[SBS_sim] g15 replay results

[Ole Hansen]

On 12/15/2010 07:59 PM, Bogdan Wojtsekhowski wrote:
> Hi Ole,
>
> I would like to check that you have these selection parameters
> which Lubomir used (attached). 

My cuts are slightly different (20x0.2 cm^2 instead of 18x0.2 cm^2 and
10x10 mrad^2 instead of 30x0.7 mrad^2). These cuts only affect the ghost
track fraction.  I'll adjust the cuts and recalculate the numbers. I
suspect they will be comparable, at least I didn't find the angle cut to
make much difference.

> More see in his report 1/22/2010.
> I would like also to remind recommendation to made simple
> event display. You can not miss hits at "0%" background.
>

Well, we can miss hits, as you can see, but we clearly should not.  It
is obvious that there is some kind of bug.

I am presently working on a simple event display. It's the tool of
choice for a problem like this, no question.

Ole

>> Hi folks,
>>
>> attached are two plots with the tracking efficiency and ghost track
>> fraction of Evaristo's latest g15 replay. The replay was done with
>> analyzing only the first 6 planes and so should be directly comparable to
>> last week's results. Interesting points:
>>
>> 1) The tracking efficiency with 0% background is only ~78%.  This gives us
>> a good handle on chasing an obvious bug in the reconstruction.
>>
>> 2) I get slightly higher tracking efficiencies than I got with g9-g14 for
>> all background strengths except 100%.  For example, for 10% I get 72% vs.
>> 65% before.  This is odd since nothing should have changed.
>>
>> 3) The 100% background run seems to have only ~3810 events.  We could use
>> a little more statistics. Recently, I've been replaying 5000 events for
>> each setting.
>>
>> Results as a function of number of planes will follow shortly.
>>
>> Regards,
>> Ole
>>
>> PS: To reproduce these results, please check out the current software as
>> follows:
>>
>> setenv CVS_RSH ssh
>> cvs -d :ext:cvs.jlab.org:/group/halla/analysis/cvs co TreeSearch-GEM
>>
>> PPS: If you'd like to get regular updates on the SBS tracking simulations,
>> please subscribe to this mailing list. You can do so via a web interface
>> at JLab (see the signature for the link).
>>
>> --------------------------------------------
>> Parameters (for reference/expert use):
>>
>> number replayed = 5000
>>
>> search_depth = 12
>> 3d_ampcorr_maxmiss = 4
>> 3d_ampcorr_nsigma = 0.18
>> 3d_chi2_conflevel = 1e-6
>> 3d_maxmiss = 4
>> maxmiss  = 3
>> maxpat   = 1000
>> maxslope = 0.1
>> chi2_conflevel = 1e-6
>> xp.res       = 7e-5
>> maxclustsiz  = 4
>> adc.min      = 200
>> split.frac   = 0.1
>> maxhits      = 1000
>> maxsamp      = 3
>> adc.sigma    = 0.2
>>
>>
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>