KLOE Elba Meeting 23-25/05/2001. Charged Kaons Analysis. http://www.fisica.unile.it/~ventura. Ratio K ± ± 0 / K ± ± K ± Life Time K ± 0 e ± Branching Ratio K ± ± 0 0 Branching Ratio K ± ± + – Branching Ratio. Introductory notes.
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KLOE Elba Meeting 23-25/05/2001
http://www.fisica.unile.it/~ventura
Ratio K±±0/K±±
K± Life Time
K±0e± Branching Ratio
K±±00 Branching Ratio
K±±+– Branching Ratio
M. Martemianov , V. Kulikov
-peak :
225 MeV/c < PCM < 245 MeV/c
-peak :
195 MeV/c < PCM < 215 MeV/c
+ – , e±0
± 0, 0 0
K
K0
Corrections for K
Kaon track
splitting (15 %)
Correct Vertex
(preliminary estimation)
A. Ventura , E. Gorini , M. Primavera
V
A DVFS*
B DHIT*
C DTFS
D DVFS
xy view
D
L
C
O : vertex
P : DC walls crossing
F : track first hit
L : track last hit
V : K± decay vertex
A
B
F
O
P
MCpro:
Geanfi
MCrec:
DataRec
MC pro
MC rec
t (ns)
t (ns)
12 ns 28+45 cm
Fiducial region=[12,40] ns
40 ns 28+210 cm
# Data / e(t)
17.5 pb–1
(end 2000)
(stat)+(?)(sys)
t (ns)
supposing de=0stat 0.030 ns
}
resolutions and offsets vst
B. Sciascia
}±
}
0
Momentum of secondaries
(K frame in m hypothesis)
0 mass
in K0 tag
=132Mev/c2
=5Mev/c2
=205Mev/c
=2Mev/c
Momentum of secondaries
(K frame in m hypothesis)
( pmissc – Emiss ) vspsec
=235Mev/c
=3Mev/c
Efficiency of K selection ~30% (from MC)
Momentum of secondaries
(K frame in m hypothesis)
0 mass
for K0 signal
=205Mev/c
=3Mev/c
=133Mev/c2
=18Mev/c2
Efficiency of K0 selection ~20% (from MC)
0 mass
for K0l signal
=131Mev/c2
=20Mev/c2
ml2obtained imposing 0 = T
me
m
ml2 < 6000 MeV2Ke3
ml2 > 6000 MeV2K3
ml2
Efficiency of Kl3 selection ~ 4–8 % (from MC)
C. Lecci , E. Gorini , M. Primavera
Kinematical cuts
Data
MC
Data
MC
4 clus, rv>40cm,
no FakeVtx + Kinematical cuts
4 clus, rv>40cm
g1+g2fitperformed
=490.5 MeV/c2
=19 MeV/c2
1=131.5MeV/c2
1=18MeV/c2
1=130.5MeV/c2
1=16MeV/c2
=488.9 MeV/c2
=19 MeV/c2
Invariant mass of selected
clusters couples
Invariant mass of selected
secondary particles triplets
Experimental Data
Selection: 1099682 K± , 869 K±±00
3.16 pb-1(July 2000, DBV4)
Selection: 299880 K±, 347 K±±00
(very preliminary estimation)
*
**
*Background contamination subtracted (~0.3% in MCpreliminary)
**0.34% subtraction KPMFILT selecting nonK+K– events (MC)
V. Casavola , E. Gorini , M. Primavera
Kinematical cuts
Data
MC
Data
MC
85MeV/c
85MeV/c
=493.6 MeV/c2
=0.9 MeV/c2
=494.2 MeV/c2
=1.2 MeV/c2
Momentum of selected
secondary particles
Invariant mass of selected
secondary particles triplets
Experimental Data
Selection: 1099682 K± , 1075 K±3
3.16 pb-1(July 2000, DBV4)
Selection: 299880 K±, 352 K±3
(preliminary estimation)
*
**
*Background contamination negligible (<0.3% from MC)
**0.34% subtraction KPMFILT selecting nonK+K– events (MC)