fPtHardMaxQ[jev]);
	107	fEtMinJet = fEtMinJetQ[jev];
	108	fEtMaxJet = fEtMaxJetQ[jev];
	109	}
	110
	111	fPythia->Pyevnt();
	112	if (gAlice->GetEvNumber()>=fDebugEventFirst &&
	113	gAlice->GetEvNumber()<=fDebugEventLast) fPythia->Pylist(1);
114	fTrials++;
115	//
116	// Has this jet triggered
117	//
118	if ((fEtMinJet != -1) && ! CheckTrigger()) continue;
119	//
120	fPythia->ImportParticles(fParticles,"All");
121	Int_t i;
122	Int_t np = fParticles->GetEntriesFast();
123	if (np == 0 ) continue;
124	// Get event vertex and discard the event if the z coord. is too big
125	TParticle iparticle = (TParticle ) fParticles->At(0);
126	Float_t distz = iparticle->Vz()/10.;
127	if(TMath::Abs(distz)>fCutVertexZ*fOsigma[2]) continue;
128	//
129	//
d25cfd65	130	fVertex[0] = iparticle->Vx()/10.+fOrigin.At(0);
	131	fVertex[1] = iparticle->Vy()/10.+fOrigin.At(1);
	132	fVertex[2] = iparticle->Vz()/10.+fOrigin.At(2);
8d2cd130	133
	134	Int_t* pParent = new Int_t[np];
	135	for (i=0; i< np; i++) pParent[i] = -1;
	136
	137
	138	//
	139	for (i = 0; i<np; i++) {
	140	Int_t trackIt = 0;
	141	TParticle * iparticle = (TParticle *) fParticles->At(i);
	142	kf = CheckPDGCode(iparticle->GetPdgCode());
	143	Int_t ks = iparticle->GetStatusCode();
	144	Int_t km = iparticle->GetFirstMother();
	145	if ((ks == 1 && kf !=0 && KinematicSelection(iparticle, 0)) \|\|
	146	(ks != 1) \|\|
	147	(fProcess == kPyJets && ks == 21 && km == 0 && i > 1)) {
	148	nc++;
	149	if (ks == 1) trackIt = 1;
	150	Int_t ipa = iparticle->GetFirstMother() - 1;
	151	iparent = (ipa > -1) ? pParent[ipa] : -1;
	152	//
	153	// Store track information
	154	//
	155	p[0] = iparticle->Px();
	156	p[1] = iparticle->Py();
	157	p[2] = iparticle->Pz();
	158	origin[0] = fOrigin[0]+iparticle->Vx()/10.;
	159	origin[1] = fOrigin[1]+iparticle->Vy()/10.;
	160	origin[2] = fOrigin[2]+iparticle->Vz()/10.;
	161	Float_t tof=kconv*iparticle->T();
642f15cf	162	PushTrack(fTrackIt*trackIt, iparent, kf, p, origin, polar,
8d2cd130	163	tof, kPPrimary, nt, 1., ks);
	164	KeepTrack(nt);
	165	pParent[i] = nt;
	166	} // select particle
	167	} // particle loop
	168
	169	if (pParent) delete[] pParent;
	170	printf("\n AliGenPythiaJets: I've put %i particles on the stack \n",nc);
	171	if (nc > 0) {
	172	jev += 1;
	173	if ((fQuench <= 0.) \|\| (fQuench > 0. && jev == 2)) {
	174	fKineBias=Float_t(fNpart)/Float_t(fTrials);
	175	printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
	176	fNev++;
	177	MakeHeader();
	178	break;
	179	}
	180	}
	181	}
	182	SetHighWaterMark(nt);
	183	// Get cross-section
	184	fXsection=fPythia->GetPARI(1);
	185	}
	186
	187	Bool_t AliGenPythiaJets::CheckTrigger()
	188	{
	189	// Check the kinematic trigger condition
	190	//
	191	Bool_t triggered = kFALSE;
	192	Int_t njets = 0;
	193	Int_t ntrig = 0;
	194	Float_t jets[4][10];
	195	//
	196	// Use Pythia clustering on parton level to determine jet axis
	197	//
	198	GetJets(njets, ntrig, jets);
	199
	200	if (ntrig) {
	201	triggered = kTRUE;
	202	Float_t px = jets[0][0];
	203	Float_t py = jets[1][0];
	204	Float_t pz = jets[2][0];
	205	Float_t e = jets[3][0];
	206	Float_t beta = pz/e;
	207	Float_t phi = TMath::Pi()+TMath::ATan2(-py,-px);
	208	TransformEvent(beta, -2. * TMath::Pi() / 3. + phi);
	209	}
	210	return triggered;
	211	}
8d2cd130	212
	213	void AliGenPythiaJets::TransformEvent(Float_t beta, Float_t phi)
	214	{
	215	//
	216	// Perform Lorentz Transformation and Rotation
	217	//
	218	Float_t gamma = 1./TMath::Sqrt(1. - beta * beta);
	219	Int_t npart = (fPythia->GetPyjets())->N;
	220
	221	for (Int_t part = 0; part < npart; part++) {
	222	Float_t px = (fPythia->GetPyjets())->P[0][part];
	223	Float_t py = (fPythia->GetPyjets())->P[1][part];
	224	Float_t pz = (fPythia->GetPyjets())->P[2][part];
	225	Float_t e = (fPythia->GetPyjets())->P[3][part];
	226	//
	227	// Lorentz Transform
	228	//
	229	Float_t pzt = gamma * pz - gamma * beta * e;
	230	Float_t et = -gamma * beta * pz + gamma * e;
	231	//
	232	// Rotation
	233	//
	234	Float_t pxt = TMath::Cos(phi) * px + TMath::Sin(phi) * py;
	235	Float_t pyt = - TMath::Sin(phi) * px + TMath::Cos(phi) * py;
	236	//
	237	//
	238	(fPythia->GetPyjets())->P[0][part] = pxt;
	239	(fPythia->GetPyjets())->P[1][part] = pyt;
	240	(fPythia->GetPyjets())->P[2][part] = pzt;
	241	(fPythia->GetPyjets())->P[3][part] = et;
	242	}
	243	}
	244