Silvia Goy López, Mauro Raggi
29th June 2006
Systematic Studies for K±±0
Last meeting:Table for suggested systematics 0<T<80 MeV
Effect Syst. DE Syst. INT
Emin +0.49 +1.16
Eovp +0.13 +0.24
Cog -0.11 -0.26
Misstag +0.38 +0.79
Ppi -0.38 -0.78
Energy scale +0.09 +0.21
Different analyses
(0.04) (0.39)
TOTAL +0.64
-0.40
+1.44
-0.82
Effect Syst. DE Syst. INT
Kaon mass _ _
Delta z _ _
Dist pi-g _ _
Radius DCHs _ _
Non linearity _ _
DE=(3.30 ± 0.34stat)%INT= (-2.37 ± 0.79stat)%
Central value for 0<T<80 MeV, Emin=5GeV, after L1 eff correction:
TO DO
• Could it be that some ‘systematic’ effects could be due to statistical fluctuations?– Suggested by Mauro’s studies on MC and
SS0 for Emin– Silvia must check on SS0
• Are we ‘forgetting’ any possible source of systematic errors?
DONE
• Silvia checks on SS0 for Emin and other effects
• New effects checked:– High T* cut, related to L2 efficiency– Resolution/ misstagging effects– Computation of uncorrelated errors
Results 3 PAR fit SS123 Emin> 5GeV, 0.2<W<0.9, after trigger correction.
SILVIA MAURO
3.36 ± 0.35 3.34 ± 0.31
-2.57 ± 0.81 -2.76 ± 0.74
0<T<80 MeV
Silvia was not using Mauro’s trigger correction. Mauro was using ‘old’ fitting routine.
AverDE=3.35, Aver INT= 2.67, Diff DE= 0.02, Diff INT=0.19
SILVIA MAURO
3.30 ± 0.34 3.34 ± 0.26
-2.37 ± 0.79 -2.76 ± 0.66
0<T<80 MeV
Previous meeting New
Results
DE:
3.36 ± 0.35
INT:
-2.57 ± 0.81
High correlation between INT and DE ~-93%
Emin from last meeting
Eg min (GeV)
Eg min (GeV)
Fra
c D
EF
rac
INT
Reference point 5 GeV, after teff correctionFor syst take full difference between 5 GeV and 7 GeV, disagreement within uncorrelated errors
Fit Stat error
Max diff
Syst error
DE 3.30 0.34 0.54 +0.49
INT -2.37 0.79 1.34 -1.16
Emin: No Syst
• When looking at SS0 no effect found. Corroborates Mauro’s results.
Eg min (GeV)
Eg min (GeV)
Fra
c D
EF
rac
INT
SS0
DE:
3.48 ± 0.29
INT:
-2.55 ± 0.67
DE:
3.36 ± 0.35
INT:
-2.57 ± 0.81
SS0 SS123
Emin: No Syst
SS123 All points within first two ellipses:
Prob ellipse 1: 0.393
Prob ellipse 2: 0.865
Eovp: No Syst
EOVP
Fra
c D
EF
rac
INT
EOVP
EOVP
Fra
c D
EF
rac
INT
EOVP
SS0SS123
Kaon mass: No SystF
rac
DE
Fra
c IN
T
Sigmas Kaon Mass
Sigmas Kaon Mass
SS123 SS0
Cog: No Syst
Cog (cm)
Fra
c D
EF
rac
INT
Cog (cm)
SS123 SS0
Delta z: No Syst
Delta zvn-zvc (cm)
Fra
c D
EF
rac
INT
Delta zvn-zvc (cm)
SS123 SS0
Misstag: Last meeting
zvc-zvnsec (cm)
Fra
c D
EF
rac
INT
zvc-zvnsec (cm)
Fit Stat error
Max diff
Syst error
DE 3.30 0.34 0.38 +0.38
INT -2.37 0.79 0.79 -0.79
Reference point at 400 cm
Take for systematic evaluation point at 750 cm
Misstag: SS0
zvc-zvnsec (cm)
Fra
c D
EF
rac
INT
zvc-zvnsec (cm)
SS0
Fit Stat error
Max diff
Syst error
DE 3.30 0.34 0.33 +0.33
INT -2.37 0.79 0.64 -0.64
If I was using same method of calculating the effect in SS0 I would get comparable results wrt SS123
Misstag: No Syst
All points within first ellipse!
Prob ellipse 1: 0.393
Prob ellipse 2: 0.865
SS123
Ppi: No syst
Ppi (GeV)
Fra
c D
EF
rac
INT
Ppi (GeV)
SS123 SS0
T* upper cut: L2 efficiency
0<T*<80 MeV 0<T*<75 MeV 0<T*<70 MeV
Frac DE (%) 3.36 ± 0.35 3.69 ± 0.37 3.77 ± 0.40
Frac INT (%) -2.57 ± 0.81 -3.60 ± 0.88 -3.80 ± 0.97
MBOX cut in mfake at 475 MeV equivalent to a cut on T*<90 MeV
Resolution effects can show near the cut
Try varying upper cut on T* to check effect
Big effect changing from 80 MeV to 75 MeV
Diff DE=0.33 Diff INT=1.03
Effect is much reduced going from 75 MeV to 70 MeV, as expected if due to edge effect of trigger cut
Proposal: assign half of the difference as systematic uncertainty
New table for suggested systematics 0<T<80 MeV
Effect Syst. DE Syst. INT
Energy scale +0.09 -0.21
Different analyses
(0.02) (0.19)
Resolution _ _
T*(L2) ±0.17 ±0.52
TOTAL +0.19
-0.17
+0.53
-0.56
Effect Syst. DE Syst. INT
Eovp _ _
Cog _ _
Misstag _ _
Emin _ _
Ppi _ _
Kaon mass _ _
Delta z _ _
Dist pi-g _ _
Radius DCHs _ _
Non linearity _ _
Results for fractions wrt IB
• Averaging Mauro’s and Silvia’s result and setting a systematic error due to difference
• For 0<T*<80 MeV– Frac DE=(3.35±0.35stat ±0.18syst)%– Frac INT=(-2.67±0.81stat ±0.55syst)%
Results with 2 PAR fit
• Useful in order to compare with other experiments
• Much smaller systematic errors
• Results have been shown on 19/05/06
Systematics 2 PAR fit: Emin
No dependency on Emin seen when fitting to 2 PAR
Eg min (GeV) Eg min (GeV)
Fra
c D
E
Fra
c D
E
Teff corr
Raw
Teff corr
Raw
55<T<80 MeV
0<T<80 MeV
Systematics 2 PAR fit: Kaon mass
Number sigmas Number of sigmas
Fra
c D
E 55<T<80 MeV
0<T<80 MeV
Fra
c D
E
No dependency for 55<T<80 MeV. For T<80 MeV tail of 3pin coming in
Systematics 2 PAR fit: Misstag
Zvc-zvnsec (cm) Zvc-zvnsec (cm)
Fra
c D
E 55<T<80 MeV
0<T<80 MeV
Fra
c D
E
No dependency from abs(zvc-zvnsec) > 400 cm
Systematics 2 PAR fit: P
P (GeV) P (GeV)
Fra
c D
E 55<T<80 MeV
0<T<80 MeV
Fra
c D
E
Results 2 PAR fit Emin> 5GeV, 0.2<W<0.9
Emin >
5GeV
SILVIA MAURO
DE (%) 1.36 ± 0.10
1.38 ± 0.07
1.42 ± 0.11
1.43 ± 0.08
SILVIA MAURO
2.27 ± 0.12 2.34 ± 0.13
2.31 ± 0.12
55<T<80 MeV 0<T<80 MeV
• Good agreement found between Mauro-Silvia• Also good agreement between values in 55<T<80 MeV and extrapolation from 0<T<80 MeV
NEW!!!
T* upper cut: L2 efficiency
0<T*<80 MeV 0<T*<75 MeV 0<T*<70 MeV
Frac DE (%) 2.31 ± 0.12 2.23 ± 0.12 2.25 ± 0.13
Big effect changing from 80 MeV to 75 MeV
Diff DE=0.08
Proposal: assign half of the difference as systematic uncertainty
Results Frac DE wrt IB for INT=0
• Averaging results for 0<T*<80 MeVFrac DE(INT=0)=(2.29±0.13stat±0.04syst)%
• Extrapolating to 55<T<90 MeV– Frac DE(INT=0)=(0.85±0.048stat±0.015syst)
%