1 #include "isajet/pilot.h"
4 C THIS IS ELECTRON PARTON DISTRIBUTION FUNCTION;
5 C SAME AS USED IN PYTHIA; NOTE! ESTRUC=0 FOR X>.999999
7 #if defined(CERNLIB_IMPNONE)
10 REAL ESTRUC,AL,PI,AME,QS,X,BT,XM,T,A,B
15 BT=2*AL/PI*(LOG(QS/AME/AME)-1.)
16 C KLEISS/SJOSTRAND PRESCRIPTION
17 C IF (X.LE..9999) THEN
18 C ESTRUC=BT/2.*(1.-X)**(BT/2.-1.)
19 C ELSE IF (X.LE..999999.AND.X.GT..9999) THEN
20 C ESTRUC=100.**(BT/2.)/(100.**(BT/2.)-1.)*BT/2.*
21 C $ (1.-X)**(BT/2.-1.)
25 C FADIN-KURAEV/DREES PRESCRIPTION
28 T = (1.+.375*BT)*(1.-XM)**(BT/2.)
30 & -.25*BT*(1.5-XM*(1.+XM/2.)))/(1.-XM)
33 B = .5*BT*T/(1.-XM) - .25*BT*(1.+XM) - A*XM
36 ESTRUC = .5*BT*((1.-X)**(.5*BT-1.)) * (1.+.375*BT)