Etude et impact du bruit de fond corrélé pour la mesure de l'angle ...

4.4 Selection
!
e ciencies and systematics 97
"#$#!%!
&'()*+"'!,+--!"#$#!%!
!,)*)!
!./!
tel-00821629, version 1 - 11 May 2013
!
!"#"$%$&'()*+,$-./$*(0+&0&'$123$
Figure 4.19: t cut e
45$$$%$&'(66&6$-./$*(*&)''70$123$
ciency (left) and data/MC discrepancy (right) as a
function of the 252 Cf source
!899$$$%$*(,*'76+$-./$*(0'6)&7$123$
position along the z-axis.
:$
"#$#!!
%&'()*"&!+*,,!"#$#!!
!+()(!
!-.!
Figure 4.20: t cut e ciency (left) and data/MC discrepancy (right) as a
function of the 252 Cf source radial position along guide tube.
Entries/2µs
3
10
2
10
10
252
Cf MC
252
Cf Data
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survival probability from the well-known oscilla
mula and N exp,R
i is given by Equation 4. The
runs over the three backgrounds: cosmogenic
correlated; and accidental. The index R runs
two reactors, Chooz B1 and B2.
Background populations were calculated base
measured rates and the livetime of the detecto
each integration period. Details on the signal p
normalization can be found in Sec. III D. Predic
ulations for both null-oscillation signal and bac
may be found in Table V.
1
0 20 40 60 80 100 120 140 160 180 200
!T(µs)
FIG. 13. Time di erence between prompt and delayed events
with 252 Cf at the detector center. The prompt time is determined
by 7-30 MeV gamma ray.
Figure 4.21: t cut e ciency extrapolation from the detector center to the
edges.
VI.
OSCILLATION ANALYSIS
Reactors One Reactor
Both On P th < 20%
Livetime [days] 139.27 88.66
IBD Candidates 6088 2161
Reactor B1 2910.9 774.6
Reactor B2 3422.4 1331.7
Cosmogenic Isotope 174.1 110.8
Correlated FN & SM 93.3 59.4
Accidentals 36.4 23.1
Total Prediction 6637.1 2299.7
The oscillation analysis is based on a combined fit to
antineutrino rate and spectral shape. IBD candidates are
selected as described in Section V A. The data are compared
to the Monte Carlo signal and background events
from high-statistics samples. The same selections are applied
to both signal and background, with corrections
made to Monte Carlo only when necessary to match detector
performance metrics.
TABLE V. Summary of observed IBD candidates,
responding signal and background predictions for
gration period, before any oscillation fit results h
applied.
Systematic and statistical uncertainties are pr
to the fit by the use of a covariance matrix M ij
to properly account for correlations between ene