Check for quarks and anti-quarks.

Phys/DaVinciMCTools/src/BackgroundCategory.cpp

@@ -585,8 +585,8 @@ BackgroundCategory::get_top_mother_of_MCParticle(const LHCb::MCParticle* candida
     finalmother = tmpmother;
     tmpmother = finalmother->mother();
     if (m_ignoreQuarks && tmpmother != NULL) {
-        if ( 1 <= tmpmother->particleID().pid() && 
-            tmpmother->particleID().pid() <= 8 ) {
+        if ( 1 <= tmpmother->particleID().abspid() && 
+            tmpmother->particleID().abspid() <= 8 ) {
             return finalmother;
         }
     }