[BLAST_ANAWARE] Wch analysis and target events

From: Tancredi Botto (tancredi@mitlns.mit.edu)
Date: Mon Nov 11 2002 - 15:33:16 EST


Attached the results of show_protons.C (repetita juvant!) for a run of
this weekend with an elstic trigger which had all combinations except the
forward (0-5) with a forward (0-5). There are also runs with a more restrictive
trigger (see chris c. email and below)

> root show_protons.C 2756 -d 2756 -c padc (see root show_protons.C --help)

shown is (time_L - timeR) and viceversa. black is all data, red is the
same run with one adc_cut, atl>8000 (for a proton on the left, in the eep
ntuple, likewise atr>8000 on the right)

Restricting the trigger is not enough, you have to do a data cut to see an
elastic proton. Even with a restricted trigger many of the events do not
seem to come from the target.

I changed show_protons.C to show the total number of events in each data set

For the above run 2756, we had 90088 events, and after adc cut we had
13320 events. Therefore elastics events (that "for sure" come from the
target) were 1:7

That result did not change when I looked at data with a little more
"selective trigger" last night (although I don't understand it, that could
have been due to something else).

-- t
________________________________________________________________________________
Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124
research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^







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