[d2n-analysis-talk] missing tracks (fwd)

[Diana Parno]

Hello all,

I have recently returned from an unexpected trip and am back to banging my 
head on the missing-tracks problem.

Last week, Matt was able to find his missing tracks (see first forwarded 
message below) by removing the line

 	HaveTrack BB.tr.n>0

from his replay_phys.cdef file. However, I had no such luck: I didn't have 
a replay_phys.cdef file. (I did have a replay_test.cdef file, called into 
action by the replay_phys.C macro, but that line was not part of my .cdef 
file). I'm curious where the replay_phys.cdef file comes from, and why 
it's missing for me; I pulled my analyzer software from the d2n cvs 
branch. We should probably be trying to keep things structured in more or 
less the same way amongst our various machines.

Matt also sent me an email from Xin (see second forwarded email; this was 
just before this list was set up) pointing us to the updated optics files 
in his directories. When I imported the db_BB.optics.dat and 
db_BB.mwdc.dat files from those directories and reran my replay, I got 
28,000 tracks, which is a lot better than the 200 tracks I was getting 
earlier -- but it's still nowhere near the 140,000+ tracks that Xin was 
previously getting from the same run. I'm going to try pulling the new BB 
library from Transversity's CVS, too; I don't know when the d2n CVS 
version dates from.

Any ideas?

Diana

---------- Forwarded message ----------
Date: Tue, 20 Oct 2009 18:20:42 -0400
From: MATTHEW R POSIK <tua88437 at temple.edu>
To: Diana Parno <dseymour at andrew.cmu.edu>
Subject: missing tracks

Hi Diana,

   Since Brad didn't set up the d2 discussion mailing list yet, I figured I'd
just email you for now. I talked to Kalyan about our tack problem and in my
replay_phys.C script I had a replay_phys.cdef file, Kalyan was telling me
that there should be no .cdef file. So I removed the cdef file and redid the
replay, and applying the track cut by hand, I now get for ~ 1 million events
I am seeing about ~400 thousand tracks which is close to the ratio that
Kalyan was seeing.

-Matt

---------- Forwarded message ----------
From: Xin Qian <xqian at jlab.org> 
Date: Tue, Oct 20, 2009 at 7:57 PM
Subject: Re: BB d2 analyzer replay and missing tracks
To: MATTHEW R POSIK <tua88437 at temple.edu>


Hi Matt,
       I am doing a physics replay on the the d2 analyzer, and I seem to be
       missing alot of tracks. I replayed run 1258 form d2, the same run 
that
       Kalyan used for the onepass d2 shower calibration, and looking at 
his
       rootfiles for that run he has 225,740 BB.tr.n>0 tracks in a million
       events
       and when I look at the ones that I replayed I end up with only 3,369
       good
       tracks in 964,699 events. I was wonder if you have any ideas on what
       may be
       causing this issue?

You can find my DB at /w/work5602/transversity/farmprod/DB/20090210 and 
20090211. These two DB is the calibrtion that I have done for the D2 
calibration run. I suspect that your database is screwed. Maybe you are 
using the database that you should used later to do the replay. I think if 
you are using my DB, you should get the exact same resulkts as KAlyan. In 
addition, please use the latest BB library as the one in the transversity 
cvs. I updated the tracking for transversity at the beginning of 
transversity experiment.

       Also another problem that I am having is that when I
       look at the invariant mass ,sqrt(PriKine.W2) , the proton peak seems 
to
       be
       shifted a little higher than the proton mass. I was looking to get
       something
       like below (jin_1251_H2.png), but I get something like (H2_w2.png).
       Brad had
       suggested that maybe the analyzer was grabbing the wrong beam 
energy,
       but I
       had the PrimaryKine class print out the beam energy it was using and 
it
       showed 1.2Gev so I don't think that is the issue. I was wondering if
       you had
       any ideas on what may be causing these issues or where may be a good
       spot to
       start looking?

    I am not sure whether this is the first time you are looking at 
bigbite. If this is the case, you may use the wrong BB optics database. 
The one you should use is @ the same location as 200902010 and 20090211. 
In transversity experiment, BigBite is at 30 degree, however, bigbite is 
at 45 degree for D2n.

    I hope this is useful. Just let me know if you have more questions.

Best regards,

Xin