Kkpipi.cxx

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//
//  Kkpipi.cxx is the single D0 tag code to reconstruct D0 or anti-D0 through the final states of
//  Kkpipi from D0 decays. Kkpipi.cxx was transfered from the Fortran routine "kkpipi.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 "Kkpipi.f" used at the BES-II experiment was coded by G. Rong in 2002.
//
//  Kkpipi.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/Kkpipi.h"
#include "SD0TagAlg/SingleBase.h"
 
Kkpipi::Kkpipi()
{}
 
Kkpipi::~Kkpipi()
{}
 
 
void Kkpipi::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,m_chargepi1,m_chargepi2;
  int ik1_temp, ik2_temp, ipi1_temp, ipi2_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;
 
  kkpipimd=false;
  double  tagmode=0;
          
  if((evtRecEvent->totalCharged() < 4)){    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]);
  //////////////////////////////////////////////////////////////////
  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(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 || 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(ik1==ik2)  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 || simple_pid->probKaon() < simple_pid->probPion()) continue;  
      } 
     /////////////////////////////////////////
 
      WTrackParameter kam(xmass[3],mdcKalTrk2->getZHelixK(),mdcKalTrk2->getZErrorK() );
 
      //    
      //select pi1
      //    
      for(int k = 0; k< evtRecEvent->totalCharged(); k++) {
        EvtRecTrackIterator itTrk = evtRecTrkCol->begin() + k;
 
        int ipi1= (*itTrk)->trackId();
        if(ipi1==ik1 || ipi1==ik2)  continue;
 
        if(!(*itTrk)->isMdcKalTrackValid()) continue;
        RecMdcKalTrack*  mdcKalTrk3 = (*itTrk)->mdcKalTrack();
        RecMdcKalTrack::setPidType(RecMdcKalTrack::pion);
 
        m_chargepi1=mdcKalTrk3->charge();
        if(m_chargepi1 != 1) 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(*itTrk);
          if(simple_pid->probPion() < 0.0 || simple_pid->probPion() < simple_pid->probKaon()) continue;  
        } 
        /////////////////////////////////////////
        WTrackParameter pip(xmass[2],mdcKalTrk3->getZHelix(),mdcKalTrk3->getZError() );
 
        //
        // select pi2
        //
        for(int l = 0; l< evtRecEvent->totalCharged();l++) {
          EvtRecTrackIterator itTrk = evtRecTrkCol->begin() + l;
 
          int ipi2= (*itTrk)->trackId();
          if(ipi2==ik1 || ipi2==ik2 || ipi2==ipi1 )  continue;
 
          if(!(*itTrk)->isMdcKalTrackValid()) continue;
          RecMdcKalTrack*  mdcKalTrk4 = (*itTrk)->mdcKalTrack();
          RecMdcKalTrack::setPidType(RecMdcKalTrack::pion);
 
          m_chargepi2 = mdcKalTrk4->charge();
          if((m_chargepi1 + m_chargepi2) != 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(*itTrk);
            if(simple_pid->probPion() < 0.0 || simple_pid->probPion() < simple_pid->probKaon()) continue;  
          } 
          /////////////////////////////////////////
 
          WTrackParameter pim(xmass[2],mdcKalTrk4->getZHelix(),mdcKalTrk4->getZError() );
 
          //////////////////////////////////////////////////////////////
          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,  kap);
          vtxfit->AddTrack(1,  kam);
          vtxfit->AddTrack(2,  pip);
          vtxfit->AddTrack(3,  pim);
          vtxfit->AddVertex(0, vxpar, 0, 1, 2, 3);
          if(!vtxfit->Fit(0))  continue;
          vtxfit->Swim(0);
 
          WTrackParameter wkap = vtxfit->wtrk(0);
          WTrackParameter wkam = vtxfit->wtrk(1);
          WTrackParameter wpip = vtxfit->wtrk(2);
          WTrackParameter wpim = vtxfit->wtrk(3);
 
          HepVector kap_val = HepVector(7,0);
          HepVector kam_val = HepVector(7,0);
          HepVector pip_val = HepVector(7,0);
          HepVector pim_val = HepVector(7,0);
          kap_val = wkap.w();
          kam_val = wkam.w();
          pip_val = wpip.w();
          pim_val = wpim.w();
 
          HepLorentzVector P_KAP(kap_val[0],kap_val[1],kap_val[2],kap_val[3]);
          HepLorentzVector P_KAM(kam_val[0],kam_val[1],kam_val[2],kam_val[3]);
          HepLorentzVector P_PIP(pip_val[0],pip_val[1],pip_val[2],pip_val[3]);
          HepLorentzVector P_PIM(pim_val[0],pim_val[1],pim_val[2],pim_val[3]);
 
          P_KAP.boost(-0.011,0,0);
          P_KAM.boost(-0.011,0,0);
          P_PIP.boost(-0.011,0,0);
          P_PIM.boost(-0.011,0,0);
          pddd = P_KAP + P_KAM + P_PIP + P_PIM; 
 
          double   pkkpipi=pddd.rho();
 
          double temp1 = (ecms/2)*(ecms/2)-pkkpipi*pkkpipi ;
          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;
            ipi1_temp=ipi1;
            ipi2_temp=ipi2;
            ncount1 = 1;
 
          }   
        }
      }
    }
  }
 
  if(ncount1 == 1){
    tagmode=20;
    if(m_chargetag<0)  tagmode=-20;
    tagmd=tagmode;
    mass_bc  = mass_bcgg;
    delE_tag = delE_tag_temp;
    cqtm     = 0.0;
 
    iGoodtag.push_back(ik1_temp);
    iGoodtag.push_back(ik2_temp);
    iGoodtag.push_back(ipi1_temp);
    iGoodtag.push_back(ipi2_temp);
 
    iGamtag.push_back(9999);
    iGamtag.push_back(9999);
    iGamtag.push_back(9999);
    iGamtag.push_back(9999);
 
    ptag = pddd_temp;
 
    kkpipimd=true;
 
  }
}