[Lowq] delayed helicity reporting correction

[Hovanes Egiyan]

Hi Raffaella,

Thanks for the helicity correction code.
What is the "Quartet signal" ? Is this the signal indicating the
beginning of a quartet? I did not know it was in the data stream
or even available in our electronics.

Hovanes.


Raffaella De Vita wrote:
> Dear All,
> you can find the code to correct for the delayed helicity reporting in 
> my home directory under helcor_eg6 .
> It can be compiled using the Makefile in the directory: the executable 
> is created locally and named helcor_Linux .
> As I mentioned the code was intended to read both bosfiles and ntuples 
> (nt10) but I checked and it would not work on ntuple because some of the 
> helicity related variables the code is using are not presently saved in 
> the eg6 nt10. I tried it on bosfiles and it works. I'm presently 
> correcting for a delayed reporting of 8 cycles: can someone confirm that 
> this is correct?
>
> When launched, the code asks for the bosfile names and as outputs it 
> creates a text file named hel_table.txt where the first 10 columns have 
> the relevant information. The meaning of these columns is the following:
>
> 1)       Correction Flag: A.B
>          A= quartet number
>          B= state in the quartet (1,2,3,4)
>                         > 0 if good quartet
>                         < 0 if good quartet but missing scaler information
>                         = 0 if bad quartet
> 2)      First Event of Helicity state
> 3)      Last Event of Helicity state
> 4)      True Helicity as determined by this code
> 5)      True Helicity as determined by Sergey code (now set to 2 because 
> the online code is not running)
> 6)      Reported Helicity
> 7)      Sync signal
> 8)      Quartet signal
> 9)      TGBI helicity Counter
> 10)     Interrupt Time from microsec clock
>
> The other columns are all set to 0 because apparently there are no 
> helicity scaler banks (HLS and HLB) in the bosfiles. I don't know if 
> this was meant to be.
> Because the helicity scaler information are missing, the correction flag 
> is set to negative values (see above).
>
> To apply the correction is sufficient to read the table and assign the 
> helicity written in column #4 to all the events with numbers between the 
> ones in column 2 and 3.
> Helicity states for which the correction flag (column 1) is set to 0 
> should be disregard because either the information to get the correct 
> helicity was missing (last states of each file) or the quartet the state 
> belongs to is incomplete (first state of each file or before and after a 
> beam trip).
>
> Best regards
>     Raffaella
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