pythiaeRHIC/pythia/pytbbc.f

0001
0002 C*********************************************************************
0003
0004 C...PYTBBC
0005 C...Calculates the three-body decay of gluinos into
0006 C...charginos and third generation fermions.
0007
0008       SUBROUTINE PYTBBC(I,NN,XMGLU,GAM)
0009
0010 C...Double precision and integer declarations.
0011       IMPLICIT DOUBLE PRECISION(A-H, O-Z)
0012       IMPLICIT INTEGER(I-N)
0013       INTEGER PYK,PYCHGE,PYCOMP
0014 C...Parameter statement to help give large particle numbers.
0015       PARAMETER (KSUSY1=1000000,KSUSY2=2000000,KTECHN=3000000,
0016      &KEXCIT=4000000,KDIMEN=5000000)
0017 C...Commonblocks.
0018       COMMON/PYDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
0019       COMMON/PYDAT2/KCHG(500,4),PMAS(500,4),PARF(2000),VCKM(4,4)
0020       COMMON/PYMSSM/IMSS(0:99),RMSS(0:99)
0021       COMMON/PYSSMT/ZMIX(4,4),UMIX(2,2),VMIX(2,2),SMZ(4),SMW(2),
0022      &SFMIX(16,4),ZMIXI(4,4),UMIXI(2,2),VMIXI(2,2)
0023       SAVE /PYDAT1/,/PYDAT2/,/PYMSSM/,/PYSSMT/
0024
0025 C...Local variables.
0026       EXTERNAL PYSIMP,PYLAMF
0027       DOUBLE PRECISION PYSIMP,PYLAMF
0028       INTEGER I,NN,LIN
0029       DOUBLE PRECISION XMG,XMG2,XMB,XMB2,XMR,XMR2
0030       DOUBLE PRECISION XMT,XMT2,XMST(4),XMSB(4)
0031       DOUBLE PRECISION ULR(2),VLR(2),XMQ2,XMQ4,AM,W,SBAR,SMIN,SMAX
0032       DOUBLE PRECISION SUMME(0:100),A(4,8)
0033       DOUBLE PRECISION COS2A,SIN2A,COS2C,SIN2C
0034       DOUBLE PRECISION GRS,XMQ3,XMGBTR,XMGTBR,ANT1,ANT2,ANB1,ANB2
0035       DOUBLE PRECISION XMGLU,GAM
0036       DOUBLE PRECISION XX1(2),XX2(2),AAA(2),BBB(2),CCC(2),
0037      &DDD(2),EEE(2),FFF(2)
0038       SAVE XX1,XX2,AAA,BBB,CCC,DDD,EEE,FFF
0039       DOUBLE PRECISION ALPHAW,ALPHAS
0040       DOUBLE PRECISION AMC(2)
0041       SAVE AMC
0042       DOUBLE PRECISION AMBOT,AMSB(2),SINC,COSC
0043       DOUBLE PRECISION AMTOP,AMST(2),SINA,COSA
0044       SAVE AMSB,AMST
0045       LOGICAL IFIRST
0046       SAVE IFIRST
0047       DATA IFIRST/.TRUE./
0048
0049       TANB=RMSS(5)
0050       SINB=TANB/SQRT(1D0+TANB**2)
0051       COSB=SINB/TANB
0052       XW=PARU(102)
0053       AMW=PMAS(24,1)
0054       COSC=SFMIX(5,1)
0055       SINC=SFMIX(5,3)
0056       COSA=SFMIX(6,1)
0057       SINA=SFMIX(6,3)
0058       AMBOT=PYMRUN(5,XMGLU**2)
0059       AMTOP=PYMRUN(6,XMGLU**2)
0060       W2=SQRT(2D0)
0061       AMW=PMAS(24,1)
0062       FAKT1=AMBOT/W2/AMW/COSB
0063       FAKT2=AMTOP/W2/AMW/SINB
0064       IF(IFIRST) THEN
0065         AMC(1)=SMW(1)
0066         AMC(2)=SMW(2)
0067         DO 100 JJ=1,2
0068           CCC(JJ)=FAKT1*UMIX(JJ,2)*SINC-UMIX(JJ,1)*COSC
0069           EEE(JJ)=FAKT2*VMIX(JJ,2)*COSC
0070           DDD(JJ)=FAKT1*UMIX(JJ,2)*COSC+UMIX(JJ,1)*SINC
0071           FFF(JJ)=FAKT2*VMIX(JJ,2)*SINC
0072           XX1(JJ)=FAKT2*VMIX(JJ,2)*SINA-VMIX(JJ,1)*COSA
0073           AAA(JJ)=FAKT1*UMIX(JJ,2)*COSA
0074           XX2(JJ)=FAKT2*VMIX(JJ,2)*COSA+VMIX(JJ,1)*SINA
0075           BBB(JJ)=FAKT1*UMIX(JJ,2)*SINA
0076   100   CONTINUE
0077         AMST(1)=PMAS(PYCOMP(KSUSY1+6),1)
0078         AMST(2)=PMAS(PYCOMP(KSUSY2+6),1)
0079         AMSB(1)=PMAS(PYCOMP(KSUSY1+5),1)
0080         AMSB(2)=PMAS(PYCOMP(KSUSY2+5),1)
0081         IFIRST=.FALSE.
0082       ENDIF
0083
0084       ULR(1)=XX1(I)*XX1(I)+AAA(I)*AAA(I)
0085       ULR(2)=XX2(I)*XX2(I)+BBB(I)*BBB(I)
0086       VLR(1)=CCC(I)*CCC(I)+EEE(I)*EEE(I)
0087       VLR(2)=DDD(I)*DDD(I)+FFF(I)*FFF(I)
0088
0089       COS2A=COSA**2-SINA**2
0090       SIN2A=SINA*COSA*2D0
0091       COS2C=COSC**2-SINC**2
0092       SIN2C=SINC*COSC*2D0
0093
0094       XMG=XMGLU
0095       XMT=PMAS(6,1)
0096       XMB=PMAS(5,1)
0097       XMR=AMC(I)
0098       XMG2=XMG*XMG
0099       ALPHAW=PYALEM(XMG2)
0100       ALPHAS=PYALPS(XMG2)
0101       XMT2=XMT*XMT
0102       XMB2=XMB*XMB
0103       XMR2=XMR*XMR
0104       XMQ2=XMG2+XMT2+XMB2+XMR2
0105       XMQ4=XMG*XMT*XMB*XMR
0106       XMQ3=XMG2*XMR2+XMT2*XMB2
0107       XMGBTR=(XMG2+XMB2)*(XMT2+XMR2)
0108       XMGTBR=(XMG2+XMT2)*(XMB2+XMR2)
0109
0110       XMST(1)=AMST(1)*AMST(1)
0111       XMST(2)=AMST(1)*AMST(1)
0112       XMST(3)=AMST(2)*AMST(2)
0113       XMST(4)=AMST(2)*AMST(2)
0114       XMSB(1)=AMSB(1)*AMSB(1)
0115       XMSB(2)=AMSB(2)*AMSB(2)
0116       XMSB(3)=AMSB(1)*AMSB(1)
0117       XMSB(4)=AMSB(2)*AMSB(2)
0118
0119       A(1,1)=-COSA*SINC*CCC(I)*AAA(I)-SINA*COSC*EEE(I)*XX1(I)
0120       A(1,2)=XMG*XMB*(COSA*COSC*CCC(I)*AAA(I)+SINA*SINC*EEE(I)*XX1(I))
0121       A(1,3)=-XMG*XMR*(COSA*COSC*CCC(I)*XX1(I)+SINA*SINC*EEE(I)*AAA(I))
0122       A(1,4)=XMB*XMR*(COSA*SINC*CCC(I)*XX1(I)+SINA*COSC*EEE(I)*AAA(I))
0123       A(1,5)=XMG*XMT*(COSA*COSC*EEE(I)*XX1(I)+SINA*SINC*CCC(I)*AAA(I))
0124       A(1,6)=-XMT*XMB*(COSA*SINC*EEE(I)*XX1(I)+SINA*COSC*CCC(I)*AAA(I))
0125       A(1,7)=XMT*XMR*(COSA*SINC*EEE(I)*AAA(I)+SINA*COSC*CCC(I)*XX1(I))
0126       A(1,8)=-XMQ4*(COSA*COSC*EEE(I)*AAA(I)+SINA*SINC*CCC(I)*XX1(I))
0127
0128       A(2,1)=-COSA*COSC*DDD(I)*AAA(I)-SINA*SINC*FFF(I)*XX1(I)
0129       A(2,2)=-XMG*XMB*(COSA*SINC*DDD(I)*AAA(I)+SINA*COSC*FFF(I)*XX1(I))
0130       A(2,3)=XMG*XMR*(COSA*SINC*DDD(I)*XX1(I)+SINA*COSC*FFF(I)*AAA(I))
0131       A(2,4)=XMB*XMR*(COSA*COSC*DDD(I)*XX1(I)+SINA*SINC*FFF(I)*AAA(I))
0132       A(2,5)=XMG*XMT*(COSA*SINC*FFF(I)*XX1(I)+SINA*COSC*DDD(I)*AAA(I))
0133       A(2,6)=XMT*XMB*(COSA*COSC*FFF(I)*XX1(I)+SINA*SINC*DDD(I)*AAA(I))
0134       A(2,7)=-XMT*XMR*(COSA*COSC*FFF(I)*AAA(I)+SINA*SINC*DDD(I)*XX1(I))
0135       A(2,8)=-XMQ4*(COSA*SINC*FFF(I)*AAA(I)+SINA*COSC*DDD(I)*XX1(I))
0136
0137       A(3,1)=-COSA*COSC*EEE(I)*XX2(I)-SINA*SINC*CCC(I)*BBB(I)
0138       A(3,2)=XMG*XMB*(COSA*SINC*EEE(I)*XX2(I)+SINA*COSC*CCC(I)*BBB(I))
0139       A(3,3)=XMG*XMR*(COSA*SINC*EEE(I)*BBB(I)+SINA*COSC*CCC(I)*XX2(I))
0140       A(3,4)=-XMB*XMR*(COSA*COSC*EEE(I)*BBB(I)+SINA*SINC*CCC(I)*XX2(I))
0141       A(3,5)=-XMG*XMT*(COSA*SINC*CCC(I)*BBB(I)+SINA*COSC*EEE(I)*XX2(I))
0142       A(3,6)=XMT*XMB*(COSA*COSC*CCC(I)*BBB(I)+SINA*SINC*EEE(I)*XX2(I))
0143       A(3,7)=XMT*XMR*(COSA*COSC*CCC(I)*XX2(I)+SINA*SINC*EEE(I)*BBB(I))
0144       A(3,8)=-XMQ4*(COSA*SINC*CCC(I)*XX2(I)+SINA*COSC*EEE(I)*BBB(I))
0145
0146       A(4,1)=-COSA*SINC*FFF(I)*XX2(I)-SINA*COSC*DDD(I)*BBB(I)
0147       A(4,2)=-XMG*XMB*(COSA*COSC*FFF(I)*XX2(I)+SINA*SINC*DDD(I)*BBB(I))
0148       A(4,3)=-XMG*XMR*(COSA*COSC*FFF(I)*BBB(I)+SINA*SINC*DDD(I)*XX2(I))
0149       A(4,4)=-XMB*XMR*(COSA*SINC*FFF(I)*BBB(I)+SINA*COSC*DDD(I)*XX2(I))
0150       A(4,5)=-XMG*XMT*(COSA*COSC*DDD(I)*BBB(I)+SINA*SINC*FFF(I)*XX2(I))
0151       A(4,6)=-XMT*XMB*(COSA*SINC*DDD(I)*BBB(I)+SINA*COSC*FFF(I)*XX2(I))
0152       A(4,7)=-XMT*XMR*(COSA*SINC*DDD(I)*XX2(I)+SINA*COSC*FFF(I)*BBB(I))
0153       A(4,8)=-XMQ4*(COSA*COSC*DDD(I)*XX2(I)+SINA*SINC*FFF(I)*BBB(I))
0154
0155       SMAX=(XMG-ABS(XMR))**2
0156       SMIN=(XMB+XMT)**2+0.1D0
0157
0158       DO 120 LIN=0,NN-1
0159         SBAR=SMIN+DBLE(LIN)*(SMAX-SMIN)/DBLE(NN)
0160         AM=(XMG2-XMR2)*(XMT2-XMB2)/2D0/SBAR
0161         GRS=SBAR-XMQ2
0162         W=PYLAMF(SBAR,XMB2,XMT2)*PYLAMF(SBAR,XMG2,XMR2)
0163         W=DSQRT(W)/2D0/SBAR
0164         ANT1=LOG(ABS((GRS/2D0+AM+XMST(1)-W)/(GRS/2D0+AM+XMST(1)+W)))
0165         ANT2=LOG(ABS((GRS/2D0+AM+XMST(3)-W)/(GRS/2D0+AM+XMST(3)+W)))
0166         ANB1=LOG(ABS((GRS/2D0-AM+XMSB(1)-W)/(GRS/2D0-AM+XMSB(1)+W)))
0167         ANB2=LOG(ABS((GRS/2D0-AM+XMSB(2)-W)/(GRS/2D0-AM+XMSB(2)+W)))
0168         SUMME(LIN)=-ULR(1)*W+(ULR(1)*(XMQ2/2D0-XMST(1)-XMG*XMT*SIN2A)
0169      &  +2D0*XX1(I)*AAA(I)*XMR*XMB)*ANT1
0170      &  +(ULR(1)/2D0*(XMST(1)*(XMQ2-XMST(1))-XMGTBR
0171      &  -2D0*XMG*XMT*SIN2A*(XMST(1)-XMB2-XMR2))
0172      &  +2D0*XX1(I)*AAA(I)*XMR*XMB*(XMST(1)-XMG2-XMT2)
0173      &  +4D0*SIN2A*XX1(I)*AAA(I)*XMQ4)
0174      &  *(1D0/(GRS/2D0+AM+XMST(1)-W)-1D0/(GRS/2D0+AM+XMST(1)+W))
0175         SUMME(LIN)=SUMME(LIN)-ULR(2)*W
0176      &  +(ULR(2)*(XMQ2/2D0-XMST(3)+XMG*XMT*SIN2A)
0177      &  -2D0*XX2(I)*BBB(I)*XMR*XMB)*ANT2
0178      &  +(ULR(2)/2D0*(XMST(3)*(XMQ2-XMST(3))-XMGTBR
0179      &  +2D0*XMG*XMT*SIN2A*(XMST(3)-XMB2-XMR2))
0180      &  -2D0*XX2(I)*BBB(I)*XMR*XMB*(XMST(3)-XMG2-XMT2)
0181      &  +4D0*SIN2A*XX2(I)*BBB(I)*XMQ4)
0182      &  *(1D0/(GRS/2D0+AM+XMST(3)-W)-1D0/(GRS/2D0+AM+XMST(3)+W))
0183         SUMME(LIN)=SUMME(LIN)-VLR(1)*W
0184      &  +(VLR(1)*(XMQ2/2D0-XMSB(1)-XMG*XMB*SIN2C)
0185      &  +2D0*CCC(I)*EEE(I)*XMR*XMT)*ANB1
0186      &  +(VLR(1)/2D0*(XMSB(1)*(XMQ2-XMSB(1))-XMGBTR
0187      &  -2D0*XMG*XMB*SIN2C*(XMSB(1)-XMT2-XMR2))
0188      &  +2D0*CCC(I)*EEE(I)*XMR*XMT*(XMSB(1)-XMG2-XMB2)
0189      &  +4D0*SIN2C*CCC(I)*EEE(I)*XMQ4)
0190      &  *(1D0/(GRS/2D0-AM+XMSB(1)-W)-1D0/(GRS/2D0-AM+XMSB(1)+W))
0191         SUMME(LIN)=SUMME(LIN)-VLR(2)*W
0192      &  +(VLR(2)*(XMQ2/2D0-XMSB(2)+XMG*XMB*SIN2C)
0193      &  -2D0*DDD(I)*FFF(I)*XMR*XMT)*ANB2
0194      &  +(VLR(2)/2D0*(XMSB(2)*(XMQ2-XMSB(2))-XMGBTR
0195      &  +2D0*XMG*XMB*SIN2C*(XMSB(2)-XMT2-XMR2))
0196      &  -2D0*DDD(I)*FFF(I)*XMR*XMT*(XMSB(2)-XMG2-XMB2)
0197      &  +4D0*SIN2C*DDD(I)*FFF(I)*XMQ4)
0198      &  *(1D0/(GRS/2D0-AM+XMSB(2)-W)-1D0/(GRS/2D0-AM+XMSB(2)+W))
0199         SUMME(LIN)=SUMME(LIN)+2D0*XMG*XMT*COS2A/(XMST(3)-XMST(1))
0200      &  *((AAA(I)*BBB(I)-XX1(I)*XX2(I))
0201      &  *((XMST(3)-XMB2-XMR2)*ANT2-(XMST(1)-XMB2-XMR2)*ANT1)
0202      &  +2D0*(AAA(I)*XX2(I)-XX1(I)*BBB(I))*XMB*XMR*(ANT2-ANT1))
0203         SUMME(LIN)=SUMME(LIN)+2D0*XMG*XMB*COS2C/(XMSB(2)-XMSB(1))
0204      &  *((EEE(I)*FFF(I)-CCC(I)*DDD(I))
0205      &  *((XMSB(2)-XMT2-XMR2)*ANB2-(XMSB(1)-XMT2-XMR2)*ANB1)
0206      &  +2D0*(EEE(I)*DDD(I)-CCC(I)*FFF(I))*XMT*XMR*(ANB2-ANB1))
0207         DO 110 J=1,4
0208           SUMME(LIN)=SUMME(LIN)-2D0*A(J,1)*W
0209      &    +((-A(J,1)*(XMSB(J)*(GRS+XMSB(J))+XMQ3)
0210      &    +A(J,2)*(XMSB(J)-XMT2-XMR2)+A(J,3)*(SBAR-XMB2-XMT2)
0211      &    +A(J,4)*(XMSB(J)+SBAR-XMB2-XMR2)
0212      &    -A(J,5)*(XMSB(J)+SBAR-XMG2-XMT2)+A(J,6)*(XMG2+XMR2-SBAR)
0213      &    -A(J,7)*(XMSB(J)-XMG2-XMB2)+2D0*A(J,8))
0214      &    *LOG(ABS((GRS/2D0+XMSB(J)-AM-W)/(GRS/2D0+XMSB(J)-AM+W)))
0215      &    -(A(J,1)*(XMST(J)*(GRS+XMST(J))+XMQ3)
0216      &    +A(J,2)*(XMST(J)+SBAR-XMG2-XMB2)-A(J,3)*(SBAR-XMB2-XMT2)
0217      &    +A(J,4)*(XMST(J)-XMG2-XMT2)-A(J,5)*(XMST(J)-XMR2-XMB2)
0218      &    -A(J,6)*(XMG2+XMR2-SBAR)
0219      &    -A(J,7)*(XMST(J)+SBAR-XMT2-XMR2)-2D0*A(J,8))
0220      &    *LOG(ABS((GRS/2D0+XMST(J)+AM-W)/(GRS/2D0+XMST(J)+AM+W))))
0221      &    /(GRS+XMSB(J)+XMST(J))
0222   110   CONTINUE
0223   120 CONTINUE
0224       SUMME(NN)=0D0
0225       GAM= ALPHAW * ALPHAS * PYSIMP(SUMME,SMIN,SMAX,NN)
0226      &/ (16D0 * PARU(1) * PARU(102) * XMGLU**3)
0227
0228       RETURN
0229       END