[G12] vert2 function

[Dennis Weygand]

Not sure what you are saying here....



On Mar 20, 2013, at 10:32 PM, Michael C. Kunkel wrote:

> Greetings,
> 
> I looked into the workings of vert2. The method of obtaining the vertex for 2 tracks in this method is no different than the method I have been using for years. The problem with this method is that it will fail if the tracks are parallel, which is usually the case for conversions and low mass e+e- events (the problem are in which we are investigating).
> 
> Below is a the snipet of the code to prove it
> 
>   /*calculate dot product of direction unit vectors*/
>   R = v3dot(line1.dir,line2.dir);

R will never be '1' as R is I suspect a float (or double)

>   
>   if(R==1){ /*parallel to beamline*/
>     /*returns a negative distance so know that it was not calculated*/  
>     return;
>   }
> 
> In this case beamline is not used, this is a regurgitated function used for another program that calculates the vertex of a particles from the beamline if # of tracks ==1, otherwise all tracks in TBTR.
> 
> I will provide plots tomorrow, I wanted to give a heads up about the code, and why this might not be useful for either side of the conversion debate.

Do you have the plots?

> 
> BR


I understand the MK, but who is BR?


> MK
> _______________________________________________
> G12 mailing list
> G12 at jlab.org
> https://mailman.jlab.org/mailman/listinfo/g12

--
Dennis Weygand
weygand at jlab.org
(757) 269-5926 (office)
(757) 870-4844 (cell)




-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://mailman.jlab.org/pipermail/g12/attachments/20130322/1b7d39f2/attachment.html