E781; Lambda_c using V0 package and recon_sv

     I am testing the new version of the V0 package. It has full s,x,o kink
     reconstruction (pion, kaon or proton in RICH). The new recon_sv routine
     is used to reconstruct charm baryon decays with hyperon in final state.
     It will be available in new Soap version when I complete the test.

     The results of charmed Lambda selection in charged sigma with 2 pions
     and lambda with 3 pions (both 3 prong) are presented in    fig.1 

     Charged sigmas were identified using sigma-proton kink (a), sigma-pion
     kink (b), sigma in Rich identification (c);
     lambdas were found in m1-spectrometer (d).

     Type    entries with 4 sigma cut  entries with 5 sigma cut
     -----------------------------------------------------------
      (a)               46                       30
      (b)               50                       28
      (c)               44                       21
      (d)               14                       11
      total            154                       90

      The point back chi2 cut is highly important to extract the signal.
      I use a slightly different method to calculate pvtx_recn:
                 pvtx_recn = unco_recn**2/(s_geom+s_kine)
      where unco_recn is uncoleaniarity angle between geometrical and
      kinematical recn vectors, s_geom is sum of X,Y errors of primary
      and secondary verteces over L decay squaredand s_kine is sum of
      errors in X,Y slopes.
      The last was not included into standard pvtx_recn.

      In addition I have used foreign track cut (no foreign track in
      secondary vertex with miss distance < 0.0008 and hyperon quality
      cuts. Only best hypothesis is accepted in case of multiple kink
      answers.

      The 2 bin peak for L decay > 4 sigma statistics has 45 entries
      with background level of 6 entries/bin.
      So we have 33 +- 7 charm lambdas in our sample.
      This means 44 +- 8 per 1M or 44000 Lambda_c decays in Selex
      statistics.