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We report the first measurement of the inclusive e+e- → bb̄ → D^(±)_(s) X and e+e- → bb̄ → D0 / D̅⁰ X cross sections in the energy range from 10.63 to 11.02 GeV. Based on these results, we determine σ(e+e- → B_(s)⁰B̅_(s)⁰ X) and σ(e+e- → BB̅ X) in the same energy range. We measure the fraction of B_(s)⁰ events at Υ(10860) to be fs = (22.0_(-2.1)^(+2.0))%. We determine also the ratio of the B_(s)⁰ inclusive branching fractions 𝓑(B_(s)⁰ → D0/ D̅⁰X)/𝓑(B_(s)⁰ → D_(s)^(±)X) = 0.416 ± 0.018 ± 0.092. The results are obtained using the data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.

We report the first measurement of the inclusive e + e − →$$ b\\overline{b} $$b b ¯ →$$ {D}_s^{\\pm } $$D s ± X and e + e − →$$ b\\overline{b} $$b b ¯ → D 0 /$$ {\\overline{D}}^0 $$D ¯ 0 X cross sections in the energy range from 10 . 63 to 11 . 02 GeV. Based on these results, we determine σ ( e + e − →$$ {B}_s^0{\\overline{B}}_s^0 $$B s 0 B ¯ s 0 X ) and σ ( e + e − →$$ B\\overline{B} $$B B ¯ X ) in the same energy range. We measure the fraction of$$ {B}_s^0 $$B s 0 events at Υ(10860) to be f s = ($$ {22.0}_{-2.1}^{+2.0} $$22.0 − 2.1 + 2.0 )%. We determine also the ratio of the$$ {B}_s^0 $$B s 0 inclusive branching fractions$$ \\mathcal{B} $$B ($$ {B}_s^0 $$B s 0 → D 0 /$$ {\\overline{D}}^0 $$D ¯ 0 X ) /$$ \\mathcal{B} $$B ($$ {B}_s^0 $$B s 0 →$$ {D}_s^{\\pm } $$D s ± X ) = 0 . 416 ± 0 . 018 ± 0 . 092. The results are obtained using the data collected with the Belle detector at the KEKB asymmetric-energy e + e − collider.

We present a search for the lepton-flavor-violating decays$$ {B}_s^0 $$B s 0 → ℓ ∓ τ ± , where ℓ = e, μ , using the full data sample of 121 fb − 1 collected at the Υ(5 S ) resonance with the Belle detector at the KEKB asymmetric-energy e + e − collider. We use$$ {B}_s^0{\\overline{B}}_s^0 $$B s 0 B ¯ s 0 events in which one$$ {B}_s^0 $$B s 0 meson is reconstructed in a semileptonic decay mode and the other in the signal mode. We find no evidence for$$ {B}_s^0 $$B s 0 → ℓ ∓ τ ± decays and set upper limits on their branching fractions at 90% confidence level as$$ \\mathcal{B} $$B ($$ {B}_s^0 $$B s 0 → e ∓ τ ± ) < 14 × 10 − 4 and$$ \\mathcal{B} $$B ($$ {B}_s^0 $$B s 0 → μ ∓ τ ± ) < 7 . 3 × 10 − 4 . Our result represents the first upper limit on the$$ {B}_s^0 $$B s 0 → e ∓ τ ± decay rate.

We measure the branching fractions and CP asymmetries for the singly Cabibbo-suppressed decays $D^0 → π^+π^-η, D^0 → K^+K^-η$, and $D^0 → Φη$, using 980 fb-1 of data from the Belle experiment at the KEKB e+e- collider. We obtain $$\\mathcal{B}(D^0 → π^+π^-η = \\mathrm{[1.22 ± 0.02 (stat) ± 0.02(syst) ± 0.03}(\\mathcal{B}_{\\mathrm{ref}})] \\mathrm{x 10^{-3}}$$ $$\\mathcal{B}(D^0 → K^+K^-η = \\mathrm{[1.80^{+0.07}_{-0.06}(stat) ± 0.04 (syst) ± 0.05}(\\mathcal{B}_{\\mathrm{ref}})] \\mathrm{x 10^{-4}}$$ $$\\mathcal{B}(D^0 → Φη = \\mathrm{[1.84 ± 0.09 (stat) ± 0.0 (syst) ± 0.05}(\\mathcal{B}_{\\mathrm{ref}})] \\mathrm{x 10^{-4}}$$ where the third uncertainty ($\\mathcal{B}_{\\mathrm{ref}}$) is from the uncertainty in the branching fraction of the reference mode $D^0 → K^-π^+η$. The color-suppressed decay $D^0 → Φη$ is observed for the first time, with very high significance. The results for the CP asymmetries are $$A_{CP} (D^0 → π^+π^-η) = \\mathrm{[0.9 ± 1.2 (stat) ± 0.5 (syst)]}\\%$$ $$A_{CP} (D^0 → K^+K^-η) = \\mathrm{[-1.4 ± 3.3 (stat) ± 1.1 (syst)]}\\%$$ $$A_{CP} (D^0 → Φη) = \\mathrm{[-1.9 ± 4.4 (stat) ± 0.6 (syst)]}\\%$$ The results for $D^0 → π^+π^-η$ are a significant improvement over previous results. The branching fraction and ACP results for $D^0 → K^+K^-η$, and the ACP result for $D^0 → Φη$, are the first such measurements. No evidence for CP violation is found in any of these decays.

We present a measurement of the Cabibbo-Kobayashi-Maskawa unitarity triangle angle φ3 (also known as γ) using a model-independent Dalitz plot analysis of B+ → D( K_(S)⁰ h+h–)h+, where D is either a Do or Do¯ meson and h is either a π or K. This is the first measurement that simultaneously uses Belle and Belle II data, combining samples corresponding to integrated luminosities of 711 fb–1 and 128 fb–1, respectively. All data were accumulated from energy-asymmetric e+e– collisions at a centre-of-mass energy corresponding to the mass of the Υ(4S) resonance. We measure φ3 = (78.4 ± 11.4 ± 0.5 ± 1.0)°, where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is from the uncertainties on external measurements of the D-decay strong-phase parameters.

We present a measurement of the Cabibbo-Kobayashi-Maskawa unitarity triangle angle φ3 (also known as γ) using a model-independent Dalitz plot analysis of B+ → D( K_(S)⁰ h+h–)h+, where D is either a Do or Do¯ meson and h is either a π or K. This is the first measurement that simultaneously uses Belle and Belle II data, combining samples corresponding to integrated luminosities of 711 fb–1 and 128 fb–1, respectively. All data were accumulated from energy-asymmetric e+e– collisions at a centre-of-mass energy corresponding to the mass of the Υ(4S) resonance. We measure φ3 = (78.4 ± 11.4 ± 0.5 ± 1.0)°, where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is from the uncertainties on external measurements of the D-decay strong-phase parameters.

We present the first measurement of the branching fraction of the singly Cabibbo-suppressed (SCS) decay \\( {\\Lambda}_c^{+} \\) → pη' with η' → ηπ+π–, using a data sample corresponding to an integrated luminosity of 981 fb–1, collected by the Belle detector at the KEKB e+e– asymmetric-energy collider. A significant \\( {\\Lambda}_c^{+} \\) → pη' signal is observed for the first time with a signal significance of 5.4σ. The relative branching fraction with respect to the normalization mode \\( {\\Lambda}_c^{+} \\) → pK–π+ is measured to be $$ \\frac{\\mathcal{B}\\left({\\Lambda}_c^{+}\\to p\\eta^{\\prime}\\right)}{\\mathcal{B}\\left({\\Lambda}_c^{+}\\to {pK}^{-}{\\pi}^{+}\\right)}=\\left(7.54\\pm 1.32\\pm 0.73\\right)\\times {10}^{-3}, $$ where the uncertainties are statistical and systematic, respectively. Using the world-average value of \\( \\mathcal{B}\\left({\\Lambda}_c^{+}\\to {pK}^{-}{\\pi}^{+}\\right) \\) = (6.28 ± 0.32) × 10–2, we obtain $$ \\mathcal{B}\\left({\\Lambda}_c^{+}\\to p\\eta^{\\prime}\\right)=\\left(4.73\\pm 0.82\\pm 0.46\\pm 0.24\\right)\\times {10}^{-4}, $$ where the uncertainties are statistical, systematic, and from \\( \\mathcal{B}\\left({\\Lambda}_c^{+}\\to {pK}^{-}{\\pi}^{+}\\right) \\) , respectively.

We present the first measurement of the branching fraction of the singly Cabibbo-suppressed (SCS) decay$$ {\\Lambda}_c^{+} $$Λ c + → pη ′ with η ′ → ηπ + π − , using a data sample corresponding to an integrated luminosity of 981 fb − 1 , collected by the Belle detector at the KEKB e + e − asymmetric-energy collider. A significant$$ {\\Lambda}_c^{+} $$Λ c + → pη ′ signal is observed for the first time with a signal significance of 5.4 σ . The relative branching fraction with respect to the normalization mode$$ {\\Lambda}_c^{+} $$Λ c + → pK − π + is measured to be$$ \\frac{\\mathcal{B}\\left({\\Lambda}_c^{+}\\to p\\eta^{\\prime}\\right)}{\\mathcal{B}\\left({\\Lambda}_c^{+}\\to {pK}^{-}{\\pi}^{+}\\right)}=\\left(7.54\\pm 1.32\\pm 0.73\\right)\\times {10}^{-3}, $$B Λ c + → pη ′ B Λ c + → pK − π + = 7.54 ± 1.32 ± 0.73 × 10 − 3 , where the uncertainties are statistical and systematic, respectively. Using the world-average value of$$ \\mathcal{B}\\left({\\Lambda}_c^{+}\\to {pK}^{-}{\\pi}^{+}\\right) $$B Λ c + → pK − π + = (6 . 28 ± 0 . 32) × 10 − 2 , we obtain$$ \\mathcal{B}\\left({\\Lambda}_c^{+}\\to p\\eta^{\\prime}\\right)=\\left(4.73\\pm 0.82\\pm 0.46\\pm 0.24\\right)\\times {10}^{-4}, $$B Λ c + → pη ′ = 4.73 ± 0.82 ± 0.46 ± 0.24 × 10 − 4 , where the uncertainties are statistical, systematic, and from$$ \\mathcal{B}\\left({\\Lambda}_c^{+}\\to {pK}^{-}{\\pi}^{+}\\right) $$B Λ c + → pK − π + , respectively.

We report the first measurement of the exclusive cross sections e + e − →$$ B\\overline{B} $$B B ¯ , e + e − →$$ B{\\overline{B}}^{\\ast } $$B B ¯ ∗ , and e + e − →$$ {B}^{\\ast }{\\overline{B}}^{\\ast } $$B ∗ B ¯ ∗ in the energy range from 10 . 63 GeV to 11 . 02 GeV. The B mesons are fully reconstructed in a large number of hadronic final states and the three channels are identified using a beam-constrained-mass variable. The shapes of the exclusive cross sections show oscillatory behavior with several maxima and minima. The results are obtained using data collected by the Belle experiment at the KEKB asymmetric-energy e + e − collider.

We report the first measurement of the exclusive cross sections e+e- → BB̅, e+e- → BB̅^(∗), and e+e- → B^(∗)B̅^(∗) in the energy range from 10.63 GeV to 11.02 GeV. The B mesons are fully reconstructed in a large number of hadronic final states and the three channels are identified using a beam-constrained-mass variable. The shapes of the exclusive cross sections show oscillatory behavior with several maxima and minima. The results are obtained using data collected by the Belle experiment at the KEKB asymmetric-energy e+e- collider.