[PWGLF] K892PM Flow: Allow modifying v2 axis (#9700)

Author: BongHwi

PWGLF/Tasks/Resonances/chk892Flow.cxx

@@ -116,6 +116,7 @@ struct Chk892Flow {
   ConfigurableAxis cfgBinsVtxZ{"cfgBinsVtxZ", {VARIABLE_WIDTH, -10.0, -9.0, -8.0, -7.0, -6.0, -5.0, -4.0, -3.0, -2.0, -1.0, 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0}, "Binning of the z-vertex axis"};
   Configurable<int> cNbinsDiv{"cNbinsDiv", 1, "Integer to divide the number of bins"};
   Configurable<int> cNbinsDivQA{"cNbinsDivQA", 1, "Integer to divide the number of bins for QA"};
+  ConfigurableAxis cfgAxisV2{"cfgAxisV2", {200, -2, 2}, "Binning of the v2 axis"};
 
   /// Event cuts
   o2::analysis::CollisonCuts colCuts;
@@ -243,7 +244,7 @@ struct Chk892Flow {
     AxisSpec epAxis = {100, -1.0 * constants::math::PI, constants::math::PI};
     AxisSpec ptAxis = {cfgBinsPt, "#it{p}_{T} (GeV/#it{c})"};
     AxisSpec ptAxisQA = {cfgBinsPtQA, "#it{p}_{T} (GeV/#it{c})"};
-    AxisSpec v2Axis = {200, -1, 1, "#v_{2}"};
+    AxisSpec v2Axis = {cfgAxisV2, "#v_{2}"};
     AxisSpec radiusAxis = {50, 0, 5, "Radius (cm)"};
     AxisSpec cpaAxis = {30, 0.97, 1.0, "CPA"};
     AxisSpec tauAxis = {250, 0, 25, "Lifetime (cm)"};
@@ -868,7 +869,7 @@ struct Chk892Flow {
                 lDaughterRot.RotateZ(lRotAngle);
                 lResonanceRot = lDecayDaughter_bach + lDaughterRot;
               }
-              auto lPhiMinusPsiKstar = RecoDecay::constrainAngle(lResonanceRot.Phi() - lEPDet, 0.0, 1); // constrain angle to range 0, Pi
+              auto lPhiMinusPsiKstar = RecoDecay::constrainAngle(lResonanceRot.Phi() - lEPDet, 0.0, 2); // constrain angle to range 0, Pi
               auto v2Kstar = std::cos(static_cast<float>(nmode) * lPhiMinusPsiKstar);
               typeKstar = bTrack.sign() > 0 ? BinType::kKstarP_Rot : BinType::kKstarN_Rot;
               histos.fill(HIST("hInvmass_Kstar"), typeKstar, lCentrality, lResonanceRot.Pt(), lResonanceRot.M(), v2Kstar);