loop-induced: stop the run when the poles do not cancel

Template/loop_material/StandAlone/Cards/MadLoopParams.dat

@@ -81,6 +81,28 @@
 #MLStabThres
 !1.0d-3
 ! Default :: 1.0d-3
+
+!     Relative threshold above which a non-vanishing pole of a *loop-induced*
+!     process is considered an error and stops the run.
+!     A loop-induced amplitude is finite, so its single and double poles must
+!     cancel; anything else means the result is wrong. This has no effect on
+!     processes with a Born, whose poles are not supposed to vanish.
+!     Set it to a negative value to disable the check.
+!     Note that the check is inactive when the reduction tool in use does not
+!     compute the poles at all (COLLIER with COLLIERComputeUV/IRpoles off).
+!     The default comes from the measured size of (|1eps|+|2eps|)/|finite| over
+!     ~800 phase-space points of g g > z z / h h / z z g / h h g, whose ceiling
+!     is 6.0d-5, leaving a factor ~20 of headroom. At 1.0d-3 an error of 0.7%
+!     or more on one of the *dominant* pole contributions is caught; an error
+!     on a subdominant amplitude is not, at any usable threshold.
+!     Points sitting on a soft or collinear singularity can legitimately reach
+!     5.0d-2. A madevent run never sees them, since the cuts are applied before
+!     the matrix element, but check_sa and launch feed uncut phase-space points,
+!     so raise this value if you hit it there.
+#MLPoleCheckThres
+!1.0d-3
+! Default :: 1.0d-3
+
 !     You can add other evaluation method to check for the stability in DP and QP.
 !     Below you can chose if you want to use zero, one or two rotations of the PS point 
 !     in QP.

Template/loop_material/StandAlone/SubProcesses/MadLoopParamReader.f

@@ -59,6 +59,9 @@ subroutine MadLoopParamReader(filename, printParam)
                  stop 'MLStabThres must be >= 0'
              endif
 
+           else if (buff .eq. '#MLPoleCheckThres') then
+             read(666,*,end=999) MLPoleCheckThres
+
            else if (buff .eq. '#COLLIERRequiredAccuracy') then
              read(666,*,end=999) COLLIERRequiredAccuracy
              if (COLLIERRequiredAccuracy.le.0.0d0.and.
@@ -256,6 +259,7 @@ subroutine MadLoopParamReader(filename, printParam)
      $     //TRIM(MLReductionLib_str_save)
       write(*,*) ' > CTModeRun                 = ',CTModeRun
       write(*,*) ' > MLStabThres               = ',MLStabThres
+      write(*,*) ' > MLPoleCheckThres          = ',MLPoleCheckThres
       write(*,*) ' > NRotations_DP             = ',NRotations_DP
       write(*,*) ' > NRotations_QP             = ',NRotations_QP
       write(*,*) ' > CTStabThres               = ',CTStabThres
@@ -324,6 +328,7 @@ subroutine DefaultParam()
       NRotations_DP=0
       NRotations_QP=0
       MLStabThres=1.0d-3
+      MLPoleCheckThres=1.0d-3
       CTStabThres=1.0d-2
       CTLoopLibrary=3
       CheckCycle=3

Template/loop_material/StandAlone/SubProcesses/MadLoopParams.inc

@@ -11,6 +11,7 @@
      &COLLIERGlobalCache
 
       real*8 MLStabThres,CTStabThres,ZeroThres,OSThres,COLLIERRequiredAccuracy
+      real*8 MLPoleCheckThres
 
       logical UseLoopFilter,LoopInitStartOver,DoubleCheckHelicityFilter,
      &COLLIERComputeIRpoles,COLLIERComputeUVpoles,COLLIERCanOutput
@@ -21,6 +22,7 @@
       common /MADLOOP/CTModeInit,CTModeRun,NRotations_DP,NRotations_QP,
      &COLLIERMode,COLLIERGlobalCache,
      &ImprovePSPoint,CheckCycle, MaxAttempts,UseLoopFilter,MLStabThres,
+     &MLPoleCheckThres,
      &COLLIERRequiredAccuracy,
      &CTStabThres,CTLoopLibrary,LoopInitStartOver,
      &COLLIERComputeIRpoles,COLLIERComputeUVpoles,COLLIERCanOutput,

madgraph/iolibs/template_files/loop/loop_matrix_standalone.inc

@@ -217,7 +217,7 @@ c     the previous points
       LOGICAL FOUND_VALID_REDUCTION_METHOD
       DATA FOUND_VALID_REDUCTION_METHOD/.FALSE./
 
-	  %(real_dp_format)s ACC
+	  %(real_dp_format)s ACC%(loop_induced_pole_check_decl)s
 	  %(real_dp_format)s DP_RES(3,MAXSTABILITYLENGTH)
 C QP_RES STORES THE QUADRUPLE PRECISION RESULT OBTAINED FROM DIFFERENT EVALUATION METHODS IN ORDER TO ASSESS STABILITY.
 	  %(real_dp_format)s QP_RES(3,MAXSTABILITYLENGTH)
@@ -689,10 +689,7 @@ IF(SKIPLOOPEVAL) THEN
   GOTO 1226
 ENDIF
 
-%(loop_helas_calls)s
-
-%(actualize_ans)s
-
+%(loop_helas_calls)s%(actualize_ans)s
 1226 CONTINUE
 
 IF (CHECKPHASE.OR.(.NOT.HELDOUBLECHECKED)) THEN
@@ -927,7 +924,7 @@ ANSRETURNED(0,0)=ANS(0)
 ANSRETURNED(1,0)=ANS(1)
 ANSRETURNED(2,0)=ANS(2)
 ANSRETURNED(3,0)=ANS(3)
-
+%(loop_induced_pole_check)s
 C Reinitialize the check phase logicals and the filters if check bypassed
 IF (BYPASS_CHECK) THEN
   CHECKPHASE = OLD_CHECKPHASE

madgraph/iolibs/template_files/loop_optimized/loop_matrix_standalone.inc

@@ -185,6 +185,9 @@ C QP_RES STORES THE QUADRUPLE PRECISION RESULT OBTAINED FROM DIFFERENT EVALUATIO
 	  INTEGER ITEMP
 	  LOGICAL LTEMP
 	  %(real_dp_format)s BORNBUFF(0:NSQSO_BORN),TMPR
+## if(LoopInduced){
+	  LOGICAL POLES_COMPUTED, DO_POLE_CHECK
+## }
 	  %(real_dp_format)s BUFFR(3,0:NSQUAREDSO),BUFFR_BIS(3,0:NSQUAREDSO),TEMP(0:3,0:NSQUAREDSO),TEMP1(0:NSQUAREDSO)
 	  %(complex_dp_format)s CTEMP
 ## if(not AmplitudeReduction){
@@ -534,6 +537,12 @@ C SKIP THE ONES THAT NOT AVAILABLE
   IF(MLReductionLib(1).EQ.0)THEN
      STOP "No available loop reduction lib is provided. Make sure MLReductionLib is correct."
   ENDIF
+## if(LoopInduced){
+C The poles must vanish here, but COLLIER can be asked not to compute them at all.
+  IF (MLPoleCheckThres.GT.0.0d0.AND.MLReductionLib(1).EQ.7.AND.(.NOT.COLLIERComputeUVpoles.OR..NOT.COLLIERComputeIRpoles)) THEN
+    WRITE(*,*) '##INFO: The vanishing-pole check of this loop-induced process is inactive because COLLIER is not computing the poles. A madevent run turns them off on purpose and the card cannot override that; in a standalone run, set COLLIERComputeUVpoles and COLLIERComputeIRpoles to .TRUE. in MadLoopParams.dat.'
+  ENDIF
+## }
   J=0
   DO I=1,NLOOPLIB
      IF(LOOPLIBS_QPAVAILABLE(MLReductionLib(I)))THEN
@@ -1879,6 +1888,29 @@ DO I=1,NSQUAREDSO
     ENDDO
   ENDIF
 ENDDO
+## if(LoopInduced){
+C A loop-induced amplitude is finite: its poles must cancel.
+C Nothing to compare against if the reduction tool does not compute them.
+POLES_COMPUTED = .NOT.(MLReductionLib(I_LIB).EQ.7.AND.(.NOT.COLLIERComputeUVpoles.OR..NOT.COLLIERComputeIRpoles))
+DO_POLE_CHECK = MLPoleCheckThres.GT.0.0d0.AND.POLES_COMPUTED.AND.NTRY.GT.0
+DO_POLE_CHECK = DO_POLE_CHECK.AND..NOT.CHECKPHASE.AND.HELDOUBLECHECKED
+DO_POLE_CHECK = DO_POLE_CHECK.AND.RET_CODE_H.NE.4.AND.ANS(1,0).NE.0.0d0
+IF (DO_POLE_CHECK) THEN
+  TMPR = (ABS(ANS(2,0))+ABS(ANS(3,0)))/ABS(ANS(1,0))
+  IF (TMPR.GT.MLPoleCheckThres) THEN
+    WRITE(*,*) '##E03 ERROR The poles of this loop-induced process do not cancel.'
+    WRITE(*,*) 'Finite contribution         = ',ANS(1,0)
+    WRITE(*,*) 'single pole contribution    = ',ANS(2,0)
+    WRITE(*,*) 'double pole contribution    = ',ANS(3,0)
+    WRITE(*,*) 'relative size of the poles  = ',TMPR
+    WRITE(*,*) 'tolerated                   = ',MLPoleCheckThres
+    WRITE(*,*) 'The finite part returned here cannot be trusted, so the run is stopped.'
+    WRITE(*,*) 'Edit MLPoleCheckThres in MadLoopParams.dat to change this tolerance; a negative value disables the check.'
+    CALL %(proc_prefix)sWRITE_MOM(P)
+    STOP 1
+  ENDIF
+ENDIF
+## }
 
 C Reinitialize the default threshold if it was specified by the user
 IF (USER_STAB_PREC.GT.0.0d0) THEN

madgraph/iolibs/template_files/matrix_loop_induced_madevent.inc

@@ -415,11 +415,11 @@ c   ----
 	  return
 	endif
 
-	IF (U.NE.7.AND.((OneEps+TwoEps)/finite).gt.(1000d0*PREC).AND.(((OneEps+TwoEps)/finite).gt.1.0d-5)) THEN
+	IF (U.NE.7.AND.((ABS(OneEps)+ABS(TwoEps))/ABS(finite)).gt.(1000d0*PREC).AND.(((ABS(OneEps)+ABS(TwoEps))/ABS(finite)).gt.1.0d-5)) THEN
 	  WARNING_COUNTERS(2) = WARNING_COUNTERS(2) + 1
 	  IF (WARNING_COUNTERS(2).le.10) THEN
 	    WRITE(*,*) "WARNING : The residue of the single and double pole of the loop matrix element being integrated does not seem to vanish."
-		WRITE(*,*) "          Its contribution relative to the finite part is : ",((OneEps+TwoEps)/finite)
+		WRITE(*,*) "          Its contribution relative to the finite part is : ",((ABS(OneEps)+ABS(TwoEps))/ABS(finite))
 		WRITE(*,*) "          while the estimated numerical accuracy is       : ",PREC
 		WRITE(*,*) "          MadLoop results (fin, 1eps, 2eps)               : ",finite, OneEps, TwoEps
 		WRITE(*,*) " The warning above was triggered when processing the following phase space point:"

madgraph/iolibs/template_files/matrix_loop_induced_madevent_group.inc

@@ -425,11 +425,11 @@ c   ----
 	  return
 	endif
 
-	IF (U.NE.7.and.((OneEps+TwoEps)/finite).gt.(1000d0*PREC).AND.(((OneEps+TwoEps)/finite).gt.1.0d-5)) THEN
+	IF (U.NE.7.and.((ABS(OneEps)+ABS(TwoEps))/ABS(finite)).gt.(1000d0*PREC).AND.(((ABS(OneEps)+ABS(TwoEps))/ABS(finite)).gt.1.0d-5)) THEN
 	  WARNING_COUNTERS(2) = WARNING_COUNTERS(2) + 1
 	  IF (WARNING_COUNTERS(2).le.10) THEN
 	    WRITE(*,*) "WARNING : The residue of the single and double pole of the loop matrix element being integrated does not seem to vanish."
-		WRITE(*,*) "          Its contribution relative to the finite part is : ",((OneEps+TwoEps)/finite)
+		WRITE(*,*) "          Its contribution relative to the finite part is : ",((ABS(OneEps)+ABS(TwoEps))/ABS(finite))
 		WRITE(*,*) "          while the estimated numerical accuracy is       : ",PREC
 		WRITE(*,*) "          MadLoop results (fin, 1eps, 2eps)               : ",finite, OneEps, TwoEps		
 		WRITE(*,*) " The warning above was triggered when processing the following phase space point:"

madgraph/loop/loop_exporters.py

@@ -267,13 +267,10 @@ def finalize(self, matrix_element, cmdhistory, MG5options, outputflag):
         # (which is the default for standalone usage), COLLIER is faster than Ninja.
         if self.has_loop_induced:
             MLCard['MLReductionLib'] = "7|6|1"
-            # Computing the poles with COLLIER also unnecessarily slows down the code
-            # It should only be set to True for checks and it's acceptable to remove them
-            # here because for loop-induced processes they should be zero anyway.
-            # We keep it active for non-loop induced processes because COLLIER is not the
-            # main reduction tool in that case, and the poles wouldn't be zero then
-            MLCard['COLLIERComputeUVpoles'] = False
-            MLCard['COLLIERComputeIRpoles'] = False
+            # The COLLIER pole computation is left on here: the poles must vanish
+            # for a loop-induced process and MadLoop only checks that when they are
+            # computed. 'check timing'/'check stability' turn them off themselves,
+            # and so does the madevent event loop, where the cost is not worth it.
 
         MLCard.write(pjoin(self.dir_path, 'Cards', 'MadLoopParams_default.dat'))
         MLCard.write(pjoin(self.dir_path, 'Cards', 'MadLoopParams.dat'))
@@ -1578,12 +1575,6 @@ def write_loopmatrix(self, writer, matrix_element, fortran_model,
                  WRITE(*,*) '##W03 WARNING Contribution ',I
                  WRITE(*,*) ' is unstable for helicity ',H
                ENDIF
-C                IF(.NOT.%(proc_prefix)sISZERO(ABS(AMPL(2,I))+ABS(AMPL(3,I)),REF,-1,H)) THEN
-C                  WRITE(*,*) '##W04 WARNING Contribution ',I,' for helicity ',H,' has a contribution to the poles.'
-C                  WRITE(*,*) 'Finite contribution         = ',AMPL(1,I)
-C                  WRITE(*,*) 'single pole contribution    = ',AMPL(2,I)
-C                  WRITE(*,*) 'double pole contribution    = ',AMPL(3,I)
-C                ENDIF
                ENDDO
                1227 CONTINUE
                HELPICKED=HELPICKED_BU""")%replace_dict
@@ -1592,10 +1583,9 @@ def write_loopmatrix(self, writer, matrix_element, fortran_model,
             replace_dict['nbornamps_or_nloopamps']='nloopamps'
             replace_dict['squaring']=\
                     """ANS(1)=ANS(1)+DBLE(CFTOT*AMPL(1,I)*DCONJG(AMPL(1,J)))
-                       IF (J.EQ.1) THEN
-                         ANS(2)=ANS(2)+DBLE(CFTOT*AMPL(2,I))+DIMAG(CFTOT*AMPL(2,I))
-                         ANS(3)=ANS(3)+DBLE(CFTOT*AMPL(3,I))+DIMAG(CFTOT*AMPL(3,I))                         
-                       ENDIF"""      
+C The poles below must cancel: the loop-induced amplitude is finite.
+                       ANS(2)=ANS(2)+DBLE(CFTOT*(AMPL(2,I)*DCONJG(AMPL(1,J))+AMPL(1,I)*DCONJG(AMPL(2,J))))
+                       ANS(3)=ANS(3)+DBLE(CFTOT*(AMPL(3,I)*DCONJG(AMPL(1,J))+AMPL(1,I)*DCONJG(AMPL(3,J))+AMPL(2,I)*DCONJG(AMPL(2,J))))"""
         else:
             replace_dict['compute_born']=\
 """C Compute the born, for a specific helicity if asked so.
@@ -1632,16 +1622,35 @@ def write_loopmatrix(self, writer, matrix_element, fortran_model,
             actualize_ans.append(\
                    "WRITE(*,*) '##W03 WARNING Contribution ',I,' is unstable.'")
             actualize_ans.extend(["ENDIF","ENDDO"])
-            replace_dict['actualize_ans']='\n'.join(actualize_ans)
+            replace_dict['actualize_ans']='\n\n'+'\n'.join(actualize_ans)+'\n'
+            replace_dict['loop_induced_pole_check'] = ""
+            replace_dict['loop_induced_pole_check_decl'] = ""
         else:
-            replace_dict['actualize_ans']=\
-            ("""C We add five powers to the reference value to loosen a bit the vanishing pole check.
-C               IF(.NOT.(CHECKPHASE.OR.(.NOT.HELDOUBLECHECKED)).AND..NOT.%(proc_prefix)sISZERO(ABS(ANS(2))+ABS(ANS(3)),ABS(ANS(1))*(10.0d0**5),-1,H)) THEN
-C                 WRITE(*,*) '##W05 WARNING Found a PS point with a contribution to the single pole.'
-C                 WRITE(*,*) 'Finite contribution         = ',ANS(1)
-C                 WRITE(*,*) 'single pole contribution    = ',ANS(2)
-C                 WRITE(*,*) 'double pole contribution    = ',ANS(3)
-C               ENDIF""")%replace_dict
+            replace_dict['actualize_ans']=""
+            # A loop-induced amplitude is finite: a surviving pole means the
+            # result is wrong, so refuse to return it. This output only ever
+            # reduces with CutTools, which always computes the poles.
+            replace_dict['loop_induced_pole_check_decl']=\
+                ("\n\t  %(real_dp_format)s TMPPOLE"
+                 "\n\t  LOGICAL DO_POLE_CHECK")%replace_dict
+            replace_dict['loop_induced_pole_check']=("""DO_POLE_CHECK = MLPoleCheckThres.GT.0.0d0.AND.NTRY.GT.0
+DO_POLE_CHECK = DO_POLE_CHECK.AND..NOT.CHECKPHASE.AND.HELDOUBLECHECKED
+DO_POLE_CHECK = DO_POLE_CHECK.AND.RET_CODE_H.NE.4.AND.ANS(1).NE.0.0d0
+IF (DO_POLE_CHECK) THEN
+  TMPPOLE = (ABS(ANS(2))+ABS(ANS(3)))/ABS(ANS(1))
+  IF (TMPPOLE.GT.MLPoleCheckThres) THEN
+    WRITE(*,*) '##E03 ERROR The poles of this loop-induced process do not cancel.'
+    WRITE(*,*) 'Finite contribution         = ',ANS(1)
+    WRITE(*,*) 'single pole contribution    = ',ANS(2)
+    WRITE(*,*) 'double pole contribution    = ',ANS(3)
+    WRITE(*,*) 'relative size of the poles  = ',TMPPOLE
+    WRITE(*,*) 'tolerated                   = ',MLPoleCheckThres
+    WRITE(*,*) 'The finite part returned here cannot be trusted, so the run is stopped.'
+    WRITE(*,*) 'Edit MLPoleCheckThres in MadLoopParams.dat to change this tolerance; a negative value disables the check.'
+    CALL %(proc_prefix)sWRITE_MOM(P)
+    STOP 1
+  ENDIF
+ENDIF""")%replace_dict
 
         # Write out the color matrix
         (CMNum,CMDenom) = self.get_color_matrix(matrix_element)

madgraph/various/banner.py

@@ -7414,6 +7414,7 @@ def default_setup(self):
         self.add_param("IREGIRECY", True)
         self.add_param("CTModeRun", -1)
         self.add_param("MLStabThres", 1e-3)
+        self.add_param("MLPoleCheckThres", 1e-3)
         self.add_param("NRotations_DP", 0)
         self.add_param("NRotations_QP", 0)
         self.add_param("ImprovePSPoint", 2)

tests/input_files/IOTestsComparison/short_ML_SMQCD_LoopInduced/gg_hh/loop_matrix.f → tests/input_files/IOTestsComparison/short_ML_SMQCD_LoopInduced_default/gg_hh/loop_matrix.f

@@ -229,6 +229,8 @@ SUBROUTINE ML5_0_SLOOPMATRIX(P_USER,ANSRETURNED)
       DATA FOUND_VALID_REDUCTION_METHOD/.FALSE./
 
       REAL*8 ACC
+      REAL*8 TMPPOLE
+      LOGICAL DO_POLE_CHECK
       REAL*8 DP_RES(3,MAXSTABILITYLENGTH)
 C     QP_RES STORES THE QUADRUPLE PRECISION RESULT OBTAINED FROM
 C      DIFFERENT EVALUATION METHODS IN ORDER TO ASSESS STABILITY.
@@ -871,14 +873,6 @@ SUBROUTINE ML5_0_SLOOPMATRIX(P_USER,ANSRETURNED)
               WRITE(*,*) '##W03 WARNING Contribution ',I
               WRITE(*,*) ' is unstable for helicity ',H
             ENDIF
-C           IF(.NOT.ML5_0_ISZERO(ABS(AMPL(2,I))+ABS(AMPL(3,I)),REF,-1,H)
-C           ) THEN
-C           WRITE(*,*) '##W04 WARNING Contribution ',I,' for helicity'
-C           //' ',H,' has a contribution to the poles.'
-C           WRITE(*,*) 'Finite contribution         = ',AMPL(1,I)
-C           WRITE(*,*) 'single pole contribution    = ',AMPL(2,I)
-C           WRITE(*,*) 'double pole contribution    = ',AMPL(3,I)
-C           ENDIF
           ENDDO
  1227     CONTINUE
           HELPICKED=HELPICKED_BU
@@ -887,12 +881,13 @@ SUBROUTINE ML5_0_SLOOPMATRIX(P_USER,ANSRETURNED)
               CFTOT=DCMPLX(CF_N(I,J)/DBLE(ABS(CF_D(I,J))),0.0D0)
               IF(CF_D(I,J).LT.0) CFTOT=CFTOT*IMAG1
               ANS(1)=ANS(1)+DBLE(CFTOT*AMPL(1,I)*DCONJG(AMPL(1,J)))
-              IF (J.EQ.1) THEN
-                ANS(2)=ANS(2)+DBLE(CFTOT*AMPL(2,I))+DIMAG(CFTOT*AMPL(2
-     $           ,I))
-                ANS(3)=ANS(3)+DBLE(CFTOT*AMPL(3,I))+DIMAG(CFTOT*AMPL(3
-     $           ,I))
-              ENDIF
+C             The poles below must cancel: the loop-induced amplitude
+C              is finite.
+              ANS(2)=ANS(2)+DBLE(CFTOT*(AMPL(2,I)*DCONJG(AMPL(1,J))
+     $         +AMPL(1,I)*DCONJG(AMPL(2,J))))
+              ANS(3)=ANS(3)+DBLE(CFTOT*(AMPL(3,I)*DCONJG(AMPL(1,J))
+     $         +AMPL(1,I)*DCONJG(AMPL(3,J))+AMPL(2,I)*DCONJG(AMPL(2,J))
+     $         ))
             ENDDO
           ENDDO
         ENDIF
@@ -909,18 +904,6 @@ SUBROUTINE ML5_0_SLOOPMATRIX(P_USER,ANSRETURNED)
       ENDIF
 
 
-
-C     We add five powers to the reference value to loosen a bit the
-C      vanishing pole check.
-C     IF(.NOT.(CHECKPHASE.OR.(.NOT.HELDOUBLECHECKED)).AND..NOT.ML5_0_IS
-C     ZERO(ABS(ANS(2))+ABS(ANS(3)),ABS(ANS(1))*(10.0d0**5),-1,H)) THEN
-C     WRITE(*,*) '##W05 WARNING Found a PS point with a contribution'
-C     //' to the single pole.'
-C     WRITE(*,*) 'Finite contribution         = ',ANS(1)
-C     WRITE(*,*) 'single pole contribution    = ',ANS(2)
-C     WRITE(*,*) 'double pole contribution    = ',ANS(3)
-C     ENDIF
-
  1226 CONTINUE
 
       IF (CHECKPHASE.OR.(.NOT.HELDOUBLECHECKED)) THEN
@@ -1193,7 +1176,30 @@ SUBROUTINE ML5_0_SLOOPMATRIX(P_USER,ANSRETURNED)
       ANSRETURNED(1,0)=ANS(1)
       ANSRETURNED(2,0)=ANS(2)
       ANSRETURNED(3,0)=ANS(3)
-
+      DO_POLE_CHECK = MLPOLECHECKTHRES.GT.0.0D0.AND.NTRY.GT.0
+      DO_POLE_CHECK =
+     $  DO_POLE_CHECK.AND..NOT.CHECKPHASE.AND.HELDOUBLECHECKED
+      DO_POLE_CHECK = DO_POLE_CHECK.AND.RET_CODE_H.NE.4.AND.ANS(1)
+     $ .NE.0.0D0
+      IF (DO_POLE_CHECK) THEN
+        TMPPOLE = (ABS(ANS(2))+ABS(ANS(3)))/ABS(ANS(1))
+        IF (TMPPOLE.GT.MLPOLECHECKTHRES) THEN
+          WRITE(*,*) '##E03 ERROR The poles of this loop-induced'
+     $     //' process do not cancel.'
+          WRITE(*,*) 'Finite contribution         = ',ANS(1)
+          WRITE(*,*) 'single pole contribution    = ',ANS(2)
+          WRITE(*,*) 'double pole contribution    = ',ANS(3)
+          WRITE(*,*) 'relative size of the poles  = ',TMPPOLE
+          WRITE(*,*) 'tolerated                   = ',MLPOLECHECKTHRES
+          WRITE(*,*) 'The finite part returned here cannot be trusted,'
+     $     //' so the run is stopped.'
+          WRITE(*,*) 'Edit MLPoleCheckThres in MadLoopParams.dat to'
+     $     //' change this tolerance; a negative value disables the'
+     $     //' check.'
+          CALL ML5_0_WRITE_MOM(P)
+          STOP 1
+        ENDIF
+      ENDIF
 C     Reinitialize the check phase logicals and the filters if check
 C      bypassed
       IF (BYPASS_CHECK) THEN

tests/input_files/IOTestsComparison/short_ML_SMQCD_LoopInduced_optimized/gg_hh/%..%..%Source%MODEL%actualize_mp_ext_params.inc

@@ -0,0 +1,7 @@
+ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
+c      written by the UFO converter
+ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
+
+      MP__MU_R=MU_R
+      MP__AS=AS
+      MP__G=G