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Showing 1–50 of 266 results for author: Dingfelder, J

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  1. arXiv:2505.09705  [pdf, other

    hep-ex

    Search for a dark Higgs boson produced in association with inelastic dark matter at the Belle II experiment

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, S. Alghamdi, M. Alhakami, A. Aloisio, N. Althubiti, K. Amos, M. Angelsmark, N. Anh Ky, C. Antonioli, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal , et al. (415 additional authors not shown)

    Abstract: Inelastic dark matter models that have two dark matter particles and a massive dark photon can reproduce the observed relic dark matter density without violating cosmological limits. The mass splitting between the two dark matter particles χ_{1} and χ_{2}, with m(χ_{2}) > m(χ_{1}), is induced by a dark Higgs field and a corresponding dark Higgs boson h^{\prime}. We present a search for dar… ▽ More

    Submitted 14 May, 2025; originally announced May 2025.

    Comments: Submitted for publication with Physical Review Letters

    Report number: Belle II Preprint 2025-015, KEK Preprint 2025-14

  2. arXiv:2505.08418  [pdf, ps, other

    hep-ex

    Search for lepton flavor-violating decay modes B^0 \to K^{\ast 0}τ^\pm\ell^\mp (\ell = e,μ) with hadronic B-tagging at Belle and Belle II

    Authors: Belle, Belle II Collaborations, :, I. Adachi, Y. Ahn, H. Aihara, N. Akopov, S. Alghamdi, M. Alhakami, A. Aloisio, K. Amos, M. Angelsmark, N. Anh Ky, C. Antonioli, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee , et al. (353 additional authors not shown)

    Abstract: We present the results of a search for the charged-lepton-flavor violating decays B^0 \rightarrow K^{*0}τ^\pm \ell^{\mp}, where \ell^{\mp} is either an electron or a muon. The results are based on 365 fb^{-1} and 711 fb^{-1} datasets collected with the Belle II and Belle detectors, respectively. We use an exclusive hadronic B-tagging technique, and search for a signal decay in the system… ▽ More

    Submitted 13 May, 2025; originally announced May 2025.

    Comments: 19 pages, 4 figures

    Report number: Belle II preprint: 2025-014, KEK preprint: 2025-13

  3. arXiv:2505.02912  [pdf, other

    hep-ex

    Measurement of the time-integrated CP asymmetry in D^0\toπ^0π^0 decays at Belle II

    Authors: Belle II Collaboration, I. Adachi, Y. Ahn, N. Akopov, S. Alghamdi, M. Alhakami, A. Aloisio, N. Althubiti, K. Amos, M. Angelsmark, N. Anh Ky, C. Antonioli, D. M. Asner, H. Atmacan, T. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Barrett, M. Bartl , et al. (350 additional authors not shown)

    Abstract: We measure the time-integrated CP asymmetry, A_{CP}, in D^0\toπ^0π^0 decays reconstructed in e^+e^-\to c\bar{c} events collected by Belle II during 2019--2022. The data corresponds to an integrated luminosity of 428\mathrm{fb}^{-1}. The D^0 decays are required to originate from the flavor-conserving D^{*+} \to D^0 π^+ decay to determine the charm flavor at production time. Control sa… ▽ More

    Submitted 5 May, 2025; originally announced May 2025.

    Report number: Belle II Preprint 2025-009, KEK Preprint 2025-7

  4. arXiv:2504.15881  [pdf, other

    hep-ex

    Measurement of the time-integrated CP asymmetry in D^0 \to K^0_{\rm S} K^0_{\rm S} decays using opposite-side flavor tagging at Belle and Belle II

    Authors: Belle, Belle II Collaborations, :, I. Adachi, Y. Ahn, N. Akopov, S. Alghamdi, M. Alhakami, A. Aloisio, N. Althubiti, K. Amos, M. Angelsmark, N. Anh Ky, C. Antonioli, D. M. Asner, H. Atmacan, T. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee , et al. (356 additional authors not shown)

    Abstract: We measure the time-integrated CP asymmetry in D^0 \to K^0_{\rm S} K^0_{\rm S} decays reconstructed in e^+e^-\to c{\overline c} events collected by the Belle and Belle II experiments. The corresponding data samples have integrated luminosities of 980 and 428 fb{}^{-1}, respectively. To infer the flavor of the D^0 meson, we exploit the correlation between the flavor of the reconstructed d… ▽ More

    Submitted 22 April, 2025; originally announced April 2025.

    Report number: Belle II Preprint 2025-006, KEK Preprint 2025-4

  5. arXiv:2504.15745  [pdf, other

    hep-ex

    Search for lepton-flavor-violating τ^- \to \ell^- K_s^0 decays at Belle and Belle II

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Ahmed, Y. Ahn, H. Aihara, N. Akopov, S. Alghamdi, M. Alhakami, A. Aloisio, N. Althubiti, K. Amos, M. Angelsmark, N. Anh Ky, C. Antonioli, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, S. Bahinipati , et al. (397 additional authors not shown)

    Abstract: We present the results of a search for charged-lepton-flavor violating decays τ^{-} \rightarrow \ell^{-}K_{S}^{0}, where \ell^{-} is either an electron or a muon. We combine e^+e^- data samples recorded by the Belle II experiment at the SuperKEKB collider (428 fb^{-1}) with samples recorded by the Belle experiment at the KEKB collider (980 fb^{-1}) to obtain a sample of 1.3 billion… ▽ More

    Submitted 22 April, 2025; originally announced April 2025.

  6. arXiv:2504.11220  [pdf, other

    hep-ex

    Test of lepton flavor universality with measurements of R(D^{+}) and R(D^{*+}) using semileptonic B tagging at the Belle II experiment

    Authors: Belle II Collaboration, I. Adachi, K. Adamczyk, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, S. Alghamdi, M. Alhakami, A. Aloisio, N. Althubiti, K. Amos, M. Angelsmark, N. Anh Ky, C. Antonioli, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati , et al. (428 additional authors not shown)

    Abstract: We report measurements of the ratios of branching fractions \mathcal{R}(D^{(*)+}) = \mathcal{B}(\overline{B}{}^0 \to D^{(*)+} \,τ^- \, \overlineν_τ) / \mathcal{B}(\overline{B}{}^0 \to D^{(*)+} \, \ell^- \, \overlineν_\ell), where \ell denotes either an electron or a muon. These ratios test the universality of the charged-current weak interaction. The results are based on a… ▽ More

    Submitted 15 April, 2025; originally announced April 2025.

    Report number: Belle II Preprint 2025-011, KEK Preprint 2025-9

  7. arXiv:2504.10042  [pdf, other

    hep-ex

    Search for B^0 \to K^{\ast 0} τ^+ τ^- decays at the Belle II experiment

    Authors: Belle II Collaboration, I. Adachi, K. Adamczyk, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, M. Angelsmark, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett , et al. (424 additional authors not shown)

    Abstract: We present a search for the rare flavor-changing neutral-current decay B^0 \to K^{\ast 0} τ^+ τ^- with data collected by the Belle II experiment at the SuperKEKB electron-positron collider. The analysis uses a 365 fb^{-1} data sample recorded at the center-of-mass energy of the Υ(4S) resonance. One of the B mesons produced in the Υ(4S)\to B^0 \bar{B}^0 process is fully reconstructed in a… ▽ More

    Submitted 14 April, 2025; originally announced April 2025.

    Report number: Belle II Preprint 2025-010; KEK Preprint 2025-8

  8. arXiv:2503.22195  [pdf, other

    hep-ex

    Search for lepton-flavor-violating tau decays to \ellα at Belle

    Authors: Belle Collaboration, K. Uno, K. Inami, K. Hayasaka, H. Aihara, R. Ayad, Sw. Banerjee, K. Belous, J. Bennett, M. Bessner, D. Biswas, D. Bodrov, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, K. Cho, S. -K. Choi, Y. Choi, S. Choudhury, G. De Nardo, G. De Pietro, F. Di Capua, J. Dingfelder , et al. (99 additional authors not shown)

    Abstract: We report a search for the lepton-flavor-violating decays τ^{\pm}\to\ell^{\pm}α~(\ell=e,μ), where α is an undetected spin-0 particle, such as an axion-like particle using 736\times10^{6} tau lepton pairs collected by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We find no evidence of signal and obtain the most stringent upper limits on the branching fractions at… ▽ More

    Submitted 28 March, 2025; originally announced March 2025.

  9. arXiv:2503.17643  [pdf, other

    hep-ex hep-ph

    Measurements of the branching fractions of Ξ_{c}^{+}\to Σ^{+}K_{S}^{0}, Ξ_{c}^{+}\to Ξ^{0}π^{+}, and Ξ_{c}^{+}\to Ξ^{0}K^{+} at Belle and Belle II

    Authors: Belle, Belle II Collaborations, :, I. Adachi, J. K. Ahn, Y. Ahn, N. Akopov, S. Alghamdi, M. Alhakami, N. Althubiti, K. Amos, N. Anh Ky, C. Antonioli, D. M. Asner, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, P. Bambade, Sw. Banerjee, M. Barrett, M. Bartl, J. Baudot, A. Beaubien, F. Becherer , et al. (335 additional authors not shown)

    Abstract: Using 983.0 \rm{fb}^{-1} and 427.9 \rm{fb}^{-1} data samples collected with the Belle and Belle II detectors at the KEKB and SuperKEKB asymmetric energy e^+e^- colliders, respectively, we present studies of the Cabibbo-favored Ξ_c^+ decays {Ξ_{c}^{+}\to Σ^{+}K_{S}^{0}} and Ξ_{c}^{+}\to Ξ^{0}π^{+}, and the singly Cabibbo-suppressed decay Ξ_{c}^{+}\to Ξ^{0}K^{+}. The ratios of branchin… ▽ More

    Submitted 22 March, 2025; originally announced March 2025.

    Comments: 20 pages, 4 figures, 3 Tables

    Report number: Belle II Preprint 2025-005; KEK Preprint 2025-2

  10. arXiv:2503.04371  [pdf, other

    hep-ex

    Measurement of the Branching Fraction of Λ_c^+ \to p K_S^0 π^0 at Belle

    Authors: The Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Ahmed, J. K. Ahn, H. Aihara, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, M. Angelsmark, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade , et al. (404 additional authors not shown)

    Abstract: We report a precise measurement of the ratio of branching fractions \mathcal{B}(Λ_c^+\to p K_S^0 π^0)/\mathcal{B}(Λ_c^+\to p K^- π^+) using 980 fb^{-1} of e^+e^- data from the Belle experiment. We obtain a value of \mathcal{B}(Λ_c^+\to p K_S^0 π^0)/\mathcal{B}(Λ_c^+\to p K^- π^+)=0.339\pm 0.002\pm 0.009, where the first and second uncertainties are statistical and systematic, respectively.… ▽ More

    Submitted 18 March, 2025; v1 submitted 6 March, 2025; originally announced March 2025.

    Comments: 20 pages, 7 figures

    Report number: Belle II Preprint: 2024-022, KEK preprint: 2024-20

  11. arXiv:2502.09951  [pdf, other

    hep-ex

    Evidence of the P_ccbars(4459)0 in Upsilon(1S, 2S) inclusive decays at Belle

    Authors: I. Adachi, L. Aggarwal, H. Ahmed, J. K. Ahn, H. Aihara, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, M. Bartl, J. Baudot, A. Baur , et al. (380 additional authors not shown)

    Abstract: Using data samples of 102 million Upsilon(1S) events and 158 million Upsilon(2S) events collected by the Belle detector at the KEKB asymmetric-energy e^+e^- collider, we search for [udsccbar] pentaquark states decaying to Jpsi Lambda. Using the first observations of Upsilon(1S, 2S) inclusive decays to Jpsi Lambda, we find evidence of the P_ccbars(4459)0 state with a significance of 3.3 standard… ▽ More

    Submitted 14 February, 2025; originally announced February 2025.

    Comments: 8 pages, 3 figures

    Report number: Belle II Preprint 2025-002, KEK Preprint 2024-50

  12. arXiv:2502.04885  [pdf, other

    hep-ex

    Measurement of B^+\toτ^+ν_τ branching fraction with a hadronic tagging method at Belle II

    Authors: Belle II Collaboration, I. Adachi, K. Adamczyk, H. Ahmed, Y. Ahn, H. Aihara, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, M. Angelsmark, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Bartl, J. Baudot, A. Baur , et al. (319 additional authors not shown)

    Abstract: We present a measurement of the branching fraction of B^+\toτ^+ν_τ decays using (387\pm6)\times 10^6 Υ(4S) collected between 2019 and 2022 with the Belle II detector at the SuperKEKB e^+e^- collider. We reconstruct the accompanying B^- meson using the hadronic tagging method, while B^+\toτ^+ν_τ candidates are identified in the recoil. We find evidence for B^+\toτ^+ν_τ decays at 3.0 s… ▽ More

    Submitted 7 February, 2025; originally announced February 2025.

    Report number: Belle II preprint 2024-033, KEK preprint 2024-48

  13. Measurement of the branching fraction, polarization, and time-dependent CP asymmetry in B^0 \to ρ^+ρ^- decays and constraint on the CKM angle φ_2

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, P. Bambade, Sw. Banerjee, M. Barrett, M. Bartl, J. Baudot, A. Baur, A. Beaubien, J. Becker, J. V. Bennett , et al. (355 additional authors not shown)

    Abstract: We present a measurement of the branching fraction and fraction of longitudinal polarization of B^0 \to ρ^+ ρ^- decays, which have two π^0's in the final state. We also measure time-dependent {\it CP} violation parameters for decays into longitudinally polarized ρ^+ ρ^- pairs. This analysis is based on a data sample containing (387\pm6) \times 10^6 Υ(4S) mesons collected with the Belle~I… ▽ More

    Submitted 2 May, 2025; v1 submitted 27 December, 2024; originally announced December 2024.

    Report number: Belle II preprint 2024-024, KEK preprint 2024-23

    Journal ref: Phys. Rev. D 111, 092001, 2025

  14. arXiv:2412.16470  [pdf, other

    hep-ex

    Search for lepton flavor-violating decay modes B^0\to K_S^0τ^\pm\ell^\mp~(\ell=μ, e) with hadronic B-tagging at Belle and Belle II

    Authors: Belle, Belle II Collaborations, :, I. Adachi, K. Adamczyk, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal , et al. (403 additional authors not shown)

    Abstract: We present the first search for the lepton flavor-violating decay modes B^0 \rightarrow K_S^0 τ^\pm \ell^\mp~(\ell=μ, e) using the 711 fb^{-1} and 365 fb^{-1} data samples recorded by the Belle and Belle II detectors, respectively. We use a hadronic B-tagging technique, and search for the signal decay in the system recoiling against the fully reconstructed B meson. We find no evidence fo… ▽ More

    Submitted 20 December, 2024; originally announced December 2024.

    Report number: Belle II Preprint 2024-031, KEK Preprint 2024-33

  15. arXiv:2412.14260  [pdf, other

    hep-ex

    Measurement of the branching fraction and \it CP-violating asymmetry of the decay B^{0} \rightarrow π^{0} π^{0} using 387 million bottom-antibottom meson pairs in Belle II data

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, M. Alhakami, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, M. Bartl, J. Baudot, A. Baur , et al. (415 additional authors not shown)

    Abstract: We measure the branching fraction and \it CP-violating flavor-dependent rate asymmetry of B^{0} \to π^{0} π^{0} decays reconstructed using the Belle II detector in an electron-positron collision sample containing 387 \times 10^{6} B\overline{B} pairs. Using an optimized event selection, we find 126\pm 20 signal decays in a fit to background-discriminating and flavor-sensitive distributio… ▽ More

    Submitted 18 December, 2024; originally announced December 2024.

    Report number: Belle II Preprint 2024-032, KEK Preprint 2024-34

  16. Observation of the decay B^0 \to J/ψω at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Barrett, J. Baudot, A. Baur, A. Beaubien, J. Becker , et al. (361 additional authors not shown)

    Abstract: We measure the branching fraction of the decay B^0 \to J/ψω using data collected with the Belle II detector at the SuperKEKB collider. The data contain (387 \pm 6) \times 10^6 B\overline{B} meson pairs produced in energy-asymmetric e^+e^- collisions at the Υ(4S) resonance. The measured branching fraction \mathcal{B}(B^0 \to J/ψω) = \left( 2.16 \pm 0.30 \pm 0.14 \right) \times 10^{-5},… ▽ More

    Submitted 25 February, 2025; v1 submitted 16 December, 2024; originally announced December 2024.

    Report number: Belle II preprint: 2024-021, KEK preprint: 2024-18

    Journal ref: Phys. Rev. D 111, 032012 (2025)

  17. Observations of the singly Cabibbo-suppressed decays Ξ_c^{+} \to pK_{S}^{0}, Ξ_c^+ \to Λπ^+, and Ξ_c^+ \to Σ^{0} π^+ at Belle and Belle II

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Barrett, J. Baudot, A. Baur, A. Beaubien , et al. (323 additional authors not shown)

    Abstract: Using data samples of 983.0~\rm fb^{-1} and 427.9~\rm fb^{-1} accumulated with the Belle and Belle~II detectors operating at the KEKB and SuperKEKB asymmetric-energy e^+e^- colliders, singly Cabibbo-suppressed decays Ξ_c^{+} \to pK_{S}^{0}, Ξ_c^+ \to Λπ^+, and Ξ_c^+ \to Σ^{0} π^+ are observed for the first time. The ratios of branching fractions of Ξ_{c}^{+}\to p K_{S}^{0},… ▽ More

    Submitted 13 December, 2024; originally announced December 2024.

    Comments: 21 pages, 5 pages

    Report number: Belle II Preprint 2024-028; KEK Preprint 2024-29

    Journal ref: JHEP03(2025)061

  18. arXiv:2411.14032  [pdf, other

    hep-ex

    Measurement of the inclusive branching fractions for B_s^0 decays into D mesons via hadronic tagging

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, S. Al Said, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal , et al. (430 additional authors not shown)

    Abstract: We report measurements of the absolute branching fractions \mathcal{B}(B_s^0 \to D_s^{\pm} X), \mathcal{B}(B_s^0 \to D^0/\bar{D}^0 X), and \mathcal{B}(B_s^0 \to D^{\pm} X), where the latter is measured for the first time. The results are based on a 121.4\,fb^{-1} data sample collected at the Υ(10860) resonance by the Belle detector at the KEKB asymmetric-energy e^+ e^- collider. We rec… ▽ More

    Submitted 18 February, 2025; v1 submitted 21 November, 2024; originally announced November 2024.

    Comments: 23 pages, 9 figures, submitted to JHEP

    Report number: Belle II Preprint 2024-030, KEK Preprint 2024-32

  19. Production cross sections of light and charmed mesons in e^+e^- annihilation near 10.58 GeV

    Authors: Belle Collaboration, R. Seidl, I. Adachi, H. Aihara, T. Aushev, R. Ayad, Sw. Banerjee, K. Belous, J. Bennett, M. Bessner, B. Bhuyan, D. Biswas, D. Bodrov, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, K. Chilikin, K. Cho, S. -K. Choi, Y. Choi, S. Choudhury, S. Das, G. De Nardo , et al. (109 additional authors not shown)

    Abstract: We report measurements of production cross sections for ρ^+, ρ^0, ω, K^{*+}, K^{*0}, φ, η, K_S^0, f_0(980), D^+, D^0, D_s^+, D^{*+}, D^{*0}, and D^{*+}_s in e^+e^- collisions at a center-of-mass energy near 10.58 GeV. The data were recorded by the Belle experiment, consisting of 571 fb^{-1} at 10.58 GeV and 74 fb^{-1} at 10.52 GeV. Production cross sections are… ▽ More

    Submitted 13 March, 2025; v1 submitted 18 November, 2024; originally announced November 2024.

    Comments: 21 pages, 18 figures, published in Phys. Rev. D

    Report number: Belle Preprint 2024-09, KEK Preprint 2024-30

    Journal ref: Phys. Rev. D 111 (2025) 052003

  20. arXiv:2411.10127  [pdf, other

    hep-ex

    Measurement of B \to K{}^{*}(892)γ decays at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, M. Bartl, J. Baudot , et al. (429 additional authors not shown)

    Abstract: We present measurements of B \to K{}^{*}(892)γ decays using 365\,{\rm fb}^{-1} of data collected from 2019 to 2022 by the Belle~II experiment at the SuperKEKB asymmetric-energy e^+e^- collider. The data sample contains (387 \pm 6) \times 10^6 Υ(4S) events. We measure branching fractions (\mathcal{B}) and C\!P asymmetries (\mathcal{A}_{C\!P}) for both B^{0}\to K{}^{*0}γ and… ▽ More

    Submitted 19 March, 2025; v1 submitted 15 November, 2024; originally announced November 2024.

    Report number: Belle II Preprint 2024-029; KEK Preprint 2024-31

  21. Measurement of the time-integrated CP asymmetry in D^{0}\rightarrow K^{0}_{S}K^{0}_{S} decays using Belle and Belle II data

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, M. Bartl, J. Baudot , et al. (338 additional authors not shown)

    Abstract: We measure the time-integrated CP asymmetry in D^{0} \rightarrow K^{0}_{S}K^{0}_{S} decays reconstructed in e^{+}e^{-} \rightarrow c\overline{c} events collected by the Belle and Belle II experiments. The corresponding data samples have integrated luminosities of 980 fb^{-1} and 428 fb^{-1}, respectively. The D^{0} decays are required to originate from the… ▽ More

    Submitted 4 February, 2025; v1 submitted 31 October, 2024; originally announced November 2024.

    Comments: 10 pages, 3 figures. arXiv admin note: text overlap with arXiv:2410.22961

    Report number: KEK Preprint 2024-26, Belle II Preprint 2024-026

    Journal ref: Phys. Rev. D 111, 012015 (2025)

  22. arXiv:2410.22961  [pdf, other

    hep-ex

    Model-independent measurement of D^0-\overline{D}{}^0 mixing parameters in D^0\rightarrow K^0_{S}π^+π^- decays at Belle and Belle II

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, N. K. Baghel, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, M. Bartl, J. Baudot, A. Beaubien, J. Becker , et al. (317 additional authors not shown)

    Abstract: We perform a model-independent measurement of the D^0-\overline{D}{}^0 mixing parameters using samples of e^+e^--collision data collected by the Belle and Belle II experiments that have integrated luminosities of 951\ \text{fb}^{-1} and 408\ \text{fb}^{-1}, respectively. Approximately 2.05\times10^6 neutral D mesons are reconstructed in the D^0\rightarrow K^0_{S}π^+π^- channel, wit… ▽ More

    Submitted 7 May, 2025; v1 submitted 30 October, 2024; originally announced October 2024.

    Report number: Belle II Preprint 2024-027; KEK Preprint 2024-27

  23. Observation of time-dependent CP violation and measurement of the branching fraction of B^0 \to J/ψπ^0 decays

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, J. Baudot, A. Baur, A. Beaubien, F. Becherer , et al. (369 additional authors not shown)

    Abstract: We present a measurement of the branching fraction and time-dependent charge-parity (CP) decay-rate asymmetries in B^0 \to J/ψπ^0 decays. The data sample was collected with the Belle~II detector at the SuperKEKB asymmetric e^+e^- collider in 2019-2022 and contains (387\pm 6)\times 10^6 B\overline{B} meson pairs from Υ(4S) decays. We reconstruct 392\pm 24 signal decays and fit the… ▽ More

    Submitted 27 January, 2025; v1 submitted 11 October, 2024; originally announced October 2024.

    Report number: Belle II preprint: 2024-018, KEK preprint: 2024-14

    Journal ref: Phys. Rev. D 111, 012011 (2025)

  24. arXiv:2409.17749  [pdf, other

    physics.ins-det hep-ex

    TCAD Simulation of Stitching for Passive CMOS Strip Detectors

    Authors: Marta Baselga, Jan Hendrik Arling, Naomi Davis, Jochen Dingfelder, Ingrid-Maria Gregor, Marc Hauser, Fabian Huegging, Karl Jakobs, Michael Karagounis, Roland Koppenhoefer, Kevin Kroeninger, Fabian Lex, Ulrich Parzefall, Birkan Sari, Simon Spannagel, Dennis Sperlich, Jens Weingarten, Iveta Zatocilova

    Abstract: Most of the tracking detectors for high energy particle experiments are filled with silicon detectors since they are radiation hard, they can give very small spatial resolution and they can take advantage of the silicon electronics foundries developments and production lines. Strip detectors are very useful to cover large areas for tracking purposes, while consuming less power per area compared… ▽ More

    Submitted 19 November, 2024; v1 submitted 26 September, 2024; originally announced September 2024.

    Comments: 8 pages, 7 figures, IWORID2024 workshop

  25. Search for C\!P violation in D^+_{(s)}\to{}K_{S}^{0}K^{-}π^{+}π^{+} decays using triple and quadruple products

    Authors: Belle, Belle II Collaborations, :, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, J. Baudot, A. Baur, A. Beaubien, F. Becherer , et al. (344 additional authors not shown)

    Abstract: We perform the first search for C\!P violation in {D_{(s)}^{+}\to{}K_{S}^{0}K^{-}π^{+}π^{+}} decays. We use a combined data set from the Belle and Belle II experiments, which study e^+e^- collisions at center-of-mass energies at or near the Υ(4S) resonance. We use 980 fb^{-1} of data from Belle and 428 fb^{-1} of data from Belle~II. We measure six C\!P-violating asymmetries that are… ▽ More

    Submitted 12 February, 2025; v1 submitted 24 September, 2024; originally announced September 2024.

    Comments: 21 pages, 10 figures

    Report number: Belle II Preprint 2024-025, KEK Preprint 2024-24, UCHEP-24-05

    Journal ref: JHEP 04 (2025) 036

  26. arXiv:2407.17403  [pdf, other

    hep-ex

    Determination of |V_{ub}| from simultaneous measurements of untagged B^0\toπ^- \ell^+ ν_{\ell} and B^+\toρ^0 \ell^+ν_{\ell} decays

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, M. Bauer, A. Baur, A. Beaubien , et al. (395 additional authors not shown)

    Abstract: We present a measurement of |V_{ub}| from a simultaneous study of the charmless semileptonic decays B^0\toπ^- \ell^+ ν_{\ell} and B^+\toρ^0 \ell^+ν_{\ell}, where \ell = e, μ. This measurement uses a data sample of 387 million B\overline{B} meson pairs recorded by the Belle~II detector at the SuperKEKB electron-positron collider between 2019 and 2022. The two decays are reconstructed with… ▽ More

    Submitted 24 July, 2024; originally announced July 2024.

    Report number: Belle II Preprint 2024-023, KEK Preprint 2024-21

  27. arXiv:2407.09139  [pdf, other

    hep-ex

    Measurement of CP asymmetries in B^0 \to K^0_S π^0 γ decays at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer , et al. (414 additional authors not shown)

    Abstract: We report measurements of time-dependent CP asymmetries in B^0 \to K^0_S π^0 γ decays based on a data sample of (388\pm6)\times10^6 B\bar{B} events collected at the Υ(4S) resonance with the Belle II detector. The Belle II experiment operates at the SuperKEKB asymmetric-energy e^+e^- collider. We measure decay-time distributions to determine CP-violating parameters S and C. We det… ▽ More

    Submitted 12 July, 2024; originally announced July 2024.

    Comments: 10 pages, 4 figures

    Report number: Belle II Preprint 2024-009, KEK Preprint 2024-1

  28. arXiv:2407.08984  [pdf, ps, other

    hep-ex

    Measurement of branching fractions, CP asymmetry, and isospin asymmetry for \boldsymbol{B\rightarrowργ} decays using Belle and Belle II data

    Authors: Belle II Collaboration, I. Adachi, K. Adamczyk, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer , et al. (385 additional authors not shown)

    Abstract: We present measurements of B^{+}\rightarrowρ^{+}γ and B^{0}\rightarrowρ^{0}γ decays using a combined data sample of 772 \times 10^6 B\overline{B} pairs collected by the Belle experiment and 387\times 10^6 B\overline{B} pairs collected by the Belle II experiment in e^{+}e^{-} collisions at the Υ(4S) resonance. After an optimized selection, a simultaneous fit to the Belle and Belle I… ▽ More

    Submitted 12 July, 2024; originally announced July 2024.

    Comments: 12 pages, 4 figures

    Report number: Belle II Preprint 2023-019; KEK Preprint 2023-37; UCHEP-24-04

  29. Search for the baryon number and lepton number violating decays τ^-\to Λπ^- and τ^-\to \barΛπ^- at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien , et al. (349 additional authors not shown)

    Abstract: We present a search for the baryon number B and lepton number L violating decays τ^- \rightarrow Λπ^- and τ^- \rightarrow \barΛ π^- produced from the e^+e^-\to τ^+τ^- process, using a 364 fb^{-1} data sample collected by the Belle~II experiment at the SuperKEKB collider. No evidence of signal is found in either decay mode, which have |Δ(B-L)| equal to 2 and 0, respectively. Upper… ▽ More

    Submitted 6 July, 2024; originally announced July 2024.

    Comments: 8 pages, 4 figures

    Report number: Belle II Preprint 2024-020; KEK Preprint 2024-17

    Journal ref: Physical Review D 110, 112003 (2024)

  30. Measurement of the integrated luminosity of data samples collected during 2019-2022 by the Belle II experiment

    Authors: The Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, J. K. Ahn, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Barrett, J. Baudot, A. Baur, A. Beaubien , et al. (382 additional authors not shown)

    Abstract: A series of data samples was collected with the Belle~II detector at the SuperKEKB collider from March 2019 to June 2022. We determine the integrated luminosities of these data samples using three distinct methodologies involving Bhabha (e^+e^- \to e^+e^-(nγ)), digamma (e^+e^- \to γγ(nγ)), and dimuon (e^+e^- \to μ^+ μ^- (nγ)) events. The total integrated luminosity obtained with Bhabha, diga… ▽ More

    Submitted 19 September, 2024; v1 submitted 1 July, 2024; originally announced July 2024.

    Comments: 12 pages, 3 figures; accepted for publication in Chinese Physics C

    Report number: Belle II Preprint 2024-019; KEK Preprint 2024-16

    Journal ref: Chin. Phys. C 49, 013001 (2025)

  31. arXiv:2406.19421  [pdf, other

    hep-ex physics.ins-det

    The Belle II Detector Upgrades Framework Conceptual Design Report

    Authors: H. Aihara, A. Aloisio, D. P. Auguste, M. Aversano, M. Babeluk, S. Bahinipati, Sw. Banerjee, M. Barbero, J. Baudot, A. Beaubien, F. Becherer, T. Bergauer, F. U. Bernlochner., V. Bertacchi, G. Bertolone, C. Bespin, M. Bessner, S. Bettarini, A. J. Bevan, B. Bhuyan, M. Bona, J. F. Bonis, J. Borah, F. Bosi, R. Boudagga , et al. (186 additional authors not shown)

    Abstract: We describe the planned near-term and potential longer-term upgrades of the Belle II detector at the SuperKEKB electron-positron collider operating at the KEK laboratory in Tsukuba, Japan. These upgrades will allow increasingly sensitive searches for possible new physics beyond the Standard Model in flavor, tau, electroweak and dark sector physics that are both complementary to and competitive wit… ▽ More

    Submitted 4 July, 2024; v1 submitted 26 June, 2024; originally announced June 2024.

    Comments: Editor: F. Forti 170 pages

    Report number: KEK-REPORT-2024-1, BELLE2-REPORT-2024-042

  32. Search for charmed baryons in the Λ_c^+η system and measurement of the branching fractions of Λ_c(2880)^+ and Λ_c(2940)^+ decaying to Λ_c^+η and pD^0 relative to Σ_c(2455)π

    Authors: Belle Collaboration, S. X. Li, C. P. Shen, I. Adachi, J. K. Ahn, H. Aihara, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, Sw. Banerjee, K. Belous, J. Bennett, M. Bessner, T. Bilka, D. Biswas, D. Bodrov, A. Bozek, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, M. -C. Chang, B. G. Cheon , et al. (103 additional authors not shown)

    Abstract: We search for excited charmed baryons in the Λ_c^+η system using a data sample corresponding to an integrated luminosity of 980 \rm fb^{-1}. The data were collected by the Belle detector at the KEKB e^{+}e^{-} asymmetric-energy collider. No significant signals are found in the Λ_c^+η mass spectrum, including the known Λ_c(2880)^+ and Λ_c(2940)^+. Clear Λ_c(2880)^+ and… ▽ More

    Submitted 28 July, 2024; v1 submitted 22 June, 2024; originally announced June 2024.

    Comments: 10 pages, 4 figures, accepted for publication as a Regular Article in Physical Review D

    Report number: Belle Preprint: 2024-06;KEK Preprint: 2024-15

    Journal ref: Phys. Rev. D 110, 032021 (2024)

  33. Measurement of the branching fractions of \bar{B}\to D^{(*)} K^- K^{(*)0}_{(S)} and \bar{B}\to D^{(*)}D_s^{-} decays at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer , et al. (382 additional authors not shown)

    Abstract: We present measurements of the branching fractions of eight \overline B{}^0\to D^{(*)+} K^- K^{(*)0}_{(S)}, B^{-}\to D^{(*)0} K^- K^{(*)0}_{(S)} decay channels. The results are based on data from SuperKEKB electron-positron collisions at the Υ(4S) resonance collected with the Belle II detector, corresponding to an integrated luminosity of 362~\text{fb}^{-1}. The event yields are extracted… ▽ More

    Submitted 4 September, 2024; v1 submitted 10 June, 2024; originally announced June 2024.

    Comments: 34 pages, 14 figures. arXiv admin note: text overlap with arXiv:2305.01321

    Report number: Belle II Preprint: 2024-014, KEK Preprint: 2024-8

    Journal ref: J. High Energ. Phys. 08 (2024) 206

  34. Measurements of the branching fractions of Ξ_{c}^{0}\toΞ^{0}π^{0}, Ξ_{c}^{0}\toΞ^{0}η, and Ξ_{c}^{0}\toΞ^{0}η^{\prime} and asymmetry parameter of Ξ_{c}^{0}\toΞ^{0}π^{0}

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Barrett, J. Baudot, A. Baur, A. Beaubien , et al. (360 additional authors not shown)

    Abstract: We present a study of Ξ_{c}^{0}\toΞ^{0}π^{0}, Ξ_{c}^{0}\toΞ^{0}η, and Ξ_{c}^{0}\toΞ^{0}η^{\prime} decays using the Belle and Belle~II data samples, which have integrated luminosities of 980~\mathrm{fb}^{-1} and 426~\mathrm{fb}^{-1}, respectively. We measure the following relative branching fractions… ▽ More

    Submitted 5 October, 2024; v1 submitted 7 June, 2024; originally announced June 2024.

    Comments: 23 pages, 5 figures, accepted for publication by JHEP

    Report number: Belle II Preprint 2024-015; KEK Preprint 2024-9

    Journal ref: JHEP10(2024)045

  35. Search for the decay B^{0}\toγγ using Belle and Belle II data

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, S. Al Said, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot , et al. (385 additional authors not shown)

    Abstract: We report the result of a search for the rare decay B^{0} \to γγ using a combined dataset of 753\times10^{6} B\bar{B} pairs collected by the Belle experiment and 387\times10^{6} B\bar{B} pairs collected by the Belle II experiment from decays of the \rm Υ(4S) resonance produced in e^{+}e^{-} collisions. A simultaneous fit to the Belle and Belle II data sets yields… ▽ More

    Submitted 27 August, 2024; v1 submitted 30 May, 2024; originally announced May 2024.

    Comments: Published in PRD(L)

    Report number: Belle II Preprint: 2024-017, KEK Preprint: 2024-13

    Journal ref: Phys. Rev. D 110, L031106 (2024)

  36. arXiv:2405.18928  [pdf, other

    hep-ex

    Measurement of the energy dependence of the e^+e^- \to B\bar{B}, B\bar{B}{}^*, and B^*\bar{B}{}^* cross sections at Belle~II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, M. Bauer, A. Baur , et al. (444 additional authors not shown)

    Abstract: We report measurements of the e^+e^- \to B\bar{B}, B\bar{B}{}^*, and B^*\bar{B}{}^* cross sections at four energies, 10653, 10701, 10746 and 10805 MeV, using data collected by the Belle~II experiment. We reconstruct one B meson in a large number of hadronic final states and use its momentum to identify the production process. In the first 2-5 MeV above B^*\bar{B}{}^* threshold, the… ▽ More

    Submitted 4 October, 2024; v1 submitted 29 May, 2024; originally announced May 2024.

    Comments: 30 pages, 15 figures, version accepted by JHEP

    Report number: Belle II Preprint 2024-016, KEK Preprint 2024-12

  37. Test of light-lepton universality in τ decays with the Belle II experiment

    Authors: Belle II Collaboration, I. Adachi, K. Adamczyk, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer, J. Becker , et al. (406 additional authors not shown)

    Abstract: We present a measurement of the ratio R_μ= \mathcal{B}(τ^-\to μ^-\barν_μν_τ) / \mathcal{B}(τ^-\to e^-\barν_eν_τ) of branching fractions \mathcal{B} of the τ lepton decaying to muons or electrons using data collected with the Belle II detector at the SuperKEKB e^+e^- collider. The sample has an integrated luminosity of 362\!\pm\!2\,\text{fb}^{-1} at a centre-of-mass energy of… ▽ More

    Submitted 30 August, 2024; v1 submitted 23 May, 2024; originally announced May 2024.

    Comments: 22 pages, 7 figures

    Report number: Belle II Preprint 2024-002, KEK Preprint 2023-49

    Journal ref: Journal of High Energy Physics 08 (2024) 205

  38. arXiv:2405.11390  [pdf, other

    hep-ex

    Search for Two-Body B Meson Decays to Λ^{0} and Ω^{(*)0}_{c}

    Authors: Belle Collaboration, V. Savinov, I. Adachi, J. K. Ahn, H. Aihara, D. M. Asner, H. Atmacan, R. Ayad, Sw. Banerjee, J. Bennett, M. Bessner, V. Bhardwaj, D. Biswas, A. Bobrov, D. Bodrov, J. Borah, M. Bračko, P. Branchini, T. E. Browder, A. Budano, D. Červenkov, M. -C. Chang, P. Chang, B. G. Cheon, K. Cho , et al. (124 additional authors not shown)

    Abstract: We report the results of the first search for Standard Model and baryon-number-violating two-body decays of the neutral B mesons to Λ^{0} and Ω^{(*)0}_c using 711~{\rm fb^{-1}} of data collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider. We observe no evidence of signal from any such decays and set 95\% confidence-level upper limits o… ▽ More

    Submitted 18 May, 2024; originally announced May 2024.

    Comments: 6 pages, 2 figures, submitted to PRD(L)

    Report number: Belle Preprint 2024-04, KEK Preprint 2024-5

  39. Characterisation and simulation of stitched CMOS strip sensors

    Authors: Naomi Davis, Jan-Hendrik Arling, Marta Baselga, Leena Diehl, Jochen Dingfelder, Ingrid-Maria Gregor, Marc Hauser, Fabian Hügging, Tomasz Hemperek, Karl Jakobs, Michael Karagounis, Roland Koppenhöfer, Kevin Kröninger, Fabian Lex, Ulrich Parzefall, Arturo Rodriguez, Birkan Sari, Niels Sorgenfrei, Simon Spannagel, Dennis Sperlich, Tianyang Wang, Jens Weingarten, Iveta Zatocilova

    Abstract: In high-energy physics, there is a need to investigate alternative silicon sensor concepts that offer cost-efficient, large-area coverage. Sensors based on CMOS imaging technology present such a silicon sensor concept for tracking detectors. The CMOS Strips project investigates passive CMOS strip sensors fabricated by LFoundry in a 150nm technology. By employing the technique of stitching, two dif… ▽ More

    Submitted 14 May, 2024; originally announced May 2024.

    Comments: 5 pages, 6 figures, submitted to Nuclear Instruments and Methods in Physics Research, Section A as a conference proceeding for the 13th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detectors

    Journal ref: Nuclear Instruments and Methods in Physics Research A 1064 (2024) 169407

  40. Search for lepton-flavor-violating τ^- \to μ^-μ^+μ^- decays at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer, J. Becker , et al. (407 additional authors not shown)

    Abstract: We present the result of a search for the charged-lepton-flavor violating decay τ^- \to μ^-μ^+μ^- using a 424fb^{-1} sample of data recorded by the Belle II experiment at the SuperKEKB e^{-}e^{+} collider. The selection of e^{-}e^{+}\toτ^+τ^- events is based on an inclusive reconstruction of the non-signal tau decay, and on a boosted decision tree to suppress background. We observe one sig… ▽ More

    Submitted 28 November, 2024; v1 submitted 12 May, 2024; originally announced May 2024.

    Report number: Belle II Preprint 2024-012 KEK Preprint 2024-6

    Journal ref: J. High Energ. Phys. 2024, 62 (2024).

  41. arXiv:2404.12817  [pdf, other

    hep-ex

    Determination of the CKM angle φ_{3} from a combination of Belle and Belle II results

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, S. Al Said, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien , et al. (377 additional authors not shown)

    Abstract: We report a determination of the CKM angle φ_{3}, also known as γ, from a combination of measurements using samples of up to 711~fb^{-1} from the Belle experiment and up to 362~fb^{-1} from the Belle II experiment. We combine results from analyses of B^+\to DK^+, B^+\to Dπ^+, and B^+ \to D^{*}K^+ decays, where D is an admixture of D^0 and \overline{D}{}^{0} mesons, in a likelihoo… ▽ More

    Submitted 12 August, 2024; v1 submitted 19 April, 2024; originally announced April 2024.

    Comments: 31 pages, 4 figures

    Report number: Belle II Preprint 2023-015, KEK Preprint 2023-31

  42. A beam-driven proton irradiation setup for precision radiation damage tests of silicon detectors

    Authors: Pascal Wolf, Dennis Sauerland, Reinhard Beck, Jochen Dingfelder

    Abstract: A proton irradiation site for silicon detectors has been developed and commissioned at the Bonn Isochronous Cyclotron. The accelerator provides 14 MeV proton beams of up to 1 μA at beam widths of a few mm to the setup. Devices Under Test (DUTs) are irradiated inside a cooled, thermally-insulated box at \le-20°C, while being moved through the beam in a row-based scan pattern to achieve uniform… ▽ More

    Submitted 5 May, 2024; v1 submitted 17 April, 2024; originally announced April 2024.

  43. Measurement of the branching fraction of the decay B^- \to D^0 ρ(770)^- at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer, J. Becker, J. V. Bennett , et al. (367 additional authors not shown)

    Abstract: We measure the branching fraction of the decay B^- \to D^0 ρ(770)^- using data collected with the Belle II detector. The data contain 387 million B\overline{B} pairs produced in e^+e^- collisions at the Υ(4S) resonance. We reconstruct 8360\pm 180 decays from an analysis of the distributions of the B^- energy and the ρ(770)^- helicity angle. We determine the branching fraction to be… ▽ More

    Submitted 27 June, 2024; v1 submitted 16 April, 2024; originally announced April 2024.

    Report number: Belle II Preprint 2024-011, KEK Preprint 2024-4

    Journal ref: PRD 109, 111103 (2024)

  44. Search for Rare b \to d\ell^+\ell^- Transitions at Belle

    Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, S. Al Said, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Beaubien, F. Becherer, J. Becker , et al. (371 additional authors not shown)

    Abstract: We present the results of a search for the b \to d\ell^+\ell^- flavor-changing neutral-current rare decays B^{+, 0} \to (η, ω, π^{+,0}, ρ^{+, 0}) e^+e^- and B^{+, 0} \to (η, ω, π^{0}, ρ^{+}) μ^+μ^- using a 711 fb^{-1} data sample that contains 772 \times 10^{6} B\overline{B} events. The data were collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy… ▽ More

    Submitted 6 September, 2024; v1 submitted 11 April, 2024; originally announced April 2024.

    Comments: 7 pages, 12 figures

    Report number: Belle II Preprint 2024-005, KEK Preprint 2023-52

    Journal ref: Phys. Rev. Lett. 133, 101804 (2024)

  45. Measurement of the e^+e^- \to π^+π^-π^0 cross section in the energy range 0.62-3.50 GeV at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer, J. Becker, J. V. Bennett , et al. (338 additional authors not shown)

    Abstract: We report a measurement of the e^+e^- \to π^+π^-π^0 cross section in the energy range from 0.62 to 3.50 GeV using an initial-state radiation technique. We use an e^+e^- data sample corresponding to 191 \text{fb}^{-1} of integrated luminosity, collected at a center-of-mass energy at or near the Υ{(4S)} resonance with the Belle II detector at the SuperKEKB collider. Signal yields are extract… ▽ More

    Submitted 8 December, 2024; v1 submitted 7 April, 2024; originally announced April 2024.

    Comments: 23 pages, 24 figures, submitted to PRD

    Report number: KEK Preprint 2023-51, Belle II Preprint 2024-004

    Journal ref: Phys. Rev. D 110 (2024) 112005

  46. arXiv:2404.00201  [pdf, other

    hep-ex

    Angular analysis of B \to K^* e^+ e^- in the low-q^2 region with new electron identification at Belle

    Authors: Belle Collaboration, D. Ferlewicz, P. Urquijo, I. Adachi, K. Adamczyk, H. Aihara, D. M. Asner, H. Atmacan, R. Ayad, V. Babu, Sw. Banerjee, P. Behera, K. Belous, J. Bennett, M. Bessner, V. Bhardwaj, B. Bhuyan, T. Bilka, D. Biswas, D. Bodrov, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola , et al. (145 additional authors not shown)

    Abstract: We perform an angular analysis of the B\to K^* e^+ e^- decay for the dielectron mass squared, q^2, range of 0.0008 to 1.1200 ~\text{GeV}^2 /c^4 using the full Belle data set in the K^{*0} \to K^+ π^- and K^{*+} \to K_S^0 π^+ channels, incorporating new methods of electron identification to improve the statistical power of the data set. This analysis is sensitive to contributions from r… ▽ More

    Submitted 11 September, 2024; v1 submitted 29 March, 2024; originally announced April 2024.

    Comments: Accepted by PRD

    Report number: Belle preprint 2023-20, KEK preprint 2023-38

  47. arXiv:2403.04340  [pdf, other

    hep-ex

    Search for a pentaquark state decaying into pJ/ψ in Υ(1,2S) inclusive decays at Belle

    Authors: Belle Collaboration, X. Dong, H. Y. Zhang, X. L. Wang, I. Adachi, J. K. Ahn, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, R. Ayad, S. Bahinipati, Sw. Banerjee, M. Bessner, V. Bhardwaj, D. Biswas, D. Bodrov, A. Bozek, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, D. Červenkov, M. -C. Chang , et al. (139 additional authors not shown)

    Abstract: Using the data samples of 102 million Υ(1S) and 158 million Υ(2S) events collected by the Belle detector, we search for a pentaquark state in the pJ/ψ final state from Υ(1,2S) inclusive decays. Here, the charge-conjugate \bar{p}J/ψ is included. We observe clear pJ/ψ production in Υ(1,2S) decays and measure the branching fractions to be… ▽ More

    Submitted 20 March, 2025; v1 submitted 7 March, 2024; originally announced March 2024.

    Report number: Belle Preprint 2024-02, KEK Preprint 2023-54

  48. Search for a μ^+μ^- resonance in four-muon final states at Belle II

    Authors: Belle II Collaboration, I. Adachi, K. Adamczyk, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer , et al. (379 additional authors not shown)

    Abstract: We report on a search for a resonance X decaying to a pair of muons in e^{+}e^{-}\rightarrow μ^+ μ^- X events in the 0.212-9.000 GeV/c^{2} mass range, using 178 fb^{-1} of data collected by the BelleII experiment at the SuperKEKB collider at a center of mass energy of 10.58 GeV. The analysis probes two different models of X beyond the standard model: a Z^{\prime} vector boson in the… ▽ More

    Submitted 26 June, 2024; v1 submitted 5 March, 2024; originally announced March 2024.

    Report number: 2024-007, 2023-55

    Journal ref: Phys. Rev. D 109, 112015 (2024)

  49. arXiv:2403.02590  [pdf, other

    hep-ex

    Measurement of CP asymmetries in B^0 \rightarrow K^0_S K^0_S K^0_S decays at Belle II

    Authors: Belle II Collaboration, I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, M. Bauer, A. Baur, A. Beaubien , et al. (428 additional authors not shown)

    Abstract: We report a measurement of decay-time dependent charge-parity (CP) asymmetries in B^0 \rightarrow K^0_S K^0_S K^0_S decays. We use 387 \times 10^6 B\bar{B} pairs collected at the Υ(4S) resonance with the Belle II detector at the SuperKEKB asymmetric-energy electron-positron collider. We reconstruct 220 signal events and extract the CP-violating parameters S and C from a fit to the di… ▽ More

    Submitted 4 March, 2024; originally announced March 2024.

    Comments: 10 pages, 5 figures

    Report number: Belle II Preprint 2024-008, KEK Preprint 2023-56

  50. arXiv:2402.12153  [pdf, other

    physics.ins-det

    Cross talk of a large-scale depleted monolithic active pixel sensor (DMAPS) in 180 nm CMOS technology

    Authors: Lars Schall, Christian Bespin, Ivan Caicedo, Jochen Dingfelder, Tomasz Hemperek, Toko Hirono, Fabian Hügging, Hans Krüger, Konstantinos Moustakas, Heinz Pernegger, Petra Riedler, Walter Snoeys, Norbert Wermes, Sinuo Zhang

    Abstract: Monolithic pixel detectors combine readout electronics and sensor in a single entity of silicon, which simplifies the production procedure and lowers the material budget compared to conventional hybrid pixel detector concepts. Benefiting from the advances in commercial CMOS processes towards large biasing voltage capabilities and the increasing availability of high-resistivity substrates, depleted… ▽ More

    Submitted 19 February, 2024; originally announced February 2024.

    Comments: Conference proceedings for 13th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detectors (HSTD13), submitted to NIM-A