Richard,
I agree with you and the data supports this also. Two points, though.
The preliminary analysis does not include 47 degree data. This data set
is quet sizable (60kC), though it was taken at lower polarization/figure
of merit. Also, in the latest plot of GeN that I have sent the error
bars scale more or less as expected, from first to third data points and
so do the projected error bars. So this issue is worked out now. The
issue might the possition of the 3rd data point. I'm still not sure why
the asymmetry is so low in this bin. I'm currently looking at the 47
degree data.
Cheers, Vitaliy
Richard Milner wrote:
>Vitaliy et al,
>The projections for GEn from the original proposal have been checked
>numerous times and, within the assumptions made, are realistic up to to
>at least Q^2 of 0.35 where we run out of Cerenkov detector. For 1000
>hours of running at design figure-of-merit (and we are running at least
>equal to that right now), i.e. for about 300 kC of data, we should get
>uncertainties at the lowest three points of about 7% of the Galster fit.
>I think the first two bins in the recent (very preliminary) results from
>Vitaliy support this. I do not understand the very large increase in the
>uncertainty in the third bin of Vitaliy's preliminary results.
>
>In conclusion, the proposal projections stand and should be modified only
>with respect to the real detector acceptance we now have.
>
>Let's try to sort this out in the next day or so.
>
>Richard
>
>
>
>On Tue, 20 Jul 2004, Vitaliy Ziskin wrote:
>
>
>
>>John,
>>I redid some of the fits plus I scaled my present errobars to come up
>>with the prjections to the end of the run period. I scaled it by the
>>propose amount of charge we are going to collect by november. I also,
>>took liberty to scale it by a "fudge" factor. This factor is not big
>>(1.22) and it reflects the fact that the data I'm using currently was
>>run at times in unfavorable conditions for neutron detection. The
>>conditions have since improved and thus the factor. It also reflects a
>>slighly higher polarization of current running as compared to the data
>>I'm using right now. The first two plots are the same as before only
>>with little more data improved cuts. The next two plots are the same
>>plots as projections. I made the data points to be perfectly on Galster
>>curve for ease of fitting. Chi^2 fit looks good for that reason. So
>>the errors, might be to optimistic since I'm willing to be that our data
>>is not going to look this perfect. It's hard to quantify how what
>>bearing this "imperfection" has on the error bar though. So my GeN plot
>>includes best case scenario for first 3 data points. In the light of
>>these next 3 points look somewhat too high. I will try to work that
>>rest of the time to make any kind of statement about higher Q^2 points.
>>The last question is the third Q^2 point. Why is it so low? I'm
>>looking into this. But it would be nice to get some idea about background.
>>
>> Cheers, Vitaliy
>>
>>
>>
>
>
>
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