61 research outputs found
Search for Resonant Decays at Belle
We report measurements and searches for resonant decays where is a
meson or
the X(3872) particle.Comment: accepted by Physics Letters
Study of charmonia in four-meson final states produced in two-photon collisions
We report measurements of charmonia produced in two-photon collisions and
decaying to four-meson final states, where the meson is either a charged pion
or a charged kaon. The analysis is based on a 395fb^{-1} data sample
accumulated with the Belle detector at the KEKB electron-positron collider. We
observe signals for the three C-even charmonia eta_c(1S), chi_{c0}(1P) and
chi_{c2}(1P) in the pi^+pi^-pi^+pi^-, K^+K^-pi^+pi^- and K^+K^-K^+K^- decay
modes. No clear signals for eta_c(2S) production are found in these decay
modes. We have also studied resonant structures in charmonium decays to
two-body intermediate meson resonances. We report the products of the
two-photon decay width and the branching fractions, Gamma_{gamma gamma}B, for
each of the charmonium decay modes.Comment: 22 pages, 12 figure
Observation of the and the Y(2175) in
The cross sections for and e^+ e^- \to \phi
\fzero are measured from threshold to using
initial state radiation. The analysis is based on a data sample of 673
fb collected on and below the resonance with the Belle
detector at the KEKB asymmetric-energy collider. First measurements
are reported for the resonance parameters of the in the
mode: MeV/ and MeV/. A structure at ,
corresponding to the so called Y(2175), is observed; its mass and width are
determined to be MeV/ and , respectively.Comment: 11 pages, 6 figures. Add one plot. Accepted by Phys.Rev.D(RC
Search for lepton-flavor-violating decays at Belle
We have searched for neutrinoless lepton decays into and ,
where stands for an electron or muon, and for a vector meson
(, , , or ), using 543 fb
of data collected with the Belle detector at the KEKB asymmetric-energy
collider. No excess of signal events over the expected background has
been observed, and we set upper limits on the branching fractions in the range
at the 90% confidence level. These upper limits
include the first results for the mode as well as new limits that
are significantly more restrictive than our previous results for the , , and modes.Comment: 7 pages, 16 figure
Measurement of the ratio B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) and the time-integrated CP asymmetry in D0->pi+pi-pi0
We report a high-statistics measurement of the relative branching fraction
B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) using a 532 fb^{-1} data sample collected with
the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured
value of the relative branching fraction is B(D0->pi+pi-pi0)/B(D0->K-pi+pi0) =
(10.12 +/- 0.04(stat) +/- 0.18(syst))x10^{-2} which has an accuracy comparable
to the world average. We also present a measurement of the time-integrated CP
asymmetry in D0->pi+pi-pi0 decay. The result, A_{CP} = (0.43 +/- 1.30)%, shows
no significant CP violation.Comment: 15 pages, 11 figures, submitted to Physics Letters
Observation of B+ -> K+ eta gamma
We report measurements of radiative B decays with K eta gamma final states,
using a data sample of 253 /fb recorded at the Upsilon(4S) resonance with the
Belle detector at the KEKB e+e- storage ring. We observe B+ -> K+ eta gamma for
the first time with a branching fraction of (8.4 +- 1.5(stat) +1.2 -0.9(syst))
X 10^{-6} for M(Keta) K0 eta gamma.
We also search for B -> K3*(1780) gamma.Comment: 12 pages, 5 figures, accepted by Phys. Lett.
Measurement of cross sections of exclusive processes at GeV
The cross sections for the reactions have been measured using a data sample of 516
fb collected with the Belle detector at the KEKB asymmetric-energy
collider. The corresponding values of the cross sections are: fb , fb , fb and fb . The
energy dependence of the cross sections is presented using Belle measurements
together with those of CLEO and BaBar.Comment: 8 pages, 8 figure
Search for Lepton Flavor Violating tau- Decays Including with a K0s Meson
We have searched for the lepton flavor violating decays \tau^-\to \ell^-\ks
(), using a data sample of 281 fb collected with the
Belle detector at the KEKB asymmetric-energy collider. No evidence for
a signal was found in either of the decay modes, and we set the following upper
limits for the branching fractions: {\cal{B}}(\tau^-\to e^-\ks) < 5.6\times
10^{-8} and {\cal{B}}(\tau^-\to \mu^-\ks) < 4.9\times 10^{-8} at the 90%
confidence level. These results improve the previously published limits set by
the CLEO collaboration by factors of 16 and 19, respectively.Comment: 9 pages, 3figures, submitted to Phys.Lett.
Search for Lepton Flavor Violating tau Decays into Three Leptons
We search for lepton-flavor-violating tau decays into three leptons (electron
or muon) using 535 fb-1 of data collected with the Belle detector at the KEKB
asymmetric-energy e+e- collider. No evidence for these decays is observed, and
we set 90% confidence level upper limits on the branching fractions of
(2.0-4.1)x10^-8. These results improve upon our previously published upper
limits by factors of 4.9 to 10.Comment: 11 pages, 4 figures, submitted to Phys. Lett.
The first observation of decay
We present the first measurement of tau-decays to hadronic final states with
a -meson. This is based on 401.4 fb of data accumulated at the
Belle experiment. The branching ratio obtained is .Comment: 10 pages, 5 figures, ICHEP2006 contribution pape
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