main-PYTHIA-lhef.f main-HERWIG-lhef.f: changes to deal with Z+1jet

LesHouches.f: typos corrected in comments and added printed info in 
              setcolour_rad when entering the error condition 

gen_radiation.f: Added saving of current random seeds
                 In gen_remnant, if pwhg_pt2().lt.rad_ptsqmin then set 
                 kn_csi = 0d0 and do not call set_rad_scales in this case
                 In gen_rad_isr and gen_rad_fsr, if born=0 return a 
                 Born-like event 
bbinit.f: introduced a randomsave and randomrestore around the subroutine
          gen , when computing the generation efficiency

sigcollsoft.f: deleted an Italian sentence

lhefwrite.f: save in the <extra-info-previous-event> the current random seeds

random.f: created subroutines savecurrentrandom, getcurrentrandom and
          printcurrentrandom

Z_plus_jet/Born_phsp.f: fixed kn_minmass



git-svn-id: svn://powhegbox.mib.infn.it/trunk/POWHEG-BOX@33 9e129b38-c2c0-4eec-9301-dc54fda404de

Author: Oleari

LesHouches.f

@@ -214,9 +214,9 @@ subroutine getnewcolor(newcolor)
       end
 
 c Given a vertex with 3 partons, the first parton with incoming colour
-c colin, the second and third partons with incoming flavours flavour fl2, fl3,
+c colin, the second and third partons with incoming flavours fl2, fl3,
 c it assigns the incoming colours of the second and third partons
-c colout2, colout3. The colour assignment is unambiguous is all cases, but in
+c colout2, colout3. The colour assignment is unambiguous in all cases, but in
 c the one where both fl2 and fl3 are gluons, where a 50% random choice is made
 c over the two possible colour connections.
       subroutine setcolour_rad(colin,fl2,fl3,colout2,colout3)
@@ -286,7 +286,10 @@ subroutine setcolour_rad(colin,fl2,fl3,colout2,colout3)
       return
  998  continue
       write(*,*)
-     #' setcolour_rad: Error: inconsistent colour flavour input'
+     #     ' Error in setcolour_rad: inconsistent colour flavour input'
+      write(*,*) 'colin[1:2] ',colin(1),' ',colin(2)
+      write(*,*) 'fl2, fl3 ',fl2,' ',fl3
+      write(*,*) 'newcolor ',newcolor
       call exit(1)
       end
 

Z_plus_jet/Born_phsp.f

@@ -105,9 +105,8 @@ subroutine born_phsp(xborn)
 c      call checkmomzero(nlegborn,kn_pborn)
 c      call checkmass(2,kn_pborn(0,3))
 
-c CAVEAT!!!
-c minimal final state mass (after init_couplings, Zmass is defined
-      kn_minmass=ph_Zmass
+c minimal final state mass 
+      kn_minmass=sqrt(ph_Zmass2low)
 
       end
 

Z_plus_jet/powheg.input

@@ -1,14 +1,19 @@
 numevts 100000    ! number of events to be generated
 ih1   1           ! hadron 1 (1 for protons, -1 for antiprotons)
 ih2   1           ! hadron 2 (1 for protons, -1 for antiprotons)
+! 131 cteq4m
+!  83 cteq4l
 ndns1 131         ! pdf set for hadron 1 (mlm numbering)
 ndns2 131         ! pdf set for hadron 2 (mlm numbering)
 ebeam1 7000d0     ! energy of beam 1
 ebeam2 7000d0     ! energy of beam 2
 
 ! To be set only if using LHA pdfs
-! lhans1           ! pdf set for hadron 1 (LHA numbering)
-! lhans2	   ! pdf set for hadron 2 (LHA numbering)	
+! 19150 cteq4m
+! 19170 cteq4l
+! 10050 cteq6m
+lhans1  10050         ! pdf set for hadron 1 (LHA numbering)
+lhans2  10050         ! pdf set for hadron 2 (LHA numbering)	
 ! To be set only if using different pdf sets for the two incoming hadrons
 ! QCDLambda5  0.25 ! for not equal pdf sets 
 

bbinit.f

@@ -173,11 +173,15 @@ subroutine bbinit
 c initialize gen for remnants
          call gen(sigremnant,ndiminteg,xgridrm,ymaxrm,xmmmrm,ifoldrm,
      #            0,mcalls,icalls,xx)
+c     save random number seeds
+         call randomsave
 c generate few events from remnants, just to determine the generation efficiency
          do j=1,min(powheginput('nubound'),100d0)
             call gen(sigremnant,ndiminteg,xgridrm,ymaxrm,xmmmrm,ifoldrm,
      #            1,mcalls,icalls,xx)
          enddo
+c     restore  random number seeds
+         call randomrestore
 c     print statistics
          call gen(sigremnant,ndiminteg,xgridrm,ymaxrm,xmmmrm,ifoldrm,
      #            3,mcalls,icalls,xx)

gen_radiation.f

@@ -11,6 +11,8 @@ subroutine pwhgevent
       integer mcalls,icalls
       real * 8 pwhg_pt2,pt2max_regular
       external pwhg_pt2,pt2max_regular
+c     store current random seeds. To be used to restart at problematic events
+      call savecurrentrandom
       if(random().gt.rad_sigrm/rad_sigtot) then
 c     generate underlying Born kinematics
          call gen_btilde(mcalls,icalls)
@@ -36,13 +38,28 @@ subroutine pwhgevent
 c iret=1: rem contribution (leftover from damping factor on R)
 c iret=2: reg contribution (real graphs without singular regions)
          call gen_remnant(iret)
+CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
+c     check if pt2 is greater than 
+         if (pwhg_pt2().lt.rad_ptsqmin) then
+            write(*,*) '****************************************'
+            write(*,*) 'WARNING in gen_remnant'
+            write(*,*) 'pwhg_pt2 < rad_ptsqmin ',
+     #           pwhg_pt2(),' < ',rad_ptsqmin
+            write(*,*) 'To generate this event, use the following seeds'
+            call printcurrentrandom
+            write(*,*) '****************************************'
+            kn_csi = 0d0                        
+         endif
+CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
          call add_azimuth
          if(iret.eq.1) then
+            if (kn_csi.ne.0d0) then
 c     set st_muren2 equal to pt2 for scalup value
-            rad_pt2max=pwhg_pt2()
-            call set_rad_scales(rad_pt2max)
+               rad_pt2max=pwhg_pt2()
+               call set_rad_scales(rad_pt2max)
+            endif
             call gen_leshouches
-c rad_type=2 for remnants
+c     rad_type=2 for remnants
             rad_type=2
          else
 c     Set st_muren2 for scalup value for regular contributions
@@ -411,6 +428,12 @@ subroutine gen_rad_isr(t)
       if(born.lt.0) then
          born=0
       endif
+      if(born.eq.0) then
+c bizarre situation that may arise when the scale gets so low
+c that some pdf vanish (typically heavy flavour pdf's)
+         t=-1
+         goto 3
+      endif
       kn_y=y
       kn_csi=1-x
       kn_azi=2*pi*random()
@@ -556,6 +579,12 @@ subroutine gen_rad_fsr(t)
       if(born.lt.0) then
          born=0
       endif
+      if(born.eq.0) then
+c bizarre situation that may arise when the scale gets so low
+c that some pdf vanish (typically heavy flavour pdf's)
+         t=-1
+         goto 3
+      endif
       kn_y=y
       kn_csi=csi
       kn_azi=2*pi*random()

lhefwrite.f

@@ -77,9 +77,13 @@ subroutine lhefwritextra(nlf)
       include 'include/pwhg_kn.h'
       include 'include/pwhg_flg.h'
       integer nlf
+      integer iran,n1ran,n2ran
       write(nlf,'(a)') '<extra-info-previous-event>'
       write(nlf,*) rad_kinreg,'      ! rad_kinreg'
       write(nlf,*) rad_type,'        ! rad_type'
+      call getcurrentrandom(iran,n1ran,n2ran)
+      write(nlf,*) iran,' ',n1ran,' ',n2ran,
+     #     "   ! previous event's random seeds "
       write(nlf,'(a)') '</extra-info-previous-event>'
       end
 

main-HERWIG-lhef.f

@@ -39,40 +39,40 @@ PROGRAM HWIGPR
       CALL HWEINI
 C---LOOP OVER EVENTS
       DO N=1,maxev
-C---INITIALISE EVENT
-      CALL HWUINE
+C---  INITIALISE EVENT
+         CALL HWUINE
 C---GENERATE HARD SUBPROCESS
-      CALL HWEPRO
-      if(nup.eq.0) goto 111
+         CALL HWEPRO
+         if(nup.eq.0) goto 111
 C---GENERATE PARTON CASCADES
-      CALL HWBGEN
+         CALL HWBGEN
 C---DO HEAVY OBJECT DECAYS
-      CALL HWDHOB
+         CALL HWDHOB
 C---DO CLUSTER FORMATION
-      CALL HWCFOR
+         CALL HWCFOR
 C---DO CLUSTER DECAYS
-      CALL HWCDEC
+         CALL HWCDEC
 C---DO UNSTABLE PARTICLE DECAYS
-      CALL HWDHAD
+         CALL HWDHAD
 C---DO HEAVY FLAVOUR HADRON DECAYS
-      CALL HWDHVY
+         CALL HWDHVY
 C---ADD SOFT UNDERLYING EVENT IF NEEDED
-      CALL HWMEVT
+         CALL HWMEVT
 C---FINISH EVENT
-      CALL HWUFNE    
+         CALL HWUFNE    
 C---USER'S EVENT ANALYSIS
-      CALL HWANAL
-      if (mod(nevhep,20000).eq.0) then
-         write(*,*) "# of events processed =",nevhep
-         call hwaend
-      endif
+         CALL HWANAL
+         if (mod(nevhep,20000).eq.0) then
+            write(*,*) "# of events processed =",nevhep
+            call hwaend
+         endif
       ENDDO
  111  continue
-C---TERMINATE ELEMENTARY PROCESS
+C---  TERMINATE ELEMENTARY PROCESS
       CALL HWEFIN
-C---USER'S TERMINAL CALCULATIONS
+C---  USER'S TERMINAL CALCULATIONS
       CALL HWAEND
-
+      
 c      call newunit(iun)
 c      open(unit=iun,file='HERWIGcounters.dat',status='unknown')
 c      call printcnt(iun)
@@ -116,6 +116,7 @@ subroutine hwabeg
       call init_hist
       end
 
+
       subroutine hwaend
       character * 20 pwgprefix
       integer lprefix

main-PYTHIA-lhef.f

@@ -93,11 +93,13 @@ program main_pythia
          call pyhepc(1)
          nevhep=temp
 C     Print out the event record
-         IF (IEV.le.1) THEN 
+         IF (IEV.le.6) THEN 
 c     list the event
-c     CALL PYLIST(7) ! print the HEPEUP common block
-c     CALL PYLIST(5) ! print the HEPEVT common block
+c            CALL PYLIST(7)      ! print the HEPEUP common block
+c            CALL PYLIST(5)      ! print the HEPEVT common block
+
             CALL PYLIST(5)      ! print the event
+
 c     call PYLIST(1) ! as PYLIST(2) but with less information
          ENDIF
 

pwhg_init.f

@@ -11,7 +11,7 @@ subroutine pwhginit
       external powheginput
       integer i1,n1,n2
       call init_flsttag
-      flg_debug=.false.
+      flg_debug=.true.
       if(powheginput("#flg_debug").eq.1) flg_debug=.true.
 c     Set to true to remember and use identical values of the computed 
 c     amplitudes, for Born, real and virtual contributions

random.f

@@ -58,3 +58,29 @@ subroutine setrandom(i1,n1,n2)
          call resetrandom
       endif
       end
+
+
+      subroutine savecurrentrandom
+      implicit none
+      integer ipar(3)
+      common/crandom/ipar
+      call rm48ut(ipar(1),ipar(2),ipar(3))
+      end
+
+
+      subroutine getcurrentrandom(i1,n1,n2)
+      implicit none
+      integer i1,n1,n2
+      integer ipar(3)
+      common/crandom/ipar
+      i1 = ipar(1)
+      n1 = ipar(2)
+      n2 = ipar(3)
+      end
+
+      subroutine printcurrentrandom
+      implicit none
+      integer ipar(3)
+      common/crandom/ipar
+      write(*,*) 'Random number seeds: ',ipar(1),ipar(2), ipar(3)
+      end

sigcollsoft.f

@@ -470,9 +470,6 @@ subroutine softalr(alr,em,y,res)
 
 
 
-c Commentare sull'uso delle funzioni qui sotto
-
-
       subroutine softbtl(r0)
 c blegs:        integer, number of legs of born
 c bflav(nlegs): integer, flavours of the incoming partons, according to PDG conventions,