Hi Vitality,
Thank you for your feedback. I am using the empty runs including the
deuterium periods. I will try the stricter z-cut, since I am using a
very loose cut (|z|<35 cm) now, and see if the error bars shrink.
Thank you,
aki
vitalik wrote:
> Aki,
> I'm familiar with this background. In fact this is not the background
> from the empty cell, but the electromagnetic shower events. They
> separate well from the quasielastic peak but clash with the pion
> production region. One thing you can do is try to restrict the
> z-cut. A big source of those showers is the collimator upstream.
> Ultimately, I believe that you will have to rely on the subtraction of
> the empty cell rate. The good news is that I believe that you can use
> empty runs from deuterium running period also, to increase your empty
> run set. Aaron has a comprehensive empty run list.
> Cheers,
> Vitaliy
>
> Akihisa Shinozaki wrote:
>
>> Hi Tavi,
>>
>> Please never mind my previous results. I found at least four mistakes
>> in my code. Both data and simulations were not right results. I was
>> basically collecting the "garbages" for the data. Also, the
>> simulations did not took the pi+ channel into account by my mistakes.
>> I am sorry if I made another confusions for you.
>>
>> So this is my another attempt for the p(e',e) results for you. This
>> time only trigger 7 is considered. For e' selection, Cerenkov hits
>> were required for the corresponding TOF counters.
>>
>> The file, asymmetryi.ps, shows the asymmetries from all the data
>> obtained from last October to December (48 deg. only). The data are
>> compared with my MAID and SL simulations. The simulated curves assume
>> the dilution factor = 0.5 with no asymmetry offset. The data make
>> good agreement with the simulations. It *seems* to me that your data
>> do not quite match with mine in the left sector since your data do
>> not go beyond the zero as much as my current result. I think we can
>> discuss this later.
>>
>> peei_md.ps and peei_sl.ps show the data distributions of W, Q^2,
>> Ee'(lab), and, Theta^e'(lab) . The blue (red) + points are the
>> counting rate in events per Coulomb in the electron left (right)
>> sector. The thiner lines are background (empty target spectrum). The
>> thick curves are my MAID or SL simulations. The data spectra in
>> peei_md.ps and peei_sl.ps are not the same because W<1.4 GeV is
>> applied for MAID while the SL simulation requires W<1.3 GeV. There is
>> no radiative process considered and this should be one of the sources
>> of the differences between the data and simulations. Since you are
>> doing with GEANT, you could tell me more on the characteristics of my
>> simulations.
>>
>> It is quite striking that the background rates are as high as the
>> foreground, which is the main source of the error in the asymmetries.
>> I am using the all empty target runs available but the statistics is
>> still about one tenth of the foreground.
>>
>> I think that is all for now. Thank you!
>> aki
>>
>
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