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Commit | Line | Data |
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0795afa3 | 1 | #include "isajet/pilot.h" |
2 | COMPLEX*16 FUNCTION SSB1(XS,XMI,XMJ) | |
3 | C Modified by M. Drees 10/26/95 | |
4 | #include "isajet/ssinf.inc" | |
5 | REAL XS,XMI,XMJ | |
6 | DOUBLE PRECISION S,MI,MJ,A0MI,A0MJ | |
7 | COMPLEX*16 SSB0 | |
8 | S=XS | |
9 | MI=XMI | |
10 | MJ=XMJ | |
11 | IF(S.GT.1.D-4*(MI**2+MJ**2)) THEN | |
12 | IF(MI.GE.1.D-10) THEN | |
13 | A0MI = MI**2*( 1.D0 - LOG(MI**2) + XLAM ) | |
14 | ELSE | |
15 | A0MI = 0.D0 | |
16 | ENDIF | |
17 | IF(MJ.GE.1.D-10) THEN | |
18 | A0MJ = MJ**2*( 1.D0 - LOG(MJ**2) + XLAM ) | |
19 | ELSE | |
20 | A0MJ = 0.D0 | |
21 | ENDIF | |
22 | SSB1 = ( (S+MI**2-MJ**2)*SSB0(XS,XMI,XMJ) + A0MJ - A0MI )/2.D0/S | |
23 | ELSE IF(ABS(MI-MJ).GT.1.D-4*MJ) THEN | |
24 | IF(MI.GT.1.D-10.AND.MJ.GT.1.D-10) THEN | |
25 | SSB1 = -(LOG(MI)*(MI**4-2.*MJ**2*MI**2) + MJ**4*LOG(MJ) | |
26 | $ -MJ**4/4.D0-.75*MI**4 + MI**2*MJ**2) / (MI**2-MJ**2)**2 | |
27 | $ + XLAM/2.D0 | |
28 | ELSEIF(MI.GT.1.D-10) THEN | |
29 | SSB1 = -LOG(MI) + .75 + .5*XLAM | |
30 | ELSEIF(MJ.GT.1.D-10) THEN | |
31 | SSB1 = -LOG(MJ) + .25 + .5*XLAM | |
32 | ENDIF | |
33 | ELSE IF(MI.NE.0.D0) THEN | |
34 | SSB1 = -LOG(MI) + XLAM/2.D0 | |
35 | ENDIF | |
36 | RETURN | |
37 | END |