[PWGEM] Add histogram that retrieves DCAz vs. Pt for V0 in data and MC (#9956)

Co-authored-by: Youssef El Mard Bouziani <youssef.el.mard.bouziani@cern.ch>

Author: yelmardb

PWGEM/PhotonMeson/Tasks/pcmQC.cxx

@@ -156,6 +156,7 @@ struct PCMQC {
     fRegistry.add("V0/hThetaResolution", "#theta resolution;p_{#gamma} (GeV/c);#Delta#theta (rad.)", kTH2F, {{1000, 0.0f, 10}, {100, 0, 0.01}}, false);
     fRegistry.add("V0/hPhiResolution", "#varphi resolution;p_{#gamma} (GeV/c);#Delta#varphi (rad.)", kTH2F, {{1000, 0.0f, 10}, {100, 0, 0.01}}, false);
     fRegistry.add("V0/hNgamma", "Number of #gamma candidates per collision", kTH1F, {{101, -0.5f, 100.5f}});
+    fRegistry.add("V0/hDCAz_Pt", "DCA to PV vs. p_{T} (GeV/c);DCA_{z} (cm);p_{T} (GeV/c)", kTH2F, {{200, -5.f, +5.f}, {1000, 0.0f, 10}}, false);
 
     // v0leg info
     fRegistry.add("V0Leg/hPt", "pT;p_{T,e} (GeV/c)", kTH1F, {{1000, 0.0f, 10}}, false);
@@ -316,6 +317,7 @@ struct PCMQC {
     fRegistry.fill(HIST("V0/hEtaResolution"), v0.p(), getEtaResolution(v0));
     fRegistry.fill(HIST("V0/hThetaResolution"), v0.p(), getThetaResolution(v0));
     fRegistry.fill(HIST("V0/hPhiResolution"), v0.p(), getPhiResolution(v0));
+    fRegistry.fill(HIST("V0/hDCAz_Pt"), v0.dcaZtopv(), v0.pt());
   }
 
   template <typename TLeg>

PWGEM/PhotonMeson/Tasks/pcmQCMC.cxx

@@ -206,6 +206,7 @@ struct PCMQCMC {
     fRegistry.add("V0/primary/hPtGen_DeltaPhi", "photon #varphi resolution;p_{T}^{gen} (GeV/c);#varphi^{rec} - #varphi^{gen} (rad.)", kTH2F, {{1000, 0, 10}, {400, -1.0f, 1.0f}}, true);
     fRegistry.add("V0/primary/hXY_Photon_MC", "X vs. Y of true photon conversion point.;X (cm);Y (cm)", kTH2F, {{400, -100.0f, +100}, {400, -100, +100}}, true);
     fRegistry.add("V0/primary/hRZ_Photon_MC", "R vs. Z of true photon conversion point;Z (cm);R_{xy} (cm)", kTH2F, {{200, -100.0f, +100}, {200, 0, 100}}, true);
+    fRegistry.add("V0/primary/hDCAz_Pt", "DCA to PV vs. p_{T} (GeV/c);DCA_{z} (cm);p_{T} (GeV/c)", kTH2F, {{200, -5.f, +5.f}, {1000, 0.0f, 20}}, true);
     fRegistry.addClone("V0/primary/", "V0/fromWD/"); // from weak decay
     fRegistry.addClone("V0/primary/", "V0/fromHS/"); // from hadronic shower in detector materials
 
@@ -381,6 +382,7 @@ struct PCMQCMC {
     fRegistry.fill(HIST("V0/") + HIST(mcphoton_types[mctype]) + HIST("hConvPoint_diffZ"), mcleg.vz(), v0.vz() - mcleg.vz());
     fRegistry.fill(HIST("V0/") + HIST(mcphoton_types[mctype]) + HIST("hXY_Photon_MC"), mcleg.vx(), mcleg.vy());
     fRegistry.fill(HIST("V0/") + HIST(mcphoton_types[mctype]) + HIST("hRZ_Photon_MC"), mcleg.vz(), std::sqrt(std::pow(mcleg.vx(), 2) + std::pow(mcleg.vy(), 2)));
+    fRegistry.fill(HIST("V0/") + HIST(mcphoton_types[mctype]) + HIST("hDCAz_Pt"), v0.dcaZtopv(), v0.pt());
   }
 
   template <int mctype, typename TLeg>