Tracking Efficiency
 
 Erich Varnes describes this page. "Efficiency is simply the fraction of muons 
 that have a charged track pointing near them.  I'm not sure how much Harry has 
 modified what I've done (he's at least added the effVsTick plot)." His muon 
 definition is essentially "Tight" (see descriptions of muon id) with some scintillator
 time cuts and pT > 2 GeV. Erich defines "near" as being within 0.15 in phi and theta.

 effyvEta
 --------

 Exchange 15-Apr-2003:
 Question (HTD): What is the reason the eff'y is lower forward, peaks at |eta|~1.2,
    and is lower at eta=0?
 Answer    (EV):  Low forward makes sense, in that we begin to lose layers of the CFT, 
    making tracking more difficult.  The peak at eta of 1.2 is a little harder 
    to explain.  Part of it may be the "random track overlap" effect I mentioned 
    earlier.  Since I defined matching using theta rather than eta, the odds of 
    a random track pointing toward the muon increases as one moves forward.  
       In my latest versions of the plots (using p14 tracking and correcting 
    bin-by-bin for random overlaps) the peaks are less noticable.  To the 
    extent that they remain, they are an indication that tracking in the 
    CFT-dominated/SMT-dominated transition region is better than in the 
    central region.

 
 effyvPhi
 --------
 This should be flat. 

 effyvPt
 -------

 Exchange 15-Apr-2003:
 Question (HTD): The shape of this distribution is typical. Does the efficiency really 
    go down with pT? 
 Answer    (EV): I'm not sure.  Statistics do get sparse out at high pT, and it's 
    possible that the fraction of muons that are from cosmics becomes 
    significant.  The dropoff with pT was certainly much more dramatic before 
    I put in the muon timing and z0 cuts to supress cosmics.  
       The bottom line, though, is that this is more likely to be an artificial 
    effect rather than a reflection of the tracking performance.  If there are 
    other cosmic-supression cuts I could try, please let me know.


 effyvChrg
 ---------
 We don't track neutrally-charged particles.

 effyvTick
 ---------
 We expect 36 ticks out of 132 + endeffects to have collisions and tracks
 and for the efficiency not to depend on the tick.
 
 effyvTrkMult
 ------------
 Efficiency vs. Track Multiplicity.