HES HKS meeting
13
HES HKS meeting 21 May 2010 T.Gogami
description
HES HKS meeting. 2 1 May 2010 T.Gogami. C ontent. Coincidence Time difference EHODO17 Chi square cut. Coincidence Time (htimetar - etimetar). Run 76956 – 77124 for 52 Cr target. ( 1/3 of all runs ). ?. coincidence time abs(htimetar – etimetar + 55)
Transcript of HES HKS meeting
HES HKS meeting
21 May 2010T.Gogami
Content
Coincidence Time difference
EHODO17Chi square cut
Coincidence Time(htimetar - etimetar)
coincidence timeabs(htimetar – etimetar + 55)<1coincidence time
abs(htimetar – etimetar + 55 + 0.6)<1
?
Run 76956 – 77124for 52Cr target( 1/3 of all
runs )
Coin timeRun num. 77032 - 77091
Something happened
Check “Hall C Log”
•RunID < 77065• htimetar – etimetar +55.0
+ 0.6•RunID >=77065• htimetar – etimetar +55.0
1. EH hitpat. changed at Run 770632. Signals which going to 2nd discri. are
small due to high rate. EH 2nd discri. thereshold changed to -100 [mV]
from -200 [mV]3. After pushed the cable connected to F1
TDC , EH hitpat. became normal !
77062
77063
EHODO 17 hitpattern77068
Chi square cut
CH2 , HKS track
CH2 , HES track
52Cr , HKS track
52Cr , HES track
Scan htrkchi2 / htrkndf < X etrkchi2 / etrkndf < 3
FIXED
FIXED
S/N with different χ2 cut
NAcc.NAcc.
NReal
definition
BETTER than without χ2 cut
not so good
CH2
ex.) X=3 CH2 : 69
% 52Cr : 25
%
Event num. ratio with different χ2 cut
Missing Mass for 52Cr
Λ binding regionΛ binding region
Acc. Background
Acc. Background
QF
QF
Summary and to do Summary
Cointime cut RunID < 77065
htimetar – etimetar +55.0 + 0.6 RunID >=77065
htimetar – etimetar +55.0 EHODO 17
cable connection before F1 TDC chi square cut
a lot of bad tracks for 52Cr chi square cut S/N improve in Λ-binding
region to do
check cointime golden data to analyzer matrix with GEANT4
END
5/17/2010
2次会
