[PWGLF] Add lambdastar-deuteron and f0-phi proxy tasks for coalescence studies (#17959)

Co-authored-by: Sushanta Tripathy <sushantatripathy@Sushantas-MacBook-Pro-M4-Max.local>
Co-authored-by: ALICE Action Bot <alibuild@cern.ch>

Author: 3 people

PWGLF/Tasks/Resonances/CMakeLists.txt

@@ -338,3 +338,13 @@ o2physics_add_dpl_workflow(xi1530kaoncorrelation
     SOURCES xi1530kaoncorrelation.cxx
     PUBLIC_LINK_LIBRARIES O2Physics::AnalysisCore
     COMPONENT_NAME Analysis)
+
+o2physics_add_dpl_workflow(f0phiproxy
+    SOURCES f0phiproxy.cxx
+    PUBLIC_LINK_LIBRARIES O2Physics::AnalysisCore
+    COMPONENT_NAME Analysis)
+
+o2physics_add_dpl_workflow(lambdastarproxy
+    SOURCES lambdastarproxy.cxx
+    PUBLIC_LINK_LIBRARIES O2Physics::AnalysisCore
+    COMPONENT_NAME Analysis)

PWGLF/Tasks/Resonances/f0phiproxy.cxx

@@ -0,0 +1,334 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+/// \file f0phiproxy.cxx
+/// \brief task for dipion f0 candidates with a half-momentum kaon proxy and bachelor kaon.
+/// \author Sushanta Tripathy
+
+#include "Common/DataModel/EventSelection.h"
+#include "Common/DataModel/Multiplicity.h"
+#include "Common/DataModel/PIDResponseTOF.h"
+#include "Common/DataModel/PIDResponseTPC.h"
+#include "Common/DataModel/TrackSelectionTables.h"
+
+#include <CommonConstants/PhysicsConstants.h>
+#include <Framework/ASoA.h>
+#include <Framework/AnalysisDataModel.h>
+#include <Framework/AnalysisTask.h>
+#include <Framework/Configurable.h>
+#include <Framework/HistogramRegistry.h>
+#include <Framework/HistogramSpec.h>
+#include <Framework/InitContext.h>
+#include <Framework/OutputObjHeader.h>
+#include <Framework/runDataProcessing.h>
+
+#include <Math/Vector4D.h> // IWYU pragma: keep (do not replace with Math/Vector4Dfwd.h)
+#include <Math/Vector4Dfwd.h>
+
+#include <cmath>
+#include <cstddef>
+#include <cstdint>
+#include <deque>
+#include <map>
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
+using namespace o2;
+using namespace o2::framework;
+
+struct F0phiproxy {
+  using Collisions = soa::Join<aod::Collisions, aod::EvSels, aod::Mults>;
+  using Tracks =
+    soa::Join<aod::Tracks, aod::TracksExtra, aod::TracksDCA,
+              aod::TrackSelection, aod::pidTPCFullPi, aod::pidTOFFullPi,
+              aod::pidTPCFullKa, aod::pidTOFFullKa>;
+  using FourVector = ROOT::Math::PxPyPzMVector;
+  Preslice<Tracks> perCollision = aod::track::collisionId;
+  HistogramRegistry histos{
+    "histos",
+    {},
+    OutputObjHandlingPolicy::AnalysisObject};
+  Configurable<float> vertexMax{"vertexMax", 10.f,
+                                "Maximum absolute vertex z (cm)"};
+  Configurable<bool> requireSel8{"requireSel8", true, "Require sel8"};
+  Configurable<bool> requireINELgt0{"requireINELgt0", true,
+                                    "Require at least one PV track in |eta|<1"};
+  Configurable<float> trackPtMin{"trackPtMin", 0.15f,
+                                 "Minimum track pT (GeV/c)"};
+  Configurable<float> trackEtaMax{"trackEtaMax", 0.8f, "Maximum track |eta|"};
+  Configurable<bool> requireGlobalTrack{"requireGlobalTrack", true,
+                                        "Require global track selection"};
+  Configurable<bool> requirePVContributor{"requirePVContributor", true,
+                                          "Require PV contributor"};
+  Configurable<float> pionTPC{"pionTPC", 3.f, "Pion TPC nSigma cut"};
+  Configurable<float> pionTOF{"pionTOF", 3.f, "Pion TOF veto when matched"};
+  Configurable<float> kaonTPC{"kaonTPC", 3.f, "Kaon TPC nSigma cut"};
+  Configurable<float> kaonTOF{"kaonTOF", 3.f, "Kaon TOF veto when matched"};
+  Configurable<bool> requireTOF{"requireTOF", false, "Require TOF for both species instead of veto-only"};
+  Configurable<float> dipionYMax{"dipionYMax", 0.5f, "Maximum dipion |y|"};
+  Configurable<float> proxyYMax{"proxyYMax", 0.5f,
+                                "Maximum proxy+bachelor |y|"};
+  Configurable<float> dipionMassMin{"dipionMassMin", 0.6f,
+                                    "Lower dipion mass for proxy construction"};
+  Configurable<float> dipionMassMax{"dipionMassMax", 1.4f,
+                                    "Upper dipion mass for proxy construction"};
+  Configurable<int> mixDepth{"mixDepth", 5, "Previous events per mixing bin; zero disables mixing"};
+  Configurable<float> mixZWidth{"mixZWidth", 2.f, "Vertex bin width (cm)"};
+  Configurable<float> mixMultWidth{"mixMultWidth", 20.f,
+                                   "PV multiplicity bin width"};
+
+  struct TrackCandidate {
+    int64_t id;
+    int sign;
+    double px, py, pz;
+    bool hasTOF;
+    [[nodiscard]] FourVector vector(double mass) const
+    {
+      return {px, py, pz, mass};
+    }
+  };
+  struct Event {
+    std::vector<TrackCandidate> pions, kaons;
+  };
+
+  void init(InitContext const&)
+  {
+    if (mixDepth < 0 || mixZWidth <= 0.f || mixMultWidth <= 0.f ||
+        vertexMax <= 0.f || pionTPC <= 0.f || pionTOF <= 0.f ||
+        kaonTPC <= 0.f || kaonTOF <= 0.f || dipionMassMin >= dipionMassMax) {
+      throw std::runtime_error("Invalid F0PhiProxy configuration");
+    }
+    AxisSpec massPi{300, 0.2, 1.7, "m_{#pi#pi} (GeV/c^{2})"};
+    AxisSpec massProxy{600, 0.9, 1.5, "m_{K,proxy K} (GeV/c^{2})"};
+    AxisSpec pt{100, 0., 10., "p_{T} (GeV/c)"};
+    AxisSpec mult{100, 0., 200., "N_{PV}(|#eta|<1)"};
+    AxisSpec charge{3, -0.5, 2.5, "dipion: 0=unlike, 1=++, 2=--"};
+    AxisSpec bachelorCharge{2, -1.5, 1.5, "bachelor charge"};
+    AxisSpec tof{2, -0.5, 1.5, "bachelor has TOF"};
+    histos.add("hEventSelection", "Received; selected", HistType::kTH1D,
+               {{2, 0.5, 2.5}});
+    histos.add("hMixPartners", "Mixing partners;N", HistType::kTH1D,
+               {{101, -0.5, 100.5}});
+    histos.add("hPionTPC", "Quality-selected tracks;pT;nSigmaTPC pion",
+               HistType::kTH2F, {pt, {100, -10., 10.}});
+    histos.add("hPionTOF", "TOF-matched quality tracks;pT;nSigmaTOF pion",
+               HistType::kTH2F, {pt, {100, -10., 10.}});
+    histos.add("hKaonTPC", "Quality-selected tracks;pT;nSigmaTPC kaon",
+               HistType::kTH2F, {pt, {100, -10., 10.}});
+    histos.add("hKaonTOF", "TOF-matched quality tracks;pT;nSigmaTOF kaon",
+               HistType::kTH2F, {pt, {100, -10., 10.}});
+    histos.add("hDipionSE", "Dipion SE", HistType::kTHnSparseF,
+               {massPi, pt, mult, charge});
+    histos.add("hDipionME", "Dipion ME (raw)", HistType::kTHnSparseF,
+               {massPi, pt, mult, charge});
+    // Keep measured dipion mass: no f0 identification by a mass window alone.
+    histos.add("hProxySE", "Dipion plus bachelor proxy SE",
+               HistType::kTHnSparseF,
+               {massProxy, pt, massPi, mult, charge, bachelorCharge, tof});
+    histos.add("hProxyME", "Intact same-event dipion plus mixed bachelor (raw)",
+               HistType::kTHnSparseF,
+               {massProxy, pt, massPi, mult, charge, bachelorCharge, tof});
+    AxisSpec massKK{600, 0.9, 1.5, "m_{KK} (GeV/c^{2})"};
+    histos.add("hPhiKK", "Unlike-sign kaon control SE", HistType::kTHnSparseF,
+               {massKK, pt, mult});
+    histos.add("hPhiKKLikePP", "K+K+ control SE", HistType::kTHnSparseF,
+               {massKK, pt, mult});
+    histos.add("hPhiKKLikeMM", "K-K- control SE", HistType::kTHnSparseF,
+               {massKK, pt, mult});
+    histos.add("hPhiKKMixed", "Unlike-sign kaon control ME (raw)", HistType::kTHnSparseF,
+               {massKK, pt, mult});
+    histos.add("hPhiKKMixedLikePP", "K+K+ control ME (raw)", HistType::kTHnSparseF,
+               {massKK, pt, mult});
+    histos.add("hPhiKKMixedLikeMM", "K-K- control ME (raw)", HistType::kTHnSparseF,
+               {massKK, pt, mult});
+  }
+
+  bool passPID(float tpc, float tof, bool matched, float tpcCut,
+               float tofCut) const
+  {
+    return std::isfinite(tpc) && std::abs(tpc) < tpcCut &&
+           (!requireTOF.value || matched) &&
+           (!matched || (std::isfinite(tof) && std::abs(tof) < tofCut));
+  }
+
+  static int chargeCategory(int a, int b)
+  {
+    return a != b ? 0 : (a > 0 ? 1 : 2);
+  }
+
+  void fillProxy(FourVector const& dipion, TrackCandidate const& first,
+                 TrackCandidate const& second,
+                 std::vector<TrackCandidate> const& kaons, float mult,
+                 bool mixed)
+  {
+    const FourVector constituent(dipion.Px() * 0.5, dipion.Py() * 0.5,
+                                 dipion.Pz() * 0.5,
+                                 constants::physics::MassKaonCharged);
+    const int category = chargeCategory(first.sign, second.sign);
+    for (auto const& kaon : kaons) {
+      if (!mixed && (kaon.id == first.id || kaon.id == second.id)) {
+        continue;
+      }
+      const auto pair =
+        constituent + kaon.vector(constants::physics::MassKaonCharged);
+      if (std::abs(pair.Rapidity()) >= proxyYMax) {
+        continue;
+      }
+      // The neutral dipion has no measured constituent-kaon charge: fill once
+      // per bachelor.
+      if (mixed) {
+        histos.fill(HIST("hProxyME"), pair.M(), pair.Pt(), dipion.M(), mult,
+                    category, kaon.sign, kaon.hasTOF);
+      } else {
+        histos.fill(HIST("hProxySE"), pair.M(), pair.Pt(), dipion.M(), mult,
+                    category, kaon.sign, kaon.hasTOF);
+      }
+    }
+  }
+
+  void fillPhiPair(TrackCandidate const& first, TrackCandidate const& second, float mult, bool mixed)
+  {
+    const auto pair = first.vector(constants::physics::MassKaonCharged) +
+                      second.vector(constants::physics::MassKaonCharged);
+    if (std::abs(pair.Rapidity()) >= proxyYMax.value) {
+      return;
+    }
+    if (mixed) {
+      if (first.sign != second.sign) {
+        histos.fill(HIST("hPhiKKMixed"), pair.M(), pair.Pt(), mult);
+      } else if (first.sign > 0) {
+        histos.fill(HIST("hPhiKKMixedLikePP"), pair.M(), pair.Pt(), mult);
+      } else {
+        histos.fill(HIST("hPhiKKMixedLikeMM"), pair.M(), pair.Pt(), mult);
+      }
+    } else {
+      if (first.sign != second.sign) {
+        histos.fill(HIST("hPhiKK"), pair.M(), pair.Pt(), mult);
+      } else if (first.sign > 0) {
+        histos.fill(HIST("hPhiKKLikePP"), pair.M(), pair.Pt(), mult);
+      } else {
+        histos.fill(HIST("hPhiKKLikeMM"), pair.M(), pair.Pt(), mult);
+      }
+    }
+  }
+
+  void fillPhiControls(Event const& event, std::deque<Event> const& pool, float mult)
+  {
+    for (size_t i = 0; i < event.kaons.size(); ++i) {
+      // Each same-event unordered pair is counted once.
+      for (size_t j = i + 1; j < event.kaons.size(); ++j) {
+        fillPhiPair(event.kaons[i], event.kaons[j], mult, false);
+      }
+      // Includes K+current K-previous and K-current K+previous once each.
+      // Pool insertion occurs after this call; no event is mixed with itself.
+      for (auto const& previous : pool) {
+        for (auto const& second : previous.kaons) {
+          fillPhiPair(event.kaons[i], second, mult, true);
+        }
+      }
+    }
+  }
+
+  void process(Collisions const& collisions, Tracks const& tracks,
+               aod::BCsWithTimestamps const&)
+  {
+    // Local pools cannot retain track IDs across dataframes. Run is part of the
+    // key.
+    std::map<std::pair<int, std::pair<int, int>>, std::deque<Event>> pools;
+    for (auto const& collision : collisions) {
+      histos.fill(HIST("hEventSelection"), 1.);
+      if (std::abs(collision.posZ()) >= vertexMax ||
+          (requireSel8 && !collision.sel8()) ||
+          (requireINELgt0 && collision.multNTracksPVeta1() < 1)) {
+        continue;
+      }
+      histos.fill(HIST("hEventSelection"), 2.);
+      const float mult = collision.multNTracksPVeta1();
+      const int run = collision.bc_as<aod::BCsWithTimestamps>().runNumber();
+      auto& pool =
+        pools[{run,
+               {static_cast<int>(std::floor(collision.posZ() / mixZWidth)),
+                static_cast<int>(std::floor(mult / mixMultWidth))}}];
+      Event event;
+      auto selected = tracks.sliceBy(perCollision, collision.globalIndex());
+      for (auto const& track : selected) {
+        if (track.sign() == 0 || track.pt() < trackPtMin ||
+            std::abs(track.eta()) >= trackEtaMax ||
+            (requireGlobalTrack && !track.isGlobalTrack()) ||
+            (requirePVContributor && !track.isPVContributor())) {
+          continue;
+        }
+        const bool tof = track.hasTOF();
+        histos.fill(HIST("hPionTPC"), track.pt(), track.tpcNSigmaPi());
+        histos.fill(HIST("hKaonTPC"), track.pt(), track.tpcNSigmaKa());
+        if (tof) {
+          histos.fill(HIST("hPionTOF"), track.pt(), track.tofNSigmaPi());
+          histos.fill(HIST("hKaonTOF"), track.pt(), track.tofNSigmaKa());
+        }
+        TrackCandidate candidate{.id = track.globalIndex(), .sign = track.sign(), .px = track.px(), .py = track.py(), .pz = track.pz(), .hasTOF = tof};
+        if (passPID(track.tpcNSigmaPi(), track.tofNSigmaPi(), tof, pionTPC,
+                    pionTOF)) {
+          event.pions.push_back(candidate);
+        }
+        if (passPID(track.tpcNSigmaKa(), track.tofNSigmaKa(), tof, kaonTPC,
+                    kaonTOF)) {
+          event.kaons.push_back(candidate);
+        }
+      }
+      histos.fill(HIST("hMixPartners"), pool.size());
+      for (size_t i = 0; i < event.pions.size(); ++i) {
+        auto const& first = event.pions[i];
+        for (size_t j = i + 1; j < event.pions.size(); ++j) {
+          auto const& second = event.pions[j];
+          const auto pair = first.vector(constants::physics::MassPionCharged) +
+                            second.vector(constants::physics::MassPionCharged);
+          if (std::abs(pair.Rapidity()) >= dipionYMax) {
+            continue;
+          }
+          histos.fill(HIST("hDipionSE"), pair.M(), pair.Pt(), mult,
+                      chargeCategory(first.sign, second.sign));
+          if (pair.M() < dipionMassMin || pair.M() >= dipionMassMax) {
+            continue;
+          }
+          fillProxy(pair, first, second, event.kaons, mult, false);
+          for (auto const& previous : pool) {
+            fillProxy(pair, first, second, previous.kaons, mult, true);
+          }
+        }
+        for (auto const& previous : pool) {
+          for (auto const& second : previous.pions) {
+            const auto pair =
+              first.vector(constants::physics::MassPionCharged) +
+              second.vector(constants::physics::MassPionCharged);
+            if (std::abs(pair.Rapidity()) < dipionYMax) {
+              histos.fill(HIST("hDipionME"), pair.M(), pair.Pt(), mult,
+                          chargeCategory(first.sign, second.sign));
+            }
+          }
+        }
+      }
+      fillPhiControls(event, pool, mult);
+      if (mixDepth > 0) {
+        pool.push_back(std::move(event));
+        if (pool.size() > static_cast<size_t>(mixDepth.value)) {
+          pool.pop_front();
+        }
+      }
+    }
+  }
+};
+
+WorkflowSpec defineDataProcessing(ConfigContext const& context)
+{
+  return WorkflowSpec{
+    adaptAnalysisTask<F0phiproxy>(context)};
+}