First measurement of T-odd moments in D^{0}→K_{S}^{0}π^{+}π^{-}π^{0} decays

We report the first measurement of the T-odd moments in the decay D0→K0Sπ+π−π0 from a data sample corresponding to an integrated luminosity of 966 fb−1 collected by the Belle experiment at the KEKB asymmetric-energy e+e− collider. From these moments we determine the CP-violation-sensitive asymmetry aT-oddCP=[−0.28±1.38(stat.)+0.23−0.76(syst.)]×10−3, which is consistent with no CP violation. In addition, we perform aT−oddCP measurements in different regions of the D0→K0Sπ+π−π0 phase space; these are also consistent with no CP violation

Measurement of Branching Fractions of Hadronic Decays of the Ω 0 c Baryon

Using a data sample of 980  fb−1 of e+e− annihilation data taken with the Belle detector operating at the KEKB asymmetric-energy e+e− collider, we report the results of a study of the decays of the Ω0ccharmed baryon into hadronic final states. We report the most precise measurements to date of the relative branching fractions of the Ω0c into Ω−π+π0, Ω−π+π−π+, Ξ−K−π+π+, and Ξ0K−π+, as well as the first measurements of the branching fractions of the Ω0c into Ξ−¯K0π+, Ξ0¯K0, and Λ¯K0¯K0, all with respect to the Ω−π+ decay. In addition, we investigate the resonant substructure of these modes. Finally, we present a limit on the branching fraction for the decay Ω0c→Σ+K−K−π+

Measurement of the branching fraction and CP asymmetry in B 0 → π 0π 0 decays, and an improved constraint on φ2

We measure the branching fraction and CP violation asymmetry in the decay B0→π0π0, using a data sample of 752×106 B¯B pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB e+e− collider. The obtained branching fraction and direct CP asymmetry are B(B→π0π0)=[1.31±0.19(stat)±0.19(syst)]×10−6 and ACP=+0.14±0.36(stat)±0.10(syst), respectively. The signal significance, including the systematic uncertainty, is 6.4 standard deviations. We combine these results with Belle’s earlier measurements of B0→π+π− and B±→π±π0 to exclude the CP-violating parameter ϕ2 from the range 15.5°\u3cϕ

Observation of an alternative χ_{c0}(2P) candidate in e^{+}e^{-}→J/ψDD[over ¯]

We perform a full amplitude analysis of the process e+e−→J/ψD¯D, where D refers to either D0 or D+. A new charmoniumlike state X∗(3860) that decays to D¯D is observed with a significance of 6.5σ. Its mass is (3862+26−32 +40−13)  MeV/c2, and its width is (201+154−67 +88−82)  MeV. The JPC=0++ hypothesis is favored over the 2++ hypothesis at the level of 2.5σ. The analysis is based on the 980  fb−1 data sample collected by the Belle detector at the asymmetric-energy e+e− collider KEKB

Measurement of the τ Lepton Polarization and R(D^{*}) in the Decay B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ}

We report the first measurement of the τ lepton polarization Pτ (D ∗ ) in the decay B¯ → D ∗ τ −ν¯τ as well as a new measurement of the ratio of the branching fractions R(D ∗ ) = B(B¯ → D ∗ τ −ν¯τ )/B(B¯ → D ∗ ` −ν¯`), where ` − denotes an electron or a muon, and the τ is reconstructed in the modes τ − → π −ντ and τ − → ρ −ντ . We use the full data sample of 772×106 BB¯ pairs recorded with the Belle detector at the KEKB electron-positron collider. Our results, Pτ (D ∗ ) = −0.38±0.51(stat.) +0.21 −0.16(syst.) and R(D ∗ ) = 0.270 ± 0.035(stat.) +0.028 −0.025(syst.), are consistent with the theoretical predictions of the Standard Model

Study of η and dipion transitions in Υ(4 S) decays to lower bottomonia

We study hadronic transitions between bottomonium states using 496 fb−1 data collected at the Υ(4S)resonance with the Belle detector at the KEKB asymmetric energy e+e− collider. We measure B(Υ(4S)→π+π−Υ(1S))=(8.2±0.5(stat)±0.4(syst))×10−5, B(Υ(4S)→π+π−Υ(2S))=(7.9±1.0(stat)±0.4(syst))×10−5, and B(Υ(4S)→ηΥ(1S))=(1.70±0.23(stat)±0.08(syst))×10−4. We measure the ratio of branching fractions R=B(Υ(4S)→ηΥ(1S))/B(Υ(4S)→π+π−Υ(1S))=2.07±0.30(stat)±0.11(syst). We search for the decay Υ(13D1,2)→ηΥ(1S), but do not find significant evidence for such a transition. We also measure the initial-state radiation production cross sections of the Υ(2S,3S) resonances and we find values compatible with the expected ones. Finally, the analysis of the Υ(4S)→π+π−Υ(1S)events shows indications for a resonant contribution due to the f0(980) meson

Production cross sections of hyperons and charmed baryons from e + e − annihilation near √ s = 10.52 GeV

We measure the inclusive production cross sections of hyperons and charmed baryons from e+e−annihilation using a 800 fb−1 data sample taken near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for S=−1 hyperons follow an exponential function with a single slope parameter except for the Σ(1385)+ resonance. Suppression for Σ(1385)+ and Ξ(1530)0 hyperons is observed. Among the production cross sections of charmed baryons, a factor of 3 difference for Λ+c states over Σc states is observed. This observation suggests a diquark structure for these baryons

Search for C P violation in the D + → π + π 0 decay at Belle

We search for CP violation in the charged charm meson decay D+→π+π0, based on a data sample corresponding to an integrated luminosity of 921 fb−1 collected by the Belle experiment at the KEKB e+e− asymmetric-energy collider. The measured CP-violating asymmetry is [+2.31±1.24(stat)±0.23(syst)]%, which is consistent with the standard model prediction and has a significantly improved precision compared to previous results

Search for Λ + c → ϕ p π 0 and branching fraction measurement of Λ + c → K − π + p π 0

We have searched for the Cabibbo-suppressed decay Λ+c→ϕpπ0 in e+e− collisions using a data sample corresponding to an integrated luminosity of 915 fb−1. The data were collected by the Belle experiment at the KEKB e+e− asymmetric-energy collider running at or near the Υ(4S) and Υ(5S)resonances. No significant signal is observed, and we set an upper limit on the branching fraction of B(Λ+c→ϕpπ0)\u3c15.3×10−5 at 90% confidence level. The contribution of nonresonant Λ+c→K+K−pπ0 decays is found to be consistent with zero, and the corresponding upper limit on its branching fraction is set to be B(Λ+c→K+K−pπ0)NR\u3c6.3×10−5 at 90% confidence level. We also search for an intermediate hidden-strangeness pentaquark decay P+s→ϕp. We see no evidence for this intermediate decay and set an upper limit on the product branching fraction of B(Λ+c→P+sπ0)×B(P+s→ϕp)\u3c8.3×10−5 at 90% confidence level. Finally, we measure the branching fraction for the Cabibbo-favored decay Λ+c→K−π+pπ0; the result is B(Λ+c→K−π+pπ0)=(4.42±0.05(stat)±0.12(syst)±0.16(norm))%, which is the most precise measurement to date

Measurement of the decays B → η ℓ ν ℓ and B → η ′ ℓ ν ℓ in fully reconstructed events at Belle

We report branching fraction measurements of the decays B+→ηℓ+νℓ and B+→η′ℓ+νℓ based on 711 fb−1 of data collected near the Υ(4S) resonance with the Belle experiment at the KEKB asymmetric-energy e+e− collider. This data sample contains 772 million B¯B events. One of the two Bmesons is fully reconstructed in a hadronic decay mode. Among the remaining (“signal-B”) daughters, we search for the η meson in two decay channels, η→γγ and η→π+π−π0, and reconstruct the η′meson in η′→ηπ+π− with subsequent decay of the η into γγ. Combining the two η modes and using an extended maximum likelihood, the B+→ηℓ+νℓ branching fraction is measured to be (4.2±1.1(stat.)±0.3(syst.))×10−5. For B+→η′ℓ+νℓ, we observe no significant signal and set an upper limit of 0.72×10−4 at 90% confidence level