Update and rename MC/config/PWGHF/external/generator/generator_pythia8_gaptriggered_nonhfe.C to MC/config/PWGHF/trigger/selectNonHfe.C

remove gaptrigger and add trigger selection

Author: rashigupt

MC/config/PWGHF/external/generator/generator_pythia8_gaptriggered_nonhfe.C

@@ -0,0 +1,39 @@
+#include <TParticle.h>
+#include "Generators/Trigger.h"
+#include <vector>
+#include <TMath.h>
+
+///============================================================================
+
+/// Select π⁰ and η within a given rapidity window for enhancement
+/// pdgPartForAccCut: PDG of the particle to select (111=π⁰, 221=η)
+/// minNb: minimum number of such particles per event for enhancement
+
+////  authors: Rashi Gupta (rashi.gupta@cern.ch)
+///  authors: Ravindra Singh (ravindra.singh@cern.ch)
+/// ============================================================================
+
+
+
+
+o2::eventgen::Trigger selectPionEtaWithinAcc(Int_t pdgPartForAccCut = 111; 221, double rapidityMin = -1.5, double rapidityMax = 1.5, int minNb = 1)
+{
+    return [pdgPartForAccCut, rapidityMin, rapidityMax, minNb](const std::vector<TParticle>& particles) -> bool {
+        int count = 0;
+        for (const auto& particle : particles) {
+            Int_t pdg = TMath::Abs(particle.GetPdgCode());
+            if (pdg == pdgPartForAccCut) { // select π⁰ (111) or η (221)
+                double y = particle.Y();
+                if (y >= rapidityMin && y <= rapidityMax) {
+                    count++;
+                }
+            }
+        }
+
+        // Only accept events with at least minNb π⁰/η
+        if (count >= minNb)
+            return kTRUE;
+        else
+            return kFALSE;
+    };
+}