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//
//  Kkpi0.cxx is the single D0 tag code to reconstruct D0 or anti-D0 through the final states of
//  Kkpi0 from D0 decays. Kkpi0.cxx was transfered from the Fortran routine "Kkpi0.f"
//  which was orignally used for study of  the D0D0-bar production and D0 decays at the BES-II
//  experiment during the time period from 2002 to 2008.
//
//  The orignal Fortran routine "Kkpi0.f" used at the BES-II experiment was coded by H.L. Ma
//  and G. Rong in 2003.
//
//  Kkpi0.cxx was transfered by G. Rong and J. Liu in December, 2005.
//
//  Since 2008, G. Rong and L.L. Jiang have been working on developing this code to analyze of
//  the data taken at 3.773 GeV with the BES-III detector at the BEPC-II collider.
//
//  During developing this code, many People made significant contributions to this code. These are
//          G. Rong, L.L. Jiang, J. Liu, H.L. Ma, J.C. Chen, D.H. Zhang,
//          M.G. Zhao, B. Zheng, L. Li, Y. Fang, Z.Y. Yi, H.H. Liu, Z.Q. Liu et al.
//
//                                       By G. Rong and L.L. Jiang
//                                       March, 2009
//
//  ==========================================================================================
//
#include "SD0TagAlg/Kkpi0.h"
#include "SD0TagAlg/SingleBase.h"


Kkpi0::Kkpi0()
{}

Kkpi0::~Kkpi0()
{}


void Kkpi0::MTotal(double event,SmartDataPtr<EvtRecTrackCol> evtRecTrkCol, Vint iGood,Vint
    iGam, double Ebeam, int PID_flag, int Charge_candidate_D)
{

  int nGood=iGood.size();
  int nGam=iGam.size();

  iGoodtag.clear();
  iGamtag.clear();
  
  double mass_bcgg,delE_tag_temp;
  int m_chargetag,m_chargek1,m_chargek2;
  int ik1_temp,ik2_temp, iGam1_temp, iGam2_temp;
  HepLorentzVector pddd;
  HepLorentzVector pddd_temp;

  IDataProviderSvc* eventSvc = NULL;
  Gaudi::svcLocator()->service("EventDataSvc", eventSvc);
  SmartDataPtr<EvtRecEvent> evtRecEvent(eventSvc,EventModel::EvtRec::EvtRecEvent);
  SmartDataPtr<Event::EventHeader> eventHeader(eventSvc,"/Event/EventHeader");

  int runNo=eventHeader->runNumber();
  int rec=eventHeader->eventNumber();

  double xecm=2*Ebeam;

  kkpi0md=false;
  double  tagmode=0;

  if((evtRecEvent->totalCharged() < 2||nGam<2)){    return;  }

  double ecms = xecm; 


  ISimplePIDSvc* simple_pid;
  Gaudi::svcLocator()->service("SimplePIDSvc", simple_pid);

  double deltaE_tem = 0.20;
  int ncount1 = 0; 

  Hep3Vector xorigin(0,0,0);
  IVertexDbSvc*  vtxsvc;
  Gaudi::svcLocator()->service("VertexDbSvc", vtxsvc);
  if(vtxsvc->isVertexValid())
  {
    double* dbv = vtxsvc->PrimaryVertex();
    double*  vv = vtxsvc->SigmaPrimaryVertex();
    xorigin.setX(dbv[0]);
    xorigin.setY(dbv[1]);
    xorigin.setZ(dbv[2]);
  }

  double xv=xorigin.x();
  double yv=xorigin.y();
  double zv=xorigin.z();

  HepPoint3D point0(0.,0.,0.);
  HepPoint3D IP(xorigin[0],xorigin[1],xorigin[2]);

  HepLorentzVector p2gfit;
  HepLorentzVector p2gg;

  for(int i = 0; i < evtRecEvent->totalCharged(); i++) {
    EvtRecTrackIterator itTrk = evtRecTrkCol->begin() + i;

    int ik1 = (*itTrk)->trackId();

    if(!(*itTrk)->isMdcKalTrackValid()) continue;
    RecMdcKalTrack*  mdcKalTrk1 = (*itTrk)->mdcKalTrack();
    RecMdcKalTrack::setPidType(RecMdcKalTrack::kaon);

    m_chargek1 = mdcKalTrk1->charge();
    if(abs(m_chargek1) != 1) continue;

    HepVector a1 = mdcKalTrk1->getZHelixK();
    HepSymMatrix Ea1 = mdcKalTrk1->getZErrorK();

    VFHelix helixip3_1(point0,a1,Ea1);
    helixip3_1.pivot(IP);
    HepVector  vecipa1 = helixip3_1.a();

    double dr1 = fabs(vecipa1[0]);
    double dz1 = fabs(vecipa1[3]);
    double costheta1 = cos(mdcKalTrk1->theta());

    if (  dr1 >= 1.0) continue;
    if (  dz1 >= 10.0) continue; 
    if ( fabs(costheta1) >= 0.93) continue; 
    if(PID_flag == 5) {
      simple_pid->preparePID(*itTrk);
      if(simple_pid->probKaon() < 0.0 || simple_pid->probKaon() < simple_pid->probPion()) continue;  
    } 
    WTrackParameter kap(xmass[3],mdcKalTrk1->getZHelixK(),mdcKalTrk1->getZErrorK() );

    //  
    // select K2
    //  
    for(int j = 0; j< evtRecEvent->totalCharged(); j++) {
      EvtRecTrackIterator itTrk = evtRecTrkCol->begin() + j;

      int ik2= (*itTrk)->trackId();
      if(ik2==ik1)  continue;

      if(!(*itTrk)->isMdcKalTrackValid()) continue;
      RecMdcKalTrack*  mdcKalTrk2 = (*itTrk)->mdcKalTrack();
      RecMdcKalTrack::setPidType(RecMdcKalTrack::kaon);

      m_chargek2 = mdcKalTrk2->charge();
      if((m_chargek1 + m_chargek2) != 0) continue;

      HepVector a2 = mdcKalTrk2->getZHelixK();
      HepSymMatrix Ea2 = mdcKalTrk2->getZErrorK();
      VFHelix helixip3_2(point0,a2,Ea2);
      helixip3_2.pivot(IP);
      HepVector  vecipa2 = helixip3_2.a();

      double dr2 = fabs(vecipa2[0]);
      double dz2 = fabs(vecipa2[3]);
      double costheta2 = cos(mdcKalTrk2->theta());
      if (  dr2 >= 1.0) continue;
      if (  dz2 >= 10.0) continue; 
      if ( fabs(costheta2) >= 0.93) continue; 
      if(PID_flag == 5) {
        simple_pid->preparePID(*itTrk);
        if(simple_pid->probKaon() < 0.0 || simple_pid->probKaon() < simple_pid->probPion()) continue;  
      } 
      WTrackParameter kam(xmass[3],mdcKalTrk2->getZHelixK(),mdcKalTrk2->getZErrorK() );


      for(int m = 0; m < nGam-1; m++) {
        if(iGam[m]==-1) continue;
        RecEmcShower *g1Trk = (*(evtRecTrkCol->begin()+iGam[m]))->emcShower();
        double eraw1 = g1Trk->energy();
        double phi1 = g1Trk->phi();
        double the1 = g1Trk->theta();
        HepLorentzVector ptrkg1,ptrkg10,ptrkg12;
        ptrkg1.setPx(eraw1*sin(the1)*cos(phi1));
        ptrkg1.setPy(eraw1*sin(the1)*sin(phi1));
        ptrkg1.setPz(eraw1*cos(the1));
        ptrkg1.setE(eraw1);
        ptrkg10 = ptrkg1;
        ptrkg12 = ptrkg1.boost(-0.011,0,0);


        for(int n = m+1; n < nGam; n++) {
          if(iGam[n]==-1) continue;
          RecEmcShower *g2Trk = (*(evtRecTrkCol->begin()+iGam[n]))->emcShower();
          double eraw2 = g2Trk->energy();
          double phi2 = g2Trk->phi();
          double the2 = g2Trk->theta();
          HepLorentzVector ptrkg2,ptrkg20,ptrkg22;
          ptrkg2.setPx(eraw2*sin(the2)*cos(phi2));
          ptrkg2.setPy(eraw2*sin(the2)*sin(phi2));
          ptrkg2.setPz(eraw2*cos(the2));
          ptrkg2.setE(eraw2);
          ptrkg20 = ptrkg2;
          ptrkg22 = ptrkg2.boost(-0.011,0,0);

          HepLorentzVector  ptrkpi0;
          ptrkpi0 = ptrkg12+ptrkg22;
          double m_xmpi0_tem = ptrkpi0.m();
          if(m_xmpi0_tem>0.150||m_xmpi0_tem<0.115)  continue;
          bool IsEndcap1 = false; bool IsEndcap2 = false;
          if(fabs(cos(the1)) > 0.86 && fabs(cos(the1)) < 0.92) IsEndcap1 = true; 
          if(fabs(cos(the2)) > 0.86 && fabs(cos(the2)) < 0.92) IsEndcap2 = true; 
          if(IsEndcap1 && IsEndcap2)  continue;
          KalmanKinematicFit * kmfit = KalmanKinematicFit::instance();
          kmfit->init();
          kmfit->setChisqCut(2500);
          kmfit->AddTrack(0, 0.0, g1Trk);
          kmfit->AddTrack(1, 0.0, g2Trk);
          kmfit->AddResonance(0, mpi0, 0, 1);

          kmfit->Fit(0);  // Perform fit
          kmfit->BuildVirtualParticle(0);

          double pi0_chisq = kmfit->chisq(0);
          if ( pi0_chisq >= 2500) continue;
          HepLorentzVector p2gfit = kmfit->pfit(0) + kmfit->pfit(1);
          p2gfit.boost(-0.011,0,0);

          HepPoint3D vx(xorigin.x(), xorigin.y(), xorigin.z());
          HepSymMatrix Evx(3, 0);
          double bx = 1E+6; Evx[0][0] = bx*bx;
          double by = 1E+6; Evx[1][1] = by*by;
          double bz = 1E+6; Evx[2][2] = bz*bz;
          VertexParameter vxpar; vxpar.setVx(vx); vxpar.setEvx(Evx);

          VertexFit* vtxfit = VertexFit::instance();
          vtxfit->init();
          vtxfit->AddTrack(0,  kam);
          vtxfit->AddTrack(1,  kap);
          vtxfit->AddVertex(0, vxpar, 0, 1);
          if(!vtxfit->Fit(0))  continue;
          vtxfit->Swim(0);

          WTrackParameter wkam = vtxfit->wtrk(0);
          WTrackParameter wkap = vtxfit->wtrk(1);

          HepVector kam_val = HepVector(7,0);
          kam_val = wkam.w();
          HepVector kap_val = HepVector(7,0);
          kap_val = wkap.w();

          HepLorentzVector P_KAM(kam_val[0],kam_val[1],kam_val[2],kam_val[3]);
          HepLorentzVector P_KAP(kap_val[0],kap_val[1],kap_val[2],kap_val[3]);

          P_KAM.boost(-0.011,0,0);
          P_KAP.boost(-0.011,0,0);
          pddd = P_KAM + P_KAP + p2gfit;

          double pkkpi0 = pddd.rho(); 

          double temp1 = (ecms/2)*(ecms/2)-pkkpi0*pkkpi0 ;
          if(temp1<0) temp1 =0;
          double mass_bc_tem  = sqrt(temp1);
          if(mass_bc_tem < 1.82 || mass_bc_tem > 1.89) continue;
          
          double delE_tag_tag = ecms/2-pddd.e();

          if(fabs(delE_tag_tag)<deltaE_tem)  {
            deltaE_tem = fabs(delE_tag_tag);
            delE_tag_temp = delE_tag_tag;
            mass_bcgg = mass_bc_tem;

            pddd_temp = pddd;

            ik1_temp = ik1;
            ik2_temp = ik2;
            iGam1_temp = iGam[m];
            iGam2_temp = iGam[n];
            ncount1 = 1;

          }
        }
      }
    }
  }

  if(ncount1 == 1) {
    tagmode=23;
    if(m_chargetag<0)  tagmode=-23;
    tagmd=tagmode;
    mass_bc  = mass_bcgg;
    delE_tag = delE_tag_temp;
    cqtm     = 0.0;

    iGoodtag.push_back(ik1_temp);
    iGoodtag.push_back(ik2_temp);
 
    iGamtag.push_back(iGam1_temp); 
    iGamtag.push_back(iGam2_temp); 
    iGamtag.push_back(9999); 
    iGamtag.push_back(9999); 

    ptag = pddd_temp;

    kkpi0md = true;
  }
}

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