From 5ce3297c5be85a820e54212bb4c72590b099b11b Mon Sep 17 00:00:00 2001
From: miedema-11 <1260971129@qq.com>
Date: Wed, 26 Aug 2026 23:57:15 +0800
Subject: [PATCH 1/3] get weff2 corrected

---
 PWGUD/Tasks/flowCorrelationsUpc.cxx | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/PWGUD/Tasks/flowCorrelationsUpc.cxx b/PWGUD/Tasks/flowCorrelationsUpc.cxx
index 57114a3f977..faeb7de083f 100644
--- a/PWGUD/Tasks/flowCorrelationsUpc.cxx
+++ b/PWGUD/Tasks/flowCorrelationsUpc.cxx
@@ -470,9 +470,11 @@ struct FlowCorrelationsUpc {
       double phi1 = RecoDecay::phi(momentum1);
       double eta1 = RecoDecay::eta(momentum1);
 
-      float weff1 = 1., wacc1 = 1.;
+      float weff1 = 1.;
+      if (!getEfficiencyCorrection(weff1, eta1, pt1, posZ))
+        continue;
       if (system == SameEvent) {
-        registry.fill(HIST("Trig_hist"), fSampleIndex, posZ, independent, pt1, eventWeight * weff1 * wacc1);
+        registry.fill(HIST("Trig_hist"), fSampleIndex, posZ, independent, pt1, eventWeight * weff1);
       }
 
       for (auto const& track2 : tracks2) {
@@ -495,7 +497,7 @@ struct FlowCorrelationsUpc {
         double phi2 = RecoDecay::phi(momentum2);
         double eta2 = RecoDecay::eta(momentum2);
 
-        float weff2 = 1., wacc2 = 1.;
+        float weff2 = 1.;
         if (mEfficiency) {
           weff2 = efficiencyCache[track2.filteredIndex()];
         } else {
@@ -505,7 +507,7 @@ struct FlowCorrelationsUpc {
         float deltaPhi = RecoDecay::constrainAngle(phi1 - phi2, -PIHalf);
         float deltaEta = eta1 - eta2;
 
-        float weight = eventWeight * weff1 * weff2 * wacc1 * wacc2;
+        float weight = eventWeight * weff1 * weff2;
 
         // Merging cut
         if (std::abs(deltaEta) < cfgCutMerging) {

From 639628660ac698165b04c8855e02245c1a9298c7 Mon Sep 17 00:00:00 2001
From: miedema-11 <1260971129@qq.com>
Date: Thu, 3 Sep 2026 20:33:04 +0800
Subject: [PATCH 2/3] fix zdc gapside selection

---
 PWGUD/Tasks/flowCorrelationsUpc.cxx | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/PWGUD/Tasks/flowCorrelationsUpc.cxx b/PWGUD/Tasks/flowCorrelationsUpc.cxx
index faeb7de083f..d708c17e5ae 100644
--- a/PWGUD/Tasks/flowCorrelationsUpc.cxx
+++ b/PWGUD/Tasks/flowCorrelationsUpc.cxx
@@ -281,11 +281,15 @@ struct FlowCorrelationsUpc {
         return false;
       }
       // if A or C gap is requested, keep corresponding neutron class
-      if (cfgGapSide == 0 || cfgGapSide == 1) {
-        if ((cfgGapSide == 0 && neutronClass == 1) || (cfgGapSide == 1 && neutronClass == 2)) { // o2-linter: disable=magic-number (ZDC time cut)
-          // accepted
-        } else {
-          return false;
+      if (cfgGapSideMerge) {
+        // accepted
+      } else {
+        if (cfgGapSide == 0 || cfgGapSide == 1) {
+          if ((cfgGapSide == 0 && neutronClass == 1) || (cfgGapSide == 1 && neutronClass == 2)) { // o2-linter: disable=magic-number (ZDC time cut)
+            // accepted
+          } else {
+            return false;
+          }
         }
       }
     }

From 750de87c87d2df692fc211422d8434a436c6cf5a Mon Sep 17 00:00:00 2001
From: miedema-11 <1260971129@qq.com>
Date: Tue, 29 Sep 2026 16:20:35 +0800
Subject: [PATCH 3/3] ZDCtiming gapside fixed

---
 PWGUD/Tasks/flowCumulantsUpc.cxx | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/PWGUD/Tasks/flowCumulantsUpc.cxx b/PWGUD/Tasks/flowCumulantsUpc.cxx
index e7ccfdb51e4..19f29620a21 100644
--- a/PWGUD/Tasks/flowCumulantsUpc.cxx
+++ b/PWGUD/Tasks/flowCumulantsUpc.cxx
@@ -738,13 +738,13 @@ struct FlowCumulantsUpc {
       registry.fill(HIST("neutronClass"), 0, 0);
     }
     if (std::abs(timeZNA) <= cfgZdcTimeCut && std::abs(timeZNC) > cfgZdcTimeCut) {
-      neutronClass = 1;
-      registry.fill(HIST("neutronClass"), 0, 1);
-    }
-    if (std::abs(timeZNA) > cfgZdcTimeCut && std::abs(timeZNC) <= cfgZdcTimeCut) {
       neutronClass = 2;
       registry.fill(HIST("neutronClass"), 1, 0);
     }
+    if (std::abs(timeZNA) > cfgZdcTimeCut && std::abs(timeZNC) <= cfgZdcTimeCut) {
+      neutronClass = 1;
+      registry.fill(HIST("neutronClass"), 0, 1);
+    }
     if (std::abs(timeZNA) <= cfgZdcTimeCut && std::abs(timeZNC) <= cfgZdcTimeCut) {
       neutronClass = 3;
       registry.fill(HIST("neutronClass"), 1, 1);