Log entry time 06:22:12 on January18,2001

Entry number 54956

keyword=Scintillator trigger inefficiency and contamination

The following is just an attempt to look the performance of scintillators.
Your comments are welcome, no matter on on the method or one the results.

I estimated the scintillator trigger efficiency by applying good_vdc cut on the event_type. And then to compare the percentage of T2,T4 events among the total good events.

The definition of good_vdc_l cut I used:

define/logical good_vdc_l high_mult_l&&spec_l.th_rot_l
define/cut/1d spec_l.u1.mult-1 2.5 10.
define/cut/1d spec_l.v1.mult-1 2.5 10.
define/cut/1d spec_l.u2.mult-1 2.5 10.
define/cut/1d spec_l.v2.mult-1 2.5 10.
define/cut/1d spec_l.th_rot-1 -.4 .4
define/log high_mult_l _
spec_l.u1.mult-1&&spec_l.v1.mult-1&&spec_l.u2.mult-1&&spec_l.v2.mult-1

Inefficiency :
==========
Run#....1296....1418....1424+1425
Right....1.0%......5%.........3.1%
Left......3.7%....16%........13.0%

If I use vdc track cut, the results will be even worse.

*****************************

The contamination were estimated from the difference of 1 and the ratio of good triggers with vdc cut to that without vdc cut. I used good_vdc_l&&good_vdc_r cut defined as above, as well as using the one track cut spec_l.track-1&&spec_r.track-1 with definitions:

define/cut/1d spec_r.track-1 0.5 1.5
define/cut/1d spec_l.track-1 0.5 1.5

Percentage of T1 triggers without good vdc
================================
Run#................1296....1418
good_vdc cut....11%.....80%
one track cut......4%......60%

Pacentage of T3 triggers without good vdc
================================
Run#................1296....1418
good_vdc cut....37%.....76%
one track cut.....30%.....68%

Percentage of T5 triggers without good vdc
================================
Run#................1296....1418
good_vdc cut....40%.....82%
one track cut.....29%.....80%.

User name Lingyan

Log entry time 06:22:12 on January18,2001

Entry number 54956