[u/mrichter/AliRoot.git] / EVGEN / AliSlowNucleonModelExp.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.                  *
 **************************************************************************/

/* $Id$ */

//
// Experimental data inspired Gray Particle Model for p-Pb collisions
// The number of gray nucleons  is proportional to the number of collisions.
// The number of black nucleons is proportional to the number of collisions
// Fluctuations are calculated from a binomial distribution.
// Author: A.Morsch
//

#include "AliSlowNucleonModelExp.h"
#include "AliCollisionGeometry.h"
#include <TRandom.h>
#include <TMath.h>

ClassImp(AliSlowNucleonModelExp)


AliSlowNucleonModelExp::AliSlowNucleonModelExp():
    fP(82),
    fN (126),
    fAlphaGray(2.3),
    fAlphaBlack(3.6),
    fApplySaturation(kTRUE),
    fnGraySaturation(15),
    fnBlackSaturation(28),
    fLCPparam(0.585),
    fSigmaSmear(0.25)
{
  //
  // Default constructor
  //
  //
  fSlownparam[0] = 60.;
  fSlownparam[1] = 469.2;
  fSlownparam[2] = 8.762;
  /*printf("\n\n ******** Initializing slow nucleon model with parameters:\n");
  printf(" \t alpha_{gray} %1.2f  alpha_{black} %1.2f\n",fAlphaGray, fAlphaBlack);
  printf(" \t SATURATION %d w. %d (gray) %d (black) \n\n",fApplySaturation,fnGraySaturation,fnBlackSaturation);
  printf(" \t LCP parameter %f   Slown parameters = {%f, %f,
  %f}\n\n",fLCPparam,fSlownparam[0],fSlownparam[1],fSlownparam[2]); */
}


void AliSlowNucleonModelExp::GetNumberOfSlowNucleons(AliCollisionGeometry* geo, 
						      Int_t& ngp, Int_t& ngn, Int_t & nbp, Int_t & nbn) const
{
//
// Return the number of black and gray nucleons
//
// Number of collisions

    Float_t nu = geo->NN() + geo->NwN() + geo->NNw(); 

// Mean number of gray nucleons 

    Float_t nGray         = fAlphaGray * nu;
    Float_t nGrayNeutrons = nGray * fN / (fN + fP);
    Float_t nGrayProtons  = nGray - nGrayNeutrons;

// Mean number of black nucleons 
    Float_t nBlack  = 0.;
    if(!fApplySaturation || (fApplySaturation && nGray<fnGraySaturation)) nBlack = fAlphaBlack * nu;
    else if(fApplySaturation && nGray>=fnGraySaturation) nBlack = fnBlackSaturation;
    Float_t nBlackNeutrons = nBlack * 0.84;
    Float_t nBlackProtons  = nBlack - nBlackNeutrons;

// Actual number (including fluctuations) from binomial distribution
    Double_t p;

//  gray neutrons
    p =  nGrayNeutrons/fN;
    ngn = gRandom->Binomial((Int_t) fN, p);
    
//  gray protons
    p =  nGrayProtons/fP;
    ngp = gRandom->Binomial((Int_t) fP, p);

//  black neutrons
    p =  nBlackNeutrons/fN;
    nbn = gRandom->Binomial((Int_t) fN, p);
    
//  black protons
    p =  nBlackProtons/fP;
    nbp = gRandom->Binomial((Int_t) fP, p);

}

void AliSlowNucleonModelExp::GetNumberOfSlowNucleons2(AliCollisionGeometry* geo, 
						      Int_t& ngp, Int_t& ngn, Int_t & nbp, Int_t & nbn) const
{
//
// Return the number of black and gray nucleons
//
// Number of collisions

   // based on E910 model ================================================================

   Float_t nu = (Float_t) (geo->NN() + geo->NwN() + geo->NNw()); 
   //
   //nu = nu+1.*gRandom->Rndm();
   nu = gRandom->Gaus(nu, 0.5);
   if(nu<0.) nu=0.;
   //
   Float_t  poverpd = 0.843; 
   Float_t  zAu2zPb = 82./79.;
   Float_t  nGrayp = (-0.27 + 0.63 * nu - 0.0008 *nu *nu)*poverpd*zAu2zPb;

//  gray protons
    Double_t p;
    p =  nGrayp/fP;
    ngp = gRandom->Binomial((Int_t) fP, p);
    //ngp = gRandom->Gaus(nGrayp, TMath::Sqrt(fP*p*(1-p)));
    if(nGrayp<0.) ngp=0;
    
    //Float_t blackovergray = 3./7.;// from spallation
    Float_t blackovergray = 0.65; // from COSY
    Float_t nBlackp  = blackovergray*nGrayp; 

//  black protons
    p =  nBlackp/fP;
    nbp = gRandom->Binomial((Int_t) fP, p);
    //nbp = gRandom->Gaus(nBlackp, TMath::Sqrt(fP*p*(1-p)));
    if(nBlackp<0.) nbp=0;
    
    if(nu<3.){
      nGrayp = -0.836 + 0.9112 *nu - 0.05381 *nu *nu;
      nBlackp  = blackovergray*nGrayp; 
    }
    
    //printf(" \t Using LCP parameter %f   Slown parameters = {%f, %f, %f}\n\n",fLCPparam,fSlownparam[0],fSlownparam[1],fSlownparam[2]); 
    Float_t nGrayNeutrons = 0.;
    Float_t nBlackNeutrons = 0.;
    Float_t cp = (nGrayp+nBlackp)/fLCPparam;
    
    if(cp>0.){
      Float_t nSlow      = fSlownparam[0]+fSlownparam[1]/(-fSlownparam[2]-cp);
      Float_t paramRetta = fSlownparam[0]+fSlownparam[1]/(-fSlownparam[2]-3);
      if(cp<3.) nSlow = 0.+(paramRetta-0.)/(3.-0.)*(cp-0.);
    
      nGrayNeutrons = nSlow * 0.1; 
      nBlackNeutrons = nSlow - nGrayNeutrons;
    }
    else{
      // Sikler "pasturato" (qui non entra mai!!!!)
      nGrayNeutrons = 0.47 * fAlphaGray *  nu; 
      nBlackNeutrons = 0.88 * fAlphaBlack * nu;      
      //printf("nslowp=0 -> ncoll = %1.0f -> ngrayn = %1.0f  nblackn = %1.0f \n", nu, nGrayNeutrons, nBlackNeutrons);
    }
    
//  gray neutrons
    p =  nGrayNeutrons/fN;
//    ngn = gRandom->Binomial((Int_t) fN, p);
    ngn = gRandom->Gaus(nGrayNeutrons, TMath::Sqrt(fN*p*(1-p)));

//  black neutrons
    p =  nBlackNeutrons/fN;
//    nbn = gRandom->Binomial((Int_t) fN, p);
    nbn = gRandom->Gaus(nBlackNeutrons, TMath::Sqrt(fN*p*(1-p)));
    
    
}

void AliSlowNucleonModelExp::GetNumberOfSlowNucleons2s(AliCollisionGeometry* geo, 
						      Int_t& ngp, Int_t& ngn, Int_t & nbp, Int_t & nbn) const
{
//
// Return the number of black and gray nucleons
//
// Number of collisions

   // based on E910 model ================================================================

   Float_t nu = (Float_t) (geo->NN() + geo->NwN() + geo->NNw()); 
   //
   Float_t  poverpd = 0.843; 
   Float_t  zAu2zPb = 82./79.;
   Float_t  grayp = (-0.27 + 0.63 * nu - 0.0008 *nu *nu)*poverpd*zAu2zPb;
   Float_t  nGrayp = gRandom->Gaus(grayp, fSigmaSmear);
   if(nGrayp<0.) nGrayp=0.;

//  gray protons
    Double_t p=0.;
    p = nGrayp/fP;
    ngp = gRandom->Binomial((Int_t) fP, p);
    //ngp = gRandom->Gaus(nGrayp, TMath::Sqrt(fP*p*(1-p)));
    if(nGrayp<0.) ngp=0;
    
    //Float_t blackovergray = 3./7.;// from spallation
    Float_t blackovergray = 0.65; // from COSY
    //Float_t blackp  = blackovergray*grayp; 
    //Float_t nBlackp = gRandom->Gaus(nblackp, fSigmaSmear);
    Float_t nBlackp = blackovergray*nGrayp;
    if(nBlackp<0.) nBlackp=0.;

//  black protons
    p =  nBlackp/fP;
    nbp = gRandom->Binomial((Int_t) fP, p);
    //nbp = gRandom->Gaus(nBlackp, TMath::Sqrt(fP*p*(1-p)));
    if(nBlackp<0.) nbp=0;
    
    Float_t nGrayNeutrons = 0.;
    Float_t nBlackNeutrons = 0.;
    Float_t cp = (nGrayp+nBlackp)/fLCPparam;
    
    if(cp>0.){
      Float_t nSlow = fSlownparam[0]+fSlownparam[1]/(-fSlownparam[2]-cp);
      
      nGrayNeutrons = nSlow * 0.1; 
      nBlackNeutrons = nSlow - nGrayNeutrons;
    }
    else{
      // Sikler "pasturato" (qui non entra mai!!!!)
      nGrayNeutrons = 0.47 * fAlphaGray *  nu; 
      nBlackNeutrons = 0.88 * fAlphaBlack * nu;      
      //printf("nslowp=0 -> ncoll = %1.0f -> ngrayn = %1.0f  nblackn = %1.0f \n", nu, nGrayNeutrons, nBlackNeutrons);
    }
    //
    if(nGrayNeutrons<0.) nGrayNeutrons=0.;
    if(nBlackNeutrons<0.) nBlackNeutrons=0.;
    
//  gray neutrons
    p =  nGrayNeutrons/fN;
//    ngn = gRandom->Binomial((Int_t) fN, p);
    ngn = gRandom->Gaus(nGrayNeutrons, TMath::Sqrt(fN*p*(1-p)));
    if(nGrayNeutrons<0.) ngn=0;

//  black neutrons
    p =  nBlackNeutrons/fN;
//    nbn = gRandom->Binomial((Int_t) fN, p);
    nbn = gRandom->Gaus(nBlackNeutrons, TMath::Sqrt(fN*p*(1-p)));
    if(nBlackNeutrons<0.) nbn=0;
    
}

void AliSlowNucleonModelExp::SetParameters(Float_t alpha1, Float_t alpha2)
{
    // Set the model parameters
    fAlphaGray  = alpha1;
    fAlphaBlack = alpha2;
}
Commit	Line	Data
c9a8628a	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
803d1ab0	16	/* $Id$ */
c9a8628a	17
c9a8628a	18	//
ac3faee4	19	// Experimental data inspired Gray Particle Model for p-Pb collisions
c9a8628a	20	// The number of gray nucleons is proportional to the number of collisions.
	21	// The number of black nucleons is proportional to the number of collisions
	22	// Fluctuations are calculated from a binomial distribution.
ac3faee4	23	// Author: A.Morsch
c9a8628a	24	//
	25
	26	#include "AliSlowNucleonModelExp.h"
	27	#include "AliCollisionGeometry.h"
	28	#include <TRandom.h>
58776b75	29	#include <TMath.h>
c9a8628a	30
706938e6	31	ClassImp(AliSlowNucleonModelExp)
c9a8628a	32
1c56e311	33
	34	AliSlowNucleonModelExp::AliSlowNucleonModelExp():
	35	fP(82),
58776b75	36	fN (126),
1ffc7bfa	37	fAlphaGray(2.3),
1ffc7bfa	38	fAlphaBlack(3.6),
230d85c6	39	fApplySaturation(kTRUE),
230d85c6	40	fnGraySaturation(15),
aa3eb8eb	41	fnBlackSaturation(28),
c3e58d2c	42	fLCPparam(0.585),
c3e58d2c	43	fSigmaSmear(0.25)
c9a8628a	44	{
ac3faee4	45	//
	46	// Default constructor
	47	//
1ffc7bfa	48	//
aa3eb8eb	49	fSlownparam[0] = 60.;
	50	fSlownparam[1] = 469.2;
	51	fSlownparam[2] = 8.762;
c3e58d2c	52	/printf("\n\n ******* Initializing slow nucleon model with parameters:\n");
1ffc7bfa	53	printf(" \t alpha_{gray} %1.2f alpha_{black} %1.2f\n",fAlphaGray, fAlphaBlack);
aa3eb8eb	54	printf(" \t SATURATION %d w. %d (gray) %d (black) \n\n",fApplySaturation,fnGraySaturation,fnBlackSaturation);
c3e58d2c	55	printf(" \t LCP parameter %f Slown parameters = {%f, %f,
c3e58d2c	56	%f}\n\n",fLCPparam,fSlownparam[0],fSlownparam[1],fSlownparam[2]); */
c9a8628a	57	}
	58
	59
	60	void AliSlowNucleonModelExp::GetNumberOfSlowNucleons(AliCollisionGeometry* geo,
ac3faee4	61	Int_t& ngp, Int_t& ngn, Int_t & nbp, Int_t & nbn) const
c9a8628a	62	{
	63	//
	64	// Return the number of black and gray nucleons
	65	//
	66	// Number of collisions
	67
58776b75	68	Float_t nu = geo->NN() + geo->NwN() + geo->NNw();
c9a8628a	69
	70	// Mean number of gray nucleons
	71
	72	Float_t nGray = fAlphaGray * nu;
	73	Float_t nGrayNeutrons = nGray * fN / (fN + fP);
	74	Float_t nGrayProtons = nGray - nGrayNeutrons;
	75
	76	// Mean number of black nucleons
230d85c6	77	Float_t nBlack = 0.;
	78	if(!fApplySaturation \|\| (fApplySaturation && nGray<fnGraySaturation)) nBlack = fAlphaBlack * nu;
	79	else if(fApplySaturation && nGray>=fnGraySaturation) nBlack = fnBlackSaturation;
1ffc7bfa	80	Float_t nBlackNeutrons = nBlack * 0.84;
c9a8628a	81	Float_t nBlackProtons = nBlack - nBlackNeutrons;
	82
	83	// Actual number (including fluctuations) from binomial distribution
	84	Double_t p;
	85
	86	// gray neutrons
	87	p = nGrayNeutrons/fN;
	88	ngn = gRandom->Binomial((Int_t) fN, p);
	89
	90	// gray protons
	91	p = nGrayProtons/fP;
	92	ngp = gRandom->Binomial((Int_t) fP, p);
	93
	94	// black neutrons
	95	p = nBlackNeutrons/fN;
	96	nbn = gRandom->Binomial((Int_t) fN, p);
	97
	98	// black protons
	99	p = nBlackProtons/fP;
	100	nbp = gRandom->Binomial((Int_t) fP, p);
58776b75	101
	102	}
	103
	104	void AliSlowNucleonModelExp::GetNumberOfSlowNucleons2(AliCollisionGeometry* geo,
	105	Int_t& ngp, Int_t& ngn, Int_t & nbp, Int_t & nbn) const
	106	{
	107	//
	108	// Return the number of black and gray nucleons
	109	//
	110	// Number of collisions
	111
	112	// based on E910 model ================================================================
	113
	114	Float_t nu = (Float_t) (geo->NN() + geo->NwN() + geo->NNw());
	115	//
c3e58d2c	116	//nu = nu+1.*gRandom->Rndm();
	117	nu = gRandom->Gaus(nu, 0.5);
	118	if(nu<0.) nu=0.;
58776b75	119	//
	120	Float_t poverpd = 0.843;
	121	Float_t zAu2zPb = 82./79.;
	122	Float_t nGrayp = (-0.27 + 0.63 * nu - 0.0008 nu nu)poverpdzAu2zPb;
	123
	124	// gray protons
	125	Double_t p;
	126	p = nGrayp/fP;
	127	ngp = gRandom->Binomial((Int_t) fP, p);
	128	//ngp = gRandom->Gaus(nGrayp, TMath::Sqrt(fPp(1-p)));
	129	if(nGrayp<0.) ngp=0;
	130
	131	//Float_t blackovergray = 3./7.;// from spallation
	132	Float_t blackovergray = 0.65; // from COSY
	133	Float_t nBlackp = blackovergray*nGrayp;
	134
	135	// black protons
	136	p = nBlackp/fP;
	137	nbp = gRandom->Binomial((Int_t) fP, p);
	138	//nbp = gRandom->Gaus(nBlackp, TMath::Sqrt(fPp(1-p)));
	139	if(nBlackp<0.) nbp=0;
	140
	141	if(nu<3.){
	142	nGrayp = -0.836 + 0.9112 nu - 0.05381 nu *nu;
	143	nBlackp = blackovergray*nGrayp;
	144	}
	145
aa3eb8eb	146	//printf(" \t Using LCP parameter %f Slown parameters = {%f, %f, %f}\n\n",fLCPparam,fSlownparam[0],fSlownparam[1],fSlownparam[2]);
58776b75	147	Float_t nGrayNeutrons = 0.;
58776b75	148	Float_t nBlackNeutrons = 0.;
aa3eb8eb	149	Float_t cp = (nGrayp+nBlackp)/fLCPparam;
58776b75	150
58776b75	151	if(cp>0.){
aa3eb8eb	152	Float_t nSlow = fSlownparam[0]+fSlownparam[1]/(-fSlownparam[2]-cp);
	153	Float_t paramRetta = fSlownparam[0]+fSlownparam[1]/(-fSlownparam[2]-3);
	154	if(cp<3.) nSlow = 0.+(paramRetta-0.)/(3.-0.)*(cp-0.);
58776b75	155
	156	nGrayNeutrons = nSlow * 0.1;
	157	nBlackNeutrons = nSlow - nGrayNeutrons;
	158	}
	159	else{
aa3eb8eb	160	// Sikler "pasturato" (qui non entra mai!!!!)
58776b75	161	nGrayNeutrons = 0.47 * fAlphaGray * nu;
58776b75	162	nBlackNeutrons = 0.88 * fAlphaBlack * nu;
c3e58d2c	163	//printf("nslowp=0 -> ncoll = %1.0f -> ngrayn = %1.0f nblackn = %1.0f \n", nu, nGrayNeutrons, nBlackNeutrons);
58776b75	164	}
	165
	166	// gray neutrons
	167	p = nGrayNeutrons/fN;
	168	// ngn = gRandom->Binomial((Int_t) fN, p);
	169	ngn = gRandom->Gaus(nGrayNeutrons, TMath::Sqrt(fNp(1-p)));
	170
	171	// black neutrons
	172	p = nBlackNeutrons/fN;
	173	// nbn = gRandom->Binomial((Int_t) fN, p);
	174	nbn = gRandom->Gaus(nBlackNeutrons, TMath::Sqrt(fNp(1-p)));
	175
	176
c9a8628a	177	}
c9a8628a	178
c3e58d2c	179	void AliSlowNucleonModelExp::GetNumberOfSlowNucleons2s(AliCollisionGeometry* geo,
	180	Int_t& ngp, Int_t& ngn, Int_t & nbp, Int_t & nbn) const
	181	{
	182	//
	183	// Return the number of black and gray nucleons
	184	//
	185	// Number of collisions
	186
	187	// based on E910 model ================================================================
	188
	189	Float_t nu = (Float_t) (geo->NN() + geo->NwN() + geo->NNw());
	190	//
	191	Float_t poverpd = 0.843;
	192	Float_t zAu2zPb = 82./79.;
	193	Float_t grayp = (-0.27 + 0.63 * nu - 0.0008 nu nu)poverpdzAu2zPb;
	194	Float_t nGrayp = gRandom->Gaus(grayp, fSigmaSmear);
	195	if(nGrayp<0.) nGrayp=0.;
	196
	197	// gray protons
	198	Double_t p=0.;
	199	p = nGrayp/fP;
	200	ngp = gRandom->Binomial((Int_t) fP, p);
	201	//ngp = gRandom->Gaus(nGrayp, TMath::Sqrt(fPp(1-p)));
	202	if(nGrayp<0.) ngp=0;
	203
	204	//Float_t blackovergray = 3./7.;// from spallation
	205	Float_t blackovergray = 0.65; // from COSY
	206	//Float_t blackp = blackovergray*grayp;
	207	//Float_t nBlackp = gRandom->Gaus(nblackp, fSigmaSmear);
	208	Float_t nBlackp = blackovergray*nGrayp;
	209	if(nBlackp<0.) nBlackp=0.;
	210
	211	// black protons
	212	p = nBlackp/fP;
	213	nbp = gRandom->Binomial((Int_t) fP, p);
	214	//nbp = gRandom->Gaus(nBlackp, TMath::Sqrt(fPp(1-p)));
	215	if(nBlackp<0.) nbp=0;
	216
	217	Float_t nGrayNeutrons = 0.;
	218	Float_t nBlackNeutrons = 0.;
	219	Float_t cp = (nGrayp+nBlackp)/fLCPparam;
	220
	221	if(cp>0.){
	222	Float_t nSlow = fSlownparam[0]+fSlownparam[1]/(-fSlownparam[2]-cp);
	223
	224	nGrayNeutrons = nSlow * 0.1;
	225	nBlackNeutrons = nSlow - nGrayNeutrons;
	226	}
	227	else{
	228	// Sikler "pasturato" (qui non entra mai!!!!)
	229	nGrayNeutrons = 0.47 * fAlphaGray * nu;
	230	nBlackNeutrons = 0.88 * fAlphaBlack * nu;
	231	//printf("nslowp=0 -> ncoll = %1.0f -> ngrayn = %1.0f nblackn = %1.0f \n", nu, nGrayNeutrons, nBlackNeutrons);
	232	}
	233	//
	234	if(nGrayNeutrons<0.) nGrayNeutrons=0.;
	235	if(nBlackNeutrons<0.) nBlackNeutrons=0.;
	236
	237	// gray neutrons
	238	p = nGrayNeutrons/fN;
	239	// ngn = gRandom->Binomial((Int_t) fN, p);
	240	ngn = gRandom->Gaus(nGrayNeutrons, TMath::Sqrt(fNp(1-p)));
	241	if(nGrayNeutrons<0.) ngn=0;
	242
243	// black neutrons
244	p = nBlackNeutrons/fN;
245	// nbn = gRandom->Binomial((Int_t) fN, p);
246	nbn = gRandom->Gaus(nBlackNeutrons, TMath::Sqrt(fNp(1-p)));
247	if(nBlackNeutrons<0.) nbn=0;
248
249	}
250
c9a8628a	251	void AliSlowNucleonModelExp::SetParameters(Float_t alpha1, Float_t alpha2)
	252	{
	253	// Set the model parameters
	254	fAlphaGray = alpha1;
	255	fAlphaBlack = alpha2;
	256	}
230d85c6	257