Fermilab, 18-JUL-1995
							  Dylan Casey

    Status of Hits Info analysis to recover electrons from PPHOs in Z signal--
    
    The CC efficiencies and fake rates for RECO 12.15-12.19 recovering
electrons from PPHOs are done. The cut on 3D CDC hits (NHCDC3D) 
provides most of the efficiency and rejection, though a little may be gained
by adding in the ratio of wires hit (RHCDCW). 

        sample is from WZ streamed Z sample. WZ triggers only. Both E_t>25
        |det eta| < 1.1
        signal: chi^2<100 iso<0.15 81<M_ee<101
        background: chi^2>250 iso>0.15 60<M_ee<70 + 110<M_ee<120

                        NHCDC3D>1       NHCDC3D>0       NHCDC3D>0+RHCDCW>25
            
        eff(PELC) =         0.87          0.91              0.89
        eff(PPHO) =         0.65          0.81              0.78
        fake(PELC) =        0.17          0.30              0.22
        fake(PPHO) =        0.09          0.22              0.16

    
    The EC efficiencies and fake rates have also been investigated. The fake
rate is much worse, as one would expect due to high hit densities in the
forward region. There is no 3D hit in the FDC. Of all the hits quantities,
the ratio of wires hit (RHFDCW) provides the lowest fake rate for efficiencies
greater than 0.50.

        sample is from WZ streamed Z sample. WZ triggers only. Both E_t>25
        |det eta| > 1.3 and |det eta| < 2.5 of EC object 
        signal: chi^2<100 iso<0.15 81<M_ee<101
        background: chi^2>250 iso>0.15 60<M_ee<70 + 110<M_ee<120

                        RHFDCW>75

        eff(PELC) =         0.89
        eff(PPHO) =         0.82
        fake(PELC) =        0.49
        fake(PPHO) =        0.59


    Work is still in progress on using the grid search method to optimize the
clean photon cuts.