Evidence for a vector charmonium-like state in e+e−→D+sD∗s2(2573)−+c.c.

We report the measurement of e+e−→D+sD∗s2(2573)−+c.c. via initial-state radiation using a data sample of an integrated luminosity of 921.9 fb−1 collected with the Belle detector at the Υ(4S) and nearby. We find evidence for an enhancement with a 3.4σ significance in the invariant mass of D+sD∗s2(2573)−+c.c. The measured mass and width are (4619.8+8.9−8.0(stat.)±2.3(syst.)) MeV/c2 and (47.0+31.3−14.8(stat.)±4.6(syst.)) MeV, respectively. The mass, width, and quantum numbers of this enhancement are consistent with the charmonium-like state at 4626 MeV/c2 recently reported by Belle in e+e−→D+sDs1(2536)−+c.c. The product of the e+e−→D+sD∗s2(2573)−+c.c. cross section and the branching fraction of D∗s2(2573)−→D¯0K− is measured from D+sD∗s2(2573)− threshold to 5.6 GeV

Observation of the radiative decays of Υ(1S) to χc1

We report the first observation of the radiative decay of the Υ(1S) into a charmonium state. The significance of the observed signal of Υ(1S) → γχc1 is 6.3 standard deviations including systematics. The branching fraction is calculated to be B(Υ(1S) → γχc1) = (4.7 +2.4 −1.8 (stat)+0.4 −0.5 (sys)) · 10−5 . We also searched for Υ(1S) radiative decays into χc0,2 and ηc(1S, 2S), and set upper limits on their branching fractions. These results are obtained from a 24.9 fb−1 data sample collected with the 3 Belle detector at the KEKB asymmetric-energy e +e − collider at a center-of-mass energy equal to the Υ(2S) mass using Υ(1S) tagging by the Υ(2S) → Υ(1S)π +π − transitions

Measurements of branching fractions and asymmetry parameters of Ξc0→ΛK¯∗0 , Ξc0→Σ0 K¯∗0 , and Ξc0→Σ+ K∗− decays

Using a data sample of 980 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− collider, we study the processes of Ξc0→ΛK¯∗0, Ξc0→Σ0K¯∗0, and Ξc0→Σ+K∗− for the first time. The relative branching ratios to the normalization mode of Ξc0→Ξ−π+ are measured to beB(Ξc0→ΛK¯∗0)/B(Ξc0→Ξ−π+)=0.18±0.02(stat.)±0.01(syst.),B(Ξc0→Σ0K¯∗0)/B(Ξc0→Ξ−π+)=0.69±0.03(stat.)±0.03(syst.),B(Ξc0→Σ+K∗−)/B(Ξc0→Ξ−π+)=0.34±0.06(stat.)±0.02(syst.), where the uncertainties are statistical and systematic, respectively. We obtainB(Ξc0→ΛK¯∗0)=(3.3±0.3(stat.)±0.2(syst.)±1.0(ref.))×10−3,B(Ξc0→Σ0K¯∗0)=(12.4±0.5(stat.)±0.5(syst.)±3.6(ref.))×10−3,B(Ξc0→Σ+K∗0)=(6.1±1.0(stat.)±0.4(syst.)±1.8(ref.))×10−3, where the uncertainties are statistical, systematic, and from B(Ξc0→Ξ−π+), respectively. The asymmetry parameters α(Ξc0→ΛK¯∗0) and α(Ξc0→Σ+K∗−) are 0.15 ± 0.22(stat.) ± 0.04(syst.) and −0.52 ± 0.30(stat.) ± 0.02(syst.), respectively, where the uncertainties are statistical followed by systematic. [Figure not available: see fulltext.] © 2021, The Author(s)

Search for B0 meson decays into Λ and missing energy with a hadronic tagging method at Belle

We present a search for the decays of B0 mesons into a final state containing a Λ baryon and missing energy. These results are obtained from a 711 fb-1 data sample that contains 772×106 BB¯ pairs and was collected near the (4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode and require the remainder of the event to consist of only a single Λ. No evidence for these decays is found, and we set 90% confidence level upper limits on the branching fractions in the range 2.1-3.8×10-5. This measurement provides the world's most restrictive limits, with implications for baryogenesis and dark matter production. © 2022 authors

Search for B0 →τ±∓ (ℓ=e, μ) with a hadronic tagging method at Belle

We present a search for the lepton-flavor-violating decays B0→τ±∓, where ℓ=(e,μ), using the full data sample of 772×106 BB¯ pairs recorded by the Belle detector at the KEKB asymmetric-energy e+e- collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. The τ± lepton is reconstructed indirectly using the momentum of the reconstructed B and that of the ∓ from the signal decay. We find no evidence for B0→τ±∓ decays and set upper limits on their branching fractions at 90% confidence level of B(B0→τ±μ∓)<1.5×10-5 and B(B0→τ±e∓)<1.6×10-5. © 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3

Search for the ηc2(1D) in e+e−→γηc2(1D)at √s near 10.6 GeV at Belle

For the first time we search for the in at , 10.58, and 10.867 GeV with data samples of , , and , respectively, accumulated with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signal is observed in the mass range between 3.8 and . The upper limit at 90% confidence level on the product of the Born cross section for and branching fraction for is determined to be at near 10.6 GeV. © 2021 Published by the American Physical Societ

Measurement of the νe -Nucleus Charged-Current Double-Differential Cross Section at «eν »=2.4 GeV Using NOvA

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×1020 protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃7.4% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on Q2 (squared four-momentum transfer) and energy, in the range 1 GeV≤Eν<6 GeV. Detailed comparisons are made to the predictions of the GENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the others consistently across all three cross sections measured, though some models have especially good or poor agreement in the single differential cross section vs Q2

Measurement of branching fraction and search for CP violation in B →φφK

We report the measurement of branching fractions and CP-violation asymmetries in B→φφK decays based on a 711 fb-1 data sample containing 772×106 BB¯ events. The data were recorded at the I(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. For B+→φφK+, the branching fraction and CP-violation asymmetry measured below the ηc threshold (mφφ<2.85 GeV/c2) are [3.43-0.46+0.48(stat)±0.22(syst)]×10-6 and -0.02±0.11(stat)±0.01(syst), respectively. Similarly, the branching fraction obtained for B0→φφK0 below the ηc threshold is [3.02-0.66+0.75(stat)±0.20(syst)]×10-6. We also measure the CP-violation asymmetry for B+→φφK+ within the ηc region (mφφ[2.94,3.02] GeV/c2) to be +0.12±0.12(stat)±0.01(syst). © 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3

Search for B+→K+νν¯ Decays Using an Inclusive Tagging Method at Belle II

A search for the flavor-changing neutral-current decay is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of collected at the resonance and a sample of collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the decay, but also the inclusive properties of the other meson in the event, to suppress the background from other meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of of is set at the 90% confidence level. © 2021 Published by the American Physical Societ

Measurement of Differential Branching Fractions of Inclusive B →xuℓ+νℓ Decays

The first measurements of differential branching fractions of inclusive semileptonic B→Xuℓ+νℓ decays are performed using the full Belle data set of 711 fb-1 of integrated luminosity at the (4S) resonance and for ℓ=e, μ. With the availability of these measurements, new avenues for future shape-function model-independent determinations of the Cabibbo-Kobayashi-Maskawa matrix element |Vub| can be pursued to gain new insights in the existing tension with respect to exclusive determinations. The differential branching fractions are reported as a function of the lepton energy, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting the backgrounds from semileptonic B→Xcℓ+νℓ decays and other processes, and corrected for resolution and acceptance effects. © 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3