wmass_util/wmass_util/CAFEMObj.hpp
Bool_t       has_spatial_track_match(Float_t Chi2Cut=0.01) const {return _tmbemcluster_ptr->has_spatial_track_match(Chi2Cut);}

/tmb_tree/p21-br-53/tmb_tree/TMBEMCluster.hpp
Bool_t       has_spatial_track_match(Float_t Chi2Cut=0.01)  const {return (_SpatialTrMatchChi2ProbBest>Chi2Cut);}

tmb_tree/p21-br-53/src/TMBEMCluster.cpp
void TMBEMCluster::Set1(Bool_t is_in_phi_fiducial,
...,Float_t SpatialTrMatchChi2ProbBest):
_SpatialTrMatchChi2ProbBest =  SpatialTrMatchChi2ProbBest;

Set1 function is called from tmb_tree_maker

tmb_tree_maker/p21-br-19/src/TMBEmclMaker.cpp 
...
const emid::EMparticle* em_objptr=&(*em_v)[iem];
el_SpatialTrMatchChi2ProbBest = em_objptr->track_match_spatialchi2prob(); 

TMBEMCluster* pobj = (TMBEMCluster*)emref.GetObject();
pobj->Set1(..., el_SpatialTrMatchChi2ProbBest, ...);


p20.13.00/em_evt/src/EMparticle.cpp
float EMparticle::track_match_spatialchi2prob() const {
  return track_match_chi2prob(false);
}
float EMparticle::track_match_chi2prob(bool use_Eoverp) const {
  if( use_Eoverp ) {
    const EMQualityInfo::TrackMatchInfo & trkInfo = TrackInfoSpatialEoP();
    return trkInfo._chi2prob;
  } else {
    const EMQualityInfo::TrackMatchInfo & trkInfo = TrackInfoSpatial();
    return trkInfo._chi2prob;
  }
}

p20.13.00/em_evt/em_evt/EMQualityInfo.hpp
  // methods to get/set new track realted quantites
  struct TrackMatchInfo {
    TrackMatchInfo() : _chi2prob(-1.), 
		       _ntrkConeSmall(0),
		       _ntrkConeLarge(0),
		       _pttrkConeSmall(0),
		       _pttrkConeLarge(0) {;}


chi^2 is calculated in
emreco/src/EMTrackFinder.cpp