status report on f h ’ g

Status report on Status report on ’’

Status report on Status report on ’’

Camilla Di DonatoCamilla Di DonatoI.N.F.N. NapoliI.N.F.N. Napoli

Frascati 13/02/2003

• 2000: ˜17 pb-1 2000: ˜17 pb-1

• 2001: ˜108 pb-1 2001: ˜108 pb-1

• 2002: ˜223 pb-1 2002: ˜223 pb-1

SummarySummary SummarySummary

2000200020002000

KLOE memo n.268: update at the end of feb.

•time window = min(5t,2ns)•EMC-MC threshold•time calibration 2000 data•accidentals in DC (mbckadd)•input kin.fit: pull•more stat. mc background•cut on cos<-0.9 removed

Ks

Kl

Ks

Kl

2000200020002000

New mc efficiency: SGN 20.46% s/b N BG1 1,93x10-7 (90% c.l.) >252 <0,5 BG2 2,75x10-5 6 20BG3 29x10-5 24 5,5

N(2000) = 179 (no bg subtracted)

N’= N(2000)-Nbg = 179 – 25.5 = 153.5

2000200020002000

Systematics: /

filfo 1.1% evcl 1.75% vertex 1.4%Total 2.5%

(N/) /(N/)z =±15% ±0.4%=±1° ±4%E =±10% -0.4%/+3.0%2/Ndof (±1) -0.4%/+2.5%

Total -4%/+6%

2000200020002000

Systematics: BR’’ 3% luminosity 1%-2% cross section 2.5%

total 4.5%

BR(BR(’’)=(7,05 ± 0,50 )x10)=(7,05 ± 0,50 )x10-5-5BR(BR(’’)=(7,05 ± 0,50 )x10)=(7,05 ± 0,50 )x10-5-5+0,53+0,53-0,46-0,46

P.L.B541(2002)P.L.B541(2002):: BR(BR(’’)=(6,10 ± 0,61 ± 0,43 )x10)=(6,10 ± 0,61 ± 0,43 )x10-5-5P.L.B541(2002)P.L.B541(2002):: BR(BR(’’)=(6,10 ± 0,61 ± 0,43 )x10)=(6,10 ± 0,61 ± 0,43 )x10-5-5

2000200020002000

BACKGROUND

cos

Ks

Kl

Ks Kl

data

2000200020002000

2000200020002000

2000200020002000

2000200020002000

2000200020002000

Ks

Kl

Ks Kl

data

EE(MeV)

2000200020002000Ks

Kl

Ks Kl

data

E(MeV)

2000200020002000Ks

Kl

Ks Kl

data

2/Ndof

2001200120012001

Lint = 108pb-1

Nbg

BG1 1.93x10-7 (90% c.l.) < 3 (90%

c.l.)

BG2 2.75x10-5 127

BG3 29x10-5 35

N(2001) = 1046 (no bg subtracted)

N’= N(2001)-Nbg = 1046 – 162 = 884

BR(BR(’’)=(6,20±0,19)x10)=(6,20±0,19)x10-5-5BR(BR(’’)=(6,20±0,19)x10)=(6,20±0,19)x10-5-5

2001(2)2001(2)2001(2)2001(2)

Systematics: / filfo - evcl - vertex -

(N/) /(N/)z =±15% -=±1° 2%E =±10% -2/Ndof (±1) -0,5%/+1,5%

BR’’ 3% luminosity 1%-2% cross section 2.5%

2001200120012001Ks

Kl

Ks Kl

data

cos

2001200120012001Ks

Kl

Ks Kl

data

EE(MeV)

2001200120012001Ks

Kl

Ks Kl

data

E(MeV)

2001200120012001Ks

Kl

Ks Kl

data

2/Ndof

2000/2001/20022000/2001/20022000/2001/20022000/2001/2002

EE(MeV)

2/Ndof

200020012002

2002200220022002

cos

2002200220022002

EE(MeV)

2002200220022002

2/Ndof

•2000: analysis updated with referees’ 2000: analysis updated with referees’ useful suggestions useful suggestions •2001: systematics under study2001: systematics under study•2002: ntuples ready2002: ntuples ready•2001/2002: evcl -> discussion2001/2002: evcl -> discussion

ConclusionsConclusionsConclusionsConclusions