From 7ea883f8897e2d5ecdee3638150e675565d14074 Mon Sep 17 00:00:00 2001
From: Daiki Sekihata <daiki.sekihata@cern.ch>
Date: Sat, 10 Jan 2026 21:27:36 +0100
Subject: [PATCH] PWGEM/Dilepton: fix in matchingMFT.cxx

---
 PWGEM/Dilepton/Tasks/matchingMFT.cxx | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/PWGEM/Dilepton/Tasks/matchingMFT.cxx b/PWGEM/Dilepton/Tasks/matchingMFT.cxx
index 3a980efe756..706c0c98213 100644
--- a/PWGEM/Dilepton/Tasks/matchingMFT.cxx
+++ b/PWGEM/Dilepton/Tasks/matchingMFT.cxx
@@ -692,7 +692,9 @@ struct matchingMFT {
         }
 
         float deta = 999.f, dphi = 999.f;
-        getDeltaEtaDeltaPhiAtMatchingPlane<TFwdTracks, TMFTTracks>(collision, muon_tmp, mftCovs, deta, dphi);
+        if constexpr (withMFTCov) {
+          getDeltaEtaDeltaPhiAtMatchingPlane<TFwdTracks, TMFTTracks>(collision, muon_tmp, mftCovs, deta, dphi);
+        }
         float dr = std::sqrt(deta * deta + dphi * dphi);
 
         // auto mcParticle_MFTMCHMID = muon_tmp.template mcParticle_as<aod::McParticles>(); // this is identical to mcParticle_MCHMID
@@ -750,6 +752,17 @@ struct matchingMFT {
 
   void processWithoutFTTCA(FilteredMyCollisions const& collisions, MyFwdTracks const& fwdtracks, MyMFTTracks const& mfttracks, aod::BCsWithTimestamps const&, aod::McParticles const&)
   {
+    vec_min_chi2MatchMCHMFT.reserve(fwdtracks.size());
+    vec_min_dr.reserve(fwdtracks.size());
+    for (const auto& collision : collisions) {
+      auto bc = collision.template bc_as<aod::BCsWithTimestamps>();
+      initCCDB(bc);
+      auto fwdtracks_per_coll = fwdtracks.sliceBy(perCollision, collision.globalIndex());
+      for (const auto& fwdtrack : fwdtracks_per_coll) {
+        findBestMatchPerMCHMID<false>(collision, fwdtrack, fwdtracks, mfttracks, nullptr);
+      } // end of fwdtrack loop
+    } // end of collision loop
+
     for (const auto& collision : collisions) {
       auto bc = collision.template bc_as<aod::BCsWithTimestamps>();
       initCCDB(bc);
@@ -786,6 +799,18 @@ struct matchingMFT {
 
   void processWithFTTCA(FilteredMyCollisions const& collisions, MyFwdTracks const& fwdtracks, MyMFTTracks const& mfttracks, aod::BCsWithTimestamps const&, aod::FwdTrackAssoc const& fwdtrackIndices, aod::McParticles const&)
   {
+    vec_min_chi2MatchMCHMFT.reserve(fwdtracks.size());
+    vec_min_dr.reserve(fwdtracks.size());
+    for (const auto& collision : collisions) {
+      auto bc = collision.template bc_as<aod::BCsWithTimestamps>();
+      initCCDB(bc);
+      auto fwdtrackIdsThisCollision = fwdtrackIndices.sliceBy(fwdtrackIndicesPerCollision, collision.globalIndex());
+      for (const auto& fwdtrackId : fwdtrackIdsThisCollision) {
+        auto fwdtrack = fwdtrackId.template fwdtrack_as<MyFwdTracks>();
+        findBestMatchPerMCHMID<false>(collision, fwdtrack, fwdtracks, mfttracks, nullptr);
+      } // end of fwdtrack loop
+    } // end of collision loop
+
     for (const auto& collision : collisions) {
       auto bc = collision.template bc_as<aod::BCsWithTimestamps>();
       initCCDB(bc);