| 1 | SUBROUTINE PI0DEC
|
|---|
| 2 |
|
|---|
| 3 | C-----------------------------------------------------------------------
|
|---|
| 4 | C PI 0 DEC(AY)
|
|---|
| 5 | C
|
|---|
| 6 | C DECAY OF PI0 INTO 2 GAMMAS OR INTO E(+) + E(-) + GAMMA
|
|---|
| 7 | C THIS SUBROUTINE IS CALLED FROM BOX3
|
|---|
| 8 | C
|
|---|
| 9 | C DESIGN : D. HECK IK3 FZK KARLSRUHE
|
|---|
| 10 | C-----------------------------------------------------------------------
|
|---|
| 11 |
|
|---|
| 12 | IMPLICIT NONE
|
|---|
| 13 | *KEEP,CONST.
|
|---|
| 14 | COMMON /CONST/ PI,PI2,OB3,TB3,ENEPER
|
|---|
| 15 | DOUBLE PRECISION PI,PI2,OB3,TB3,ENEPER
|
|---|
| 16 | *KEEP,DECAY.
|
|---|
| 17 | COMMON /DECAY/ GAM345,COS345,PHI345
|
|---|
| 18 | DOUBLE PRECISION GAM345(3),COS345(3),PHI345(3)
|
|---|
| 19 | *KEEP,GENER.
|
|---|
| 20 | COMMON /GENER/ GEN,ALEVEL
|
|---|
| 21 | DOUBLE PRECISION GEN,ALEVEL
|
|---|
| 22 | *KEEP,PAM.
|
|---|
| 23 | COMMON /PAM/ PAMA,SIGNUM
|
|---|
| 24 | DOUBLE PRECISION PAMA(6000),SIGNUM(6000)
|
|---|
| 25 | *KEEP,PARPAR.
|
|---|
| 26 | COMMON /PARPAR/ CURPAR,SECPAR,PRMPAR,OUTPAR,C,
|
|---|
| 27 | * E00,E00PN,PTOT0,PTOT0N,THICKH,ITYPE,LEVL
|
|---|
| 28 | DOUBLE PRECISION CURPAR(14),SECPAR(14),PRMPAR(14),OUTPAR(14),
|
|---|
| 29 | * C(50),E00,E00PN,PTOT0,PTOT0N,THICKH
|
|---|
| 30 | INTEGER ITYPE,LEVL
|
|---|
| 31 | *KEEP,PARPAE.
|
|---|
| 32 | DOUBLE PRECISION GAMMA,COSTHE,PHI,H,T,X,Y,CHI,BETA,GCM,ECM
|
|---|
| 33 | EQUIVALENCE (CURPAR(2),GAMMA), (CURPAR(3),COSTHE),
|
|---|
| 34 | * (CURPAR(4), PHI ), (CURPAR(5), H ),
|
|---|
| 35 | * (CURPAR(6), T ), (CURPAR(7), X ),
|
|---|
| 36 | * (CURPAR(8), Y ), (CURPAR(9), CHI ),
|
|---|
| 37 | * (CURPAR(10),BETA), (CURPAR(11),GCM ),
|
|---|
| 38 | * (CURPAR(12),ECM )
|
|---|
| 39 | *KEEP,RANDPA.
|
|---|
| 40 | COMMON /RANDPA/ FAC,U1,U2,RD,NSEQ,ISEED,KNOR
|
|---|
| 41 | DOUBLE PRECISION FAC,U1,U2
|
|---|
| 42 | REAL RD(3000)
|
|---|
| 43 | INTEGER ISEED(103,10),NSEQ
|
|---|
| 44 | LOGICAL KNOR
|
|---|
| 45 | *KEEP,RUNPAR.
|
|---|
| 46 | COMMON /RUNPAR/ FIXHEI,THICK0,HILOECM,HILOELB,
|
|---|
| 47 | * STEPFC,NRRUN,NSHOW,PATAPE,MONIIN,
|
|---|
| 48 | * MONIOU,MDEBUG,NUCNUC,
|
|---|
| 49 | * CETAPE,
|
|---|
| 50 | * SHOWNO,ISHW,NOPART,NRECS,NBLKS,MAXPRT,NDEBDL,
|
|---|
| 51 | * N1STTR,MDBASE,
|
|---|
| 52 | * DEBDEL,DEBUG,FDECAY,FEGS,FIRSTI,FIXINC,FIXTAR,
|
|---|
| 53 | * FIX1I,FMUADD,FNKG,FPRINT,FDBASE
|
|---|
| 54 | * ,GHEISH,GHESIG
|
|---|
| 55 | COMMON /RUNPAC/ DSN,HOST,USER
|
|---|
| 56 | DOUBLE PRECISION FIXHEI,THICK0,HILOECM,HILOELB
|
|---|
| 57 | REAL STEPFC
|
|---|
| 58 | INTEGER NRRUN,NSHOW,PATAPE,MONIIN,MONIOU,MDEBUG,NUCNUC,
|
|---|
| 59 | * SHOWNO,ISHW,NOPART,NRECS,NBLKS,MAXPRT,NDEBDL,
|
|---|
| 60 | * N1STTR,MDBASE
|
|---|
| 61 | INTEGER CETAPE
|
|---|
| 62 | CHARACTER*79 DSN
|
|---|
| 63 | CHARACTER*20 HOST,USER
|
|---|
| 64 |
|
|---|
| 65 | LOGICAL DEBDEL,DEBUG,FDECAY,FEGS,FIRSTI,FIXINC,FIXTAR,
|
|---|
| 66 | * FIX1I,FMUADD,FNKG,FPRINT,FDBASE
|
|---|
| 67 | * ,GHEISH,GHESIG
|
|---|
| 68 | *KEND.
|
|---|
| 69 |
|
|---|
| 70 | DOUBLE PRECISION AUX1,AUX2,COSTH1,COSTH2,EPITO2,FI1
|
|---|
| 71 | INTEGER I
|
|---|
| 72 | C-----------------------------------------------------------------------
|
|---|
| 73 |
|
|---|
| 74 | IF ( DEBUG ) WRITE(MDEBUG,444) (CURPAR(I),I=1,9)
|
|---|
| 75 | 444 FORMAT (' PI0DEC: CURPAR=',1P,9E10.3)
|
|---|
| 76 |
|
|---|
| 77 | C COPY VERTEX COORDINATES INTO SECPAR
|
|---|
| 78 | DO 1 I = 5,8
|
|---|
| 79 | SECPAR(I) = CURPAR(I)
|
|---|
| 80 | 1 CONTINUE
|
|---|
| 81 | SECPAR( 9) = GEN
|
|---|
| 82 | SECPAR(10) = ALEVEL
|
|---|
| 83 |
|
|---|
| 84 | C LOOK FOR DECAY MODE
|
|---|
| 85 | CALL RMMAR (RD,3,1)
|
|---|
| 86 |
|
|---|
| 87 | C DECAY PI(0) ----> GAMMA + GAMMA
|
|---|
| 88 | IF ( RD(3) .LT. 0.98802 ) THEN
|
|---|
| 89 | C HALF OF TOTAL ENERGY OF THE PION = EPITO2
|
|---|
| 90 | EPITO2 = 0.5D0 * GAMMA * PAMA(7)
|
|---|
| 91 | AUX1 = 1.D0 + BETA * RD(1)
|
|---|
| 92 | AUX2 = 1.D0 - BETA * RD(1)
|
|---|
| 93 | COSTH1 = (BETA + RD(1)) / AUX1
|
|---|
| 94 | COSTH2 = (BETA - RD(1)) / AUX2
|
|---|
| 95 |
|
|---|
| 96 | C FIRST GAMMA (WITH HIGHER ENERGY)
|
|---|
| 97 | FI1 = PI2 * RD(2)
|
|---|
| 98 | CALL ADDANG( COSTHE,PHI, COSTH1,FI1, SECPAR(3),SECPAR(4) )
|
|---|
| 99 | IF ( SECPAR(3) .GT. C(29) ) THEN
|
|---|
| 100 | SECPAR(1) = 1.D0
|
|---|
| 101 | C ENERGY OF GAMMA
|
|---|
| 102 | SECPAR(2) = AUX1 * EPITO2
|
|---|
| 103 | CALL TSTACK
|
|---|
| 104 | ENDIF
|
|---|
| 105 |
|
|---|
| 106 | C SECOND GAMMA (WITH LOWER ENERGY)
|
|---|
| 107 | CALL ADDANG( COSTHE,PHI, COSTH2,FI1+PI, SECPAR(3),SECPAR(4) )
|
|---|
| 108 | IF ( SECPAR(3) .GT. C(29) ) THEN
|
|---|
| 109 | SECPAR(1) = 1.D0
|
|---|
| 110 | C ENERGY OF GAMMA
|
|---|
| 111 | SECPAR(2) = AUX2 * EPITO2
|
|---|
| 112 | CALL TSTACK
|
|---|
| 113 | ENDIF
|
|---|
| 114 |
|
|---|
| 115 | C DECAY PI(0) ----> E(+) + E(-) + GAMMA (DALITZ DECAY)
|
|---|
| 116 | C (UNIFORM PHASE SPACE DISTRIBUTION IS ASSUMED FOR THIS DECAY)
|
|---|
| 117 | ELSE
|
|---|
| 118 | CALL DECAY6( PAMA(7), PAMA(3), PAMA(2), 0.D0,
|
|---|
| 119 | * 0.D0,0.D0,0.D0, 1.D0, 2)
|
|---|
| 120 | DO 11 I = 1,3
|
|---|
| 121 | CALL ADDANG( COSTHE,PHI, COS345(I),PHI345(I),
|
|---|
| 122 | * SECPAR(3),SECPAR(4) )
|
|---|
| 123 | IF ( SECPAR(3) .GT. C(29) ) THEN
|
|---|
| 124 | SECPAR(1) = FLOAT(4 - I)
|
|---|
| 125 | SECPAR(2) = GAM345(I)
|
|---|
| 126 | CALL TSTACK
|
|---|
| 127 | ENDIF
|
|---|
| 128 | 11 CONTINUE
|
|---|
| 129 |
|
|---|
| 130 | ENDIF
|
|---|
| 131 |
|
|---|
| 132 | RETURN
|
|---|
| 133 | END
|
|---|
