We search for lepton-flavor and lepton-number-violating I decays into a lepton (a= electron or muon) and two charged mesons (h , h a2 = pi +/- or K +/-) using 854 fb - 1 of data collected with the ...Belle detector at the KEKB asymmetric-energy e + e - collider. We obtain 90% confidence level upper limits on the I a a h h a2 branching fractions in the range (2.0 a 8.4) X 10 - 8 . These results improve upon our previously published upper limits by factors of about 1.8 on average.
We have searched for CP violation in the decays D(0)→K(S)(0)P(0) where P(0) denotes a neutral pseudoscalar meson that is either a π(0), η, or η' using KEKB asymmetric-energy e(+)e(-) collision data ...corresponding to an integrated luminosity of 791 fb(-1) collected with the Belle detector. No evidence of significant CP violation is observed. We report the most precise CP asymmetry measurement in the decay D(0)→K(S)(0)π(0) to date: A(CP)(D(0)→K(S)(0)π(0))=(-0.28±0.19±0.10)%. We also report the first measurements of CP asymmetries in the decays D(0)→K(S)(0)η and D(0)→K(S)(0)η': A(CP)(D(0)→K(S)(0)η)=(+0.54±0.51±0.16)% and A(CP)(D(0)→K(S)(0)η')=(+0.98±0.67±0.14)%, respectively.
We have searched for the lepton-flavor-violating decays l-K sub(s) super(0) and l-K sub(s) super(0)K sub(s) super(0) (l=e or k), using a data sample of 671 fb super(-1) collected with the Belle ...detector at the KEKB asymmetric-energy e super(+)e super(-) collider. No evidence for a signal was found in any of the decay modes, and we set the following upper limits for the branching fractions: Display omitted at the 90% confidence level.
We present a search for lepton-flavor-violating tau decays into three leptons (electrons or muons) using 782 fb super(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e ...super(+)e super(-) collider. No evidence for these decays is observed and we set 90% confidence level upper limits on the branching fractions between 1.5x10 super(-8) and 2.7x10 super(-8).
We report on a search for CP violation in
τ
±
→
K
S
0
π
±
ν
τ
decays using a data sample of
699
fb
−
1
collected in the Belle experiment at the KEKB electron-positron asymmetric-energy collider. The ...CP asymmetry is measured in four bins of the invariant mass of the
K
S
0
π
±
system and found to be compatible with zero with a precision of
O
(
10
−
3
)
in each mass bin. Limits for the CP violation parameter
ℑ
(
η
s
)
are given at a 90% confidence level. These limits are |
ℑ
(
η
s
)
|
<
0.026
or better, depending on the parameterization used to describe the hadronic form factors, and improve upon previous limits by one order of magnitude.
The cross sections for the reactions e+e−→ϕη, ϕη′, ρη, ρη′ have been measured using a data sample of 516 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− collider. The ...corresponding values of the cross sections are: 1.4±0.4±0.1 fb (ϕη), 5.3±1.1±0.4 fb (ϕη′), 3.1±0.5±0.1 fb (ρη) and 3.3±0.6±0.2 fb (ρη′). The energy dependence of the cross sections is presented using Belle measurements together with those of CLEO and BaBar.
PDF
