HIJING/hipyset1_35/pyklim_hijing.F

   1 * $Id$
   2
   3 C***********************************************************************
   4
   5       SUBROUTINE PYKLIM_HIJING(ILIM)
   6
   7 C...Checks generated variables against pre-set kinematical limits;
   8 C...also calculates limits on variables used in generation.
   9 #include "ludat1_hijing.inc"
  10 #include "ludat2_hijing.inc"
  11 #include "ludat3_hijing.inc"
  12 #include "pypars_hijing.inc"
  13 #include "pysubs_hijing.inc"
  14 #include "pyint1_hijing.inc"
  15 #include "pyint2_hijing.inc"
  16
  17 C...Common kinematical expressions.
  18       ISUB=MINT(1)
  19       IF(ISUB.EQ.96) GOTO 110
  20       SQM3=VINT(63)
  21       SQM4=VINT(64)
  22       IF(ILIM.NE.1) THEN
  23         TAU=VINT(21)
  24         RM3=SQM3/(TAU*VINT(2))
  25         RM4=SQM4/(TAU*VINT(2))
  26         BE34=SQRT((1.-RM3-RM4)**2-4.*RM3*RM4)
  27       ENDIF
  28       PTHMIN=CKIN(3)
  29       IF(MIN(SQM3,SQM4).LT.CKIN(6)**2) PTHMIN=MAX(CKIN(3),CKIN(5))
  30
  31       IF(ILIM.EQ.0) THEN
  32 C...Check generated values of tau, y*, cos(theta-hat), and tau' against
  33 C...pre-set kinematical limits.
  34         YST=VINT(22)
  35         CTH=VINT(23)
  36         TAUP=VINT(26)
  37         IF(ISET(ISUB).LE.2) THEN
  38           X1=SQRT(TAU)*EXP(YST)
  39           X2=SQRT(TAU)*EXP(-YST)
  40         ELSE
  41           X1=SQRT(TAUP)*EXP(YST)
  42           X2=SQRT(TAUP)*EXP(-YST)
  43         ENDIF
  44         XF=X1-X2
  45         IF(TAU*VINT(2).LT.CKIN(1)**2) MINT(51)=1
  46         IF(CKIN(2).GE.0..AND.TAU*VINT(2).GT.CKIN(2)**2) MINT(51)=1
  47         IF(X1.LT.CKIN(21).OR.X1.GT.CKIN(22)) MINT(51)=1
  48         IF(X2.LT.CKIN(23).OR.X2.GT.CKIN(24)) MINT(51)=1
  49         IF(XF.LT.CKIN(25).OR.XF.GT.CKIN(26)) MINT(51)=1
  50         IF(YST.LT.CKIN(7).OR.YST.GT.CKIN(8)) MINT(51)=1
  51         IF(ISET(ISUB).EQ.2.OR.ISET(ISUB).EQ.4) THEN
  52           PTH=0.5*BE34*SQRT(TAU*VINT(2)*(1.-CTH**2))
  53           Y3=YST+0.5*LOG((1.+RM3-RM4+BE34*CTH)/(1.+RM3-RM4-BE34*CTH))
  54           Y4=YST+0.5*LOG((1.+RM4-RM3-BE34*CTH)/(1.+RM4-RM3+BE34*CTH))
  55           YLARGE=MAX(Y3,Y4)
  56           YSMALL=MIN(Y3,Y4)
  57           ETALAR=10.
  58           ETASMA=-10.
  59           STH=SQRT(1.-CTH**2)
  60           IF(STH.LT.1.E-6) GOTO 100
  61           EXPET3=((1.+RM3-RM4)*SINH(YST)+BE34*COSH(YST)*CTH+
  62      &    SQRT(((1.+RM3-RM4)*COSH(YST)+BE34*SINH(YST)*CTH)**2-4.*RM3))/
  63      &    (BE34*STH)
  64           EXPET4=((1.-RM3+RM4)*SINH(YST)-BE34*COSH(YST)*CTH+
  65      &    SQRT(((1.-RM3+RM4)*COSH(YST)-BE34*SINH(YST)*CTH)**2-4.*RM4))/
  66      &    (BE34*STH)
  67           ETA3=LOG(MIN(1.E10,MAX(1.E-10,EXPET3)))
  68           ETA4=LOG(MIN(1.E10,MAX(1.E-10,EXPET4)))
  69           ETALAR=MAX(ETA3,ETA4)
  70           ETASMA=MIN(ETA3,ETA4)
  71   100     CTS3=((1.+RM3-RM4)*SINH(YST)+BE34*COSH(YST)*CTH)/
  72      &    SQRT(((1.+RM3-RM4)*COSH(YST)+BE34*SINH(YST)*CTH)**2-4.*RM3)
  73           CTS4=((1.-RM3+RM4)*SINH(YST)-BE34*COSH(YST)*CTH)/
  74      &    SQRT(((1.-RM3+RM4)*COSH(YST)-BE34*SINH(YST)*CTH)**2-4.*RM4)
  75           CTSLAR=MAX(CTS3,CTS4)
  76           CTSSMA=MIN(CTS3,CTS4)
  77           IF(PTH.LT.PTHMIN) MINT(51)=1
  78           IF(CKIN(4).GE.0..AND.PTH.GT.CKIN(4)) MINT(51)=1
  79           IF(YLARGE.LT.CKIN(9).OR.YLARGE.GT.CKIN(10)) MINT(51)=1
  80           IF(YSMALL.LT.CKIN(11).OR.YSMALL.GT.CKIN(12)) MINT(51)=1
  81           IF(ETALAR.LT.CKIN(13).OR.ETALAR.GT.CKIN(14)) MINT(51)=1
  82           IF(ETASMA.LT.CKIN(15).OR.ETASMA.GT.CKIN(16)) MINT(51)=1
  83           IF(CTSLAR.LT.CKIN(17).OR.CTSLAR.GT.CKIN(18)) MINT(51)=1
  84           IF(CTSSMA.LT.CKIN(19).OR.CTSSMA.GT.CKIN(20)) MINT(51)=1
  85           IF(CTH.LT.CKIN(27).OR.CTH.GT.CKIN(28)) MINT(51)=1
  86         ENDIF
  87         IF(ISET(ISUB).EQ.3.OR.ISET(ISUB).EQ.4) THEN
  88           IF(TAUP*VINT(2).LT.CKIN(31)**2) MINT(51)=1
  89           IF(CKIN(32).GE.0..AND.TAUP*VINT(2).GT.CKIN(32)**2) MINT(51)=1
  90         ENDIF
  91
  92       ELSEIF(ILIM.EQ.1) THEN
  93 C...Calculate limits on tau
  94 C...0) due to definition
  95         TAUMN0=0.
  96         TAUMX0=1.
  97 C...1) due to limits on subsystem mass
  98         TAUMN1=CKIN(1)**2/VINT(2)
  99         TAUMX1=1.
 100         IF(CKIN(2).GE.0.) TAUMX1=CKIN(2)**2/VINT(2)
 101 C...2) due to limits on pT-hat (and non-overlapping rapidity intervals)
 102         TM3=SQRT(SQM3+PTHMIN**2)
 103         TM4=SQRT(SQM4+PTHMIN**2)
 104         YDCOSH=1.
 105         IF(CKIN(9).GT.CKIN(12)) YDCOSH=COSH(CKIN(9)-CKIN(12))
 106         TAUMN2=(TM3**2+2.*TM3*TM4*YDCOSH+TM4**2)/VINT(2)
 107         TAUMX2=1.
 108 C...3) due to limits on pT-hat and cos(theta-hat)
 109         CTH2MN=MIN(CKIN(27)**2,CKIN(28)**2)
 110         CTH2MX=MAX(CKIN(27)**2,CKIN(28)**2)
 111         TAUMN3=0.
 112         IF(CKIN(27)*CKIN(28).GT.0.) TAUMN3=
 113      &  (SQRT(SQM3+PTHMIN**2/(1.-CTH2MN))+
 114      &  SQRT(SQM4+PTHMIN**2/(1.-CTH2MN)))**2/VINT(2)
 115         TAUMX3=1.
 116         IF(CKIN(4).GE.0..AND.CTH2MX.LT.1.) TAUMX3=
 117      &  (SQRT(SQM3+CKIN(4)**2/(1.-CTH2MX))+
 118      &  SQRT(SQM4+CKIN(4)**2/(1.-CTH2MX)))**2/VINT(2)
 119 C...4) due to limits on x1 and x2
 120         TAUMN4=CKIN(21)*CKIN(23)
 121         TAUMX4=CKIN(22)*CKIN(24)
 122 C...5) due to limits on xF
 123         TAUMN5=0.
 124         TAUMX5=MAX(1.-CKIN(25),1.+CKIN(26))
 125         VINT(11)=MAX(TAUMN0,TAUMN1,TAUMN2,TAUMN3,TAUMN4,TAUMN5)
 126         VINT(31)=MIN(TAUMX0,TAUMX1,TAUMX2,TAUMX3,TAUMX4,TAUMX5)
 127         IF(MINT(43).EQ.1.AND.(ISET(ISUB).EQ.1.OR.ISET(ISUB).EQ.2)) THEN
 128           VINT(11)=0.99999
 129           VINT(31)=1.00001
 130         ENDIF
 131         IF(VINT(31).LE.VINT(11)) MINT(51)=1
 132
 133       ELSEIF(ILIM.EQ.2) THEN
 134 C...Calculate limits on y*
 135         IF(ISET(ISUB).EQ.3.OR.ISET(ISUB).EQ.4) TAU=VINT(26)
 136         TAURT=SQRT(TAU)
 137 C...0) due to kinematics
 138         YSTMN0=LOG(TAURT)
 139         YSTMX0=-YSTMN0
 140 C...1) due to explicit limits
 141         YSTMN1=CKIN(7)
 142         YSTMX1=CKIN(8)
 143 C...2) due to limits on x1
 144         YSTMN2=LOG(MAX(TAU,CKIN(21))/TAURT)
 145         YSTMX2=LOG(MAX(TAU,CKIN(22))/TAURT)
 146 C...3) due to limits on x2
 147         YSTMN3=-LOG(MAX(TAU,CKIN(24))/TAURT)
 148         YSTMX3=-LOG(MAX(TAU,CKIN(23))/TAURT)
 149 C...4) due to limits on xF
 150         YEPMN4=0.5*ABS(CKIN(25))/TAURT
 151         YSTMN4=SIGN(LOG(SQRT(1.+YEPMN4**2)+YEPMN4),CKIN(25))
 152         YEPMX4=0.5*ABS(CKIN(26))/TAURT
 153         YSTMX4=SIGN(LOG(SQRT(1.+YEPMX4**2)+YEPMX4),CKIN(26))
 154 C...5) due to simultaneous limits on y-large and y-small
 155         YEPSMN=(RM3-RM4)*SINH(CKIN(9)-CKIN(11))
 156         YEPSMX=(RM3-RM4)*SINH(CKIN(10)-CKIN(12))
 157         YDIFMN=ABS(LOG(SQRT(1.+YEPSMN**2)-YEPSMN))
 158         YDIFMX=ABS(LOG(SQRT(1.+YEPSMX**2)-YEPSMX))
 159         YSTMN5=0.5*(CKIN(9)+CKIN(11)-YDIFMN)
 160         YSTMX5=0.5*(CKIN(10)+CKIN(12)+YDIFMX)
 161 C...6) due to simultaneous limits on cos(theta-hat) and y-large or
 162 C...   y-small
 163         CTHLIM=SQRT(1.-4.*PTHMIN**2/(BE34*TAU*VINT(2)))
 164         RZMN=BE34*MAX(CKIN(27),-CTHLIM)
 165         RZMX=BE34*MIN(CKIN(28),CTHLIM)
 166         YEX3MX=(1.+RM3-RM4+RZMX)/MAX(1E-10,1.+RM3-RM4-RZMX)
 167         YEX4MX=(1.+RM4-RM3-RZMN)/MAX(1E-10,1.+RM4-RM3+RZMN)
 168         YEX3MN=MAX(1E-10,1.+RM3-RM4+RZMN)/(1.+RM3-RM4-RZMN)
 169         YEX4MN=MAX(1E-10,1.+RM4-RM3-RZMX)/(1.+RM4-RM3+RZMX)
 170         YSTMN6=CKIN(9)-0.5*LOG(MAX(YEX3MX,YEX4MX))
 171         YSTMX6=CKIN(12)-0.5*LOG(MIN(YEX3MN,YEX4MN))
 172         VINT(12)=MAX(YSTMN0,YSTMN1,YSTMN2,YSTMN3,YSTMN4,YSTMN5,YSTMN6)
 173         VINT(32)=MIN(YSTMX0,YSTMX1,YSTMX2,YSTMX3,YSTMX4,YSTMX5,YSTMX6)
 174         IF(MINT(43).EQ.1) THEN
 175           VINT(12)=-0.00001
 176           VINT(32)=0.00001
 177         ELSEIF(MINT(43).EQ.2) THEN
 178           VINT(12)=0.99999*YSTMX0
 179           VINT(32)=1.00001*YSTMX0
 180         ELSEIF(MINT(43).EQ.3) THEN
 181           VINT(12)=-1.00001*YSTMX0
 182           VINT(32)=-0.99999*YSTMX0
 183         ENDIF
 184         IF(VINT(32).LE.VINT(12)) MINT(51)=1
 185
 186       ELSEIF(ILIM.EQ.3) THEN
 187 C...Calculate limits on cos(theta-hat)
 188         YST=VINT(22)
 189 C...0) due to definition
 190         CTNMN0=-1.
 191         CTNMX0=0.
 192         CTPMN0=0.
 193         CTPMX0=1.
 194 C...1) due to explicit limits
 195         CTNMN1=MIN(0.,CKIN(27))
 196         CTNMX1=MIN(0.,CKIN(28))
 197         CTPMN1=MAX(0.,CKIN(27))
 198         CTPMX1=MAX(0.,CKIN(28))
 199 C...2) due to limits on pT-hat
 200         CTNMN2=-SQRT(1.-4.*PTHMIN**2/(BE34**2*TAU*VINT(2)))
 201         CTPMX2=-CTNMN2
 202         CTNMX2=0.
 203         CTPMN2=0.
 204         IF(CKIN(4).GE.0.) THEN
 205           CTNMX2=-SQRT(MAX(0.,1.-4.*CKIN(4)**2/(BE34**2*TAU*VINT(2))))
 206           CTPMN2=-CTNMX2
 207         ENDIF
 208 C...3) due to limits on y-large and y-small
 209         CTNMN3=MIN(0.,MAX((1.+RM3-RM4)/BE34*TANH(CKIN(11)-YST),
 210      &  -(1.-RM3+RM4)/BE34*TANH(CKIN(10)-YST)))
 211         CTNMX3=MIN(0.,(1.+RM3-RM4)/BE34*TANH(CKIN(12)-YST),
 212      &  -(1.-RM3+RM4)/BE34*TANH(CKIN(9)-YST))
 213         CTPMN3=MAX(0.,(1.+RM3-RM4)/BE34*TANH(CKIN(9)-YST),
 214      &  -(1.-RM3+RM4)/BE34*TANH(CKIN(12)-YST))
 215         CTPMX3=MAX(0.,MIN((1.+RM3-RM4)/BE34*TANH(CKIN(10)-YST),
 216      &  -(1.-RM3+RM4)/BE34*TANH(CKIN(11)-YST)))
 217         VINT(13)=MAX(CTNMN0,CTNMN1,CTNMN2,CTNMN3)
 218         VINT(33)=MIN(CTNMX0,CTNMX1,CTNMX2,CTNMX3)
 219         VINT(14)=MAX(CTPMN0,CTPMN1,CTPMN2,CTPMN3)
 220         VINT(34)=MIN(CTPMX0,CTPMX1,CTPMX2,CTPMX3)
 221         IF(VINT(33).LE.VINT(13).AND.VINT(34).LE.VINT(14)) MINT(51)=1
 222
 223       ELSEIF(ILIM.EQ.4) THEN
 224 C...Calculate limits on tau'
 225 C...0) due to kinematics
 226         TAPMN0=TAU
 227         TAPMX0=1.
 228 C...1) due to explicit limits
 229         TAPMN1=CKIN(31)**2/VINT(2)
 230         TAPMX1=1.
 231         IF(CKIN(32).GE.0.) TAPMX1=CKIN(32)**2/VINT(2)
 232         VINT(16)=MAX(TAPMN0,TAPMN1)
 233         VINT(36)=MIN(TAPMX0,TAPMX1)
 234         IF(MINT(43).EQ.1) THEN
 235           VINT(16)=0.99999
 236           VINT(36)=1.00001
 237         ENDIF
 238         IF(VINT(36).LE.VINT(16)) MINT(51)=1
 239
 240       ENDIF
 241       RETURN
 242
 243 C...Special case for low-pT and multiple interactions:
 244 C...effective kinematical limits for tau, y*, cos(theta-hat).
 245   110 IF(ILIM.EQ.0) THEN
 246       ELSEIF(ILIM.EQ.1) THEN
 247         IF(MSTP(82).LE.1) VINT(11)=4.*PARP(81)**2/VINT(2)
 248         IF(MSTP(82).GE.2) VINT(11)=PARP(82)**2/VINT(2)
 249         VINT(31)=1.
 250       ELSEIF(ILIM.EQ.2) THEN
 251         VINT(12)=0.5*LOG(VINT(21))
 252         VINT(32)=-VINT(12)
 253       ELSEIF(ILIM.EQ.3) THEN
 254         IF(MSTP(82).LE.1) ST2EFF=4.*PARP(81)**2/(VINT(21)*VINT(2))
 255         IF(MSTP(82).GE.2) ST2EFF=0.01*PARP(82)**2/(VINT(21)*VINT(2))
 256         VINT(13)=-SQRT(MAX(0.,1.-ST2EFF))
 257         VINT(33)=0.
 258         VINT(14)=0.
 259         VINT(34)=-VINT(13)
 260       ENDIF
 261
 262       RETURN
 263       END