Role of hyperfine coupling in magnetic and quadrupolar ordering of Pr3Pd20Si6.

We study the ternary clathrate Pr3Pd20Si6 in specific heat and ac susceptibility measurements on a high-quality single crystal, distinguishing antiferromagnetic and antiferroquadrupolar ordering, as well as a hitherto unknown magnetic low-temperature transition. The specific heat shows the direct involvement of nuclear spin degrees of freedom in the antiferromagnetic ordering, which is well supported by our calculation of the hyperfine level scheme without adjustable parameters. Pr3Pd20Si6 is, therefore, one of the rare materials where the nuclear moments are involved in the formation of the magnetic ground state.

Magnetic phase diagram of clathrate compound Ce3Pd20Si6 with quadrupolar ordering.

We present results of specific heat measurements on a Ce3Pd20Si6 single crystal and construct the magnetic phase diagram for the three cubic principal directions [100], [110] and [111]. The highly anisotropic phase diagram is discussed and can be qualitatively explained by the Zeeman splitting at the 8c-site. For B â€– [100], the present study found two different quadrupolar ordered phases, which meet the paramagnetic phase at a tri-critical point and establish the new phase boundaries.

Development of MBR with reduced operational and maintenance costs.

To reduce MBR O&M costs, a new MBR process that conducts efficient simultaneous biological nitrogen and phosphorus removal (BNR) was developed. In the development of this process, various approaches were taken, including reduction of power demand, chemical consumption and sludge disposal costs. To address power demand reductions, air supply requirements for membrane cleaning were reduced. The process adopted an improved membrane that requires less air for cleaning than conventional membranes. It also introduced cyclic aeration, which alternately supplies washing air to the two series of membrane units. Adoption of biological phosphorus removal eliminated chemical costs for phosphorus removal and contributed to the reduction of sludge disposal costs. By combining these technologies, compared to conventional MBR processes, an approximately 27% reduction in O&M costs was achieved.

Observation of the D1(2420)-->Dpi + pi- decays.

We report on the first observation of D0/1(2420)-->D0pi- pi+ and D+/1(2420-->D+ pi- pi+ decays (where the contribution from the dominant known D1-->D*pi decay mode is excluded) in the B- -->D0/1pi-) and (-)B0-->D+/1pi- decays, respectively. The observation is based on 15.2 x 10(7) B(-)B events collected with the Belle detector at the KEKB collider. We also set 90% confidence level upper limits for the branching fractions of the four following decays: B- -->D0/1pi-, D01-->D(*0)pi- pi+, (-)B0-->D+/1pi-, D+/1-->D(*+) pi- pi+, B- -->D(*0)2(2460)pi-, D(*0)2 -->D(*0) pi- pi+, (-)B0-->D(*+)2(2460)pi-, D(*+)2-->D(*+)pi- pi+.

Observation of an isotriplet of excited charmed baryons decaying to lambda+c pi.

We report the observation of an isotriplet of excited charmed baryons, decaying into Lambda(+)(c)pi(-), Lambda(+)(c)pi(0), and Lambda(+)(c)pi(+). We measure the mass differences M(Lambda(+)(c)pi)-M(Lambda(+)(c)) and widths to be 515.4(+3.2+2.1)(-3.1-6.0) MeV/c(2), 61(+18+22)(-13-13) MeV for the neutral state; 505.4(+5.8+12.4)(-4.6-2.0) MeV/c(2), 62(+37+52)(-23-38) MeV for the charged state; and 514.5(+3.4+2.8)(-3.1-4.9) MeV/c(2), 75(+18+12)(-13-11) MeV for the doubly charged state, where the uncertainties are statistical and systematic, respectively. These results are obtained from a 281 fb(-1) data sample collected with the Belle detector near the Upsilon(4S) resonance, at the KEKB asymmetric energy e(+)e(-) collider.

Observation of B0-->pi0pi0.

We report the observation of the decay B0-->pi(0)pi(0), using a 253 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) collider. The measured branching fraction is B(B0-->pi(0)pi(0))=(2.3(+0.4+0.2)(-0.5-0.3))x10(-6), with a significance of 5.8 standard deviations including systematic uncertainties. We also make a measurement of the direct CP violating asymmetry in this mode.

Observation of B0-->D*sJ(2317)+K- decay.

The decays B0-->D+sJK- and B0-->D-sJpi+ are studied for the first time. A significant signal is observed in the B0-->D*sJ(2317)+K- decay channel with B(B0-->D*sJ(2317)+K-) x B(D*sJ(2317)+-->D+spi0)=(5.3(+1.5)(-1.3)+/-0.7+/-1.4) x 10(-5). No signals are observed in the B0-->D*sJ(2317)-pi+, B0-->DsJ(2460)+K-, and B 0-->DsJ(2460)-pi+ decay modes, and upper limits are obtained. The analysis is based on a data set of 140 fb(-1) collected by the Belle experiment at the asymmetric e+e- collider KEKB.

Search for D0-D0 mixing in D0 --> K+ pi(-) decays and measurement of the doubly-Cabibbo-suppressed decay rate.

We have searched for mixing in the D(0)-D (0) system by measuring the decay-time distribution of D(0) --> K(+) pi(-) decays. The analysis uses 90 fb(-1) of data collected by the Belle detector at the KEKB e(+) e(-) collider. We fit the decay-time distribution for the mixing parameters x' and y' and also for the parameter R(D), which is the ratio of the rate for the doubly-Cabibbo-suppressed decay D(0)--> K+ pi(-) to that for the Cabibbo-favored decay D(0)--> K-pi(+). We do these fits both assuming CP conservation and allowing for CP violation. We use a frequentist method to obtain a 95% C.L. region in the x'(2) - y' plane. Assuming no mixing, we measure R(D) = (0.381 +/- 0.017(+0.008)(-0.016))%.

Study of the suppressed decays B- -->[K+pi-](D)K- and B- -->[K+pi-]Dpi-.

We report a study of the suppressed decays B--->[K(+)pi(-)](D)K- and B--->[K(+)pi(-)](D)pi(-), where [K(+)pi(-)](D) indicates that the K+pi(-) pair originates from a neutral D meson. These decay modes are sensitive to the unitarity triangle angle varphi(3). We use a data sample containing 275 x 10(6) BB pairs recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) storage ring. The signal for B--->[K(+)pi(-)](D)K- is not statistically significant, and we set a limit r(B)<0.27 at 90% confidence level, where r(B) is the magnitude of the ratio of amplitudes |A(B--->D 0K-)/A(B--->D0K-)|. We observe a signal with 6.4sigma statistical significance in the related mode, B--->[K(+)pi(-)](D)pi(-).

Evidence for direct CP violation in B0-->K+pi- decays.

We report evidence for direct CP violation in the decay B0-->K+pi(-) with 253 fb(-1) of data collected with the Belle detector at the KEKB e(+)e(-) collider. Using 275x10(6) BB pairs we observe a B-->K+/-pi(-/+) signal with 2140+/-53 events. The measured CP violating asymmetry is A(CP)(K+pi(-))=-0.101+/-0.025(stat)+/-0.005(syst), corresponding to a significance of 3.9sigma including systematics. We also search for CP violation in the decays B+-->K+pi(0) and B+-->pi(+)pi(0). The measured CP violating asymmetries are A(CP)(K+pi(0))=0.04+/-0.05(stat)+/-0.02(syst) and A(CP)(pi(+)pi(0))=-0.02+/-0.10(stat)+/-0.01(syst), corresponding to the intervals -0.05

Search for CP violation in the decay B0-->D*+/-D-/+.

We report a search for CP-violating asymmetry in B0-->D(*+/-)D-/+ decays. The analysis employs two methods of B0 reconstruction: full and partial. In the full reconstruction method all daughter particles of the B0 are required to be detected; the partial reconstruction technique requires a fully reconstructed D- and only a slow pion from the D(*+)-->D0pi(+)(slow) decay. From a fit to the distribution of the time interval corresponding to the distance between two B meson decay points we calculate the CP-violating parameters and find the significance of nonzero CP asymmetry to be 2.7 standard deviations.

Evidence for B+-->omegal+nu.

We have searched for the decay B+-->omegal(+)nu (l=e or mu) in 78 fb(-1) of Upsilon(4S) data (85x10(6)BB events) accumulated with the Belle detector. The final state is fully reconstructed using the omega decay into pi(+)pi(-)pi(0), combined with detector hermeticity to estimate the neutrino momentum. A signal of 414+/-125 events is found in the data, corresponding to a branching fraction of (1.3+/-0.4+/-0.2+/-0.3)x10(-4), where the first two errors are statistical and systematic, respectively. The third error reflects the estimated form-factor uncertainty.

Inclusive measurement of the photon energy spectrum in b --> sgamma decays.

We report a fully inclusive measurement of the flavor changing neutral current decay b --> sgamma in the energy range 1.8 GeV < or = E*gamma < or = 2.8 GeV, covering 95% of the total spectrum. Using 140 fb(-1), we obtain B(b --> sgamma) = (3.55+/-0.32(+0.30+0.11)(-0.31-0.07)) x 10(-4), where the errors are statistical, systematic, and from theory corrections. We also measure the first and second moments of the photon energy spectrum above 1.8 GeV and obtain (Egamma) = 2.292+/-0.026+/-0.034 GeV and (E2gamma) - (Egamma)2 = 0.0305+/-0.0074+/-0.0063 GeV2, where the errors are statistical and systematic.

Observation of B+-->psi(3770)K+.

We report the first observation of the decay B+-->psi(3770)K+ where the psi(3770) is reconstructed in the D0(-)D(0) and D+D- decay channels. The obtained branching fraction is B(B+-->psi(3770)K+)=(0.48+/-0.11+/-0.07)x10(-3). We have measured the branching fraction for the decay B+-->D0(-)D0K+ to be (1.17+/-0.21+/-0.15)x10(-3) and set a 90% confidence level upper limit of 0.90 x 10(-3) for the decay B+-->D+D-K+. We also present the results of a search for possible decays to D(-)D and D0(-)D(0)pi(0) of the recently observed X(3872) particle. The analysis is based on 88 fb(-1) of data collected at the Upsilon(4S) resonance by the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

Observation of large CP violation and evidence for direct CP violation in B0-->pi(+)pi(-) decays.

We report the first observation of CP violation in B0-->pi(+)pi(-) decays based on 152x10(6) gamma (4S)-->BB decays collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We reconstruct a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the distribution of the time intervals between the two B meson decay points, we obtain A(pipi)=+0.58+/-0.15(stat)+/-0.07(syst) and S(pipi)=-1.00+/-0.21(stat)+/-0.07(syst). We rule out the CP-conserving case, A(pipi)=S(pipi)=0, at a level of 5.2 standard deviations. We also find evidence for direct CP violation with a significance at or greater than 3.2 standard deviations for any S(pipi) value.

Upper bound on the decay tau-->microgamma from the Belle detector.

We have performed a search for the lepton-flavor-violating decay tau-->microgamma using a data sample of 86.3 fb(-1) accumulated by the Belle detector at KEK. No evidence for a signal is seen, and we set an upper limit for the branching fraction of B(tau-->microgamma)<3.1 x 10(-7) at the 90% confidence level.

Observation of the radiative decay D0-->phigamma.

We report the observation of the decay D0-->phigamma with a statistical significance of 5.4sigma in 78.1 fb(-1) of data collected by the Belle experiment at the KEKB e+e- collider. This is the first observation of a flavor-changing radiative decay of a charmed meson. The Cabibbo- and color-suppressed decays D0-->phipi(0), phieta are also observed for the first time. We measure branching fractions B(D0-->phigamma)=[2.60(+0.70)(-0.61)(stat)+0.15-0.17(syst)] x 10(-5), B(D0-->phipi(0))=[8.01+/-0.26(stat)+/-0.47(syst)] x 10(-4), and B(D0-->phieta)=[1.48+/-0.47(stat)+/-0.09(syst)] x 10(-4).

Observation of radiative B-->phi K gamma decays.

The radiative decay B-->phi K gamma is observed for the first time. The branching fraction for the charged B--->phi K- gamma decay mode is measured to be B(B--->phi K- gamma)=(3.4+/-0.9+/-0.4)x10(-6). The photon energy distribution for the B--->phi K- gamma decay is presented. The signal for the neutral B(0)-->phi K(0)gamma decay mode is not statistically significant and an upper limit, B(B(0)-->phi K(0)gamma)<8.3x10(-6) at 90% C.L., is set. The analysis is based on a data set of 90 fb(-1) collected by the Belle experiment at the e(+)e(-) asymmetric collider KEKB.

Study of time-dependent CP violation in B0-->J/psipi0 decays.

We report a measurement of CP asymmetry parameters in the decay B0(B (0))-->J/psipi(0), which is governed by the b-->cc d transition. The analysis is based on a 140 fb(-1) data sample accumulated at the Upsilon(4S) resonance by the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson in the J/psipi(0) final state is fully reconstructed for events used in this analysis. The accompanying B meson flavor is identified by its decay products. From the distribution of proper-time intervals between the two B decays, we obtain the following CP-violating parameters: S(J/psipi(0))=-0.72+/-0.42(stat)+/-0.09(syst) and A(J/psipi(0))=-0.01+/-0.29(stat)+/-0.03(syst).

Evidence for B-->phiphiK.

We report evidence for the decay mode B-->phiphiK based on an analysis of 78 fb(-1) of data collected with the Belle detector at KEKB. This is the first example of a b-->sssss transition. The branching fraction for this decay is measured to be B(B+/--->phiphiK+/-)=(2.6(+1.1)(-0.9)+/-0.3)x10(-6) for a phiphi invariant mass below 2.85 GeV/c(2). Results for other related charmonium decay modes are also reported.