svertex: opt fixup

f3sch · Nov 15, 2023 · 91ba699 · 91ba699
1 parent 403e507
commit 91ba699
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Showing 2 changed files with 25 additions and 7 deletions.
diff --git a/Detectors/Vertexing/include/DetectorsVertexing/SVertexerParams.h b/Detectors/Vertexing/include/DetectorsVertexing/SVertexerParams.h
@@ -19,6 +19,7 @@
 #include "CommonUtils/ConfigurableParam.h"
 #include "CommonUtils/ConfigurableParamHelper.h"
 #include "DetectorsVertexing/SVertexHypothesis.h"
+#include "CommonConstants/GeomConstants.h"
 #include "DetectorsBase/Propagator.h"
 
 namespace o2
@@ -92,15 +93,16 @@ struct SVertexerParams : public o2::conf::ConfigurableParamHelper<SVertexerParam
   float maxRIni3body = 90.; // don't consider as a 3body seed (circles/line intersection) if its R exceeds this
 
   // Cuts for TPC only tracks
-  bool mExcludeTPCtracks = false; // don't loop over TPC tracks if true (if loaded, dEdx info is used instead)
-  float mTPCTrackMaxX = 83.f;     // don't use TPC standalone tracks with X exceeding this; 83 cm is the reference x position at minimum, hence this cuts deep conversions
-  float mTPCTrack2Beam = 21.f;    // Straight line for TPC track back to beamline
-  float minTPCdEdx = 250;         // starting from this dEdx value, tracks with p > minMomTPCdEdx are always accepted
-  float minMomTPCdEdx = 0.8;      // minimum p for tracks with dEdx > mMinTPCdEdx to be accepted
+  bool mExcludeTPCtracks = false;                      // don't loop over TPC tracks if true (if loaded, dEdx info is used instead)
+  float mTPCTrackMaxX = constants::geom::XTPCInnerRef; // don't use TPC standalone tracks with X exceeding this;
+  float mTPCTrack2Beam = 21.f;                         // Straight line for TPC track back to beamline
+  float minTPCdEdx = 250;                              // starting from this dEdx value, tracks with p > minMomTPCdEdx are always accepted
+  float minMomTPCdEdx = 0.8;                           // minimum p for tracks with dEdx > mMinTPCdEdx to be accepted
 
   // cuts on different V0 PID params
   bool checkV0Hypothesis = true;
-  float pidCutsPhoton[SVertexHypothesis::NPIDParams] = {0.001, 20, 0.60, 0.0};    // Photon
+  float pidCutsPhoton[SVertexHypothesis::NPIDParams] = {0.001, 20, 0.1, 0.0};     // Photon
+  float pidCutsPhotonAP = 0.05;                                                   // Loose Amenteros-Podolanski cut for photons in case mass-hypothesis was good
   float pidCutsK0[SVertexHypothesis::NPIDParams] = {0.003, 20, 0.07, 0.5};        // K0
   float pidCutsLambda[SVertexHypothesis::NPIDParams] = {0.001, 20, 0.07, 0.5};    // Lambda
   float pidCutsHTriton[SVertexHypothesis::NPIDParams] = {0.0025, 14, 0.07, 0.5};  // HyperTriton

diff --git a/Detectors/Vertexing/src/SVertexer.cxx b/Detectors/Vertexing/src/SVertexer.cxx
@@ -576,12 +576,28 @@ bool SVertexer::checkV0(const TrackCand& seedP, const TrackCand& seedN, int iP,
 
   bool goodHyp = false;
   std::array<bool, NHypV0> hypCheckStatus{};
-  for (int ipid = 0; ipid < NHypV0; ipid++) {
+  for (int ipid = 0; ipid < NHypV0 && mSVParams->checkV0Hypothesis; ipid++) {
     if (mV0Hyps[ipid].check(p2Pos, p2Neg, p2V0, ptV0)) {
       goodHyp = hypCheckStatus[ipid] = true;
     }
   }
 
+  // apply Podolanski cut to photons
+  if (mSVParams->checkV0Hypothesis && hypCheckStatus[HypV0::Photon]) {
+    float pV0Abs = std::sqrt(p2V0);
+    float pPos = std::sqrt(p2Pos);
+    float p1 = (pV0[0] * pP[0] + pV0[1] * pP[1] + pV0[2] * pP[2]) /
+               (pV0Abs * pPos);
+    // float p2 = (pV0[0] * pN[0] + pV0[1] * pN[1] + pV0[2] * pN[2]) /
+    //            (pV0Abs * seedN.getP());
+    // float pL1 = p1 * seedP.getP();
+    // float pL2 = p2 * seedN.getP();
+    float pT1 = pPos * std::sqrt(1 - p1);
+    if (pT1 > mSVParams->pidCutsPhotonAP) {
+      hypCheckStatus[HypV0::Photon] = false;
+    }
+  }
+
   // apply mass selections for 3-body decay
   bool good3bodyV0Hyp = false;
   for (int ipid = 2; ipid < 4; ipid++) {