Search for Resonant B±→K±h→K±γγB^{\pm}\to K^{\pm} h \to K^{\pm} \gamma \gamma Decays at Belle

We report measurements and searches for resonant $B^{\pm} \to K^{\pm} h \to K^{\pm} \gamma \gamma$ decays where $h$ is a $\eta,\eta^{\prime},\eta_{c},\eta_{c}(2S),\chi_{c0},\chi_{c2},J/\psi$ 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 ϕ(1680)\phi(1680) and the Y(2175) in e+e−→ϕπ+π−e^+ e^- \to \phi\pi^+\pi^-

The cross sections for $e^+ e^- \to \phi\pi^+\pi^-$ and e^+ e^- \to \phi \fzero are measured from threshold to $\sqrt{s}=3.0$ $\hbox{GeV}$ using initial state radiation. The analysis is based on a data sample of 673 fb$^{-1}$ collected on and below the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. First measurements are reported for the resonance parameters of the $\phi(1680)$ in the $\phi\pi^+\pi^-$ mode: $m=(1689\pm 7\pm 10)$ MeV/$c^2$ and $\Gamma=(211\pm 14\pm 19)$ MeV/$c^2$. A structure at $\sqrt{s}=2.1 \hbox{GeV}/c^2$, corresponding to the so called Y(2175), is observed; its mass and width are determined to be $2079\pm13^{+79}_{-28}$ MeV/$c^2$ and $192\pm23^{+25}_{-61} \hbox{MeV}/c^2$, respectively.Comment: 11 pages, 6 figures. Add one plot. Accepted by Phys.Rev.D(RC

Search for lepton-flavor-violating τ→ℓV0\tau\to\ell V^0 decays at Belle

We have searched for neutrinoless $\tau$ lepton decays into $\ell$ and $V^0$, where $\ell$ stands for an electron or muon, and $V^0$ for a vector meson ($\phi$, $\omega$, $K^{*0}$, $\bar{K}^{*0}$ or $\rho^0$), using 543 fb$^{-1}$ of data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ 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 $(5.9-18) \times 10^{-8}$ at the 90% confidence level. These upper limits include the first results for the $\ell \omega$ mode as well as new limits that are significantly more restrictive than our previous results for the $\ell \phi$, $\ell K^{*0}$, $\ell \bar{K}^{*0}$ and $\ell \rho^0$ 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 e+e−→VPe^+ e^- \to VP processes at s=10.58\sqrt{s}=10.58 GeV

The cross sections for the reactions $e^+e^- \to \phi\eta, \quad \phi\eta', \quad \rho\eta, \quad \rho\eta'$ 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: $1.4 \pm 0.4 \pm 0.1$ fb $(\phi\eta)$, $5.3 \pm 1.1 \pm 0.4$ fb $(\phi\eta')$, $3.1 \pm 0.5 \pm 0.1$ fb $(\rho\eta)$ and $3.3 \pm 0.6 \pm 0.2$ fb $(\rho\eta')$. 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 ($\ell = e {or} \mu$), using a data sample of 281 fb$^{-1}$ collected with the Belle detector at the KEKB $e^+e^-$ 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 τ±→ϕK±ν\tau^{\pm} \to \phi K^{\pm} \nu decay

We present the first measurement of tau-decays to hadronic final states with a $\phi$-meson. This is based on 401.4 fb$^{-1}$ of data accumulated at the Belle experiment. The branching ratio obtained is $B(\tau^{\pm}\to\phi K^{\pm}\nu) = (4.06\pm 0.25\pm 0.26)\times 10^{-5}$.Comment: 10 pages, 5 figures, ICHEP2006 contribution pape