I think that to find a correlation between the AF and the dilution it is
best to use a chi squared minimization that is used in show_ep_asym2.C
Right now we are trying to see this correlation by looking at the
asymmetry in the lowest Q^2 point. This is not as sensative let alone
it has large error bar. The reson why TB cannot make any conclusion
about the AF dependence is due to large error bars. If we use full
acceptance (24-50) we reduce the error bar in the dilution. I'm working
on calculating the error bar for the dilution from knowing the chi square.
Cheers, Vitaliy
Tancredi Botto wrote:
>Hi ben, jason
>thanks for the good work and extensive update. I think it is good
>progress but needs to be pushed a bit forward. Comments:
>
>
>_ For the beam current dependent asymmetries: it'd be surprising
> that we have different L/R results only at low current. I am sure
> you checked that the same cuts are used l/r. But are there any other
> differences ?? Are the yields & their distributions the same ? This
> you can easily check "by hand", using the integrated charge for I<75..
> (you have the charge files)
>
>_ For af dependent asymmetries: if I exclude the 3rd data point
> on the three bottom panel then I can hardly conclude anything. It may
> point to a problem in data/analysis/af-measurament local to that time.
> It may be worth while to look for possible problems there. You can
> easily add a "yields" plot right ?
>
>I agree with extirpating the "bad" fills although I have no solution on
>how to find/cut them (except by hand..). We have to first understand if
>they really make an impact, since we are dealing with few events and they
>seem nicely distributed (by eye).
>
>Also about the AF correlation: you take the low-Q2 bin as the "asymmetry
>value". I think it is more logical to take the dilution factors proper,
>with their error bar. These can be calculated in the same loop that
>calculates the chi2 in show_ep_asym2.C and are the only "junk" indicator
>we have. The sum L+R dilution factor can be just the average weighted
>by 1/errbars2
>
>
>Sorry to bother you, have fun!
>-- tancredi
>
>________________________________________________________________________________
>Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124
>research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
>
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