Star-tpc-l mailing list

["Van Buren, Gene" <gene AT bnl.gov>]

Hi, Yuri and all

Perhaps the alignment calibration effort is indeed better off without the TPC 
distortion correction for sector misalignments, Can you please point us to 
where it was demonstrated that excluding the distortion correction brings an 
improvement? It's possible that this was demonstrated long enough ago that I 
have forgotten this demonstration. I'm left wondering how it is physically 
possible for that distortion correction to be a bad thing.

Thanks,
-Gene

> On Sep 13, 2024, at 11:50 AM, Fisyak, Yuri V <fisyak AT bnl.gov> wrote:
> 
> Hi Frank, thank you for explanation. Yes, it is true. I have removed 
> “OSectorAlign” because it does compete with corrections coming from (new) 
> Alignment2024.
>  
> 
>                                                               Yuri Fisyak
> 
> STAR                                           Phone: +1 631 344 3913
> Brookhaven National Laboratory  Fax:    +1 631 344 4206
> 510A/1-161
> http://www.star.bnl.gov/~fisyak       E-mail: fisyak AT bnl.gov
>  
>  
>  
> From: Frank Geurts <geurts AT rice.edu>
> Date: Friday, September 13, 2024 at 11:40 AM
> To: Fisyak, Yuri V <fisyak AT bnl.gov>
> Cc: Witt, Richard CIV USNA Annapolis <witt AT usna.edu>, Star-tpc L 
> <Star-tpc-l AT lists.bnl.gov>
> Subject: Re: [[Star-tpc-l] ] Status of PR for New Alignment Library Code
> 
> Hi Yuri,
> 
> I am referring to these particular comment that was made in the PR and 
> which appears to indicate that the CorrZ option removes the OSectorAlign 
> chain option that implements a TPC distortion correction. That may be 
> unintentional, but should  be corrected unless there is an explanation.
> 
> What may be confusing is that it doesn't explicitly pop up in the PR as a 
> change, but for CorrX, CorrY this chain option is included, while for the 
> new CorrZ it is explicitly removed (see line 1142 of  
> StRoot/StBFChain/BigFullChain.h)
>