[Rivet-svn] r4230 - in trunk: . include/Rivet src/Core

[blackhole at projects.hepforge.org]

Author: buckley
Date: Fri Mar 22 16:12:41 2013
New Revision: 4230

Log:
Adding Particle::fromDecay() method.

Modified:
   trunk/ChangeLog
   trunk/include/Rivet/Particle.hh
   trunk/src/Core/Particle.cc

Modified: trunk/ChangeLog
==============================================================================
--- trunk/ChangeLog	Fri Mar 22 16:11:47 2013	(r4229)
+++ trunk/ChangeLog	Fri Mar 22 16:12:41 2013	(r4230)
@@ -1,3 +1,7 @@
+2013-03-22  Andy Buckley  <andy.buckley at cern.ch>
+
+	* Adding Particle::fromDecay() method.
+
 2013-03-09  Andy Buckley  <andy.buckley at cern.ch>
 
 	* Version bump to 2.0.0b1 in anticipation of first beta release.

Modified: trunk/include/Rivet/Particle.hh
==============================================================================
--- trunk/include/Rivet/Particle.hh	Fri Mar 22 16:11:47 2013	(r4229)
+++ trunk/include/Rivet/Particle.hh	Fri Mar 22 16:12:41 2013	(r4230)
@@ -79,21 +79,38 @@
       return momentum().mass();
     }
 
+
     /// @todo Enable?
     // /// The charge of this Particle.
     // double charge() const {
     //   return PID::charge(*this);
     // }
 
-    /// @todo Enable?    // /// Three times the charge of this Particle (i.e. integer multiple of smallest quark charge).
+    /// @todo Enable?
+    // /// Three times the charge of this Particle (i.e. integer multiple of smallest quark charge).
     // int threeCharge() const {
     //   return PID::threeCharge(*this);
     // }
 
-
     /// Check whether a given PID is found in the GenParticle's ancestor list
+    ///
+    /// @note This question is valid in MC, but may not be answerable
+    /// experimentally -- use this function with care when replicating
+    /// experimental analyses!
     bool hasAncestor(PdgId pdg_id) const;
 
+    /// @brief Determine whether the particle is from a hadron or tau decay
+    ///
+    /// Specifically, walk up the ancestor chain until a status 2 hadron or
+    /// tau is found, if at all.
+    ///
+    /// @note This question is valid in MC, but may not be answerable
+    /// experimentally -- use this function with care when replicating
+    /// experimental analyses!
+    bool fromDecay() const;
+
+    /// @todo Add methods like fromS/C/BHadron(), fromTau()?
+
 
   private:
 

Modified: trunk/src/Core/Particle.cc
==============================================================================
--- trunk/src/Core/Particle.cc	Fri Mar 22 16:11:47 2013	(r4229)
+++ trunk/src/Core/Particle.cc	Fri Mar 22 16:12:41 2013	(r4230)
@@ -1,10 +1,12 @@
 #include "Rivet/Particle.hh"
 #include "Rivet/RivetBoost.hh"
+#include "Rivet/Tools/ParticleIdUtils.hh"
 
 namespace Rivet {
 
 
   bool Particle::hasAncestor(PdgId pdg_id) const {
+    /// @todo Shouldn't a const vertex be being returned? Ah, HepMC...
     GenVertex* prodVtx = genParticle()->production_vertex();
     if (prodVtx == 0) return false;
     foreach (const GenParticle* ancestor, particles(prodVtx, HepMC::ancestors)) {
@@ -12,6 +14,18 @@
     }
     return false;
   }
+
+
+  bool Particle::fromDecay() const {
+    /// @todo Shouldn't a const vertex be being returned? Ah, HepMC...
+    GenVertex* prodVtx = genParticle()->production_vertex();
+    if (prodVtx == NULL) return false;
+    foreach (const GenParticle* ancestor, particles(prodVtx, HepMC::ancestors)) {
+      const PdgId pid = ancestor->pdg_id();
+      if (ancestor->status() == 2 && (PID::isHadron(pid) || abs(pid) == TAU)) return true;
+    }
+    return false;
+  }
 
 
 }