Include neutron beams, activated with ih1/ih2 = 2

git-svn-id: svn://powhegbox.mib.infn.it/trunk/POWHEG-BOX@2264 9e129b38-c2c0-4eec-9301-dc54fda404de

Author: nason

Dijet/Version-pre2-1/pwhg_init.f

@@ -103,8 +103,24 @@ subroutine pwhginit
 c proton:
       ebmup(1)=kn_beams(0,1)
       ebmup(2)=kn_beams(0,2)
-      idbmup(1) = 2212*pdf_ih1
-      idbmup(2) = 2212*pdf_ih2
+      if(abs(pdf_ih1).eq.1) then
+c proton and antiproton
+        idbmup(1) = 2212*pdf_ih1
+      elseif(abs(pdf_ih1).eq.2) then
+c neutron and antineutron
+        idbmup(1) = 2112*pdf_ih1/abs(pdf_ih1)
+      else
+         write(*,*) ' unimplemented hadron 1 ',pdf_ih1
+         call pwhg_exit(-1)
+      endif
+      if(abs(pdf_ih2).eq.1) then
+        idbmup(2) = 2212*pdf_ih2
+      elseif(abs(pdf_ih2).eq.2) then
+        idbmup(2) = 2112*pdf_ih2/abs(pdf_ih2)
+      else
+         write(*,*) ' unimplemented hadron 2 ',pdf_ih2
+         call pwhg_exit(-1)
+      endif
 c pdf group; negative to use internal herwig pdf's for showering
       pdfgup(1)=-1
       pdfgup(2)=-1

Dijet/doublefsr/pwhg_init.f

@@ -93,8 +93,24 @@ subroutine pwhginit
 c proton:
       ebmup(1)=kn_beams(0,1)
       ebmup(2)=kn_beams(0,2)
-      idbmup(1) = 2212*pdf_ih1
-      idbmup(2) = 2212*pdf_ih2
+      if(abs(pdf_ih1).eq.1) then
+c proton and antiproton
+        idbmup(1) = 2212*pdf_ih1
+      elseif(abs(pdf_ih1).eq.2) then
+c neutron and antineutron
+        idbmup(1) = 2112*pdf_ih1/abs(pdf_ih1)
+      else
+         write(*,*) ' unimplemented hadron 1 ',pdf_ih1
+         call pwhg_exit(-1)
+      endif
+      if(abs(pdf_ih2).eq.1) then
+        idbmup(2) = 2212*pdf_ih2
+      elseif(abs(pdf_ih2).eq.2) then
+        idbmup(2) = 2112*pdf_ih2/abs(pdf_ih2)
+      else
+         write(*,*) ' unimplemented hadron 2 ',pdf_ih2
+         call pwhg_exit(-1)
+      endif
 c pdf group; negative to use internal herwig pdf's for showering
       pdfgup(1)=-1
       pdfgup(2)=-1

ReweightingStuff/pwhg_init.f

@@ -93,8 +93,24 @@ subroutine pwhginit
 c proton:
       ebmup(1)=kn_beams(0,1)
       ebmup(2)=kn_beams(0,2)
-      idbmup(1) = 2212*pdf_ih1
-      idbmup(2) = 2212*pdf_ih2
+      if(abs(pdf_ih1).eq.1) then
+c proton and antiproton
+        idbmup(1) = 2212*pdf_ih1
+      elseif(abs(pdf_ih1).eq.2) then
+c neutron and antineutron
+        idbmup(1) = 2112*pdf_ih1/abs(pdf_ih1)
+      else
+         write(*,*) ' unimplemented hadron 1 ',pdf_ih1
+         call pwhg_exit(-1)
+      endif
+      if(abs(pdf_ih2).eq.1) then
+        idbmup(2) = 2212*pdf_ih2
+      elseif(abs(pdf_ih2).eq.2) then
+        idbmup(2) = 2112*pdf_ih2/abs(pdf_ih2)
+      else
+         write(*,*) ' unimplemented hadron 2 ',pdf_ih2
+         call pwhg_exit(-1)
+      endif
 c pdf group; negative to use internal herwig pdf's for showering
       pdfgup(1)=-1
       pdfgup(2)=-1

VBF_Wp_Wm/boxfiles-pre2-1/pwhg_init.f

@@ -93,8 +93,24 @@ subroutine pwhginit
 c proton:
       ebmup(1)=kn_beams(0,1)
       ebmup(2)=kn_beams(0,2)
-      idbmup(1) = 2212*pdf_ih1
-      idbmup(2) = 2212*pdf_ih2
+      if(abs(pdf_ih1).eq.1) then
+c proton and antiproton
+        idbmup(1) = 2212*pdf_ih1
+      elseif(abs(pdf_ih1).eq.2) then
+c neutron and antineutron
+        idbmup(1) = 2112*pdf_ih1/abs(pdf_ih1)
+      else
+         write(*,*) ' unimplemented hadron 1 ',pdf_ih1
+         call pwhg_exit(-1)
+      endif
+      if(abs(pdf_ih2).eq.1) then
+        idbmup(2) = 2212*pdf_ih2
+      elseif(abs(pdf_ih2).eq.2) then
+        idbmup(2) = 2112*pdf_ih2/abs(pdf_ih2)
+      else
+         write(*,*) ' unimplemented hadron 2 ',pdf_ih2
+         call pwhg_exit(-1)
+      endif
 c pdf group; negative to use internal herwig pdf's for showering
       pdfgup(1)=-1
       pdfgup(2)=-1

Version-pre2-1/pwhg_init.f

@@ -117,8 +117,24 @@ subroutine pwhginit
 c proton:
       ebmup(1)=kn_beams(0,1)
       ebmup(2)=kn_beams(0,2)
-      idbmup(1) = 2212*pdf_ih1
-      idbmup(2) = 2212*pdf_ih2
+      if(abs(pdf_ih1).eq.1) then
+c proton and antiproton
+        idbmup(1) = 2212*pdf_ih1
+      elseif(abs(pdf_ih1).eq.2) then
+c neutron and antineutron
+        idbmup(1) = 2112*pdf_ih1/abs(pdf_ih1)
+      else
+         write(*,*) ' unimplemented hadron 1 ',pdf_ih1
+         call pwhg_exit(-1)
+      endif
+      if(abs(pdf_ih2).eq.1) then
+        idbmup(2) = 2212*pdf_ih2
+      elseif(abs(pdf_ih2).eq.2) then
+        idbmup(2) = 2112*pdf_ih2/abs(pdf_ih2)
+      else
+         write(*,*) ' unimplemented hadron 2 ',pdf_ih2
+         call pwhg_exit(-1)
+      endif
 c pdf group; negative to use internal herwig pdf's for showering
       pdfgup(1)=-1
       pdfgup(2)=-1

lhapdfif.f

@@ -143,6 +143,23 @@ subroutine genericpdf(ndns,ih,xmu2,x,fx)
             fx(j)=fx(-j)
             fx(-j)=tmp
          enddo
+c Do the neutron (Suggested by Jan Kretzschmar, 17/4/2013)
+      elseif(abs(ih).eq.2) then
+c 2 is neutron: exchange u and d pdfs
+         tmp=fx(1)
+         fx(1)=fx(2)
+         fx(2)=tmp
+         tmp=fx(-1)
+         fx(-1)=fx(-2)
+         fx(-2)=tmp
+         if(ih.eq.-2) then
+c -2 is anti-neutron: exchange quarks and anti-quarks, then u and d pdfs
+            do j=1,6
+               tmp=fx(j)
+               fx(j)=fx(-j)
+               fx(-j)=tmp
+            enddo
+         endif
       elseif(ih.eq.3) then
          tmp=fx(1)
          fx(1)=fx(-1)

pwhg_init.f

@@ -88,8 +88,24 @@ subroutine pwhginit
 c proton:
       ebmup(1)=kn_beams(0,1)
       ebmup(2)=kn_beams(0,2)
-      idbmup(1) = 2212*pdf_ih1
-      idbmup(2) = 2212*pdf_ih2
+      if(abs(pdf_ih1).eq.1) then
+c proton and antiproton
+        idbmup(1) = 2212*pdf_ih1
+      elseif(abs(pdf_ih1).eq.2) then
+c neutron and antineutron
+        idbmup(1) = 2112*pdf_ih1/abs(pdf_ih1)
+      else
+         write(*,*) ' unimplemented hadron 1 ',pdf_ih1
+         call pwhg_exit(-1)
+      endif
+      if(abs(pdf_ih2).eq.1) then
+        idbmup(2) = 2212*pdf_ih2
+      elseif(abs(pdf_ih2).eq.2) then
+        idbmup(2) = 2112*pdf_ih2/abs(pdf_ih2)
+      else
+         write(*,*) ' unimplemented hadron 2 ',pdf_ih2
+         call pwhg_exit(-1)
+      endif
 c pdf group; negative to use internal herwig pdf's for showering
       pdfgup(1)=-1
       pdfgup(2)=-1