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Removing warnings (icc), adding more detailed description
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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
16// --- Standard libraries
17#include <stdlib.h>
18
19// --- ROOT system
20#include <TRandom.h>
21#include <TF1.h>
22
23// --- AliRoot classes
24#include "AliZDCFragment.h"
25
26ClassImp(AliZDCFragment)
27
28int comp(const void *i,const void *j) {return *(int *)i - *(int *)j;}
29
30
31//_____________________________________________________________________________
32AliZDCFragment::AliZDCFragment()
33{
34 //
35 // Default constructor
36 //
37 fB = 0;
38}
39
40//_____________________________________________________________________________
41AliZDCFragment::AliZDCFragment(Float_t b)
42 : TNamed(" "," ")
43{
44 //
45 // Standard constructor
46 //
47 fB = b;
48 fZbAverage = 0;
49 fNimf = 0;
50 fZmax = 0;
51 fTau = 0;
52 for(Int_t i=0; i<=99; i++){
53 fZZ[i] = 0;
54 fNN[i] = 0;
55 }
56 fNalpha = 0;
57 fZtot = 0;
58 fNtot = 0;
59
60}
61
62//_____________________________________________________________________________
63void AliZDCFragment::GenerateIMF(Int_t* fZZ, Int_t &fNalpha)
64{
65
66 // Loop variables
67 Int_t i,j;
68
69 // Coefficients of polynomial for average number of IMF
70 const Float_t kParamNimf[5]={0.011236,1.8364,56.572,-116.24,58.289};
71 // Coefficients of polynomial for fluctuations on average number of IMF
72 const Float_t kParamFluctNimf[4]={-0.13176,2.9392,-5.2147,2.3092};
73 // Coefficients of polynomial for average maximum Z of fragments
74 const Float_t kParamZmax[4]={0.16899,14.203,-2.8284,65.036};
75 // Coefficients of polynomial for fluctuations on maximum Z of fragments
76 const Float_t kParamFluctZmax[5]={0.013782,-0.17282,1.5065,1.0654,-2.4317};
77 // Coefficients of polynomial for exponent tau of fragments Z distribution
78 const Float_t kParamTau[3]={6.7233,-15.85,13.047};
79 //Coefficients of polynomial for average number of alphas
80 const Float_t kParamNalpha[4]={-0.68554,39.605,-68.311,30.165};
81 // Coefficients of polynomial for fluctuations on average number of alphas
82 const Float_t kParamFluctNalpha[5]={0.283,6.2141,-17.113,17.394,-6.6084};
83 // Coefficients of function for Pb nucleus skin
84 const Float_t kParamSkinPb[2]={0.93,11.05};
85
86 // Thickness of nuclear surface
87 const Float_t kNuclearThick = 0.52;
88 // Maximum impact parameter for U [r0*A**(1/3)]
89 const Float_t kbMaxU = 14.87;
90 // Maximum impact parameter for Pb [r0*A**(1/3)]
91 const Float_t kbMaxPb = 14.22;
92 // Z of the projectile
93 const Float_t kZProj = 82.;
94
95 // From b(Pb) to b(U)
96 Float_t bU = fB*kbMaxU/kbMaxPb;
97
98 // From b(U) to Zbound(U)
99 // --- A.Schuttauf et al, Nuc.Phys. A607 (1996) 457 ---------------
100 // From geometrical consideration and from dsigma/dZbound for U+U,
101 // which is approx. constant, the constant value is found
102 // integrating the nucleus cross surface from 0 to bmax=R1+R2 where
103 // R = 1.2*A**(1/3). This value has been measured in Aladin (U+U).
104 Float_t zbU = bU*bU*TMath::Pi()/7.48;
105
106 // Rescale Zbound for Pb
107 fZbAverage = kZProj/92.*zbU;
108
109 // Zbound is proportional to b**2 up to b < kbMaxPb-2*kNuclearThick
110 // and then it is an increasing exponential, imposing that at
111 // b=kbMaxPb-2kNuclearThick the two functions have the same derivative
112 Float_t bCore = kbMaxPb-2*kNuclearThick;
113 if(fB>bCore){
114 fZbAverage=kZProj*(1.-TMath::Exp(-kParamSkinPb[0]*(fB-kParamSkinPb[1])));
115 }
116 if(fZbAverage>kZProj) fZbAverage = kZProj;
117 Float_t zbNorm = fZbAverage/kZProj;
118 Float_t bNorm = fB/kbMaxPb;
119
120 // From Zbound to <Nimf>,<Zmax>,tau
121 // Polinomial fits to Aladin distribution
122 // --- A.Schuttauf et al, Nuc.Phys. A607 (1996) 457.
123 Float_t averageNimf = kParamNimf[0]+kParamNimf[1]*zbNorm+kParamNimf[2]*
124 TMath::Power(zbNorm,2)+kParamNimf[3]*TMath::Power(zbNorm,3)+
125 kParamNimf[4]*TMath::Power(zbNorm,4);
126
127 // Add fluctuation: from Singh et al.
128 Float_t fluctNimf = kParamFluctNimf[0]+kParamFluctNimf[1]*zbNorm+
129 kParamFluctNimf[2]*TMath::Power(zbNorm,2)+kParamFluctNimf[3]
130 *TMath::Power(zbNorm,3);
131 Float_t xx = gRandom->Gaus(0.0,1.0);
132 fluctNimf = fluctNimf*xx;
133 fNimf = Int_t(averageNimf+fluctNimf);
134 Float_t y = gRandom->Rndm();
135 if(y < ((averageNimf+fluctNimf)-fNimf)) fNimf += 1;
136 if(fNimf ==0 && zbNorm>0.75) fNimf = 1;
137
138 Float_t averageZmax = kParamZmax[0]+kParamZmax[1]*zbNorm+kParamZmax[2]*
139 TMath::Power(zbNorm,2)+kParamZmax[3]*TMath::Power(zbNorm,3);
140 fTau = kParamTau[0]+kParamTau[1]*zbNorm+kParamTau[2]*TMath::Power(zbNorm,2);
141
142 // Add fluctuation to mean value of Zmax (see Hubele)
143 Float_t fluctZmax = kParamFluctZmax[0]+kParamFluctZmax[1]*zbNorm+
144 kParamFluctZmax[2]*TMath::Power(zbNorm,2)+kParamFluctZmax[3]*
145 TMath::Power(zbNorm,3)+kParamFluctZmax[4]*TMath::Power(zbNorm,4);
146 fluctZmax = fluctZmax*kZProj/6.;
147 Float_t xg = gRandom->Gaus(0.0,1.0);
148 fluctZmax = fluctZmax*xg;
149 fZmax = averageZmax+fluctZmax;
150 if(fZmax>kZProj) fZmax = kZProj;
151
152// printf("\n\n ------------------------------------------------------------");
153// printf("\n Generation of nuclear fragments\n");
154// printf("\n fNimf = %d\n", fNimf);
155// printf("\n fZmax = %f\n", fZmax);
156
157 // Find the number of alpha particles
158 // from Singh et al. : Pb+emulsion
159 Float_t averageAlpha = kParamNalpha[0]+kParamNalpha[1]*zbNorm+
160 kParamNalpha[2]*TMath::Power(zbNorm,2)+kParamNalpha[3]*
161 TMath::Power(zbNorm,3);
162 Float_t fluctAlpha = kParamFluctNalpha[0]+kParamFluctNalpha[1]*
163 zbNorm+kParamFluctNalpha[2]*TMath::Power(zbNorm,2)+
164 kParamFluctNalpha[3]*TMath::Power(zbNorm,3)+
165 kParamFluctNalpha[4]*TMath::Power(zbNorm,4);
166 Float_t xxx = gRandom->Gaus(0.0,1.0);
167 fluctAlpha = fluctAlpha*xxx;
168 fNalpha = Int_t(averageAlpha+fluctAlpha);
169 Float_t yy = gRandom->Rndm();
170 if(yy < ((averageAlpha+fluctAlpha)-fNalpha)) fNalpha += 1;
171
172 // 2 possibilities:
173 // 1) for bNorm < 0.9 ==> first remove alphas, then fragments
174 // 2) for bNorm > 0.9 ==> first remove fragments, then alphas
175
176 Int_t choice = 0;
177 Float_t zbFrag = 0, sumZ = 0.;
178
179 if(bNorm<=0.9) {
180 // remove alpha from zbound to find zbound for fragments (Z>=3)
181 zbFrag = fZbAverage-fNalpha*2;
182 choice = 1;
183 }
184 else {
185 zbFrag = fZbAverage;
186 choice = 0;
187 }
188// printf("\n choice = %d, fZbAverage = %f, zbFrag = %f \n", choice, fZbAverage, zbFrag);
189
190
191 // Check if zbFrag < fZmax
192 if(zbFrag<=fZmax) {
193 if(fNimf>0 && zbFrag>=2){
194 fNimf = 1;
195 fZZ[0] = Int_t(zbFrag);
196 sumZ = zbFrag;
197 }
198 else {
199 fNimf = 0;
200 }
201 return;
202 }
203
204 // Prepare the exponential charge distribution dN/dZ
205 if(fZmax <= 0.01) {
206 fNimf = 0;
207 return;
208 }
209 if(fNimf == 0) {
210 fNimf = 0;
211 return;
212 }
213
214 TF1 *funTau = new TF1("funTau","1./(x**[0])",0.01,fZmax);
215 funTau->SetParameter(0,fTau);
216
217 // Extract randomly the charge of the fragments from the distribution
218
219 Float_t * zz = new Float_t[fNimf];
220 for(j=0; j<fNimf; j++){
221 zz[j] =0;
222 }
223 for(i=0; i<fNimf; i++){
224 zz[i] = Float_t(funTau->GetRandom());
225// printf("\n zz[%d] = %f \n",i,zz[i]);
226 }
227 delete funTau;
228
229 // Sorting vector in ascending order with C function QSORT
230 qsort((void*)zz,fNimf,sizeof(Float_t),comp);
231
232
233// for(Int_t i=0; i<fNimf; i++){
234// printf("\n After sorting -> zz[%d] = %f \n",i,zz[i]);
235// }
236
237 // Rescale the maximum charge to fZmax
238 for(j=0; j<fNimf; j++){
239 fZZ[j] = Int_t (zz[j]*fZmax/zz[fNimf-1]);
240 if(fZZ[j]<3) fZZ[j] = 3;
241// printf("\n fZZ[%d] = %d \n",j,fZZ[j]);
242 }
243
244 delete[] zz;
245
246 // Check that the sum of the bound charges is not > than Zbound-Zalfa
247
248 for(Int_t ii=0; ii<fNimf; ii++){
249 sumZ += fZZ[ii];
250 }
251
252 Int_t k = 0;
253 if(sumZ>zbFrag){
254 for(i=0; i< fNimf; i++){
255 k += 1;
256 sumZ -= fZZ[i];
257 if(sumZ<=zbFrag){
258 fNimf -= (i+1);
259 break;
260 }
261 }
262 }
263 else {
264 if(choice == 1) return;
265 Int_t iDiff = Int_t((zbFrag-sumZ)/2);
266 if(iDiff<fNalpha){
267 fNalpha=iDiff;
268 return;
269 }
270 else{
271 return;
272 }
273 }
274
275 fNimf += k;
276 for(i=0; i<fNimf; i++){
277 fZZ[i] = fZZ[i+k];
278 }
279 fNimf -= k;
280
281 sumZ=0;
282 for(i=0; i<fNimf; i++){
283 sumZ += fZZ[i];
284 }
285
286}
287
288//_____________________________________________________________________________
289void AliZDCFragment::AttachNeutrons(Int_t *fZZ, Int_t *fNN, Int_t &fZtot,Int_t &fNtot)
290{
291//
292// Prepare nuclear fragment by attaching a suitable number of neutrons
293//
294 const Float_t kAIon[68]={1.87612,2.80943,3.7284,5.60305,6.53536,
295 6.53622,8.39479,9.32699,10.2551,11.17793,
296 13.04378,14.89917,17.6969,18.62284,21.41483,
297 22.34193,25.13314,26.06034,28.85188,29.7818,
298 32.57328,33.50356,36.29447,37.22492,41.87617,
299 44.66324,47.45401,48.38228,51.17447,52.10307,
300 54.89593,53.96644,58.61856,59.54963,68.85715,
301 74.44178,78.16309,81.88358,83.74571,91.19832,
302 98.64997,106.10997,111.68821,122.86796,
303 128.45793,
304 130.32111,141.51236,
305 141.55,146.477,148.033,152.699,153.631,
306 155.802,157.357,162.022,162.984,166.2624,
307 168.554,171.349,173.4536,177.198,179.0518,
308 180.675,183.473,188.1345,190.77,193.729,
309 221.74295};
310 const Int_t kZIon[68]={1,1,2,3,3,
311 4,4,5,5,6,
312 7,8,9,10,11,
313 12,13,14,15,16,
314 17,18,19,20,21,
315 22,23,24,25,26,
316 27,28,29,30,32,
317 34,36,38,40,42,
318 46,48,50,54,56,
319 58,62,
320 63,64,65,66,67,
321 68,69,70,71,72,
322 73,74,75,76,77,
323 78,79,80,81,82,
324 92};
325
326 Int_t iZ, iA;
327// printf("\n fNimf=%d\n",fNimf);
328
329 for(Int_t i=0; i<fNimf; i++) {
330 for(Int_t j=0; j<68; j++) {
331 iZ = kZIon[j];
332 if((fZZ[i]-iZ) == 0){
333 iA = Int_t(kAIon[j]/0.93149432+0.5);
334 fNN[i] = iA - iZ;
335 break;
336 }
337 else if((fZZ[i]-iZ) < 0){
338 fZZ[i] = kZIon[j-1];
339 iA = Int_t (kAIon[j-1]/0.93149432+0.5);
340 fNN[i] = iA - kZIon[j-1];
341 break;
342 }
343 }
344 fZtot += fZZ[i];
345 fNtot += fNN[i];
346 }
347
348
349}