From cc2934d5b418b414131d36727aed4f1ca07c049b Mon Sep 17 00:00:00 2001
From: N-Plx <plxn@tuta.io>
Date: Wed, 11 Nov 2026 16:51:30 -0600
Subject: [PATCH] Added gemc short codes for tritium, he3 and alpha in the pdg
 database

---
 .../src/main/java/org/jlab/clas/pdg/PDGDatabase.java      | 6 +++++-
 .../mc/src/main/java/org/jlab/service/mc/TruthMatch.java  | 8 +++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/common-tools/clas-physics/src/main/java/org/jlab/clas/pdg/PDGDatabase.java b/common-tools/clas-physics/src/main/java/org/jlab/clas/pdg/PDGDatabase.java
index e607cc34c0..1d19638dc8 100644
--- a/common-tools/clas-physics/src/main/java/org/jlab/clas/pdg/PDGDatabase.java
+++ b/common-tools/clas-physics/src/main/java/org/jlab/clas/pdg/PDGDatabase.java
@@ -60,7 +60,11 @@ private static HashMap<Integer, PDGParticle> initDatabase() {
                 particleMap.put(12, new PDGParticle("nue-", 14, 4, 0.320e-6, 0));
         particleMap.put(-12, new PDGParticle("nue+", -14, 4, 0.320e-6, 0));
         particleMap.put(22, new PDGParticle("gamma", 22, 1, 0.000, 0));
-        particleMap.put(45, new PDGParticle("d", 45, 45,1.87705, 1)); // This is not a PDG code.
+        particleMap.put(45, new PDGParticle("d", 45, 45,1.87705, 1));
+        // geant3 codes used by gemc in MC::Particle for light ions (not PDG codes; PDG entries below)
+        particleMap.put(46, new PDGParticle("TRITON", 46, 46, 2.80943, 1));
+        particleMap.put(47, new PDGParticle("ALPHA",  47, 47, 3.7284,  2));
+        particleMap.put(49, new PDGParticle("HE3",    49, 49, 2.80941, 2));
                 
         //Light mesons
                 particleMap.put(211, new PDGParticle("pi+", 211, 8, 0.13957018, 1));
diff --git a/reconstruction/mc/src/main/java/org/jlab/service/mc/TruthMatch.java b/reconstruction/mc/src/main/java/org/jlab/service/mc/TruthMatch.java
index 310c4788cd..ff7c2eb903 100644
--- a/reconstruction/mc/src/main/java/org/jlab/service/mc/TruthMatch.java
+++ b/reconstruction/mc/src/main/java/org/jlab/service/mc/TruthMatch.java
@@ -5,6 +5,7 @@
 import org.jlab.io.base.DataBank;
 import org.jlab.io.base.DataEvent;
 import org.jlab.clas.pdg.PDGDatabase;
+import org.jlab.clas.pdg.PDGParticle;
 import java.util.*;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -2018,7 +2019,12 @@ void CalculateMatchCuality(DataEvent event, List<MCRecMatch> mcp, List<MCRecMatc
         for (int j = 0; j < mcp.size(); j++) {
             MCRecMatch mcMatch = mcp.get(j);
             Integer pid = mcPartBank.getInt("pid", j);
-            Integer charge = PDGDatabase.getParticleById(pid).charge();
+            PDGParticle part = PDGDatabase.getParticleById(pid);
+            if (part == null) {          // unknown species get quality = 0
+                mcMatch.quality = 0.F;
+                continue;
+            }
+            Integer charge = part.charge();
             //System.out.println("pid = " + mcPartBank.getInt("pid", j) + "    Charge = " + charge);
             Float quality = 0.F;