AddFlowByShifting.h

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/*
  Copyright (C) 2002-2022 CERN for the benefit of the ATLAS collaboration
*/
 
// File:  Generators/FlowAfterburnber/AddFlowByShifting.h
// Description:
//    This code is used to introduce particle flow
//    to particles from generated events
//    It works by modifying phi angles of particles
//    according to requested flow type and magnitude
//
//    It takes from SG a container of tracks as input
//    and registers in SG a new container with modified tracks on output
//
//    It currently uses Hijing generator specific class HijingEventParams
//    with truth event parameters information
//
// AuthorList:
// Andrzej Olszewski: Initial Code February 2006
 
#ifndef ADDFLOWBYSHIFTING_H
#define ADDFLOWBYSHIFTING_H
 
#include "AthenaBaseComps/AthAlgorithm.h"
#include "GaudiKernel/ServiceHandle.h"
 
#include <CLHEP/Random/RandomEngine.h>
#include "AthenaKernel/IAthRNGSvc.h"
#include "GeneratorObjects/McEventCollection.h"
#include "AtlasHepMC/Relatives.h"
#include "GeneratorObjects/HijingEventParams.h"
 
#include <gsl/gsl_errno.h>
#include <gsl/gsl_math.h>
#include <gsl/gsl_roots.h>
 
 
 
 
class TGraph;
 
class AddFlowByShifting:public AthAlgorithm {
public:
  AddFlowByShifting(const std::string& name, ISvcLocator* pSvcLocator);
  StatusCode initialize();
  StatusCode execute();
  StatusCode finalize();
 
  //functions used for root finding when using the "exact"(and not the "approximate")  method
  static double vn_func           (double x, void *params);
  static double vn_func_derivative(double x, void *params);//currently not used
 
 
private:
  CLHEP::HepRandomEngine* getRandomEngine(const std::string& streamName, const EventContext& ctx) const;
 
  double SetParentToRanPhi(HepMC::GenParticlePtr parent, CLHEP::HepRandomEngine *rndmEngine);
  double AddFlowToParent(HepMC::GenParticlePtr parent,
                         const HijingEventParams *hijing_pars);
  void   MoveDescendantsToParent(HepMC::GenParticlePtr parent, double phishift);
 
 
  // flow functions to set the vn values
  void (AddFlowByShifting::*m_flow_function)     (double b, double eta, double pt);//function pointer which is set to one of the functions below
  void jjia_minbias_new       (double b, double eta, double pt);
  void jjia_minbias_new_v2only(double b, double eta, double pt);
  void fixed_vn               (double b, double eta, double pt);
  void fixed_v2               (double b, double eta, double pt);
  void jjia_minbias_old       (double b, double eta, double pt);
  void ao_test                (double b, double eta, double pt);
  void custom_vn              (double b, double eta, double pt);
  void p_Pb_cent_eta_indep    (double b, double eta, double pt); //for p_Pb
 
  TGraph *m_graph_fluc{};//TGraph storing the v2_RP/delta Vs b_imp
  void Set_EbE_Fluctuation_Multipliers(HepMC::GenVertexPtr mainvtx, float b, CLHEP::HepRandomEngine *rndmEngine);
 
  // Random number service
  ServiceHandle<IAthRNGSvc> m_rndmSvc{this, "RndmSvc", "AthRNGSvc"};
 
  // Setable Properties:-
  StringProperty m_inkey{this, "McTruthKey", "GEN_EVENT"}; //FIXME use Read/WriteHandles
  StringProperty m_outkey{this, "McFlowKey", "FLOW_EVENT"}; //FIXME use Read/WriteHandles
 
  IntegerProperty   m_ranphi_sw{this, "RandomizePhi", 0};
 
  StringProperty m_flow_function_name{this, "FlowFunctionName", "jjia_minbias_new"};
  StringProperty m_flow_implementation{this, "FlowImplementation", "exact"};
  int   m_flow_implementation_type{0};
  BooleanProperty  m_flow_fluctuations{this, "FlowFluctuations", false};
 
  IntegerProperty   m_floweta_sw{this, "FlowEtaSwitch", 0 };
  FloatProperty m_flow_maxeta{this, "FlowMaxEtaCut", 10.0};
  FloatProperty m_flow_mineta{this, "FlowMinEtaCut", 0.f};
 
  IntegerProperty   m_flowpt_sw{this, "FlowPtSwitch", 0};
  FloatProperty m_flow_maxpt{this, "FlowMaxPtCut", 1000000.f};
  FloatProperty m_flow_minpt{this, "FlowMinPtCut", 0.f};
 
  IntegerProperty   m_flowb_sw{this, "FlowBSwitch", 0};//currently not used
  FloatProperty m_custom_v1{this, "custom_v1", 0.f};
  FloatProperty m_custom_v2{this, "custom_v2", 0.f};
  FloatProperty m_custom_v3{this, "custom_v3", 0.f};
  FloatProperty m_custom_v4{this, "custom_v4", 0.f};
  FloatProperty m_custom_v5{this, "custom_v5", 0.f};
  FloatProperty m_custom_v6{this, "custom_v6", 0.f};
 
  int   m_particles_processed{0};
 
  //float psi_n[6],v1,v2,v3,v4,v5,v6;
  float m_psi_n[6],m_v_n[6];
  float m_EbE_Multiplier_vn[6];
 
};
 
#endif