[Olympus] Talk on Monday

[Norair Akopov]

On Wed, 5 Feb 2014, Michael Kohl wrote:

> Dear Norik,
Dear Michael,
>> The results were obtained with the same cuts (including topology cut)
>> and PID scheme explained on Monday in my talk.
>
> Has the coplanarity cut been applied?

Yes, as I explained on Monday the full set of cuts includes also the 
coplanarity cut, which is BTW in my case with the 3 \sigma approach to 
install the cuts quite strong 3\sigma is 0.06 rad.
>
> On the bottom-right (th_p vs th_e) the elastic ridge is visible over a
> broad continuum, does this mean that a kinematic cut for the polar angle 
> correlation has *not* been applied to constrain elastics?

Yes I do not apply polar angle correlation cut, this is somehow the only 
degree of freedom not still used. I think in principle the momentum 
balance with the sum of P_z also vertex difference should mainly provide 
both the coplanarity and theta correlation?
  >
> The calculation of the lepton momentum from lepton angle assumes elastic 
> kinematics, so the 'resolution' peaks are only meaningful if all other cuts 
> to constrain elastic events have been applied to minimize/eliminate 
> non-elastic backgrounds.

I agree and I can add also the theta correlation cuts (all rest to 
constrain the elastic events is already used!), but why at least 
for electron runs the integrated case is so similar to Fig. 14, does it 
mean Jan also did not used any theta correlation, or as I said before the 
combination of already used cuts mainly constrain also \theta to be 
correlated?

>
> Best regards
>  Michael

Best regards,
Norik
>
>
> On Wed, 5 Feb 2014, Norair Akopov wrote:
>
>>
>>   Dear Colleagues,
>> 
>> 
>> In addition to what was shown on Monday I produced two new plots (e+/e-
>> reconstructed runs) reflected the momentum resolution similar to the Fig.
>> 14 (Track momentum resolution) in the report to be sent to PRC. I used the
>> same definition for the resolution as Jan explained:
>> difference between the momentum defined with the only lepton angle and
>> momentum taken from WC for the same track is divided over half of the
>> sum of those momentum and multiplied by 100 to be in %.
>> 
>> You can see 9 panels on each plot, the upper left is the resolution
>> calculated with the integration over the scattered lepton angle
>> (\theta_e), then 7 panels show different \theta_e ranges, and the last
>> lower right panel is double plot with \theta_pr vs. \theta_e (\theta_e is
>> along X axis).
>> 
>> I would say that the integrated case and the first angular region
>> (20 <\theta_e (degree) <30) are very similar for electron runs to what we
>> see on Fig. 14. Then with the increasing of \theta_e the shape of such
>> momentum resolution become quite different (as I remember Michael asked
>> how looks such resolution at different angles). For positron runs we see
>> that even for low angles (and for integrated case) the mean of momentum
>> resolution is quite shifted from zero, which is just reflection of the
>> momentum shift I showed on Monday.
>> 
>> The location of produced pdf files is:
>> 
>> http://www.desy.de/~akopov/Olympus_Monday_Meeting/
>> electron_resol.pdf
>> positron_resol.pdf
>> 
>> The results were obtained with the same cuts (including topology cut)
>> and PID scheme explained on Monday in my talk.
>> 
>> I think this information can be usefull.
>> 
>> Best regards,
>> Norik
>> _______________________________________________
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>> Olympus at mit.edu
>> http://mailman.mit.edu/mailman/listinfo/olympus
>> 
>
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