1 #include "AliGenMUONlib.h"
3 ClassImp(AliGenMUONlib)
6 Double_t AliGenMUONlib::PtPion(Double_t *px, Double_t *)
9 // PT-PARAMETERIZATION CDF, PRL 61(88) 1819
10 // POWER LAW FOR PT > 500 MEV
11 // MT SCALING BELOW (T=160 MEV)
13 const Double_t p0 = 1.3;
14 const Double_t xn = 8.28;
15 const Double_t xlim=0.5;
16 const Double_t t=0.160;
17 const Double_t xmpi=0.139;
19 Double_t y, y1, xmpi2, ynorm, a;
22 y1=TMath::Power(p0/(p0+xlim),xn);
24 ynorm=b*(TMath::Exp(-sqrt(xlim*xlim+xmpi2)/t));
27 y=a*TMath::Power(p0/(p0+x),xn);
29 y=b*TMath::Exp(-sqrt(x*x+xmpi2)/t);
35 Double_t AliGenMUONlib::YPion( Double_t *py, Double_t *)
37 const Double_t a = 7000.;
38 const Double_t dy = 4.;
40 Double_t y=TMath::Abs(*py);
42 Double_t ex = y*y/(2*dy*dy);
43 return a*TMath::Exp(-ex);
45 // particle composition
47 Int_t AliGenMUONlib::IpPion()
49 AliMC* pMC = AliMC::GetMC();
52 if (random[0] < 0.5) {
59 //____________________________________________________________
63 Double_t AliGenMUONlib::PtScal(Double_t pt, Int_t np)
65 // SCALING EN MASSE PAR RAPPORT A PTPI
66 // MASS PI,K,ETA,RHO,OMEGA,ETA',PHI
67 const Double_t hm[10] = {.13957,.493,.5488,.769,.7826,.958,1.02,0,0,0};
68 // VALUE MESON/PI AT 5 GEV
69 const Double_t fmax[10]={1.,0.3,0.55,1.0,1.0,1.0,1.0,0,0,0};
71 Double_t f5=TMath::Power(((sqrt(100.018215)+2.)/(sqrt(100.+hm[np]*hm[np])+2.0)),12.3);
72 Double_t fmax2=f5/fmax[np];
74 Double_t ptpion=100.*PtPion(&pt, (Double_t*) 0);
75 Double_t fmtscal=TMath::Power(((sqrt(pt*pt+0.018215)+2.)/
76 (sqrt(pt*pt+hm[np]*hm[np])+2.0)),12.3)/ fmax2;
77 return fmtscal*ptpion;
83 //____________________________________________________________
84 Double_t AliGenMUONlib::PtKaon( Double_t *px, Double_t *)
90 //____________________________________________________________
91 Double_t AliGenMUONlib::YKaon( Double_t *py, Double_t *)
93 const Double_t a = 1000.;
94 const Double_t dy = 4.;
97 Double_t y=TMath::Abs(*py);
99 Double_t ex = y*y/(2*dy*dy);
100 return a*TMath::Exp(-ex);
103 // particle composition
105 Int_t AliGenMUONlib::IpKaon()
107 AliMC* pMC = AliMC::GetMC();
110 if (random[0] < 0.5) {
121 //____________________________________________________________
122 Double_t AliGenMUONlib::PtJpsi( Double_t *px, Double_t *)
124 const Double_t pt0 = 4.;
125 const Double_t xn = 3.6;
128 Double_t pass1 = 1.+(x/pt0)*(x/pt0);
129 return x/TMath::Power(pass1,xn);
133 //____________________________________________________________
134 Double_t AliGenMUONlib::YJpsi(Double_t *py, Double_t *)
136 const Double_t y0 = 4.;
139 Double_t y=TMath::Abs(*py);
144 yj=b*TMath::Exp(-(y-y0)*(y-y0)/2);
147 // particle composition
149 Int_t AliGenMUONlib::IpJpsi()
158 //____________________________________________________________
159 Double_t AliGenMUONlib::PtUpsilon( Double_t *px, Double_t * )
161 const Double_t pt0 = 5.3;
162 const Double_t xn = 2.5;
165 Double_t pass1 = 1.+(x/pt0)*(x/pt0);
166 return x/TMath::Power(pass1,xn);
171 //____________________________________________________________
172 Double_t AliGenMUONlib::YUpsilon(Double_t *py, Double_t *)
174 const Double_t y0 = 3.;
177 Double_t y=TMath::Abs(*py);
182 yu=b*TMath::Exp(-(y-y0)*(y-y0)/2);
185 // particle composition
187 Int_t AliGenMUONlib::IpUpsilon()
196 // pt-distribution (by scaling of pion distribution)
197 //____________________________________________________________
198 Double_t AliGenMUONlib::PtPhi( Double_t *px, Double_t *)
200 return PtScal(*px,7);
203 Double_t AliGenMUONlib::YPhi( Double_t *px, Double_t *)
206 return YJpsi(px,dummy);
208 // particle composition
210 Int_t AliGenMUONlib::IpPhi()
220 //____________________________________________________________
221 Double_t AliGenMUONlib::PtCharm( Double_t *px, Double_t *)
223 const Double_t pt0 = 4.08;
224 const Double_t xn = 9.40;
227 Double_t pass1 = 1.+(x/pt0)*(x/pt0);
228 return x/TMath::Power(pass1,xn);
231 Double_t AliGenMUONlib::YCharm( Double_t *px, Double_t *)
234 return YJpsi(px,dummy);
237 Int_t AliGenMUONlib::IpCharm()
239 AliMC* pMC = AliMC::GetMC();
244 if (random[0] < 0.5) {
246 } else if (random[0] < 0.75) {
248 } else if (random[0] < 0.90) {
253 if (random[1] < 0.5) {ip=-ip;}
264 //____________________________________________________________
265 Double_t AliGenMUONlib::PtBeauty( Double_t *px, Double_t *)
267 const Double_t pt0 = 4.;
268 const Double_t xn = 3.6;
271 Double_t pass1 = 1.+(x/pt0)*(x/pt0);
272 return x/TMath::Power(pass1,xn);
275 Double_t AliGenMUONlib::YBeauty( Double_t *px, Double_t *)
278 return YJpsi(px,dummy);
281 Int_t AliGenMUONlib::IpBeauty()
283 AliMC* pMC = AliMC::GetMC();
287 if (random[0] < 0.5) {
289 } else if (random[0] < 0.75) {
291 } else if (random[0] < 0.90) {
296 if (random[1] < 0.5) {ip=-ip;}
301 typedef Double_t (*GenFunc) (Double_t*, Double_t*);
302 GenFunc AliGenMUONlib::GetPt(Param_t param)
332 GenFunc AliGenMUONlib::GetY(Param_t param)
361 typedef Int_t (*GenFuncIp) ();
362 GenFuncIp AliGenMUONlib::GetIp(Param_t param)