[Frost] tagger sag & phi dependence

[Sungkyun Park]

Hi Steffen,

To check the phi-dependence in our double-pion data, I make some histograms in the following web:

  http://hadron.physics.fsu.edu/~skpark/research/research_jun2110.html

I make 2D-histogram whose x-axis is the phi angle (LAB) of each particle and y-axis is the momentum pull of each particle and project it to 36 plots. I make the histogram using the mean of the Gaussian fitting. 
I think momentum pulls of each particle have some phi-dependence like your result. 

Sung
Florida State University

> Dear Sung et al.,
> 
> we may or may not have a tagger-sag problem in g9a. I agree with  
> Michael that it is important to have all 'known' corrections  
> implemented before the kinematic fitter is applied.  The fitter is  
> probably not a good tool to correct for 'systematic' errors.  In 
> terms  
> of these systematic effects I am still very concerned about the  
> azimuthal dependence of the g9a single-pion data.  The variation of 
> 
> the measured pi+ momentum from the expected momentum (assuming  
> correctly measured pion angles and photon energy) is very large; up 
> to  
> 10-15 MeV/c within one sector's coverage.
> 
> See: http://www.jlab.org/Hall-B/secure/g9/g9_strauch/mtg/20100414.pdf
> 
> I wonder if you see such a phi-dependence also in your double-pion  
> data or if the many particles in the final state wash out any such  
> effect.  We need to address this phi dependence.
> 
> All the best,
> Steffen
> 
> 
> 
>