source: JEM-EUSO/esaf_cc_at_lal/packages/simulation/externals/slast/src/kernel/first_depth_nu.F @ 114

      SUBROUTINE FIRST_DEPTH_NU(Xprim)
      IMPLICIT NONE
#include "event.inc"
      DOUBLE PRECISION A_LO(4,2),A_NLO(4,2),G_LO(4,2),G_NLO(4,2)
      DOUBLE PRECISION NA,Aair,CROSS_SECTION,Xprim
      INTEGER I,J
      DATA A_LO/
     +     2.72D-3,1.44D-3,8.89D-3,3.95D-3,
     +     1.17D0, 1.16D0, 3.57D0, 2.85D0/
      DATA A_NLO/
     +     2.71D-3,1.52D-3,8.82D63,4.15D-3,
     +     2.06D0, 2.06D0, 6.50D0, 5.18D0/
      DATA G_LO/
     +     0.945,0.964,0.940,0.961,
     +     0.390,0.391,0.383,0.386/
      DATA G_NLO/
     +     0.945,0.963,0.941,0.960,
     +     0.360,0.360,0.349,0.353/
      DATA NA/6.02D23/,Aair/14.483/
*
      IF(TYPER.NE.1001.AND.TYPER.NE.1002) THEN
        WRITE(6,*) 'FIRST_DEPTH_NU: UNKNOWN NEUTRINO TYPE. STOP'
        STOP
      ENDIF
*
      IF(INTTYPE.NE.1.AND.INTTYPE.NE.2) THEN
        WRITE(6,*) 'FIRST_DEPTH_NU: UNKNOWN NEUTRINO INTERACTION 
     +       TYPE. STOP', INTTYPE
        STOP
      ENDIF
*
      IF(QCDCORR.NE.1.AND.QCDCORR.NE.2) THEN
        WRITE(6,*) 'FIRST_DEPTH_NU: UNKNOWN QCD CORRECTION. STOP'
        STOP
      ENDIF
*
      IF(TYPER.EQ.1001) THEN
        IF(INTTYPE.EQ.2) I = 1
        IF(INTTYPE.EQ.1) I = 3
      ELSEIF(TYPER.EQ.1002) THEN
        IF(INTTYPE.EQ.2) I = 2
        IF(INTTYPE.EQ.1) I = 4
      ENDIF
*     ... CROSS SECTION IN CM2 ...
      IF(EINT.LT.1.e13) J = 1
      IF(EINT.GE.1.e13) J = 2
      IF(QCDCORR.EQ.1.) THEN
        CROSS_SECTION = 1.D-36*A_LO(I,J)*(DBLE(EINT)/1.D9)**G_LO(I,J)
      ELSEIF(QCDCORR.EQ.2.) THEN
        CROSS_SECTION = 1.D-36*A_NLO(I,J)*(DBLE(EINT)/1.D9)**G_NLO(I,J)
      ENDIF
*
      Xprim = Aair/CROSS_SECTION/NA
      END