11/07/2003 Sergey Burdin, Andrei Nomerotski  

this is a quick study for J/psi skimming - we used AADSTs with  2 pb^-1 of unbiased data.

all d0reco muon candidates of opposite signs were considered below, no Pt cuts applied. Note that each muon
candidate is considered twice (first as muon # 1 then as muon #2) so there is exact double counting in the below histos.

when both muons are nseg=3  N_Jpsi = 9417


when one muon is nseg=3 and another one is nseg=1  N_Jpsi = 4180



when one muon is nseg=3 and another one is nseg=0  N_Jpsi = 4470



selection Pt>2 Gev gives 1778 J/psi's and factor of 4 lower background for
one muon is nseg=3 and another one is nseg=0