[PWGEM/Dilepton] update skimmerPrimaryMuon.cxx (#15905)

Author: dsekihat

PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx

@@ -106,6 +106,7 @@ struct skimmerPrimaryMuon {
   Configurable<float> maxDEta{"maxDEta", 1e+10f, "max. deta between MFT-MCH-MID and MCH-MID"};
   Configurable<float> maxDPhi{"maxDPhi", 1e+10f, "max. dphi between MFT-MCH-MID and MCH-MID"};
   Configurable<bool> cfgApplyPreselectionInBestMatch{"cfgApplyPreselectionInBestMatch", false, "flag to apply preselection in find best match function"};
+  Configurable<bool> cfgRequireSameSign{"cfgRequireSameSign", false, "flag to require same sign between MFT and MCH-MID"};
 
   // for z shift for propagation
   Configurable<bool> cfgApplyZShiftFromCCDB{"cfgApplyZShiftFromCCDB", false, "flag to apply z shift"};
@@ -343,6 +344,10 @@ struct skimmerPrimaryMuon {
         return false;
       }
 
+      if (cfgRequireSameSign && (mfttrack.sign() != mchtrack.sign())) {
+        return false;
+      }
+
       xMFT = mfttrack.x();
       yMFT = mfttrack.y();
 
@@ -629,6 +634,9 @@ struct skimmerPrimaryMuon {
           if (muon_tmp.chi2MatchMCHMFT() > maxMatchingChi2MCHMFT) {
             continue;
           }
+          if (cfgRequireSameSign && (mfttrack.sign() != mchtrack.sign())) {
+            continue;
+          }
         }
 
         if (0.f < muon_tmp.chi2MatchMCHMFT() && muon_tmp.chi2MatchMCHMFT() < min_chi2MatchMCHMFT) {