[Eg6_analysis] new rtpc bank

[Nathan Baltzell]

Hi EG6ers,

I'm preparing the reconstructed bank for RTPC as discussed in our
meetings and here's my thoughts.  Currently I have just minimal
information for each track:

id1,id2,id3           - 3 hypotheses' pids
p1,p2,p3              - 3 hypotheses' corrected vertex momenta
poverq,dedx,theta,phi - drift momentum, dE/dX, and vertex angles
vx,vy,vz              - vertex position

The selection of these good tracks is based upon cuts, but using the
the cuts I use to get good calibration tracks may be overly tight:

npads > 3
fabs(sdist) < 5
edist > -2  &&  edist < 5
fabs(doca) < 0.002
chi2 > 0.3  &&  chi2 < 3
fabs(zvertex) < 100

Loosening them and including those additional variables in the bank
may be good:

chi2  - of the helix fit
doca  - DOCA of the helix to the beamline
sdist - path length from the first hit to the start of the drift region
edist - path length from the last  hit to the end   of the drift region
npads - number of hit pads


-Nathan