From 567ae6e5fa9aa1e36aaaf9d4e56dafd5b3009657 Mon Sep 17 00:00:00 2001
From: Andrii Verbytskyi <andrii.verbytskyi@cern.ch>
Date: Wed, 17 Nov 2021 14:27:31 +0100
Subject: [PATCH] Fix the wrong number of beam particles in SHERPA-MC in the
HepMC3 branch.
---
Generators/EvgenProdTools/src/FixHepMC.cxx | 10 ++++++++++
Generators/Sherpa_i/src/Sherpa_i.cxx | 3 ++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/Generators/EvgenProdTools/src/FixHepMC.cxx b/Generators/EvgenProdTools/src/FixHepMC.cxx
index 45fbe8675a3b..1f4ba737627c 100644
--- a/Generators/EvgenProdTools/src/FixHepMC.cxx
+++ b/Generators/EvgenProdTools/src/FixHepMC.cxx
@@ -46,6 +46,7 @@ StatusCode FixHepMC::execute() {
// Some heuristics
std::vector<HepMC::GenParticlePtr> tofix;
+ // Herwig7+EvtGen has problems with bad pdg id. 16.11.2021
std::vector<HepMC::GenParticlePtr> bad_pdg_id_particles;
for (auto ip: evt->particles()) {
// Skip this particle if (somehow) its pointer is null
@@ -60,6 +61,15 @@ StatusCode FixHepMC::execute() {
if (pdg_id == 43 || pdg_id == 44 || pdg_id == -43 || pdg_id == -44 || pdg_id == 30353 || pdg_id == -30353 || pdg_id == 30343 || pdg_id == -30343) bad_pdg_id_particles.push_back(ip);
}
+ // SHERPA has problems with bad beam particles. 16.11.2021
+ auto beams_t = evt->beams();
+ if (beams_t.size() != 2) {
+ ATH_MSG_INFO("Invalid number of beam particles " << beams_t.size() << ". Will try to fix.");
+ std::vector<HepMC::GenParticlePtr> bparttoremove;
+ for (auto bpart: beams_t) if (bpart->id() == 0 && bpart->production_vertex()) bparttoremove.push_back(bpart);
+ for (auto bpart: bparttoremove) bpart->production_vertex()->remove_particle_out(bpart);
+ }
+
/// AV: In case we have 3 particles, we try to add a vertex that correspond to 1->2 and 1->1 splitting.
if (tofix.size() == 3 || tofix.size() == 2) {
size_t no_endv = 0;
diff --git a/Generators/Sherpa_i/src/Sherpa_i.cxx b/Generators/Sherpa_i/src/Sherpa_i.cxx
index 33dc2d47c02f..6af340906e98 100644
--- a/Generators/Sherpa_i/src/Sherpa_i.cxx
+++ b/Generators/Sherpa_i/src/Sherpa_i.cxx
@@ -237,7 +237,8 @@ StatusCode Sherpa_i::fillEvt(HepMC::GenEvent* event) {
#ifdef HEPMC3
// units correction
- event->set_units(HepMC3::Units::MEV, HepMC3::Units::MM);
+ event->set_units(HepMC3::Units::GEV, HepMC3::Units::MM);
+ GeVToMeV(event);
//uncomment to list HepMC3 events
// std::cout << " print::listing Sherpa " << std::endl;
// HepMC3::Print::listing(std::cout, *event);
--
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