Log entry time 18:16:15 on January27,2003

Entry number 93581

This entry is a followup to: 93574

 

I calculated asymmetries for these three carbon runs in a slightly different way.



Below please find 

 N(T3,+): number of T3 events in the ntuple, helicity + gated;

 N(T3,-): number of T3 events in the ntuple, helicity - gated;

 A(N,T3): asymmetry from N(T3,+) and N(T3,-)

 A(I): current asymmetry from end_of_run

 A(total T3): T3 scaler asymmetry from end_of_run



run#   N(T3,+) N(T3,-)     A(N,T3)               A(I)     A(scaler T3)     A(real)

20561 144324  144671  -1201+/-1860ppm -32ppm    300ppm   268+/-1860ppm

20562 182472  182194      762+/-1656ppm   30ppm     200ppm   170+/-1656ppm

20563  66916    67057     1052+/-2732ppm   70ppm   1591ppm  1521+/-2732ppm



The real asymmetry (corrected for charge and livetime) in the last column

is given by

 A(real) = A(N,T3)-A(Q)+A(eta_livetime)



I assumed that charge asymmetry is the same as current asymmetry. The

livetime correction factor is given by

  eta_livetime(h) = N(scaler T3,h)/N(accepted T3,h)

where h is the helicity.  Note that N(accepted T3,h) is the N(T3,h) given

in the second and the 3rd columns of the table.  So 

 A(real) = A(scaler T3) - A(I)



People might have different oppinion about the livetime correction.  But

the bottom line is that both the uncorrected asymmetry w/o cut from ntuple

A(N,T3), and the 'real asymmetry' w/o cut given by my method described

above, are consistent with zero within statistical uncertainty.