[u/mrichter/AliRoot.git] / HBTAN / AliHBTCrab.cxx

#include "AliHBTCrab.h"
//______________________________________________________________________
/////////////////////////////////////////////////////////////////////////
//                                                                     //
// AliRoot wrapper to CRAB                                             //
// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html  //
// written by Scott Pratt                                              //
//                                                                     //
//                                                                     //
/////////////////////////////////////////////////////////////////////////
 
#include "AliHBTPair.h"

#include <TMath.h>

#include "volya_complex.h"

AliHBTCrab* AliHBTCrab::fgCrab = 0x0;

const Double_t AliHBTCrab::fgkWcons = 1./0.1973;
const Double_t AliHBTCrab::fgkROOT2=1.41421356237309504880;
#ifdef __DECCXX
const complex AliHBTCrab::fgkCI(0.0,1.0);
#else
const doublecomplex AliHBTCrab::fgkCI(0.0,1.0);
#endif

/************************************************************/

AliHBTCrab* AliHBTCrab::Instance()
{
// returns instance of class
 if (fgCrab == 0x0)
  {
    fgCrab = new AliHBTCrab();
  }
 return fgCrab;
}
//===================================================================

void AliHBTCrab::Set()
{
//sets this as weighitng class
 Info("Set","Setting CRAB as Weighing Class");
 
 if ( fgWeights == 0x0 )  
  {
    fgWeights = AliHBTCrab::Instance();
    return;
  }  
 if ( fgWeights == AliHBTCrab::Instance() ) return;
 delete fgWeights;
 fgWeights = AliHBTCrab::Instance();
}
//===================================================================

AliHBTCrab::AliHBTCrab():
fBreitWigner(kFALSE),
fReducedMom(kTRUE),
fMaxMomentum(100.0)
{
  //ctor
  if(fgCrab)
   {
     Fatal("AliHBTCrab","Do not use constructor directly. Use Instance() instead.");
   }
}
//===================================================================

AliHBTCrab::AliHBTCrab(const AliHBTCrab &/*source*/):
AliHBTWeights(),
fBreitWigner(kFALSE),
fReducedMom(kTRUE),
fMaxMomentum(100.0)
{
  //ctor
}
//===================================================================
AliHBTCrab & AliHBTCrab::operator=(const AliHBTCrab& /*source*/)
{
//cpy constructor
 return *AliHBTCrab::Instance();
}

void AliHBTCrab::Init(Int_t pid1,Int_t pid2)
{
//Initialization method
  fMass1 = TDatabasePDG::Instance()->GetParticle(pid1)->Mass();
  fMass2 = TDatabasePDG::Instance()->GetParticle(pid2)->Mass();
  fInteractionWsym = 1.0;
  fInteractionWanti = 0.0;
  fInteractionWnosym = 0.0;
  fInteractionDelk  = 1.0;
  fInteractionNkmax = 100;
     
  fPid1 = pid1;   
  fPid2 = pid2;
}
//===================================================================

Bool_t AliHBTCrab::SetConfig(const AliHBTPair* pair)
{
//returns the SetConfig
  
  Int_t pdg1 = pair->Particle1()->GetPdgCode();
  Int_t pdg2 = pair->Particle2()->GetPdgCode();
  
  if ( ( pdg1 == fPid1) && ( pdg2  == fPid2) ) return kFALSE;
  else Init (pdg1,pdg2);
  
  return kTRUE;
}
//===================================================================

Double_t AliHBTCrab::GetWeight(const AliHBTPair* partpair)
{
//returns the weight
  Double_t qred, r, qdotr, mom;
  Int_t test;
  
  SetConfig(partpair);
  
  GetComQuantities(partpair, &qred, &r, &qdotr, &mom, &test);
  if(test==0) 
   {
     Info("GetWeight","Test is 0");
   }
  Double_t corr = CorrCalc(qred,qdotr,r);
  
  return corr;
}
//===================================================================

void AliHBTCrab::GetComQuantities(const AliHBTPair* pair, 
       double *qred,double *r,double *qdotr,double *mom, int *test)
{
//************************************
//  ALICE //

 double p1[4]; 
 double p2[4]; 
 double r1[4]; 
 double r2[4]; 
 
 static const Double_t kCmToFm = 1.e13;
// static const Double_t cmtoOneOverGeV = kCmToFm*fgkWcons;
 
 AliHBTParticle *part1 = pair->Particle1();
 AliHBTParticle *part2 = pair->Particle2();

 p1[0] = part1->Energy()*1000.0;
 p1[1] = part1->Px()*1000.0;
 p1[2] = part1->Py()*1000.0;
 p1[3] = part1->Pz()*1000.0;
 
 p2[0] = part2->Energy()*1000.0;
 p2[1] = part2->Px()*1000.0;
 p2[2] = part2->Py()*1000.0;
 p2[3] = part2->Pz()*1000.0;

 r1[0] = part1->T();
 r1[1] = part1->Vx()*kCmToFm;
 r1[2] = part1->Vy()*kCmToFm;
 r1[3] = part1->Vz()*kCmToFm;

 r2[0] = part2->T();
 r2[1] = part2->Vx()*kCmToFm;
 r2[2] = part2->Vy()*kCmToFm;
 r2[3] = part2->Vz()*kCmToFm;

//  END OF ALICE STUFF

// This code is written by Scott Pratt
// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
  int alpha;
  double kdotr;
  double momtest;
  if (fReducedMom)
   {
     momtest=4.0*fMaxMomentum*fMaxMomentum;
   }  
  else
   {
     momtest=fMaxMomentum*fMaxMomentum;
   }  
   
  double ptot2,pdotr,pp,rr;
  
  if ( part1->GetPdgCode() == part2->GetPdgCode() )
   {
    *test=1;
    *mom=-(p2[0]-p1[0])*(p2[0]-p1[0]);
    for(alpha=1;alpha<4;alpha++){
      *mom=*mom+(p2[alpha]-p1[alpha])*(p2[alpha]-p1[alpha]);
    }
   //#if ! defined MIXED_PAIRS_FOR_DENOM
   //  if(*mom>momtest){
   //    *test=0;
   //    return;
   //  }
   //#endif
    pp=(p1[0]+p2[0]);
    rr=(r2[0]-r1[0]);
    pdotr=pp*rr;
    kdotr=(p2[0]-p1[0])*rr;
    ptot2=pp*pp;
    *r=-rr*rr;
    for(alpha=1;alpha<4;alpha++){
      pp=(p1[alpha]+p2[alpha]);
      rr=(r2[alpha]-r1[alpha]);
      pdotr=pdotr-pp*rr;
      kdotr=kdotr-(p2[alpha]-p1[alpha])*rr;
      ptot2=ptot2-pp*pp;
      *r=*r+rr*rr;
    }
    *mom=sqrt(*mom);
    *qred=0.5**mom;

    if (fReducedMom)
     {
      *mom=*qred;
     } 

    *qdotr=0.5*kdotr;
    *r=sqrt(*r+pdotr*pdotr/ptot2);
   }  
  else //identical
  {
  //  const double  kdotp=fMass2*fMass2-fMass1*fMass1;
   const double  kdotp = part2->GetMass()*part2->GetMass()- part1->GetMass()*part1->GetMass();
   *test=1;
   *mom=-(p2[0]-p1[0])*(p2[0]-p1[0]);
   ptot2=(p1[0]+p2[0])*(p1[0]+p2[0]);
   for(alpha=1;alpha<4;alpha++){
     *mom=*mom+(p2[alpha]-p1[alpha])*(p2[alpha]-p1[alpha]);
     ptot2=ptot2-(p1[alpha]+p2[alpha])*(p1[alpha]+p2[alpha]);
   }
   *mom=*mom+kdotp*kdotp/ptot2;
  //#if ! defined MIXED_PAIRS_FOR_DENOM
  //  if(*mom>momtest){
  //    *test=0;
  //    return;
  //  }
  //#endif
   pp=(p1[0]+p2[0]);
   rr=(r2[0]-r1[0]);
   pdotr=pp*rr;
   kdotr=(p2[0]-p1[0])*rr;
   *r=-rr*rr;
   for(alpha=1;alpha<4;alpha++){
     pp=(p1[alpha]+p2[alpha]);
     rr=(r2[alpha]-r1[alpha]);
     pdotr=pdotr-pp*rr;
     kdotr=kdotr-(p2[alpha]-p1[alpha])*rr;
     *r=*r+rr*rr;
   }
   kdotr=(-kdotr+kdotp*pdotr/ptot2);
   *mom=sqrt(*mom);
   *qred=0.5**mom;

   if (fReducedMom)
    {
     *mom=*qred;
    } 

   *qdotr=0.5*kdotr;
   *r=sqrt(*r+pdotr*pdotr/ptot2);
  }//not identical  

  return;
}


//===================================================================

double  AliHBTCrab::CorrCalc(double trueqred,double trueqdotr,double truer)
{
//#define REDUCED_MOM
// This code is written by Scott Pratt
// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
  double eta,arg,corr0;
//  double xx,xxprime,xxjj,p1,zk;
//  int jj,kk,ipart,ipartcount,ispin;
  int kk;
  double wsymleftover,wantileftover,wnosymleftover;
  double qred,qdotr,r;
//  const double rmass=fMass1*fMass2/(fMass1+fMass2);
#ifdef __DECCXX
  complex cphi1,cphi2,cphis,cphia;
#else
  doublecomplex cphi1,cphi2,cphis,cphia;
#endif

  arg=trueqdotr/197.323-2.0*TMath::Pi()*TMath::Floor(trueqdotr/(197.323*2.0*TMath::Pi()));
  cphi1=exp(fgkCI*arg);
  cphis=fgkROOT2*real(cphi1);
  cphia=fgkCI*fgkROOT2*imag(cphi1);
  corr0=real(fInteractionWsym*cphis*conj(cphis)
	     +fInteractionWanti*cphia*conj(cphia)
	     +fInteractionWnosym*cphi1*conj(cphi1));
  goto OUTSIDE_INTERACTION_RANGE;

#ifdef REDUCED_MOM
  kk=(int)TMath::Floor(trueqred/fInteractionDelk);
  qred=(0.5+kk)*fInteractionDelk;
#else
  kk=(int)TMath::Floor(2.0*trueqred/fInteractionDelk);
  qred=(0.5+kk)*fInteractionDelk/2.0;
#endif
  qdotr=trueqdotr*qred/trueqred;
  if(kk>=fInteractionNkmax){
    corr0=1.0;
    goto OUTSIDE_INTERACTION_RANGE;
  }
  r=truer;

  eta=0.0;
  arg=qdotr/197.323-2.0*TMath::Pi()*TMath::Floor(qdotr/(197.323*2.0*TMath::Pi()));
  cphi1=exp(fgkCI*arg);
  cphi2=conj(cphi1);

  cphis=(cphi1+cphi2)/fgkROOT2;
  cphia=(cphi1-cphi2)/fgkROOT2;
  corr0=0.0;
  /* If there are corrections for strong interactions, add the
     change for each partial wave.  If npartial = 0 then there
     are no strong int. corrections. */
  wsymleftover=fInteractionWsym;
  wantileftover=fInteractionWanti;
  wnosymleftover=fInteractionWnosym;

  corr0=corr0+real(wsymleftover*cphis*conj(cphis)
		   +wantileftover*cphia*conj(cphia)
		   +wnosymleftover*cphi1*conj(cphi1));
OUTSIDE_INTERACTION_RANGE:

#ifdef BREIT_WIGNER
  corr0=corr0+bwcalc(trueqred,truer);
#endif

  return corr0;
}

#ifdef __DECCXX
complex AliHBTCrab::CGamma(complex c){
/* This calc.s gamma functions which are in the form gamma(n+i*y)
   where n is an int and y is real. */
// This code is written by Scott Pratt
// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
#else
doublecomplex AliHBTCrab::CGamma(doublecomplex c){
/* This calc.s gamma functions which are in the form gamma(n+i*y)
   where n is an int and y is real. */
// This code is written by Scott Pratt
// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
#endif
#ifdef __DECCXX
  complex cg,cphase;
#else
  doublecomplex cg,cphase;
#endif
  int mm,j;
  double x,y,phase,delp,cgmag;
  x=real(c);
  y=imag(c);
  phase=-TMath::E()*y;
  for(j=1;j<=100000;j++){
    delp=(y/(double)j)-atan(y/(double)j);
    phase=phase+delp;
    if(TMath::Abs(delp)<1E-10) goto CGamma_ESCAPE;
  }
  printf("oops not accurate enough, increase jmax\n");
CGamma_ESCAPE:
  phase=phase-2.0*TMath::Pi()*TMath::Floor(phase/(2.0*TMath::Pi()));
  cphase=exp(fgkCI*phase);
  cgmag=sqrt(TMath::Pi()*y/sinh(TMath::Pi()*y));
  mm=(int)TMath::Floor(x+0.5);
  cg=cgmag*cphase;
  if(mm<1){
    for(j=1;j<=-mm+1;j++){
      cg=cg/(1.0+(double)(-j)+fgkCI*y);
    }
  }
  if(mm>1) {
    for(j=1;j<=mm-1;j++){
      cg=cg*((double)(j)+fgkCI*y);
    }
  }
  return cg;
}
Commit	Line	Data
dd82cadc	1	#include "AliHBTCrab.h"
	2	//______________________________________________________________________
	3	/////////////////////////////////////////////////////////////////////////
	4	// //
	5	// AliRoot wrapper to CRAB //
	6	// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html //
	7	// written by Scott Pratt //
	8	// //
c114f4f8	9	// //
dd82cadc	10	/////////////////////////////////////////////////////////////////////////
f93c53d8	11
dd82cadc	12	#include "AliHBTPair.h"
	13
	14	#include <TMath.h>
dd82cadc	15
	16	#include "volya_complex.h"
	17
dd82cadc	18	AliHBTCrab* AliHBTCrab::fgCrab = 0x0;
	19
	20	const Double_t AliHBTCrab::fgkWcons = 1./0.1973;
	21	const Double_t AliHBTCrab::fgkROOT2=1.41421356237309504880;
8882f543	22	#ifdef __DECCXX
c114f4f8	23	const complex AliHBTCrab::fgkCI(0.0,1.0);
8882f543	24	#else
c031a417	25	const doublecomplex AliHBTCrab::fgkCI(0.0,1.0);
8882f543	26	#endif
dd82cadc	27
	28	/************************************************************/
	29
	30	AliHBTCrab* AliHBTCrab::Instance()
	31	{
	32	// returns instance of class
	33	if (fgCrab == 0x0)
	34	{
	35	fgCrab = new AliHBTCrab();
	36	}
	37	return fgCrab;
	38	}
	39	//===================================================================
c114f4f8	40
dd82cadc	41	void AliHBTCrab::Set()
dd82cadc	42	{
c114f4f8	43	//sets this as weighitng class
dd82cadc	44	Info("Set","Setting CRAB as Weighing Class");
	45
	46	if ( fgWeights == 0x0 )
	47	{
	48	fgWeights = AliHBTCrab::Instance();
	49	return;
	50	}
	51	if ( fgWeights == AliHBTCrab::Instance() ) return;
	52	delete fgWeights;
	53	fgWeights = AliHBTCrab::Instance();
	54	}
	55	//===================================================================
	56
	57	AliHBTCrab::AliHBTCrab():
	58	fBreitWigner(kFALSE),
	59	fReducedMom(kTRUE),
	60	fMaxMomentum(100.0)
	61	{
	62	//ctor
8ef3740b	63	if(fgCrab)
	64	{
	65	Fatal("AliHBTCrab","Do not use constructor directly. Use Instance() instead.");
	66	}
dd82cadc	67	}
dd82cadc	68	//===================================================================
c031a417	69
	70	AliHBTCrab::AliHBTCrab(const AliHBTCrab &/source/):
	71	AliHBTWeights(),
	72	fBreitWigner(kFALSE),
	73	fReducedMom(kTRUE),
	74	fMaxMomentum(100.0)
	75	{
	76	//ctor
	77	}
	78	//===================================================================
34914285	79	AliHBTCrab & AliHBTCrab::operator=(const AliHBTCrab& /source/)
c031a417	80	{
	81	//cpy constructor
	82	return *AliHBTCrab::Instance();
	83	}
	84
dd82cadc	85	void AliHBTCrab::Init(Int_t pid1,Int_t pid2)
dd82cadc	86	{
c031a417	87	//Initialization method
c114f4f8	88	fMass1 = TDatabasePDG::Instance()->GetParticle(pid1)->Mass();
	89	fMass2 = TDatabasePDG::Instance()->GetParticle(pid2)->Mass();
	90	fInteractionWsym = 1.0;
	91	fInteractionWanti = 0.0;
	92	fInteractionWnosym = 0.0;
	93	fInteractionDelk = 1.0;
	94	fInteractionNkmax = 100;
dd82cadc	95
	96	fPid1 = pid1;
	97	fPid2 = pid2;
dd82cadc	98	}
c031a417	99	//===================================================================
dd82cadc	100
	101	Bool_t AliHBTCrab::SetConfig(const AliHBTPair* pair)
	102	{
c114f4f8	103	//returns the SetConfig
c114f4f8	104
dd82cadc	105	Int_t pdg1 = pair->Particle1()->GetPdgCode();
	106	Int_t pdg2 = pair->Particle2()->GetPdgCode();
	107
	108	if ( ( pdg1 == fPid1) && ( pdg2 == fPid2) ) return kFALSE;
	109	else Init (pdg1,pdg2);
	110
	111	return kTRUE;
	112	}
	113	//===================================================================
	114
	115	Double_t AliHBTCrab::GetWeight(const AliHBTPair* partpair)
	116	{
c114f4f8	117	//returns the weight
dd82cadc	118	Double_t qred, r, qdotr, mom;
	119	Int_t test;
	120
	121	SetConfig(partpair);
	122
c114f4f8	123	GetComQuantities(partpair, &qred, &r, &qdotr, &mom, &test);
dd82cadc	124	if(test==0)
	125	{
	126	Info("GetWeight","Test is 0");
	127	}
c114f4f8	128	Double_t corr = CorrCalc(qred,qdotr,r);
dd82cadc	129
	130	return corr;
	131	}
	132	//===================================================================
	133
c114f4f8	134	void AliHBTCrab::GetComQuantities(const AliHBTPair* pair,
dd82cadc	135	double qred,double r,double qdotr,double mom, int *test)
c031a417	136	{
dd82cadc	137	//************************************
	138	// ALICE //
	139
	140	double p1[4];
	141	double p2[4];
	142	double r1[4];
	143	double r2[4];
	144
c114f4f8	145	static const Double_t kCmToFm = 1.e13;
c114f4f8	146	// static const Double_t cmtoOneOverGeV = kCmToFm*fgkWcons;
dd82cadc	147
	148	AliHBTParticle *part1 = pair->Particle1();
	149	AliHBTParticle *part2 = pair->Particle2();
	150
	151	p1[0] = part1->Energy()*1000.0;
	152	p1[1] = part1->Px()*1000.0;
	153	p1[2] = part1->Py()*1000.0;
	154	p1[3] = part1->Pz()*1000.0;
	155
	156	p2[0] = part2->Energy()*1000.0;
	157	p2[1] = part2->Px()*1000.0;
	158	p2[2] = part2->Py()*1000.0;
	159	p2[3] = part2->Pz()*1000.0;
	160
	161	r1[0] = part1->T();
c114f4f8	162	r1[1] = part1->Vx()*kCmToFm;
	163	r1[2] = part1->Vy()*kCmToFm;
	164	r1[3] = part1->Vz()*kCmToFm;
dd82cadc	165
dd82cadc	166	r2[0] = part2->T();
c114f4f8	167	r2[1] = part2->Vx()*kCmToFm;
	168	r2[2] = part2->Vy()*kCmToFm;
	169	r2[3] = part2->Vz()*kCmToFm;
dd82cadc	170
	171	// END OF ALICE STUFF
	172
	173	// This code is written by Scott Pratt
	174	// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
	175	int alpha;
	176	double kdotr;
f93c53d8	177	double momtest;
dd82cadc	178	if (fReducedMom)
dd82cadc	179	{
f93c53d8	180	momtest=4.0fMaxMomentumfMaxMomentum;
dd82cadc	181	}
	182	else
	183	{
f93c53d8	184	momtest=fMaxMomentum*fMaxMomentum;
dd82cadc	185	}
	186
	187	double ptot2,pdotr,pp,rr;
	188
	189	if ( part1->GetPdgCode() == part2->GetPdgCode() )
	190	{
	191	*test=1;
	192	mom=-(p2[0]-p1[0])(p2[0]-p1[0]);
	193	for(alpha=1;alpha<4;alpha++){
	194	mom=mom+(p2[alpha]-p1[alpha])*(p2[alpha]-p1[alpha]);
	195	}
	196	//#if ! defined MIXED_PAIRS_FOR_DENOM
	197	// if(*mom>momtest){
	198	// *test=0;
	199	// return;
	200	// }
	201	//#endif
	202	pp=(p1[0]+p2[0]);
	203	rr=(r2[0]-r1[0]);
	204	pdotr=pp*rr;
	205	kdotr=(p2[0]-p1[0])*rr;
	206	ptot2=pp*pp;
	207	r=-rrrr;
	208	for(alpha=1;alpha<4;alpha++){
	209	pp=(p1[alpha]+p2[alpha]);
	210	rr=(r2[alpha]-r1[alpha]);
	211	pdotr=pdotr-pp*rr;
	212	kdotr=kdotr-(p2[alpha]-p1[alpha])*rr;
	213	ptot2=ptot2-pp*pp;
	214	r=r+rr*rr;
	215	}
	216	mom=sqrt(mom);
	217	qred=0.5*mom;
	218
	219	if (fReducedMom)
	220	{
	221	mom=qred;
	222	}
	223
	224	qdotr=0.5kdotr;
	225	r=sqrt(r+pdotr*pdotr/ptot2);
	226	}
	227	else //identical
	228	{
c114f4f8	229	// const double kdotp=fMass2fMass2-fMass1fMass1;
dd82cadc	230	const double kdotp = part2->GetMass()part2->GetMass()- part1->GetMass()part1->GetMass();
	231	*test=1;
	232	mom=-(p2[0]-p1[0])(p2[0]-p1[0]);
	233	ptot2=(p1[0]+p2[0])*(p1[0]+p2[0]);
	234	for(alpha=1;alpha<4;alpha++){
	235	mom=mom+(p2[alpha]-p1[alpha])*(p2[alpha]-p1[alpha]);
	236	ptot2=ptot2-(p1[alpha]+p2[alpha])*(p1[alpha]+p2[alpha]);
	237	}
	238	mom=mom+kdotp*kdotp/ptot2;
	239	//#if ! defined MIXED_PAIRS_FOR_DENOM
	240	// if(*mom>momtest){
	241	// *test=0;
	242	// return;
	243	// }
	244	//#endif
	245	pp=(p1[0]+p2[0]);
	246	rr=(r2[0]-r1[0]);
	247	pdotr=pp*rr;
	248	kdotr=(p2[0]-p1[0])*rr;
	249	r=-rrrr;
	250	for(alpha=1;alpha<4;alpha++){
	251	pp=(p1[alpha]+p2[alpha]);
	252	rr=(r2[alpha]-r1[alpha]);
	253	pdotr=pdotr-pp*rr;
	254	kdotr=kdotr-(p2[alpha]-p1[alpha])*rr;
	255	r=r+rr*rr;
	256	}
	257	kdotr=(-kdotr+kdotp*pdotr/ptot2);
	258	mom=sqrt(mom);
	259	qred=0.5*mom;
	260
	261	if (fReducedMom)
	262	{
	263	mom=qred;
	264	}
	265
	266	qdotr=0.5kdotr;
	267	r=sqrt(r+pdotr*pdotr/ptot2);
	268	}//not identical
	269
	270	return;
	271	}
	272
	273
	274	//===================================================================
	275
c114f4f8	276	double AliHBTCrab::CorrCalc(double trueqred,double trueqdotr,double truer)
dd82cadc	277	{
	278	//#define REDUCED_MOM
	279	// This code is written by Scott Pratt
	280	// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
f93c53d8	281	double eta,arg,corr0;
	282	// double xx,xxprime,xxjj,p1,zk;
	283	// int jj,kk,ipart,ipartcount,ispin;
	284	int kk;
c031a417	285	double wsymleftover,wantileftover,wnosymleftover;
dd82cadc	286	double qred,qdotr,r;
c114f4f8	287	// const double rmass=fMass1*fMass2/(fMass1+fMass2);
8882f543	288	#ifdef __DECCXX
	289	complex cphi1,cphi2,cphis,cphia;
	290	#else
c031a417	291	doublecomplex cphi1,cphi2,cphis,cphia;
8882f543	292	#endif
dd82cadc	293
3294e9ff	294	arg=trueqdotr/197.323-2.0TMath::Pi()TMath::Floor(trueqdotr/(197.3232.0TMath::Pi()));
c114f4f8	295	cphi1=exp(fgkCI*arg);
dd82cadc	296	cphis=fgkROOT2*real(cphi1);
c114f4f8	297	cphia=fgkCIfgkROOT2imag(cphi1);
	298	corr0=real(fInteractionWsymcphisconj(cphis)
	299	+fInteractionWanticphiaconj(cphia)
	300	+fInteractionWnosymcphi1conj(cphi1));
dd82cadc	301	goto OUTSIDE_INTERACTION_RANGE;
	302
	303	#ifdef REDUCED_MOM
c114f4f8	304	kk=(int)TMath::Floor(trueqred/fInteractionDelk);
c114f4f8	305	qred=(0.5+kk)*fInteractionDelk;
dd82cadc	306	#else
c114f4f8	307	kk=(int)TMath::Floor(2.0*trueqred/fInteractionDelk);
c114f4f8	308	qred=(0.5+kk)*fInteractionDelk/2.0;
dd82cadc	309	#endif
dd82cadc	310	qdotr=trueqdotr*qred/trueqred;
c114f4f8	311	if(kk>=fInteractionNkmax){
dd82cadc	312	corr0=1.0;
	313	goto OUTSIDE_INTERACTION_RANGE;
	314	}
	315	r=truer;
	316
	317	eta=0.0;
3294e9ff	318	arg=qdotr/197.323-2.0TMath::Pi()TMath::Floor(qdotr/(197.3232.0TMath::Pi()));
c114f4f8	319	cphi1=exp(fgkCI*arg);
dd82cadc	320	cphi2=conj(cphi1);
	321
	322	cphis=(cphi1+cphi2)/fgkROOT2;
	323	cphia=(cphi1-cphi2)/fgkROOT2;
	324	corr0=0.0;
	325	/* If there are corrections for strong interactions, add the
	326	change for each partial wave. If npartial = 0 then there
	327	are no strong int. corrections. */
c031a417	328	wsymleftover=fInteractionWsym;
	329	wantileftover=fInteractionWanti;
	330	wnosymleftover=fInteractionWnosym;
dd82cadc	331
c031a417	332	corr0=corr0+real(wsymleftovercphisconj(cphis)
	333	+wantileftovercphiaconj(cphia)
	334	+wnosymleftovercphi1conj(cphi1));
dd82cadc	335	OUTSIDE_INTERACTION_RANGE:
	336
	337	#ifdef BREIT_WIGNER
	338	corr0=corr0+bwcalc(trueqred,truer);
	339	#endif
	340
	341	return corr0;
	342	}
	343
8882f543	344	#ifdef __DECCXX
c114f4f8	345	complex AliHBTCrab::CGamma(complex c){
c031a417	346	/* This calc.s gamma functions which are in the form gamma(n+i*y)
	347	where n is an int and y is real. */
	348	// This code is written by Scott Pratt
	349	// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
8882f543	350	#else
c031a417	351	doublecomplex AliHBTCrab::CGamma(doublecomplex c){
	352	/* This calc.s gamma functions which are in the form gamma(n+i*y)
	353	where n is an int and y is real. */
dd82cadc	354	// This code is written by Scott Pratt
dd82cadc	355	// taken from http://www.nscl.msu.edu/~pratt/freecodes/crab/home.html
c031a417	356	#endif
8882f543	357	#ifdef __DECCXX
	358	complex cg,cphase;
	359	#else
c031a417	360	doublecomplex cg,cphase;
8882f543	361	#endif
dd82cadc	362	int mm,j;
	363	double x,y,phase,delp,cgmag;
	364	x=real(c);
	365	y=imag(c);
	366	phase=-TMath::E()*y;
	367	for(j=1;j<=100000;j++){
	368	delp=(y/(double)j)-atan(y/(double)j);
	369	phase=phase+delp;
c114f4f8	370	if(TMath::Abs(delp)<1E-10) goto CGamma_ESCAPE;
dd82cadc	371	}
dd82cadc	372	printf("oops not accurate enough, increase jmax\n");
c114f4f8	373	CGamma_ESCAPE:
3294e9ff	374	phase=phase-2.0TMath::Pi()TMath::Floor(phase/(2.0*TMath::Pi()));
c114f4f8	375	cphase=exp(fgkCI*phase);
dd82cadc	376	cgmag=sqrt(TMath::Pi()y/sinh(TMath::Pi()y));
3294e9ff	377	mm=(int)TMath::Floor(x+0.5);
dd82cadc	378	cg=cgmag*cphase;
	379	if(mm<1){
	380	for(j=1;j<=-mm+1;j++){
c114f4f8	381	cg=cg/(1.0+(double)(-j)+fgkCI*y);
dd82cadc	382	}
	383	}
	384	if(mm>1) {
	385	for(j=1;j<=mm-1;j++){
c114f4f8	386	cg=cg((double)(j)+fgkCIy);
dd82cadc	387	}
	388	}
	389	return cg;
	390	}