Wang,
You are right. I just checked and my assumption that over such a long
period (12hours) the total charge in each helicity state will be the
same. However, I have to say that it's not the case. Still I'm
suprized that it make such a big difference. My result is right=0.12
and left=0.11 (down from 0.18 and 0.15). I have to say that the reason
I added cerenkov in the cut is to get rid of this painful left/right
asymmetry, which I think still does the job. However, the "inhancement"
in the asymmetry came as extra, erroneously, as it seems now. This means
that the result for 0 degrees agrees with result for 180 degrees (13
both sides). So there was no deteriation in the target cell over a
period of two weeks. Whether the af effects the asymmetry or not is
still not clear. The plot that you showed for that is not helpfull
since you can not look at the asymmetry for one run (or fill) due to
very low statistics. You need to add statistics over a day and compare
af for that day.
Cheers, Vitaliy
Wang Xu wrote:
>Dear Vitaliy,
> The meaning of "Cerekov cuts was not valid" is:
> when you analyze run 2306-2343 with Cerekov
>Cuts:"ncl>-1"or"ncr>-1"(root -l show_ep_asym2.C 2306-2343),
> charge is correct, but events after Cerekov cuts are zero.( I
>believe Cerekov detector did not working well for some reason.)
> Therefore, if you run show_ep_asym2.C all, charge summed over all
>runs. But Yield summed all except run 2306-2343. So you can not get
>correct asy.
> You can try it. for example (root -l show_ep_asym2.C 2306). You
>will fully understand what I mean.
> Best regards,
> Wang
>
>
>2306-2343,
>
>On Wed, 10 Sep 2003, vitaliy ziskin wrote:
>
>
>
>>I beg to differ.
>>First of all what do you mean "not valid". Secondly what is this cut
>>(I>75), if it is a beam current than I don't think you are doing
>>yourself a favor in making this cut. Also, if the cuts are invalid than
>>the result should bear this out. As of now you are cutting out about a
>>quarter of all events but excluding those runs. I still state that
>>cerenkov do improve the result imensely (dil. of about 0.17), until
>>proven otherwise.
>>
>> Cheers, Vitaliy
>>
>>Wang Xu wrote:
>>
>>
>>
>>>In Ben's previous email, He gave a summary of asy results with respect to
>>>different cuts.
>>>The conclusion we drawn from the results is that Cerekov cuts reduced a
>>>large amount of background. However after I checked asy. run by run. I
>>>realized the Cerekov cuts was not valid during run 2306-2343.The new
>>>results (excluded run 2306-2343) are:
>>>with Cerekov Cuts(I>75) left right
>>>dilution(Pb*Pt):(asymwccut2.ps) 0.10 0.12
>>>without Cerekov Cuts(I>75) left right
>>>dilution(Pb*Pt):(asymwccut2.ps) 0.12 0.10.
>>>Therefore the Cerekov cuts did not change Asy significantly. Overall Pb*Pt
>>>is about 0.11.
>>> Best regards,
>>> Wang
>>>
>>>
>>>
>>>
>>>
>>
>>
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