| c9c6bd3b |
1 | C ********************************************************************** |
| 2 | C Version 2.0 |
| 3 | C Generator of e+e- pairs produced in 1.10.2002 |
| 4 | C PbPb collisions at LHC |
| 5 | C |
| 6 | C Copyright (c) 2002 |
| 7 | C Authors: Kai Hencken <k.hencken@unibas.ch> |
| 8 | C Yuri Kharlov <Yuri.Kharlov@cern.ch> |
| 9 | C Serguei Sadovsky <sadovsky@mx.ihep.su>, |
| 10 | C <Serguei.Sadovski@cern.ch> |
| 11 | C |
| 12 | C Permission to use, copy and distribute this software and its |
| 13 | C documentation strictly for non-commercial purposes is hereby granted |
| 14 | C without fee, provided that the above copyright notice appears in all |
| 15 | C copies and that both the copyright notice and this permission notice |
| 16 | C appear in the supporting documentation. The authors make no claims |
| 17 | C about the suitability of this software for any purpose. It is |
| 18 | C provided "as is" without express or implied warranty. |
| 19 | C Any change of the code should be submitted to the authors |
| 20 | C |
| 21 | C Long write up: K.Hencken,Yu.Kharlov,S.Sadovsky |
| 22 | C Internal ALICE Note 2002-27 |
| 23 | C |
| 24 | C ********************************************************************** |
| 25 | subroutine ee_init(Ymin,Ymax,PTmin,PTmax) |
| 26 | C----------------------------------------------------------------------- |
| 27 | C Generator initialisation |
| 28 | C |
| 29 | C Input variables: Ymin - minimal value of rapidity \ |
| 30 | C Ymax - maximal value of rapidity | of kinematics |
| 31 | C PTmin - Pt minimum in MeV/c | range |
| 32 | C PTmax - Pt maximum in MeV/c / |
| 33 | C----------------------------------------------------------------------- |
| 34 | implicit real*8 (A-H,O-Z) |
| 35 | external DsdYpY,DsdYmY,DsdXpX,DsdXmX,DsdPhi,DsdXX,DsdYY |
| 36 | |
| 37 | common/parPh / parPhi(7) |
| 38 | common/parYp / parYpY(6) |
| 39 | common/parYm / parYmY(6) |
| 40 | common/parXp / parXpX(5) |
| 41 | common/parXm / parXmX(4) |
| 42 | |
| 43 | common/eevent/ Xsect2,Dsect2, Xsecttot,Dsecttot, Nevnt |
| 44 | common/eepars/ Xmin,Xmax,YpYmin,YpYmax,WYpYmax,YmYmin,YmYmax, |
| 45 | & Ymed1,Ymed2,sgmY1,sgmY2,XYsect, |
| 46 | & Gaus1,Gaus2,Gauss,Exp1,Exp2,Exp3, |
| 47 | & XmXmin,XmXmax,XpXmin,XpXmax,Exmx1,Exmx2,Xmed, |
| 48 | & Sgm1,AnorX,Icase |
| 49 | |
| 50 | real*8 mass |
| 51 | |
| 52 | data pi / 3.141 592 653 589 793 238 462 643d00 / |
| 53 | |
| 54 | C |
| 55 | C Exact differential Cross section: |
| 56 | C - - - - - - - - - - - - - - - - - - - |
| 57 | C |
| 58 | gm = 2750.0d0 ! Pb gamma factor at the LHC |
| 59 | mass = 0.5109991d0 ! electron mass |
| 60 | call initdiffcross (gm,mass) |
| 61 | C |
| 62 | C Cross sections: |
| 63 | C - - - - - - - - - - |
| 64 | Nevnt = 0 |
| 65 | Xsect2 = 0. |
| 66 | Dsect2 = 0. |
| 67 | |
| 68 | Nsd = 1 |
| 69 | Npt = 25 ! 7,25,64 |
| 70 | Eps = 0.00005 |
| 71 | |
| 72 | Xmin= Dlog10(Ptmin) |
| 73 | Xmax= Dlog10(Ptmax) |
| 74 | write(*,*) ' Kinematical limits:' |
| 75 | write(*,*) ' Xmin,Xmax=',Xmin,Xmax |
| 76 | write(*,*) ' Ymin,Ymax=',Ymin,Ymax |
| 77 | write(*,*) |
| 78 | |
| 79 | Xsec1 = Dtrint(DsdXX,Nsd,Npt,Eps,Xmin,Xmin,Xmin,Xmax,Xmax,Xmin) |
| 80 | Xsec2 = Dtrint(DsdXX,Nsd,Npt,Eps,Xmax,Xmax,Xmin,Xmax,Xmax,Xmin) |
| 81 | XsecX = Xsec1+Xsec2 |
| 82 | |
| 83 | Ysec1 = Dtrint(DsdYY,Nsd,Npt,Eps,Ymin,Ymin,Ymin,Ymax,Ymax,Ymin) |
| 84 | Ysec2 = Dtrint(DsdYY,Nsd,Npt,Eps,Ymax,Ymax,Ymin,Ymax,Ymax,Ymin) |
| 85 | XsecY = Ysec1+Ysec2 |
| 86 | |
| 87 | IF (Xsec1*Xsec2.le.0.or.Ysec1*Ysec2.le.0.) then |
| 88 | write(*,*) ' Error: insufficient accuracy of XY-cross sections' |
| 89 | write(*,*) ' Xsec1,Xsec2,Xsec=', Xsec1,Xsec2,XsecX |
| 90 | write(*,*) ' Ysec1,Ysec2,Ysec=', Ysec1,Ysec2,XsecY |
| 91 | endif |
| 92 | |
| 93 | XYsect = XsecX*XsecY |
| 94 | write(*,*) ' Xsections: Xsec1,Xsec2,XsecX=', Xsec1,Xsec2,XsecX |
| 95 | write(*,*) ' Ysec1,Ysec2,XsecY=', Ysec1,Ysec2,XsecY |
| 96 | C- write(*,*) ' XsecX*YsecY=', XYsect |
| 97 | C |
| 98 | XYsect = 2371.5239*(82./137.035)**4*XYsect ! Normalization factor |
| 99 | write(*,*) ' Normalized: XsecX*YsecY=', XYsect |
| 100 | write(*,*) |
| 101 | C |
| 102 | C- XsecPhi = Dgauss(DsdPhi,0.0d0, pi, eps) |
| 103 | C |
| 104 | C Rapidity initialisation: |
| 105 | C - - - - - - - - - - - - - - |
| 106 | if (Ymin.ge.Ymax) then |
| 107 | write(*,*) 'Wrong values of Ymin,Ymax:',Ymin,Ymax |
| 108 | stop |
| 109 | endif |
| 110 | CYpY- |
| 111 | C |
| 112 | YpYmin = 2.*Ymin |
| 113 | YpYmax = 2.*Ymax |
| 114 | Yp0 = 0. |
| 115 | if (YpYmin*YpYmax.gt.0.) then |
| 116 | if(YpYmin.gt.0.) Yp0 = YpYmin |
| 117 | if(YpYmin.le.0.) Yp0 = YpYmax |
| 118 | endif |
| 119 | WYpYmax = DsdYpY(Yp0) |
| 120 | C |
| 121 | C- write(*,*)' YpY: YpYmin,YpYmax,WYpYmax =',YpYmin,YpYmax,WYpYmax |
| 122 | |
| 123 | CYmY- |
| 124 | C |
| 125 | YmYmin = Ymin-Ymax |
| 126 | YmYmax = Ymax-Ymin |
| 127 | C- write(*,*) ' YmY: YmYmin,YmYmax=',YmYmin,YmYmax |
| 128 | C |
| 129 | Ymed1 = 0.18 |
| 130 | Ymed2 = 4.00 |
| 131 | |
| 132 | sgmY1 = 1./dsqrt(2.*parYmY(2)) |
| 133 | sgmY2 = 1./dsqrt(2.*parYmY(4)) |
| 134 | C |
| 135 | eps = 0.000001 |
| 136 | Gaus1 = Dgauss(DsdYmY ,0.0d0, Ymed1 , eps) |
| 137 | Gaus2 = Dgauss(DsdYmY ,Ymed1, Ymed2 , eps) |
| 138 | Expon = Dgauss(DsdYmY ,Ymed2, YmYmax, eps) |
| 139 | Summ = Gaus1+Gaus2+Expon |
| 140 | Gaus2 =(Gaus1+Gaus2)/Summ |
| 141 | Gaus1 = Gaus1/Summ |
| 142 | Expon = 1. |
| 143 | C |
| 144 | C Phi initialisation: |
| 145 | C - - - - - - - - - - - |
| 146 | Exp0 = parPhi(1)*pi |
| 147 | Exp1 = parPhi(2)*(1.-dexp(-parPhi(3)*pi))/parPhi(3) |
| 148 | Exp2 = parPhi(4)*(1.-dexp(-parPhi(5)*pi))/parPhi(5) |
| 149 | Exp3 = parPhi(6)*(1.-dexp(-parPhi(7)*pi))/parPhi(7) |
| 150 | Summ = Exp0+Exp1+Exp2+Exp3 |
| 151 | C |
| 152 | Exp0 = (Exp0+Exp1+Exp2+Exp3)/Summ |
| 153 | Exp1 = (Exp1+Exp2+Exp3)/Summ |
| 154 | Exp2 = (Exp2+Exp3)/Summ |
| 155 | Exp3 = Exp3/Summ |
| 156 | C- write(*,*) 'Exp0,Exp1,Exp2,Exp3=',Exp0,Exp1,Exp2,Exp3 |
| 157 | C |
| 158 | C Pt initialisation: |
| 159 | C - - - - - - - - - - - |
| 160 | C |
| 161 | XmXmin = Xmin-Xmax |
| 162 | XmXmax = Xmax-Xmin |
| 163 | C |
| 164 | XpXmin = 2.*Xmin |
| 165 | XpXmax = 2.*Xmax |
| 166 | C |
| 167 | CXmX- |
| 168 | Exmx1 = parXmX(1)*(1.-dexp(-parXmX(2)*dabs(XmXmax)))/parXmX(2) |
| 169 | Exmx2 = parXmX(3)*(1.-dexp(-parXmX(4)*dabs(XmXmax)))/parXmX(4) |
| 170 | Exmx1 = Exmx1/(Exmx1+Exmx2) |
| 171 | Exmx2 = 1. |
| 172 | C |
| 173 | C- write(*,*) ' XpX: XpXmin,XpXmax=',XpXmin,XpXmax |
| 174 | C- write(*,*) ' XmX: XmXmin,XmXmax=',XmXmin,XmXmax |
| 175 | C- write(*,*) ' XmX: Exmx1 ,Exmx2 =',Exmx1 ,Exmx2 |
| 176 | C |
| 177 | CXpX- |
| 178 | Icase = 2 ! Gausses and Exponent |
| 179 | Xmed = 0.6 |
| 180 | if (XpXmax.lt.Xmed) then |
| 181 | Icase = 1 ! Gauss only |
| 182 | Xmed = XpXmax |
| 183 | endif |
| 184 | C |
| 185 | if (XpXmin.gt.Xmed) then |
| 186 | Icase = 3 ! Exponent only |
| 187 | Xmed = XpXmin |
| 188 | endif |
| 189 | C |
| 190 | if (Icase.eq.2) then ! Gauss and Exponent |
| 191 | eps = 0.000001 |
| 192 | Gauss = Dgauss(DsdXpX ,XpXmin, Xmed , eps) |
| 193 | Expon = Dgauss(DsdXpX ,Xmed , XpXmax, eps) |
| 194 | Summ = Gauss+Expon |
| 195 | Gauss = Gauss/Summ |
| 196 | Expon = Expon/Summ |
| 197 | C- write(*,*) 'XpX, Case 2: Gauss,Expon=',Gauss,Expon |
| 198 | endif ! Icase = 2 |
| 199 | C |
| 200 | C |
| 201 | if (Icase.eq.1.or.Icase.eq.2) then ! Gausses only and Icase=2 |
| 202 | |
| 203 | Sgm1 = 1./dsqrt(2.*parXpX(2)) |
| 204 | |
| 205 | C- write(*,*) 'XpX, Case 1: Sgm1=',Sgm1 |
| 206 | endif |
| 207 | C |
| 208 | if (Icase.eq.3.or.Icase.eq.2) then ! Exponent only and Icase=2 |
| 209 | C |
| 210 | AnorX = 1.-dexp(-parXpX(5)*(XpXmax-Xmed)) |
| 211 | C |
| 212 | C- write(*,*) 'XpX, Case 3: AnorX=',AnorX |
| 213 | endif |
| 214 | |
| 215 | return |
| 216 | end |
| 217 | * |
| 218 | *======================================================================= |
| 219 | subroutine ee_event(Ymin,Ymax,PTmin,PTmax, |
| 220 | + Ye,Yp,Xe,Xp,Phi,Wtm2) |
| 221 | C------------------------------------------------------------------------------ |
| 222 | C Produce one event |
| 223 | C |
| 224 | C Input variables: Ymin - minimal value of rapidity \ |
| 225 | C Ymax - maximal value of rapidity | of kinematics |
| 226 | C PTmin - Pt minimum in MeV/c | range |
| 227 | C PTmax - Pt maximum in MeV/c / |
| 228 | C Output variables: Ye,Yp - rapidity of produced e- or e+ |
| 229 | C Xe,Xp - log10(pt) of produced e- or e+, pt in MeV/c |
| 230 | C Phi - azymuth angle between e- and e+ |
| 231 | C Wtm2 - event weight. The sum of these event |
| 232 | C weights, divided by the total number |
| 233 | C of generated events, gives the integral |
| 234 | C cross section of the process of e+e- pair |
| 235 | C production in the above mentioned kinematics |
| 236 | C range. |
| 237 | C Sum of the selected event weights, divided |
| 238 | C by the total number of generated events, |
| 239 | C gives the integral cross section corresponded |
| 240 | C to the set of selected events |
| 241 | C------------------------------------------------------------------------------ |
| 242 | |
| 243 | implicit real*8 (A-H,O-Z) |
| 244 | common/parPh / parPhi(7) |
| 245 | common/parYp / parYpY(6) |
| 246 | common/parYm / parYmY(6) |
| 247 | common/parXp / parXpX(5) |
| 248 | common/parXm / parXmX(4) |
| 249 | common/eevent/ Xsect2,Dsect2, Xsecttot,Dsecttot, Nevnt |
| 250 | common/eepars/ Xmin,Xmax,YpYmin,YpYmax,WYpYmax,YmYmin,YmYmax, |
| 251 | & Ymed1,Ymed2,sgmY1,sgmY2,XYsect, |
| 252 | & Gaus1,Gaus2,Gauss,Exp1,Exp2,Exp3, |
| 253 | & XmXmin,XmXmax,XpXmin,XpXmax,Exmx1,Exmx2,Xmed, |
| 254 | & Sgm1,AnorX,Icase |
| 255 | external DsdYpY,DsdYmY,DsdXpX,DsdXmX,DsdPhi |
| 256 | data pi / 3.141 592 653 589 793 238 462 643d00 / |
| 257 | |
| 258 | C Rapidity distributions: |
| 259 | C |
| 63e30ba9 |
260 | 10 YpY = YpYmin + (YpYmax-YpYmin)*eernd(0) |
| c9c6bd3b |
261 | Wt = DsdYpY(YpY) |
| 63e30ba9 |
262 | if (Wt.lt.eernd(0)*WYpYmax) go to 10 |
| c9c6bd3b |
263 | C |
| 264 | CYmY- |
| 63e30ba9 |
265 | r1 = eernd(0) |
| c9c6bd3b |
266 | if (r1.lt.Gaus1) then |
| c9e3082d |
267 | 13 call rnormlEP(rn1) |
| c9c6bd3b |
268 | YmY = sgmY1*rn1 |
| 269 | if (dabs(YmY).gt.Ymed1) go to 13 |
| 270 | else if (r1.lt.Gaus2) then |
| c9e3082d |
271 | 15 call rnormlEP(rn2) |
| c9c6bd3b |
272 | YmY = sgmY2*rn2 |
| 273 | if (dabs(YmY).lt.Ymed1) go to 15 |
| 274 | if (dabs(YmY).gt.Ymed2) go to 15 |
| 275 | else |
| 63e30ba9 |
276 | 20 r2 = eernd(0) |
| c9c6bd3b |
277 | YmY=-Dlog(r2)/parYmY(6) + Ymed2 |
| 278 | if (YmY.gt.YmYmax) go to 20 |
| 63e30ba9 |
279 | r2 = eernd(0) |
| c9c6bd3b |
280 | if (r2.lt.0.5) YmY =-YmY |
| 281 | endif |
| 282 | C |
| 283 | Ye = 0.5*(YpY+YmY) |
| 284 | Yp = 0.5*(YpY-YmY) |
| 285 | |
| 286 | if (Ye.lt.Ymin.or.Ye.gt.Ymax) go to 10 |
| 287 | if (Yp.lt.Ymin.or.Yp.gt.Ymax) go to 10 |
| 288 | |
| 289 | C |
| 290 | C Azimuthal angle: |
| 291 | C |
| 63e30ba9 |
292 | 30 r1 = eernd(0) |
| c9c6bd3b |
293 | if (r1.lt.Exp3) then |
| 63e30ba9 |
294 | 31 r2 = eernd(0) |
| c9c6bd3b |
295 | Phi=-Dlog(r2)/parPhi(7) |
| 296 | if (Phi.gt.pi) go to 31 |
| 297 | go to 50 |
| 298 | else if (r1.lt.Exp2) then |
| 63e30ba9 |
299 | 32 r2 = eernd(0) |
| c9c6bd3b |
300 | Phi=-Dlog(r2)/parPhi(5) |
| 301 | if (Phi.gt.pi) go to 32 |
| 302 | go to 50 |
| 303 | else if (r1.lt.Exp1) then |
| 63e30ba9 |
304 | 33 r2 = eernd(0) |
| c9c6bd3b |
305 | Phi=-Dlog(r2)/parPhi(3) |
| 306 | if (Phi.gt.pi) go to 33 |
| 307 | go to 50 |
| 308 | else |
| 63e30ba9 |
309 | Phi = pi*eernd(0) |
| c9c6bd3b |
310 | endif |
| 311 | C |
| 63e30ba9 |
312 | 50 if (eernd(0).gt.0.5) Phi =-Phi |
| c9c6bd3b |
313 | Phi = Phi+pi |
| 314 | if (Phi.lt.0.03.or.Phi.gt.2.*pi-0.03) go to 30 |
| 315 | C |
| 316 | C Transverse momentums: |
| 317 | C |
| 318 | CXpX- |
| 319 | |
| 320 | 60 Jcase = Icase ! Jcase = Icase, if Icase.ne.2 |
| 321 | C |
| 322 | if (Icase.eq.2) then ! Gausses and Exponent |
| 323 | Jcase = 3 |
| 63e30ba9 |
324 | if (eernd(0).lt.Gauss) Jcase = 1 |
| c9c6bd3b |
325 | endif ! of Icase 2 |
| 326 | C |
| 327 | if (Jcase.eq.1) then ! Gauss only |
| c9e3082d |
328 | 65 call rnormlEP(rn1) |
| c9c6bd3b |
329 | XpX=Sgm1*rn1-parXpX(3) |
| 330 | if (XpX.lt.XpXmin.or.XpX.gt.Xmed) go to 65 |
| 331 | endif ! of Jcase 1 |
| 332 | C |
| 333 | if (Jcase.eq.3) then ! Exponent only |
| 63e30ba9 |
334 | 70 r1 = eernd(0) |
| c9c6bd3b |
335 | XpX =-Dlog( 1.- r1*AnorX)/parXpX(5)+Xmed |
| 336 | endif ! of Jcase 3 |
| 337 | |
| 338 | CXmX- |
| 63e30ba9 |
339 | r1 = eernd(0) |
| c9c6bd3b |
340 | if (r1.lt.Exmx1) then |
| 63e30ba9 |
341 | 81 r2 = eernd(0) |
| c9c6bd3b |
342 | XmX=-Dlog(r2)/parXmX(2) |
| 343 | if (XmX.gt.dabs(XmXmax)) go to 81 |
| 344 | else |
| 63e30ba9 |
345 | 82 r2 = eernd(0) |
| c9c6bd3b |
346 | XmX=-Dlog(r2)/parXmX(4) |
| 347 | if (XmX.gt.dabs(XmXmax)) go to 82 |
| 348 | endif |
| 349 | C |
| 63e30ba9 |
350 | 85 if (eernd(0).gt.0.5) XmX =-XmX |
| c9c6bd3b |
351 | C |
| 352 | Xe = 0.5*(XpX+XmX) |
| 353 | Xp = 0.5*(XpX-XmX) |
| 354 | |
| 355 | if (Xe.lt.Xmin.or.Xe.gt.Xmax) go to 60 |
| 356 | if (Xp.lt.Xmin.or.Xp.gt.Xmax) go to 60 |
| 357 | C |
| 358 | C --- Good event: |
| 359 | C |
| 360 | Pte = 10.d0**Xe |
| 361 | Ptp = 10.d0**Xp |
| 362 | C |
| 363 | C Event weight if the events would generate uniformly |
| 364 | C |
| 365 | Wt = DsdYpY(YpY)*DsdYmY(YmY)*DsdXpX(Xpx)*DsdXmX(XmX)*DsdPhi(Phi) |
| 366 | Wt = 2.2706950/Wt |
| 367 | C |
| 368 | Wtm2=(Pte*Ptp)*Wt ! Transformation factor |
| 369 | C |
| 370 | C --- Exact diff. cross section (Adrian Alscher 1997, Kai Hencken, May '98): |
| 371 | C |
| 372 | call Diffcross(Ptp,Yp,Pte,Ye,Phi,Dsigma) |
| 373 | Wtm2= XYsect*Dsigma*(Pte*Ptp)*Wtm2 |
| 374 | C |
| 375 | Nevnt = Nevnt + 1 |
| 376 | Xsect2 = Xsect2 + Wtm2 |
| 377 | Dsect2 = Dsect2 + Wtm2*Wtm2 |
| 378 | C |
| 379 | C Calculate cross section and its error accumulated so far |
| 380 | C |
| 381 | Xsecttot = Xsect2/Nevnt |
| 382 | Dsecttot = dsqrt(Dsect2)/Nevnt |
| 383 | C |
| 384 | return |
| 385 | end |
| 386 | c |
| 387 | C================================================================= |
| 388 | Double precision function DsdYpY(Y) |
| 389 | c |
| 390 | c Y = Yp+Ye |
| 391 | c - - - - - - - - - - - - - - - - - - - |
| 392 | implicit real*8 (A-H,O-Z) |
| 393 | common/parYp/ parYpY(6) |
| 394 | C- data parYpY / -48.584, 0.11403E-01, 40.649, 0.38920E-04, |
| 395 | C- + 40.283, 0.19238E-01 / |
| 396 | data parYpY / -4.8584, 0.11403E-01, 4.0649, 0.38920E-04, |
| 397 | + 4.0283, 0.19238E-01 / |
| 398 | c |
| 399 | DsdYpY = parYpY(1)*dexp(-parYpY(2)*Y**2) |
| 400 | + + parYpY(3)*dexp(-parYpY(4)*Y**4) |
| 401 | + + parYpY(5)*dexp(-parYpY(6)*Y**2) |
| 402 | return |
| 403 | end |
| 404 | C |
| 405 | Double precision function DsdYmY(Y) |
| 406 | c |
| 407 | c Y = Yp-Ye |
| 408 | c - - - - - - - - - - - - - - - - - - - |
| 409 | implicit real*8 (A-H,O-Z) |
| 410 | common/parYm/ parYmY(6) |
| 411 | C- data parYmY / 180., 8., 174.38, 0.17867, 2418.8, 1.3097 / |
| 412 | data parYmY / 1.80, 8., 1.7438, 0.17867, 24.188, 1.3097 / |
| 413 | C |
| 414 | if (abs(Y).lt.0.18) then |
| 415 | C1- if (abs(Y).lt.0.00) then |
| 416 | DsdYmY = parYmY(1)*dexp(-parYmY(2)*abs(Y)**2) |
| 417 | else if (abs(Y).lt.4.00) then |
| 418 | DsdYmY = parYmY(3)*dexp(-parYmY(4)*abs(Y)**2) |
| 419 | else |
| 420 | DsdYmY = parYmY(5)*dexp(-parYmY(6)*abs(Y)) |
| 421 | endif |
| 422 | |
| 423 | return |
| 424 | end |
| 425 | C |
| 426 | Double precision function DsdYY(Yp,Ye) |
| 427 | c - - - - - - - - - - - - - - - - - - - - - - |
| 428 | implicit real*8 (A-H,O-Z) |
| 429 | c |
| 430 | YpY = Yp+Ye |
| 431 | YmY = Yp-Ye |
| 432 | DsdYY = DsdYpY(YpY)*DsdYmY(YmY) |
| 433 | return |
| 434 | end |
| 435 | C |
| 436 | C==================================================================== |
| 437 | C |
| 438 | Double precision function DsdXpX(X) |
| 439 | c |
| 440 | c X = Xp+Xe |
| 441 | c - - - - - - - - - - - - - - - - - - - |
| 442 | implicit real*8 (A-H,O-Z) |
| 443 | common/parXp/ parXpX(5) |
| 444 | |
| 445 | C- data parXpX / 83.668, 1.2004, 0.47225, 96.951, 2.3814 / |
| 446 | data parXpX / 8.3668, 1.2004, 0.47225, 9.6951, 2.3814 / |
| 447 | c |
| 448 | if (X.lt.0.6)then |
| 449 | DsdXpX = parXpX(1)*dexp(-parXpX(2)*(X+parXpX(3))**2) |
| 450 | else |
| 451 | DsdXpX = parXpX(4)*dexp(-parXpX(5)*X) |
| 452 | endif |
| 453 | return |
| 454 | end |
| 455 | C |
| 456 | Double precision function DsdXmX(X) |
| 457 | c |
| 458 | c X = Xp-Xe |
| 459 | c - - - - - - - - - - - - - - - - - - - |
| 460 | implicit real*8 (A-H,O-Z) |
| 461 | common/parXm/ parXmX(4) |
| 462 | c- data parXmX / 950.38, 39.040, 194.92, 3.5660 / |
| 463 | data parXmX / 9.5038, 39.040, 1.9492, 3.5660 / |
| 464 | c |
| 465 | |
| 466 | DsdXmX = parXmX(1)*dexp(-parXmX(2)*abs(X)) |
| 467 | + + parXmX(3)*dexp(-parXmX(4)*abs(X)) |
| 468 | |
| 469 | return |
| 470 | end |
| 471 | C |
| 472 | Double precision function DsdXX(Xp,Xe) |
| 473 | c - - - - - - - - - - - - - - - - - - - - - - |
| 474 | implicit real*8 (A-H,O-Z) |
| 475 | c |
| 476 | XpX = Xp+Xe |
| 477 | XmX = Xp-Xe |
| 478 | DsdXX = DsdXpX(XpX)*DsdXmX(XmX) |
| 479 | return |
| 480 | end |
| 481 | C==================================================================== |
| 482 | C |
| 483 | Double precision function DsdPhi(Phi) ! Phi distribution |
| 484 | c |
| 485 | c Phi - athimutal angle between e+ and e- (in radians) |
| 486 | c - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| 487 | implicit real*8 (A-H,O-Z) |
| 488 | common/parPh/ parPhi(7) |
| 489 | C ! For 10**7 events |
| 490 | data parPhi / 5.4825, 226.00, 11.602, 68.173, ! accuracy= 0.87 % |
| 491 | + 1.9509, 0.11864E+04, 109.61 / ! N(Wt>20)= 573 |
| 492 | |
| 493 | C |
| 494 | data pi / 3.141 592 653 589 793 238 462 643d00/ |
| 495 | C |
| 496 | DsdPhi = parPhi(1) |
| 497 | + + parPhi(2)*dexp(-parPhi(3)*dabs(Phi-pi)) |
| 498 | + + parPhi(4)*dexp(-parPhi(5)*dabs(Phi-pi)) |
| 499 | + + parPhi(6)*dexp(-parPhi(7)*dabs(Phi-pi)) |
| 500 | return |
| 501 | end |
| 502 | C==================================================================== |
| c9e3082d |
503 | SUBROUTINE rnormlEP(rnd) |
| c9c6bd3b |
504 | * Random generator of normal distribution |
| 505 | implicit real*8 (A-H,O-Z) |
| 506 | PARAMETER (pi=3.141 592 653 589 793 238 462 643d00) |
| 507 | PARAMETER (pi2=2.*pi) |
| 508 | C |
| 63e30ba9 |
509 | u1 = eernd(0) |
| 510 | u2 = eernd(0) |
| c9c6bd3b |
511 | p1 = pi2*u1 |
| 512 | p2 = dsqrt(-2.*dlog(u2)) |
| 63e30ba9 |
513 | rnd= dcos(p1)*p2 |
| c9c6bd3b |
514 | RETURN |
| 515 | END |
git://git.uio.no / u / mrichter / AliRoot.git / blame