* $Id$
    
C*********************************************************************  
    
      SUBROUTINE PYXTOT_HIJING 
    
C...Parametrizes total, double diffractive, single diffractive and  
C...elastic cross-sections for different energies and beams.    
#include "ludat1_hijing.inc"
#include "pypars_hijing.inc"
#include "pyint1_hijing.inc"
#include "pyint5_hijing.inc"
      DIMENSION BCS(5,8),BCB(2,5),BCC(3)    
    
C...The following data lines are coefficients needed in the 
C...Block, Cahn parametrization of total cross-section and nuclear  
C...slope parameter; see below. 
      DATA ((BCS(I,J),J=1,8),I=1,5)/    
     1 41.74, 0.66, 0.0000, 337.,  0.0, 0.0, -39.3, 0.48,   
     2 41.66, 0.60, 0.0000, 306.,  0.0, 0.0, -34.6, 0.51,   
     3 41.36, 0.63, 0.0000, 299.,  7.3, 0.5, -40.4, 0.47,   
     4 41.68, 0.63, 0.0083, 330.,  0.0, 0.0, -39.0, 0.48,   
     5 41.13, 0.59, 0.0074, 278., 10.5, 0.5, -41.2, 0.46/   
      DATA ((BCB(I,J),J=1,5),I=1,2)/    
     1 10.79, -0.049, 0.040, 21.5, 1.23,    
     2  9.92, -0.027, 0.013, 18.9, 1.07/    
      DATA BCC/2.0164346,-0.5590311,0.0376279/  
    
C...Total cross-section and nuclear slope parameter for pp and p-pbar   
      NFIT=MIN(5,MAX(1,MSTP(31)))   
      SIGP=BCS(NFIT,1)+BCS(NFIT,2)*(-0.25*PARU(1)**2*   
     &(1.-0.25*BCS(NFIT,3)*PARU(1)**2)+(1.+0.5*BCS(NFIT,3)*PARU(1)**2)* 
     &(LOG(VINT(2)/BCS(NFIT,4)))**2+BCS(NFIT,3)*    
     &(LOG(VINT(2)/BCS(NFIT,4)))**4)/   
     &((1.-0.25*BCS(NFIT,3)*PARU(1)**2)**2+2.*BCS(NFIT,3)*  
     &(1.+0.25*BCS(NFIT,3)*PARU(1)**2)*(LOG(VINT(2)/BCS(NFIT,4)))**2+   
     &BCS(NFIT,3)**2*(LOG(VINT(2)/BCS(NFIT,4)))**4)+BCS(NFIT,5)*    
     &VINT(2)**(BCS(NFIT,6)-1.)*SIN(0.5*PARU(1)*BCS(NFIT,6))    
      SIGM=-BCS(NFIT,7)*VINT(2)**(BCS(NFIT,8)-1.)*  
     &COS(0.5*PARU(1)*BCS(NFIT,8))  
      REFP=BCS(NFIT,2)*PARU(1)*LOG(VINT(2)/BCS(NFIT,4))/    
     &((1.-0.25*BCS(NFIT,3)*PARU(1)**2)**2+2.*BCS(NFIT,3)*  
     &(1.+0.25*BCS(NFIT,3)*PARU(1)**2)+(LOG(VINT(2)/BCS(NFIT,4)))**2+   
     &BCS(NFIT,3)**2*(LOG(VINT(2)/BCS(NFIT,4)))**4)-BCS(NFIT,5)*    
     &VINT(2)**(BCS(NFIT,6)-1.)*COS(0.5*PARU(1)*BCS(NFIT,6))    
      REFM=-BCS(NFIT,7)*VINT(2)**(BCS(NFIT,8)-1.)*  
     &SIN(0.5*PARU(1)*BCS(NFIT,8))  
      SIGMA=SIGP-ISIGN(1,MINT(11)*MINT(12))*SIGM    
      RHO=(REFP-ISIGN(1,MINT(11)*MINT(12))*REFM)/SIGMA  
    
C...Nuclear slope parameter B, curvature C: 
      NFIT=1    
      IF(MSTP(31).GE.4) NFIT=2  
      BP=BCB(NFIT,1)+BCB(NFIT,2)*LOG(VINT(2))+  
     &BCB(NFIT,3)*(LOG(VINT(2)))**2 
      BM=BCB(NFIT,4)+BCB(NFIT,5)*LOG(VINT(2))   
      B=BP-ISIGN(1,MINT(11)*MINT(12))*SIGM/SIGP*(BM-BP) 
      VINT(121)=B   
      C=-0.5*BCC(2)/BCC(3)*(1.-SQRT(MAX(0.,1.+4.*BCC(3)/BCC(2)**2*  
     &(1.E-03*VINT(1)-BCC(1)))))    
      VINT(122)=C   
    
C...Elastic scattering cross-section (fixed by sigma-tot, rho and B).   
      SIGEL=SIGMA**2*(1.+RHO**2)/(16.*PARU(1)*PARU(5)*B)    
    
C...Single diffractive scattering cross-section from Goulianos: 
      SIGSD=2.*0.68*(1.+36./VINT(2))*LOG(0.6+0.1*VINT(2))   
    
C...Double diffractive scattering cross-section (essentially fixed by   
C...sigma-sd and sigma-el). 
      SIGDD=SIGSD**2/(3.*SIGEL) 
    
C...Total non-elastic, non-diffractive cross-section.   
      SIGND=SIGMA-SIGDD-SIGSD-SIGEL 
    
C...Rescale for pions.  
      IF(IABS(MINT(11)).EQ.211.AND.IABS(MINT(12)).EQ.211) THEN  
        SIGMA=4./9.*SIGMA   
        SIGDD=4./9.*SIGDD   
        SIGSD=4./9.*SIGSD   
        SIGEL=4./9.*SIGEL   
        SIGND=4./9.*SIGND   
      ELSEIF(IABS(MINT(11)).EQ.211.OR.IABS(MINT(12)).EQ.211) THEN   
        SIGMA=2./3.*SIGMA   
        SIGDD=2./3.*SIGDD   
        SIGSD=2./3.*SIGSD   
        SIGEL=2./3.*SIGEL   
        SIGND=2./3.*SIGND   
      ENDIF 
    
C...Save cross-sections in common block PYPARA. 
      VINT(101)=SIGMA   
      VINT(102)=SIGEL   
      VINT(103)=SIGSD   
      VINT(104)=SIGDD   
      VINT(106)=SIGND   
      XSEC(95,1)=SIGND  
    
      RETURN    
      END