From dc1625ec3df606d3ca8502a274a857caf29780b5 Mon Sep 17 00:00:00 2001
From: anehrkor <alexander.nehrkorn@cern.ch>
Date: Fri, 29 May 2015 16:25:34 +0200
Subject: [PATCH] New cleaner module that works also if tau is made up of
 combination of pf charged hadrons and tracks -> solves rare problem with
 3-prongs having charge +/-3.

---
 .../plugins/RecoTauChargeCleanerPlugin.cc     | 59 +++++++++++++++++++
 .../RecoTau/python/RecoTauCleanerPlugins.py   | 12 ++++
 .../RecoTau/python/RecoTauCleaner_cfi.py      |  2 +-
 3 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 RecoTauTag/RecoTau/plugins/RecoTauChargeCleanerPlugin.cc

diff --git a/RecoTauTag/RecoTau/plugins/RecoTauChargeCleanerPlugin.cc b/RecoTauTag/RecoTau/plugins/RecoTauChargeCleanerPlugin.cc
new file mode 100644
index 0000000000000..75a03751191a9
--- /dev/null
+++ b/RecoTauTag/RecoTau/plugins/RecoTauChargeCleanerPlugin.cc
@@ -0,0 +1,59 @@
+/*
+ * Original author: Alexander Nehrkorn (RWTH Aachen)
+ *
+ * Description:
+ * This module rejects tau candidates that do not have unit charge.
+ * It takes the fact into account that taus do not necessarily need
+ * to be created from PF charged hadrons only but can be created
+ * from a combination of PF charged hadrons and tracks.
+ *
+ */
+
+#include "RecoTauTag/RecoTau/interface/RecoTauBuilderPlugins.h"
+#include "DataFormats/TauReco/interface/PFTau.h"
+#include "DataFormats/TauReco/interface/PFTauFwd.h"
+
+namespace reco { namespace tau {
+
+class RecoTauChargeCleanerPlugin : public RecoTauCleanerPlugin
+{
+public:
+	explicit RecoTauChargeCleanerPlugin(const edm::ParameterSet&, edm::ConsumesCollector &&iC);
+	~RecoTauChargeCleanerPlugin() {}
+	double operator()(const PFTauRef& tau) const override;
+
+private:
+	std::vector<unsigned> nprongs_;
+	double failResult_;
+	int charge_;
+};
+
+RecoTauChargeCleanerPlugin::RecoTauChargeCleanerPlugin(const edm::ParameterSet& pset, edm::ConsumesCollector &&iC)
+	: RecoTauCleanerPlugin(pset,std::move(iC)),
+	  nprongs_(pset.getParameter<std::vector<unsigned> >("nprongs")),
+	  failResult_(pset.getParameter<double>("selectionFailValue")),
+	  charge_(pset.getParameter<int>("passForCharge"))
+{}
+
+double RecoTauChargeCleanerPlugin::operator()(const PFTauRef& cand) const
+{
+	int charge = 0;
+	unsigned nChargedPFCandidate(0), nTrack(0);
+	for(unsigned iSignalCand = 0; iSignalCand < cand->signalTauChargedHadronCandidates().size(); iSignalCand++){
+		charge += cand->signalTauChargedHadronCandidates().at(iSignalCand).charge();
+		if(cand->signalTauChargedHadronCandidates().at(iSignalCand).algoIs(reco::PFRecoTauChargedHadron::kChargedPFCandidate)) nChargedPFCandidate++;
+		else if(cand->signalTauChargedHadronCandidates().at(iSignalCand).algoIs(reco::PFRecoTauChargedHadron::kTrack)) nTrack++;
+	}
+
+	for(auto nprong : nprongs_){
+		if(nChargedPFCandidate+nTrack == nprong) return abs(charge)-charge_;
+	}
+
+	return failResult_;
+}
+
+}}
+
+#include "FWCore/Framework/interface/MakerMacros.h"
+
+DEFINE_EDM_PLUGIN(RecoTauCleanerPluginFactory, reco::tau::RecoTauChargeCleanerPlugin, "RecoTauChargeCleanerPlugin");
diff --git a/RecoTauTag/RecoTau/python/RecoTauCleanerPlugins.py b/RecoTauTag/RecoTau/python/RecoTauCleanerPlugins.py
index 09687d9dfa2ac..8dcfc7df1ca76 100644
--- a/RecoTauTag/RecoTau/python/RecoTauCleanerPlugins.py
+++ b/RecoTauTag/RecoTau/python/RecoTauCleanerPlugins.py
@@ -28,6 +28,18 @@
     selectionFailValue = cms.double(0),
 )
 
+# similar to unitCharge but handles also cases where tau is made up of
+# a combination of tracks and pf charged hadrons
+charge = cms.PSet(
+    name = cms.string("Charge"),
+    plugin = cms.string("RecoTauChargeCleanerPlugin"),
+    # cleaner is applied to decay modes with the number of prongs given here
+    nprongs = cms.vuint32(1,3),
+    # taus with charge != 1 are rejected
+    passForCharge = cms.int32(1),
+    selectionFailValue = cms.double(0),
+)
+
 # Prefer taus with pt greater 15
 ptGt15 = cms.PSet(
     name = cms.string("PtGt15"),
diff --git a/RecoTauTag/RecoTau/python/RecoTauCleaner_cfi.py b/RecoTauTag/RecoTau/python/RecoTauCleaner_cfi.py
index 30d65dd479550..d387946755de3 100644
--- a/RecoTauTag/RecoTau/python/RecoTauCleaner_cfi.py
+++ b/RecoTauTag/RecoTau/python/RecoTauCleaner_cfi.py
@@ -6,7 +6,7 @@
     src = cms.InputTag("combinatoricRecoTaus"),
     cleaners = cms.VPSet(
         # Reject taus that have charge == 3
-        cleaners.unitCharge,
+        cleaners.charge,
         # Reject taus that are not within DR<0.1 of the jet axis
         #cleaners.matchingConeCut,
         # Reject taus that fail HPS selections