[BLAST_SHIFTS] 11.4.2 B shift

From: Jason Seely (seely@MIT.EDU)
Date: Mon Nov 04 2002 - 16:06:27 EST


Hall was open.

I worked on asymmetry study, notes are in the log book.

Basically I just used show_protons.C and applied a timing cut on the
TDCdiff spectra to isolate the proton peak. This works ok, but
asymmetries are still a few percent. Since this process is really
slow (show_protons.C is really slow when it has to make cuts), I changed
the loop in show_protons to only do one set of paddle combinations at a
time (for example, today i did 0-4 with 11-15), which speeds things up
by a factor of 4, but is still pretty slow. Anyway, it has been
suggested that a coplanarity cut in addition to the timing cut may
help. I started to work on this, but lost about an hour due to the
power outage at 3pm. Computers came back online shortly before 4pm.

Here's a table of the asymmetries: (A = (Npleft -
Npright)/(Npleft + Npright))

comb. Auncut Acut
------------------------
11-2 -5% +11.3%
12-2 +4% -2.2%
12-3 +2% -2.2%
12-4 +4% +3.4%

JS HK

--
--------------------------------------------------------------------
jason seely
26.650.b
massachusetts institute of technology
77 massachusetts avenue
cambridge, ma 02139-4307

email: seely@mit.edu phone: 617.253.4772/6734 html: web.mit.edu/seely/www --------------------------------------------------------------------



This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:28 EST