[Halld-physics] pull distributions

[Curtis A. Meyer]

Hi Everyone -

    I found a chapter of a PhD thesis that talks about
kinematic fitting. Section 6.1.2 talks about the pull distributions and 
formula
6.6 is as I remember it with the denominator having a difference inside the
square root.

    I also recall many years ago looking into what happens when the 
error matricies
are not diagonal. The denominator is defined only using the diagonal 
elements
of the covariance matrix, both for starting values and the fit values.

    With regard for Simon's work, where he is looking at individual 
tracks, I am
not 100% sure how to apply this though. The error matrix is the result 
of the fit.
In Jake's work, it is clearer a we have the pull's from the tracking, 
and then the
improved pulls after the kinematic fit.

    I have placed the chapter (6) on the portal as GlueX-doc-1635:

    Other references include:

    Eadie, W. T. et al., Statistical methods in experimental physics 
(North-Holland, Amsterdam, 1986).

   V. Blobel, Least squares methods, p. I 27, in Bock, R. K. et al. 
(eds.), Formulae and methods
   in experimental data evaluation with emphasis on high energy physics. 
(European Phys. Soc.,
   1984)
curtis

-- 
Prof. Curtis A. Meyer		Department of Physics
Phone:	(412) 268-2745		Carnegie Mellon University
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