Fire resistance performance of submerged floating tunnel under various fire conditions

Submerged Floating Tunnels (SFT) were researched by countries had many island as Norway, Italy,\ud China, and Japan. Several sites were examined in China and Norway. Most of them investigated about seismic, dynamic,\ud and collision performance. However, present researches lack to apply the construction fields, therefore, additional\ud researches need. Fire resistance performance of the SFT is important one of the various researches. If fire break out in\ud SFT, it is damaged by thermal loads. The damage of the SFT varies by type of fire. Structure of the SFT is able to\ud collapse partially by fire scale and fire exposure time. For this reason, fire resistance design of the SFT must be\ud suggested. Fire resistance performance of SFT could be investigating for fire resistance design of SFT. Fire condition\ud could be expressed fire curves which are suggested by fire scale and fire exposure time. In this paper, temperature\ud distributions of the SFT were investigated through FE analysis under various fire conditions. Heat transfer analysis was\ud applied to investigate conduction of heat by fire. And there was to draw the biggest influence fire condition to the SFT\ud from FE analysis results. Also, preliminary study was performed for fire resistance design

Neutron beam test of CsI crystal for dark matter search

We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear recoils and $\gamma$'s below 10 keV. The response of CsI crystals to nuclear recoil was studied with mono-energetic neutrons produced by the $^3$H(p,n)$^3$He reaction. This was compared to the response to Compton electrons scattered by 662 keV $\gamma$-ray. Pulse shape discrimination between the response to these $\gamma$'s and nuclear recoils was studied, and quality factors were estimated. The quenching factors for nuclear recoils were derived for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM

Precise measurement of hadronic tau-decays with an eta meson

We have studied hadronic tau decay modes involving an eta meson using 490 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The following branching fractions have been measured: B(tau- -> K- eta nu)=(1.58 +- 0.05 +- 0.09)x 10^{-4}, B(tau- -> K- pi0 eta nu)=(4.6 +- 1.1 +- 0.4)x 10^{-5}, B(tau- -> pi- pi0 eta nu)=(1.35 +- 0.03 +- 0.07)x 10^{-3}, B(tau- -> pi- KS eta nu)=(4.4 +- 0.7 +- 0.2)x 10^{-5}, and B(tau- -> K^{*-} eta nu)=(1.34 +- 0.12 +- 0.09)x 10^{-4}. These results are substantially more precise than previous measurements. The new measurements are compared with theoretical calculations based on the CVC hypothesis or the chiral perturbation theory. We also set upper limits on branching fractions for tau decays into K- KS eta nu, pi- KS pi0 eta nu, K- eta eta nu, pi- eta eta nu and non-resonant K- pi^0 eta nu final states.Comment: 24 pages, 7 figure

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

Search for Lepton-Flavor-Violating tau Decays into a Lepton and an f0(980) Meson

We search for lepton-flavor-violating tau decays into a lepton (electron or muon) and an f0(980) meson using 671 fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. No events are observed and we set the following 90% C.L. upper limits on the branching fraction products: B(tau- -> e-f0(980))*B(f0(980)->pi+pi-) mu-f0(980))*B(f0(980) -> pi+pi-)<3.4x10^-8. This is the first search performed for these modes.Comment: 10 pages, 4 figures, submitted to Phys. Lett.

Search for B+ -> D*+ pi0 decay

We report on a search for the doubly Cabibbo suppressed decay B+ -> D*+ pi0, based on a data sample of 657 million BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider. We find no significant signal and set an upper limit of Br(B+ -> D*+ pi0) < 3.6 x 10^-6 at the 90% confidence level. This limit can be used to constrain the ratio between suppressed and favored B -> D* pi decay amplitudes, r < 0.051, at the 90% confidence level.Comment: 5pages, 2figures, submitted to PRL (v1); PRL published version (v2: minor corrections in the text

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 Ds1(2536)+ -> D+pi-K+ and angular decomposition of Ds1(2536)+ -> D*+K0S

Using 462/fb of e+e- annihilation data recorded by the Belle detector, we report the first observation of the decay Ds1(2536)+ -> D+pi-K+. The ratio of branching fractions B(Ds1+ -> D+pi-K+)/B(Ds1+ -> D*+K0) is measured to be (3.27+-0.18+-0.37)%. We also study the angular distributions in the Ds1(2536)+ -> D*+K0S decay and measure the ratio of D- and S-wave amplitudes. The S-wave dominates, with a partial width of Gamma_S/Gamma_total=0.72+-0.05+-0.01.Comment: Submitted to Phys.Rev.D 16 pages, 6 figures, 3 table

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

Improved measurement of CP-violating parameters in rho+rho- decays

We present a measurement of the CP-violating asymmetry in rho+rho- decays using 535 million BBbar pairs collected with the Belle detector at the KEKB e+e- collider. We measure CP-violating coefficients A = 0.16 +- 0.21(stat) +- 0.07 (syst) and S = 0.19 +- 0.30(stat) +- 0.07 (syst}. These values are used to determine the unitarity triangle angle phi_2 using an isospin analysis; the solution consistent with Standard Model lies in the range 53 < phi_2 < 114 deg. at 90 C.L.Comment: 6 pages, 4 figures, presented at JPS/DPF 2006 (Added KEK, BELLE preprint numbers, submitted to PRD(RC)