[PWGLF] ebyeMaker: add pt dependent dca cuts (AliceO2Group#8013)

* [PWGLF] ebyeMaker.cxx: add pt-dependent dca cuts

* [PWGLF] ebyeMaker: use positive pt to get pt-dependent DCA cut

---------

Co-authored-by: Mario Ciacco <[email protected]>

Author: maciacco

PWGLF/TableProducer/Nuspex/ebyeMaker.cxx

@@ -276,6 +276,8 @@ struct ebyeMaker {
   Configurable<float> v0setting_nsigmatpc{"v0setting_nsigmatpc", 4.f, "nsigmatpc"};
   Configurable<float> lambdaMassCut{"lambdaMassCut", 0.02f, "maximum deviation from PDG mass (for QA histograms)"};
 
+  Configurable<bool> constDCASel{"constDCASel", true, "use DCA selections independent of pt"};
+
   Configurable<float> antidItsClsSizeCut{"antidItsClsSizeCut", 1.e-10f, "cluster size cut for antideuterons"};
   Configurable<float> antidPtItsClsSizeCut{"antidPtItsClsSizeCut", 10.f, "pt for cluster size cut for antideuterons"};
 
@@ -359,6 +361,11 @@ struct ebyeMaker {
     return sum / track.itsNCls();
   }
 
+  float dcaSigma(float const& pt)
+  {
+    return 0.0105 + 0.0350 / std::pow(std::abs(pt), 1.1);
+  }
+
   template <class Bc>
   void initCCDB(Bc const& bc)
   {
@@ -477,9 +484,9 @@ struct ebyeMaker {
       mask |= kChi2TPCTight;
     else if (track.tpcchi2 < cfgTrackSels->get("chi2TpcMid"))
       mask |= kChi2TPCMid;
-    if (std::abs(track.dcaxypv) < cfgTrackSels->get("dcaxyTight"))
+    if (std::abs(track.dcaxypv) < cfgTrackSels->get("dcaxyTight") * (constDCASel ? 1. : dcaSigma(track.pt)))
       mask |= kDCAxyTight;
-    else if (std::abs(track.dcaxypv) < cfgTrackSels->get("dcaxyMid"))
+    else if (std::abs(track.dcaxypv) < cfgTrackSels->get("dcaxyMid") * (constDCASel ? 1. : dcaSigma(track.pt)))
       mask |= kDCAxyMid;
     if (std::abs(track.dcazpv) < cfgTrackSels->get("dcazTight"))
       mask |= kDCAzTight;
@@ -591,7 +598,10 @@ struct ebyeMaker {
       if (dca > cfgDcaSels->get("dca")) { // dca
         continue;
       }
-      if (std::abs(dcaInfo[0]) > cfgDcaSels->get("dcaxy") || std::abs(dcaInfo[1]) > cfgDcaSels->get("dcaz")) { // dcaxy and dcaz
+      if (std::abs(dcaInfo[1]) > cfgDcaSels->get("dcaz")) { // dcaz
+        continue;
+      }
+      if (std::abs(dcaInfo[0]) > cfgDcaSels->get("dcaxy") * (constDCASel ? 1. : dcaSigma(track.pt()))) { // dcaxy
         continue;
       }
       histos.fill(HIST("QA/tpcSignal"), track.tpcInnerParam(), track.tpcSignal());