GPU TPC: Relax chi2cut for single-pad clusters

Author: davidrohr

GPU/GPUTracking/Merger/GPUTPCGMPropagator.h

@@ -108,13 +108,19 @@ class GPUTPCGMPropagator
   GPUd() float PredictChi2(float posY, float posZ, float err2Y, float err2Z) const;
   GPUd() static int32_t RejectCluster(float chiY, float chiZ, uint8_t clusterState)
   {
-    if (chiY > 9.f || chiZ > 9.f) { // TODO: Check how a track can have chi2/ncl > 18
+    if (chiY > 9.f || chiZ > 9.f) {
       return 2;
     }
-    if ((chiY > 6.25f || chiZ > 6.25f) && (clusterState & (GPUTPCGMMergedTrackHit::flagSplit | GPUTPCGMMergedTrackHit::flagShared))) {
+    if (chiZ > 6.25f && (clusterState & (GPUTPCGMMergedTrackHit::flagSplit | GPUTPCGMMergedTrackHit::flagShared | GPUTPCGMMergedTrackHit::flagEdge | GPUTPCGMMergedTrackHit::flagSingle))) {
       return 2;
     }
-    if ((chiY > 1.f || chiZ > 6.25f) && (clusterState & (GPUTPCGMMergedTrackHit::flagEdge | GPUTPCGMMergedTrackHit::flagSingle))) {
+    if (chiY > 6.25f && (clusterState & (GPUTPCGMMergedTrackHit::flagSplit | GPUTPCGMMergedTrackHit::flagShared))) {
+      return 2;
+    }
+    if (chiY > 1.f && (clusterState & GPUTPCGMMergedTrackHit::flagEdge)) {
+      return 2;
+    }
+    if (chiY > 2.f && (clusterState & GPUTPCGMMergedTrackHit::flagSingle)) {
       return 2;
     }
     return 0;