pythia8130 distributed with AliRoot

[u/mrichter/AliRoot.git] / PYTHIA8 / pythia8130 / include / ProcessLevel.h

diff --git a/PYTHIA8/pythia8130/include/ProcessLevel.h b/PYTHIA8/pythia8130/include/ProcessLevel.h
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+// ProcessLevel.h is a part of the PYTHIA event generator.
+// Copyright (C) 2008 Torbjorn Sjostrand.
+// PYTHIA is licenced under the GNU GPL version 2, see COPYING for details.
+// Please respect the MCnet Guidelines, see GUIDELINES for details.
+
+// This file contains the main class for process-level event generation.
+// ProcessLevel: administrates the selection of "hard" process.
+
+#ifndef Pythia8_ProcessLevel_H
+#define Pythia8_ProcessLevel_H
+
+#include "Basics.h"
+#include "BeamParticle.h"
+#include "Event.h"
+#include "Info.h"
+#include "ParticleData.h"
+#include "PartonDistributions.h"
+#include "ProcessContainer.h"
+#include "PythiaStdlib.h"
+#include "ResonanceDecays.h"
+#include "Settings.h"
+#include "SigmaTotal.h"
+#include "SusyLesHouches.h"
+#include "UserHooks.h"
+
+namespace Pythia8 {
+  
+//**************************************************************************
+
+// The ProcessLevel class contains the top-level routines to generate
+// the characteristic "hard" process of an event.
+
+class ProcessLevel {
+
+public:
+
+  // Constructor. 
+  ProcessLevel() : iLHACont(-1) {} 
+
+  // Destructor to delete processes in containers.
+  ~ProcessLevel();
+ 
+  // Initialization.
+  bool init( Info* infoPtrIn, BeamParticle* beamAPtrIn, 
+    BeamParticle* beamBPtrIn, SigmaTotal* sigmaTotPtrIn, bool doLHAin, 
+    SusyLesHouches* slhaPtrIn, UserHooks* userHooksPtrIn, 
+    vector<SigmaProcess*>& sigmaPtrs, ostream& os = cout);
+
+  // Store or replace Les Houches pointer.
+  void setLHAPtr( LHAup* lhaUpPtrIn) {lhaUpPtr = lhaUpPtrIn;
+  if (iLHACont >= 0) containerPtrs[iLHACont]->setLHAPtr(lhaUpPtr);}
+ 
+  // Generate the next "hard" process.
+  bool next( Event& process); 
+
+  // Accumulate and update statistics (after possible user veto).
+  void accumulate();
+
+  // Print statistics on cross sections and number of events.
+  void statistics(bool reset = false, ostream& os = cout);
+
+  // Add any junctions to the process event record list. 
+  void findJunctions( Event& junEvent);
+
+private: 
+
+  // Generic info for process generation.
+  bool   doSecondHard, allHardSame, noneHardSame, someHardSame, doResDecays;
+  int    nImpact, startColTag2;
+  double sigmaND, sumImpactFac, sum2ImpactFac;
+
+  // Vector of containers of internally-generated processes.
+  vector<ProcessContainer*> containerPtrs;
+  int    iContainer, iLHACont;
+  double sigmaMaxSum;
+
+  // Ditto for optional choice of a second hard process.
+  vector<ProcessContainer*> container2Ptrs;
+  int    i2Container;
+  double sigma2MaxSum;
+
+  // Pointer to various information on the generation.
+  Info*           infoPtr;
+
+  // Pointers to the two incoming beams.
+  BeamParticle*   beamAPtr;
+  BeamParticle*   beamBPtr;
+
+  // Pointer to SigmaTotal object needed to handle soft QCD processes.
+  SigmaTotal*     sigmaTotPtr;
+
+  // Pointer to SusyLesHouches object for interface to SUSY spectra.
+  SusyLesHouches* slhaPtr;
+
+  // Pointer to userHooks object for user interaction with program.
+  UserHooks*      userHooksPtr;
+
+  // Pointer to LHAup for generating external events.
+  LHAup*          lhaUpPtr;
+
+  // Common alphaStrong and alphaElectromagnetic calculation for SigmaProcess.
+  AlphaStrong     alphaS;
+  AlphaEM         alphaEM;
+
+  // Initialization routine for SUSY spectra.
+  bool initSLHA();
+
+  // ResonanceDecay object does sequential resonance decays.
+  ResonanceDecays resonanceDecays;
+
+  // Generate the next event with one interaction.
+  bool nextOne( Event& process);
+
+  // Generate the next event with two hard interactions.
+  bool nextTwo( Event& process);
+
+  // Append the second to the first process list.
+  void combineProcessRecords( Event& process, Event& process2);
+
+  // Check that colours match up.
+  bool checkColours( Event& process);
+
+  // Print statistics when two hard processes allowed.
+  void statistics2(bool reset, ostream& os = cout);
+
+  // Statistics for Les Houches event classification.
+  vector<int> codeLHA, nEvtLHA;
+
+};
+
+//**************************************************************************
+
+} // end namespace Pythia8
+
+#endif // Pythia8_ProcessLevel_H