Re: Monte Carlo Data

[Brendan Kiburg <kiburg@mu03.npl.uiuc.edu>]

Dearest Tom, 

>   1. Does your current mu-d MC software take any track reconstruction
>      effects into account, or is it 'omniscient'?

   Yes, I take some track reconstruction effects into account.  It is also
omniscient.  That is to say, in the language of the april 5th work log, I
plot a 2D histogram of counts vs. r, t (the displacement from the origin
at decay), as well as a 2D histo of counts vs m, t (the minimum
reconstructable displacement from the origin).  


>   2. If the latter, could we ask you to incorporate these track
>      reconstruction effects so that they could be turned on and off?
>      Basically, you'd need to generate a random decay direction for each
>      mu's displacement, calculate the impact parameter between that decay
>      track and the original mustop location, and use *that* calculated
>      impact parameter (not the 'true' drift distance) when filling the
>      lifetime histograms.  I think the code should be relatively
>      straightforward to implement.
   I store the origin and decay points, as well as a MC impact parameter
in a TTree object, so in a sense, this is turned on without losing the
value of r.

>   3. Did you fix the error bar problems which you mentioned in
>      Analysis-Run8 ELOG entry 47?  If you could do that, implement the
>      track geometry effect, and then produce ratio plots where the
>      geometry effect were turned on and off, we might be very close to
>      explaining this mystery.

  This is my current project.  

> The mechanism we have developed is pretty complex and subtle, so we'll
> wait until next week's teleconference to give a full and detailed
> explanation.  But you can trust us.

  I look forward to next week's meeting.
 
Best regards,

Brendan