Hough 工作进展

Outline Track efficiency improvement when |cos|>0.8 Pipijpsi MC tracking efficiency check D->kpipipipi0 Next ->fit? Genfit?

Tracking efficiency when |cos|>0.8 Update in Algorithm Get back lost stereo hits after hough transform Delete bad hit in calculate zPosition and flightLength of stereo hits Use only inner chamber hits in “zsFit” to get a initial parameter for global fit( outer chamber seems not accurate of zs calculation of stereohits , imperfect) Delete hit when “driftTime”<0

Tracking efficiency with single pion No kalman filter , cutpt+cutp+cutd0+dutdz Before update After update 63.07% 67.07% After kalman filter , cutpt+cutp+cutd0+dutdz Before update After update 75.16% 77.78%

Pipijpsi MC check Before upgrade About ~1% improvement when low pt combined with old HOUGH After upgrade

D->kpipipipi0 Simulate D0->k- pi+ pi- pi+ pi0 Check pt information Pt of all charged track (pion , kion ) (GeV) Pt(50MeV~120MeV): 6932/41414=16.7%

D->kpipipipi0 Method : Simulation: D0->Kpipipipi0, other side D0->all channel Reconstruction and analysis results not discussed with physics parterner

Some addition and problem Uniformed and inuniformed magnetic get large difference in efficiency(~20%) after tracking (before kalman) Use truth of 3d parameter as input for global fit can update ~1% in efficiency Problem with |cos| small , in multiple turn tracks , hits in 2nd(3st..) easily come into track , but calculate wrong flightlength both in calculate z-s of stereo hits & global fit

Next to do To amend tracking parameter in Hough Space Is it time to introduce genfit for fitting ?