From 98ae5bb874093889f575c87e8db3f9a3955534ca Mon Sep 17 00:00:00 2001
From: Daiki Sekihata <daiki.sekihata@cern.ch>
Date: Tue, 21 Apr 2026 22:31:30 +0200
Subject: [PATCH] [PWGEM/Dilepton] update skimmerPrimaryMuon.cxx

---
 PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx b/PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx
index 3ced65b2b7d..674902c2746 100644
--- a/PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx
+++ b/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) {