From 3dc7ce11df414a987a2ae87c0a61e6d54239e73f Mon Sep 17 00:00:00 2001
From: Dmitry Kalinkin <dmitry.kalinkin@gmail.com>
Date: Mon, 2 Dec 2024 14:41:29 -0500
Subject: [PATCH] UndoAfterBurner: skip particles that are not created by
 generator (#1683)

### Briefly, what does this PR introduce?

This provides a file size reduction:
```
before 3.1M
after 2.7M
```

### What kind of change does this PR introduce?
- [ ] Bug fix (issue #__)
- [x] New feature (issue #__)
- [ ] Documentation update
- [ ] Other: __

### Please check if this PR fulfills the following:
- [ ] Tests for the changes have been added
- [ ] Documentation has been added / updated
- [ ] Changes have been communicated to collaborators

### Does this PR introduce breaking changes? What changes might users
need to make to their code?
Unlikely.

### Does this PR change default behavior?
Yes
---
 src/algorithms/reco/UndoAfterBurner.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/algorithms/reco/UndoAfterBurner.cc b/src/algorithms/reco/UndoAfterBurner.cc
index 69430e97e..129674f47 100644
--- a/src/algorithms/reco/UndoAfterBurner.cc
+++ b/src/algorithms/reco/UndoAfterBurner.cc
@@ -115,6 +115,9 @@ void eicrecon::UndoAfterBurner::process(
 
     // Now, loop through events and apply operations to the MCparticles
     for (const auto& p: *mcparts) {
+        if (p.isCreatedInSimulation()) {
+            continue;
+        }
 
         ROOT::Math::PxPyPzEVector mc(p.getMomentum().x, p.getMomentum().y, p.getMomentum().z, p.getEnergy());