Merge lp:~maddevelopers/mg5amcnlo/enhance_factor_fix into lp:~maddevelopers/mg5amcnlo/3.0.2

[Rikkert Frederix]

Fix for the wrong renormalisation scale in the multi-channel enhancement factor.

[lp:~maddevelopers/mg5amcnlo/enhance_factor_fix]

969. By Rikkert Frederix on 2019-08-29

small fix

[Hua-Sheng Shao (erdissshaw)]

The fix is good for me and the previous problematic process was tested to be correct both at LO and NLO.

review: Approve

[marco zaro (marco-zaro)]

The changes in the code look all fine. I have not checked the results, as it has been already done by HuaSheng

review: Approve

=== modified file 'Template/NLO/SubProcesses/driver_mintFO.f'
--- Template/NLO/SubProcesses/driver_mintFO.f	2019-08-15 13:15:21 +0000
+++ Template/NLO/SubProcesses/driver_mintFO.f	2019-08-29 10:00:13 +0000
@@ -427,6 +427,7 @@
          pass_cuts_check=.true.
          if (ickkw.eq.3) call set_FxFx_scale(1,p1_cnt(0,1,0))
          call set_alphaS(p1_cnt(0,1,0))
+         call include_multichannel_enhance(1)
          if (abrv(1:2).ne.'vi') then
             call compute_born
          endif
@@ -472,6 +473,7 @@
             call set_cms_stuff(izero)
             if (ickkw.eq.3) call set_FxFx_scale(2,p1_cnt(0,1,0))
             call set_alphaS(p1_cnt(0,1,0))
+            call include_multichannel_enhance(3)
             call compute_soft_counter_term(0d0)
             call set_cms_stuff(ione)
             call compute_collinear_counter_term(0d0)
@@ -483,6 +485,7 @@
             call set_cms_stuff(mohdr)
             if (ickkw.eq.3) call set_FxFx_scale(3,p)
             call set_alphaS(p)
+            call include_multichannel_enhance(2)
             call compute_real_emission(p,1d0)
          endif
       enddo
 
=== modified file 'Template/NLO/SubProcesses/driver_mintMC.f'
--- Template/NLO/SubProcesses/driver_mintMC.f	2019-08-15 13:57:46 +0000
+++ Template/NLO/SubProcesses/driver_mintMC.f	2019-08-29 10:00:13 +0000
@@ -747,6 +747,7 @@
             pass_cuts_check=.true.
             if (ickkw.eq.3) call set_FxFx_scale(1,p1_cnt(0,1,0))
             call set_alphaS(p1_cnt(0,1,0))
+            call include_multichannel_enhance(1)
             if (abrv(1:2).ne.'vi') then
                call compute_born
             endif
@@ -827,6 +828,7 @@
                   call set_cms_stuff(mohdr)
                   if (ickkw.eq.3) call set_FxFx_scale(-3,p)
                   call set_alphaS(p)
+                  call include_multichannel_enhance(4)
                   call compute_MC_subt_term(p,gfactsf,gfactcl,probne)
                else
 c For UNLOPS all real-emission contributions need to be added to the
@@ -841,6 +843,7 @@
                call set_cms_stuff(izero)
                if (ickkw.eq.3) call set_FxFx_scale(-2,p1_cnt(0,1,0))
                call set_alphaS(p1_cnt(0,1,0))
+               call include_multichannel_enhance(3)
                replace_MC_subt=(1d0-gfactsf)*probne
                call compute_soft_counter_term(replace_MC_subt)
                call set_cms_stuff(ione)
@@ -856,6 +859,7 @@
                call set_cms_stuff(mohdr)
                if (ickkw.eq.3) call set_FxFx_scale(-3,p)
                call set_alphaS(p)
+               call include_multichannel_enhance(2)
                sudakov_damp=probne
                call compute_real_emission(p,sudakov_damp)
             endif
 
=== modified file 'Template/NLO/SubProcesses/fks_singular.f'
--- Template/NLO/SubProcesses/fks_singular.f	2019-08-28 11:29:57 +0000
+++ Template/NLO/SubProcesses/fks_singular.f	2019-08-29 10:00:13 +0000
@@ -979,18 +979,11 @@
       include 'run.inc'
       include 'genps.inc'
       include 'timing_variables.inc'
-      double precision pi,vegas_wgt,enhance,xnoborn_cnt,xtot
-     $     ,bpower,cpower,tiny
-      data xnoborn_cnt /0d0/
-      integer inoborn_cnt,i
-      data inoborn_cnt /0/
-      double precision wgt_c
+      double precision pi,vegas_wgt
+      integer i
       logical firsttime
       data firsttime /.true./
       parameter (pi=3.1415926535897932385d0)
-      parameter (tiny=1d-6)
-      double precision p_born(0:3,nexternal-1)
-      common/pborn/    p_born
       double precision    p1_cnt(0:3,nexternal,-2:2),wgt_cnt(-2:2)
      $                    ,pswgt_cnt(-2:2),jac_cnt(-2:2)
       common/counterevnts/p1_cnt,wgt_cnt,pswgt_cnt,jac_cnt
@@ -1007,12 +1000,15 @@
       integer                  ngluons,nquarks(-6:6),nphotons
       common/numberofparticles/fkssymmetryfactor,fkssymmetryfactorBorn,
      &                  fkssymmetryfactorDeg,ngluons,nquarks,nphotons
+<<<<<<< TREE
       integer            mapconfig(0:lmaxconfigs), this_config
       common/to_mconfigs/mapconfig,                this_config
       Double Precision amp2(ngraphs), jamp2(0:ncolor)
       common/to_amps/  amp2,          jamp2
       double precision   diagramsymmetryfactor
       common /dsymfactor/diagramsymmetryfactor
+=======
+>>>>>>> MERGE-SOURCE
       double precision      f_b,f_nb
       common /factor_nbody/ f_b,f_nb
       integer iappl
@@ -1039,6 +1035,7 @@
          if (fixed_order) call initplot
          firsttime=.false.
       endif
+<<<<<<< TREE
 c Compute the multi-channel enhancement factor 'enhance'.
       enhance=1.d0
       if (p_born(0,1).gt.0d0) then
@@ -1072,105 +1069,72 @@
             enhance=0d0
          endif
       endif
+=======
+>>>>>>> MERGE-SOURCE
       call set_cms_stuff(0)
 c f_* multiplication factors for Born and nbody
       f_b=jac_cnt(0)*xinorm_ev/(min(xiimax_ev,xiBSVcut_used)*shat/(16
-     $     *pi**2))*enhance*fkssymmetryfactorBorn*vegas_wgt
+     $     *pi**2))*fkssymmetryfactorBorn*vegas_wgt
       f_nb=f_b
       call cpu_time(tAfter)
       tf_nb=tf_nb+(tAfter-tBefore)
       return
       end
 
-      subroutine compute_prefactors_n1body(vegas_wgt,jac_ev)
-c Compute all relevant prefactors for the real emission and counter
-c terms.
+
+      subroutine include_multichannel_enhance(imode)
       implicit none
       include 'nexternal.inc'
       include 'run.inc'
       include 'genps.inc'
-      include 'fks_powers.inc'
-      include 'coupl.inc'
       include 'timing_variables.inc'
-      double precision vegas_wgt,enhance,xnoborn_cnt,xtot
-     &     ,prefact,prefact_cnt_ssc,prefact_deg,prefact_c,prefact_coll
-     &     ,jac_ev,pi,prefact_cnt_ssc_c,prefact_coll_c,prefact_deg_slxi
-     &     ,prefact_deg_sxi,zero,enhance_real
-      parameter (pi=3.1415926535897932385d0, zero=0d0)
+      double precision xnoborn_cnt,xtot,wgt_c,enhance,enhance_real
+     $     ,pas(0:3,nexternal)
       data xnoborn_cnt /0d0/
-      integer inoborn_cnt,i
+      integer inoborn_cnt,i,imode
       data inoborn_cnt /0/
-      double precision wgt_c
       double precision p_born(0:3,nexternal-1)
       common/pborn/    p_born
       double precision p_born_ev(0:3,nexternal-1)
-      common/pborn_ev/p_born_ev
+      common/pborn_ev/ p_born_ev
+      double precision p_ev(0:3,nexternal)
+      common/pev/      p_ev
       double precision    p1_cnt(0:3,nexternal,-2:2),wgt_cnt(-2:2)
      $                    ,pswgt_cnt(-2:2),jac_cnt(-2:2)
       common/counterevnts/p1_cnt,wgt_cnt,pswgt_cnt,jac_cnt
-      double precision    xi_i_fks_ev,y_ij_fks_ev
-      double precision    p_i_fks_ev(0:3),p_i_fks_cnt(0:3,-2:2)
-      common/fksvariables/xi_i_fks_ev,y_ij_fks_ev,p_i_fks_ev,p_i_fks_cnt
-      integer            i_fks,j_fks
-      common/fks_indices/i_fks,j_fks
-      double precision   xi_i_fks_cnt(-2:2)
-      common /cxiifkscnt/xi_i_fks_cnt
-      double precision  xinorm_ev
-      common /cxinormev/xinorm_ev
-      double precision  xiimax_ev
-      common /cxiimaxev/xiimax_ev
-      double precision   xiimax_cnt(-2:2)
-      common /cxiimaxcnt/xiimax_cnt
-      double precision   xinorm_cnt(-2:2)
-      common /cxinormcnt/xinorm_cnt
-      double precision    delta_used
-      common /cdelta_used/delta_used
-      double precision    xicut_used
-      common /cxicut_used/xicut_used
-      double precision     xiScut_used,xiBSVcut_used
-      common /cxiScut_used/xiScut_used,xiBSVcut_used
-      double precision        ybst_til_tolab,ybst_til_tocm,sqrtshat,shat
-      common/parton_cms_stuff/ybst_til_tolab,ybst_til_tocm,sqrtshat,shat
-      double precision         fkssymmetryfactor,fkssymmetryfactorBorn,
-     &                         fkssymmetryfactorDeg
-      integer ngluons,nquarks(-6:6),nphotons
-      common/numberofparticles/fkssymmetryfactor,fkssymmetryfactorBorn,
-     &                  fkssymmetryfactorDeg,ngluons,nquarks,nphotons
       integer            mapconfig(0:lmaxconfigs), iconfig
       common/to_mconfigs/mapconfig,                iconfig
       Double Precision amp2(ngraphs), jamp2(0:ncolor)
       common/to_amps/  amp2,          jamp2
       double precision   diagramsymmetryfactor
       common /dsymfactor/diagramsymmetryfactor
-      logical nocntevents
-      common/cnocntevents/nocntevents
+      double precision      f_b,f_nb
+      common /factor_nbody/ f_b,f_nb
+      double precision     f_r,f_s,f_c,f_dc,f_sc,f_dsc(4)
+      common/factor_n1body/f_r,f_s,f_c,f_dc,f_sc,f_dsc
+      double precision           f_s_MC_S,f_s_MC_H,f_c_MC_S,f_c_MC_H
+     $     ,f_sc_MC_S,f_sc_MC_H,f_MC_S,f_MC_H
+      common/factor_n1body_NLOPS/f_s_MC_S,f_s_MC_H,f_c_MC_S,f_c_MC_H
+     $     ,f_sc_MC_S,f_sc_MC_H,f_MC_S,f_MC_H
+      double precision f_dis_d,f_dis_p,f_dis_l
+      common/factor_dis/f_dis_d,f_dis_p,f_dis_l
       integer igranny,iaunt
       logical granny_chain(-nexternal:nexternal),granny_is_res
      &     ,granny_chain_real_final(-nexternal:nexternal)
       common /c_granny_res/igranny,iaunt,granny_is_res,granny_chain
      &     ,granny_chain_real_final
-      double precision     f_r,f_s,f_c,f_dc,f_sc,f_dsc(4)
-      common/factor_n1body/f_r,f_s,f_c,f_dc,f_sc,f_dsc
-      double precision           f_s_MC_S,f_s_MC_H,f_c_MC_S,f_c_MC_H
-     $     ,f_sc_MC_S,f_sc_MC_H,f_MC_S,f_MC_H
-      common/factor_n1body_NLOPS/f_s_MC_S,f_s_MC_H,f_c_MC_S,f_c_MC_H
-     $     ,f_sc_MC_S,f_sc_MC_H,f_MC_S,f_MC_H
-      ! prefactors for the DIS scheme
-      double precision prefact_dis_d,prefact_dis_p,prefact_dis_l
-      double precision f_dis_d,f_dis_p,f_dis_l
-      common/factor_dis/f_dis_d,f_dis_p,f_dis_l
       logical calculatedBorn
       common/ccalculatedBorn/calculatedBorn
-      double precision pmass(nexternal)
-      include 'pmass.inc'
+
       call cpu_time(tBefore)
+
+c Compute the multi-channel enhancement factor 'enhance'.
       enhance=1.d0
       if (p_born(0,1).gt.0d0) then
          call sborn(p_born,wgt_c)
       elseif(p_born(0,1).lt.0d0)then
          enhance=0d0
       endif
-c Compute the multi-channel enhancement factor 'enhance'.
       if (enhance.eq.0d0)then
          xnoborn_cnt=xnoborn_cnt+1.d0
          if(log10(xnoborn_cnt).gt.inoborn_cnt)then
@@ -1181,9 +1145,9 @@
       else
          xtot=0d0
          if (mapconfig(0).eq.0) then
-            write (*,*) 'Fatal error in compute_prefactor_n1body,'/
-     &           /' no Born diagrams ',mapconfig
-     &           ,'. Check bornfromreal.inc'
+            write (*,*) 'Fatal error in compute_prefactor_nbody:'/
+     &           /' no Born diagrams ',mapconfig,
+     &           '. Check bornfromreal.inc'
             write (*,*) 'Is fks_singular compiled correctly?'
             stop 1
          endif
@@ -1198,11 +1162,17 @@
          endif
       endif
 
+c In the case there is the special phase-space mapping for resonances,
+c use the Born computed with those as the mapping.
       enhance_real=1.d0
-      if (granny_is_res) then
+      if (granny_is_res .and. imode.eq.2) then
          if (p_born_ev(0,1).gt.0d0) then
             calculatedBorn=.false.
+            pas(0:3,nexternal)=0d0
+            pas(0:3,1:nexternal-1)=p_born_ev(0:3,1:nexternal-1)
+            call set_alphas(pas)
             call sborn(p_born_ev,wgt_c)
+            call set_alphas(p_ev)
             calculatedBorn=.false.
          elseif(p_born_ev(0,1).lt.0d0)then
             if (enhance.ne.0d0) then 
@@ -1242,18 +1212,114 @@
          enhance_real=enhance
       endif
 
+      if (imode.eq.1) then
+         f_b=      f_b      *enhance
+         f_nb=     f_nb     *enhance
+      elseif(imode.eq.2) then
+         f_r=      f_r      *enhance_real
+      elseif(imode.eq.4) then
+         f_MC_S=   f_MC_S   *enhance
+         f_MC_H=   f_MC_H   *enhance
+      elseif(imode.eq.3) then
+         f_s=      f_s      *enhance
+         f_s_MC_S= f_s_MC_S *enhance
+         f_S_MC_H= f_S_MC_H *enhance
+         f_c=      f_c      *enhance
+         f_c_MC_S= f_c_MC_S *enhance
+         f_c_MC_H= f_c_MC_H *enhance
+         f_dc=     f_dc     *enhance
+         f_sc=     f_sc     *enhance
+         f_sc_MC_S=f_sc_MC_S*enhance
+         f_sc_MC_H=f_sc_MC_H*enhance
+         f_dsc(1)= f_dsc(1) *enhance
+         f_dsc(2)= f_dsc(2) *enhance
+         f_dsc(3)= f_dsc(3) *enhance
+         f_dsc(4)= f_dsc(4) *enhance
+         f_dis_d=  f_dis_d  *enhance
+         f_dis_p=  f_dis_p  *enhance
+         f_dis_l=  f_dis_l  *enhance
+      endif
+      call cpu_time(tAfter)
+      tf_nb=tf_nb+(tAfter-tBefore)
+
+      return
+      end
+      
+
+      subroutine compute_prefactors_n1body(vegas_wgt,jac_ev)
+c Compute all relevant prefactors for the real emission and counter
+c terms.
+      implicit none
+      include 'nexternal.inc'
+      include 'run.inc'
+      include 'genps.inc'
+      include 'fks_powers.inc'
+      include 'coupl.inc'
+      include 'timing_variables.inc'
+      double precision vegas_wgt,prefact,prefact_cnt_ssc,prefact_deg
+     $     ,prefact_c,prefact_coll,jac_ev,pi,prefact_cnt_ssc_c
+     $     ,prefact_coll_c,prefact_deg_slxi,prefact_deg_sxi,zero
+      integer i
+      parameter (pi=3.1415926535897932385d0, ZERO=0d0)
+      double precision    p1_cnt(0:3,nexternal,-2:2),wgt_cnt(-2:2)
+     $                    ,pswgt_cnt(-2:2),jac_cnt(-2:2)
+      common/counterevnts/p1_cnt,wgt_cnt,pswgt_cnt,jac_cnt
+      double precision    xi_i_fks_ev,y_ij_fks_ev
+      double precision    p_i_fks_ev(0:3),p_i_fks_cnt(0:3,-2:2)
+      common/fksvariables/xi_i_fks_ev,y_ij_fks_ev,p_i_fks_ev,p_i_fks_cnt
+      integer            i_fks,j_fks
+      common/fks_indices/i_fks,j_fks
+      double precision   xi_i_fks_cnt(-2:2)
+      common /cxiifkscnt/xi_i_fks_cnt
+      double precision  xinorm_ev
+      common /cxinormev/xinorm_ev
+      double precision  xiimax_ev
+      common /cxiimaxev/xiimax_ev
+      double precision   xiimax_cnt(-2:2)
+      common /cxiimaxcnt/xiimax_cnt
+      double precision   xinorm_cnt(-2:2)
+      common /cxinormcnt/xinorm_cnt
+      double precision    delta_used
+      common /cdelta_used/delta_used
+      double precision    xicut_used
+      common /cxicut_used/xicut_used
+      double precision     xiScut_used,xiBSVcut_used
+      common /cxiScut_used/xiScut_used,xiBSVcut_used
+      double precision        ybst_til_tolab,ybst_til_tocm,sqrtshat,shat
+      common/parton_cms_stuff/ybst_til_tolab,ybst_til_tocm,sqrtshat,shat
+      double precision         fkssymmetryfactor,fkssymmetryfactorBorn,
+     &                         fkssymmetryfactorDeg
+      integer ngluons,nquarks(-6:6),nphotons
+      common/numberofparticles/fkssymmetryfactor,fkssymmetryfactorBorn,
+     &                  fkssymmetryfactorDeg,ngluons,nquarks,nphotons
+      logical nocntevents
+      common/cnocntevents/nocntevents
+      double precision     f_r,f_s,f_c,f_dc,f_sc,f_dsc(4)
+      common/factor_n1body/f_r,f_s,f_c,f_dc,f_sc,f_dsc
+      double precision           f_s_MC_S,f_s_MC_H,f_c_MC_S,f_c_MC_H
+     $     ,f_sc_MC_S,f_sc_MC_H,f_MC_S,f_MC_H
+      common/factor_n1body_NLOPS/f_s_MC_S,f_s_MC_H,f_c_MC_S,f_c_MC_H
+     $     ,f_sc_MC_S,f_sc_MC_H,f_MC_S,f_MC_H
+      ! prefactors for the DIS scheme
+      double precision prefact_dis_d,prefact_dis_p,prefact_dis_l
+      double precision f_dis_d,f_dis_p,f_dis_l
+      common/factor_dis/f_dis_d,f_dis_p,f_dis_l
+      double precision pmass(nexternal)
+      include 'pmass.inc'
+      call cpu_time(tBefore)
+
 c f_* multiplication factors for real-emission, soft counter, ... etc.       
       prefact=xinorm_ev/xi_i_fks_ev/(1-y_ij_fks_ev)
-      f_r=prefact*jac_ev*enhance_real*fkssymmetryfactor*vegas_wgt
+      f_r=prefact*jac_ev*fkssymmetryfactor*vegas_wgt
       f_MC_S=f_r
       f_MC_H=f_r
       if (.not.nocntevents) then
          prefact_cnt_ssc=xinorm_ev/min(xiimax_ev,xiScut_used)*
      $        log(xicut_used/min(xiimax_ev,xiScut_used))/(1
      $        -y_ij_fks_ev)
-         f_s=(prefact+prefact_cnt_ssc)*jac_cnt(0)*enhance
+         f_s=(prefact+prefact_cnt_ssc)*jac_cnt(0)
      $        *fkssymmetryfactor*vegas_wgt
-         f_s_MC_S=prefact*jac_cnt(0)*enhance
+         f_s_MC_S=prefact*jac_cnt(0)
      $        *fkssymmetryfactor*vegas_wgt
          f_s_MC_H=f_s_MC_S
 
@@ -1264,9 +1330,9 @@
             prefact_coll=xinorm_cnt(1)/xi_i_fks_cnt(1)*log(delta_used
      $           /deltaS)/deltaS
             f_c=(prefact_c+prefact_coll)*jac_cnt(1)
-     $           *enhance*fkssymmetryfactor*vegas_wgt
+     $           *fkssymmetryfactor*vegas_wgt
             f_c_MC_S=prefact_c*jac_cnt(1)
-     $           *enhance*fkssymmetryfactor*vegas_wgt
+     $           *fkssymmetryfactor*vegas_wgt
             f_c_MC_H=f_c_MC_S
 
             call set_cms_stuff(1)
@@ -1277,13 +1343,13 @@
             prefact_coll_c=xinorm_cnt(1)/min(xiimax_cnt(1),xiScut_used)
      $           *log(xicut_used/min(xiimax_cnt(1),xiScut_used))
      $           *log(delta_used/deltaS)/deltaS
-            f_dc=jac_cnt(1)*prefact_deg/(shat/(32*pi**2))*enhance
+            f_dc=jac_cnt(1)*prefact_deg/(shat/(32*pi**2))
      $           *fkssymmetryfactorDeg*vegas_wgt
             f_sc=(prefact_c+prefact_coll+prefact_cnt_ssc_c
-     &           +prefact_coll_c)*jac_cnt(2)*enhance
+     &           +prefact_coll_c)*jac_cnt(2)
      &           *fkssymmetryfactorDeg*vegas_wgt
             f_sc_MC_S=prefact_c*jac_cnt(2)
-     $           *enhance*fkssymmetryfactor*vegas_wgt
+     $           *fkssymmetryfactor*vegas_wgt
             f_sc_MC_H=f_sc_MC_S
 
             call set_cms_stuff(2)
@@ -1294,24 +1360,24 @@
      &           ,xiScut_used)*( log(xicut_used)**2
      &           -log(min(xiimax_cnt(1),xiScut_used))**2 )*1/(2.d0
      &           *deltaS)
-            f_dsc(1)=prefact_deg*jac_cnt(2)/(shat/(32*pi**2))*enhance
+            f_dsc(1)=prefact_deg*jac_cnt(2)/(shat/(32*pi**2))
      &           *fkssymmetryfactorDeg*vegas_wgt
             f_dsc(2)=prefact_deg_sxi*jac_cnt(2)/(shat/(32*pi**2))
-     &           *enhance*fkssymmetryfactorDeg*vegas_wgt
+     &           *fkssymmetryfactorDeg*vegas_wgt
             f_dsc(3)=prefact_deg_slxi*jac_cnt(2)/(shat/(32*pi**2))
-     &           *enhance*fkssymmetryfactorDeg*vegas_wgt
+     &           *fkssymmetryfactorDeg*vegas_wgt
             f_dsc(4)=( prefact_deg+prefact_deg_sxi )*jac_cnt(2)/(shat
-     &           /(32*pi**2))*enhance*fkssymmetryfactorDeg
+     &           /(32*pi**2))*fkssymmetryfactorDeg
      &           *vegas_wgt
             ! prefactor for the DIS scheme
             prefact_dis_d=xinorm_cnt(1)/xiScut_used/deltaS
-            f_dis_d=prefact_dis_d*jac_cnt(2)/(shat/(32*pi**2))*enhance
+            f_dis_d=prefact_dis_d*jac_cnt(2)/(shat/(32*pi**2))
      &           *fkssymmetryfactorDeg*vegas_wgt
             prefact_dis_p=xinorm_cnt(1)*dlog(xiScut_used)/xiScut_used/deltaS
-            f_dis_p=prefact_dis_p*jac_cnt(2)/(shat/(32*pi**2))*enhance
+            f_dis_p=prefact_dis_p*jac_cnt(2)/(shat/(32*pi**2))
      &           *fkssymmetryfactorDeg*vegas_wgt
             prefact_dis_l=xinorm_cnt(1)*dlog(xiScut_used)**2/2d0/xiScut_used/deltaS
-            f_dis_l=prefact_dis_l*jac_cnt(2)/(shat/(32*pi**2))*enhance
+            f_dis_l=prefact_dis_l*jac_cnt(2)/(shat/(32*pi**2))
      &           *fkssymmetryfactorDeg*vegas_wgt
          else
             f_c=0d0