sPHENIX tracking discussion

["Lajoie, John G [PHYSA]" <lajoie AT iastate.edu>]

Dear sPHENIX Tracking folks:

 

Just to make sure I’m not going off the rails here, check my numbers for me….

 

I’m interested in the *minimum* separation between two tracks that sPHENIX can resolve, as part of this effort to use N-particle correlations to look at jet substructure.  I can get a start on estimating this by looking at the parameters of the MVTX.  If I assume that the tracks are not allowed to share *any* MVTX hits, and the MVTX has a 28um pixel, then the best I can do is:  

 

~28um/24mm = 1.2 e-3

 

Assuming they have to be separated at the first MVTX layer. If they can share hits in the MVTX, but I require the last hit to be unique, I get

 

~28um/39mm = 0.7e-3

 

This is a very back-of-the-envelope estimate, and basically assumes to equal momenta particles.  If they are not equal mpomenta then they will separate based on momentum in both the MVTX, and certainly in the TPC, which would allow you to go to even smaller angles. 

 

Of course, this depends a bit on how the tracking is handled.   Are multiple TPC tracks allowed to be matched to MVTX tracks?

 

Sorry if these questions are somewhat naïve, just trying to think through this….

 

John

 

 

John Lajoie

he, him, his

Harmon-Ye Professor of Physics

Iowa State University

 

(515) 294-6952

lajoie AT iastate.edu