Silvia Goy L ó pez, Mauro Raggi 29 th June 2006

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


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


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!



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


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


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)

%

Silvia Goy L ó pez, Mauro Raggi 29 th June 2006

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