K3pipi0.cxx

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//
//  K3pipi0.cxx is the single D0 tag code to reconstruct D0 or anti-D0 through the final states of
//  K3pipi0 from D0 decays. K3pipi0.cxx was transfered from the Fortran routine "K3pipi0.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 "K3pipi0.f" used at the BES-II experiment was coded by G. Rong in 2001.
//
//  K3pipi0.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/K3pipi0.h"
#include "SD0TagAlg/SingleBase.h"
 
K3pipi0::K3pipi0()
{}
 
K3pipi0::~K3pipi0()
{}
 
 
void K3pipi0::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_chargek,m_chargepi1,m_chargepi2,m_chargepi3;
  int ika_temp,ipi1_temp,ipi2_temp,ipi3_temp,ipi4_temp, iGam1_temp, iGam2_temp;
  HepLorentzVector kmfit1,kmfit2,kmfit3,kmfit4,pddd;
 
  int cqtm_temp;
  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;
 
  k3pipi0md = false;
  double  tagmode=0;
 
  if((evtRecEvent->totalCharged() < 4 || nGam <2)){     return;   }
 
  double ecms = xecm;
 
  ISimplePIDSvc* simple_pid;
  Gaudi::svcLocator()->service("SimplePIDSvc", simple_pid);
 
  double deltaE_tem = 0.20;
  int ncount1 = 0; 
 
  HepLorentzVector p2gfit;
  HepLorentzVector p2gg;
 
  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 ptrk1_temp, ptrk2_temp, ptrk3_temp, ptrk4_temp, ptrk5_temp, ptrk6_temp, ptrk7_temp;
   //////////////////////////////////////////////////////////////////
   for(int i = 0; i < evtRecEvent->totalCharged(); i++) {
     EvtRecTrackIterator itTrk1 = evtRecTrkCol->begin() + i;
 
     int ika= (*itTrk1)->trackId();
 
     if(!(*itTrk1)->isMdcKalTrackValid()) continue;
     RecMdcKalTrack*  mdcKalTrk1 = (*itTrk1)->mdcKalTrack();
     RecMdcKalTrack::setPidType(RecMdcKalTrack::kaon);
     /////////////////////////////////////////
     m_chargek=mdcKalTrk1->charge();
     if(Charge_candidate_D != 0) {
       if(m_chargek != -Charge_candidate_D) continue;
     }
     if(Charge_candidate_D == 0) {
       if(abs(m_chargek) != 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(*itTrk1);
       if(simple_pid->probKaon() < 0.0 ||simple_pid->probKaon() < simple_pid->probPion()) continue;  
     } 
 
     /////////////////////////////////////////
 
     WTrackParameter kam(xmass[3],mdcKalTrk1->getZHelixK(),mdcKalTrk1->getZErrorK() );
 
     // 
     // select pi1
     // 
     for(int j = 0; j< evtRecEvent->totalCharged();j++) {
       EvtRecTrackIterator itTrk2 = evtRecTrkCol->begin() + j;
 
       int ipi1= (*itTrk2)->trackId();
       if(ipi1==ika)  continue;
 
       if(!(*itTrk2)->isMdcKalTrackValid()) continue;
       RecMdcKalTrack*  mdcKalTrk2 = (*itTrk2)->mdcKalTrack();
       RecMdcKalTrack::setPidType(RecMdcKalTrack::pion);
       /////////////////////////////////////////
       m_chargepi1=mdcKalTrk2->charge();
       if((m_chargek + m_chargepi1) != 0) continue;
       /////////////////////////////////////////
       HepVector a2 = mdcKalTrk2->getZHelix();
       HepSymMatrix Ea2 = mdcKalTrk2->getZError();
       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(*itTrk2);
         if(simple_pid->probPion() < 0.0 || simple_pid->probPion() < simple_pid->probKaon()) continue;  
       } 
       /////////////////////////////////////////
       WTrackParameter pip1(xmass[2],mdcKalTrk2->getZHelix(),mdcKalTrk2->getZError() );
 
       //   
       //select pi2
       //   
       for(int k = 0; k< evtRecEvent->totalCharged(); k++) {
         EvtRecTrackIterator itTrk3 = evtRecTrkCol->begin() + k;
 
         int ipi2= (*itTrk3)->trackId();
         if(ipi2==ika || ipi2==ipi1)  continue;
 
         if(!(*itTrk3)->isMdcKalTrackValid()) continue;
         RecMdcKalTrack* mdcKalTrk3 = (*itTrk3)->mdcKalTrack();
         RecMdcKalTrack::setPidType  (RecMdcKalTrack::pion);
         /////////////////////////////////////////
         m_chargepi2=mdcKalTrk3->charge();
         if((m_chargek + m_chargepi2) != 0) continue;
         /////////////////////////////////////////
         HepVector a3 = mdcKalTrk3->getZHelix();
         HepSymMatrix Ea3 = mdcKalTrk3->getZError();
         VFHelix helixip3_3(point0,a3,Ea3);
         helixip3_3.pivot(IP);
         HepVector  vecipa3 = helixip3_3.a();
 
         double dr3 = fabs(vecipa3[0]);
         double dz3 = fabs(vecipa3[3]);
         double costheta3 = cos(mdcKalTrk3->theta());
         if (  dr3 >= 1.0) continue;
         if (  dz3 >= 10.0) continue; 
         if ( fabs(costheta3) >= 0.93) continue; 
         /////////////////////////////////////////
         if(PID_flag == 5) {
           simple_pid->preparePID(*itTrk3);
           if(simple_pid->probPion() < 0.0 || simple_pid->probPion() < simple_pid->probKaon()) continue;  
         } 
         /////////////////////////////////////////
         WTrackParameter pip2(xmass[2],mdcKalTrk3->getZHelix(),mdcKalTrk3->getZError() );
 
         //
         // select pi3
         //
         for(int l = 0; l< evtRecEvent->totalCharged();l++) {
           EvtRecTrackIterator itTrk4 = evtRecTrkCol->begin() + l;
 
           int ipi3= (*itTrk4)->trackId();
           if(ipi3==ika || ipi3==ipi1 || ipi3==ipi2 )  continue;
 
           if(!(*itTrk4)->isMdcKalTrackValid()) continue;
           RecMdcKalTrack* mdcKalTrk4 = (*itTrk4)->mdcKalTrack();
           RecMdcKalTrack::setPidType  (RecMdcKalTrack::pion);
           /////////////////////////////////////////
           m_chargepi3=mdcKalTrk4->charge();
           if((m_chargepi2 + m_chargepi3) != 0) continue;
           /////////////////////////////////////////
           HepVector a4 = mdcKalTrk4->getZHelix();
           HepSymMatrix Ea4 = mdcKalTrk4->getZError();
           VFHelix helixip3_4(point0,a4,Ea4);
           helixip3_4.pivot(IP);
           HepVector  vecipa4 = helixip3_4.a();
 
           double dr4 = fabs(vecipa4[0]);
           double dz4 = fabs(vecipa4[3]);
           double costheta4 = cos(mdcKalTrk4->theta());
           if (  dr4 >= 1.0) continue;
           if (  dz4 >= 10.0) continue; 
           if ( fabs(costheta4) >= 0.93) continue; 
           /////////////////////////////////////////
           if(PID_flag == 5) {
             simple_pid->preparePID(*itTrk4);
             if(simple_pid->probPion() < 0.0 || simple_pid->probPion() < simple_pid->probKaon()) continue;  
           } 
           /////////////////////////////////////////
           WTrackParameter pip3(xmass[2],mdcKalTrk4->getZHelix(),mdcKalTrk4->getZError() );
 
 
           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.mag();
               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,  pip1);
               vtxfit->AddTrack(2,  pip2);
               vtxfit->AddTrack(3,  pip3);
               vtxfit->AddVertex(0, vxpar, 0, 1, 2, 3);
               if(!vtxfit->Fit(0))  continue;
               vtxfit->Swim(0);
 
               WTrackParameter wkam  = vtxfit->wtrk(0);
               WTrackParameter wpip1 = vtxfit->wtrk(1);
               WTrackParameter wpip2 = vtxfit->wtrk(2);
               WTrackParameter wpip3 = vtxfit->wtrk(3);
 
               HepVector kam_val  = HepVector(7,0);
               HepVector pip1_val = HepVector(7,0);
               HepVector pip2_val = HepVector(7,0);
               HepVector pip3_val = HepVector(7,0);
               kam_val  = wkam.w();
               pip1_val = wpip1.w();
               pip2_val = wpip2.w();
               pip3_val = wpip3.w();
 
               HepLorentzVector P_KAM(kam_val[0],kam_val[1],kam_val[2],kam_val[3]);
               HepLorentzVector P_PIP1(pip1_val[0],pip1_val[1],pip1_val[2],pip1_val[3]);
               HepLorentzVector P_PIP2(pip2_val[0],pip2_val[1],pip2_val[2],pip2_val[3]);
               HepLorentzVector P_PIP3(pip3_val[0],pip3_val[1],pip3_val[2],pip3_val[3]);
 
               P_KAM.boost(-0.011,0,0);
               P_PIP1.boost(-0.011,0,0);
               P_PIP2.boost(-0.011,0,0);
               P_PIP3.boost(-0.011,0,0);
               pddd = P_KAM + P_PIP1 + P_PIP2 + P_PIP3 + p2gfit;
 
               double   pk3pipi0=pddd.rho();
 
               double temp1 = (ecms/2)*(ecms/2)-pk3pipi0*pk3pipi0 ;
               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;
                cqtm_temp = m_chargek;
 
                ika_temp=ika;
                ipi1_temp=ipi1;
                ipi2_temp=ipi2;
                ipi3_temp=ipi3;
                iGam1_temp = iGam[m];
                iGam2_temp = iGam[n];
 
                ncount1 = 1;
 
 
              } 
            }   
          }
        }
      }
    }
  }
  if(ncount1 == 1){  
    tagmode=24;
    if(cqtm_temp<0)  tagmode=-24;
    tagmd=tagmode;
    mass_bc  = mass_bcgg;
    delE_tag = delE_tag_temp; 
    cqtm     = -1.0*cqtm_temp;
 
    iGoodtag.push_back(ika_temp);
    iGoodtag.push_back(ipi1_temp);
    iGoodtag.push_back(ipi2_temp);
    iGoodtag.push_back(ipi3_temp);
 
    iGamtag.push_back(iGam1_temp);
    iGamtag.push_back(iGam2_temp);
    iGamtag.push_back(9999);
    iGamtag.push_back(9999);
 
    ptag = pddd_temp;  
 
    k3pipi0md = true;
 
  }
}