Showing papers by "D. M. Asner published in 2022"

Snowmass 2021 White Paper on Upgrading SuperKEKB with a Polarized Electron Beam: Discovery Potential and Proposed Implementation

Abstract: precision sin 2 independent left-right asymmetry measurements of e + e − transitions to pairs of muons, taus, and b-quarks.

Evidence of a New Excited Charmed Baryon Decaying to Σ_{c}(2455)^{0,++}π^{±}.

Abstract: We present the study of B[over ¯]^{0}→Σ_{c}(2455)^{0,++}π^{±}p[over ¯] decays based on 772×10^{6} BB[over ¯] events collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The Σ_{c}(2455)^{0,++} candidates are reconstructed via their decay to Λ_{c}^{+}π^{∓} and Λ_{c}^{+} decays to pK^{-}π^{+}, pK_{S}^{0}, and Λπ^{+} final states. The corresponding branching fractions are measured to be B(B[over ¯]^{0}→Σ_{c}(2455)^{0}π^{+}p[over ¯])=(1.09±0.06±0.07)×10^{-4} and B(B[over ¯]^{0}→Σ_{c}(2455)^{++}π^{-}p[over ¯])=(1.84±0.11±0.12)×10^{-4}, which are consistent with the world average values with improved precision. A new structure is found in the M_{Σ_{c}(2455)^{0,++}π^{±}} spectrum with a significance of 4.2σ including systematic uncertainty. The structure is possibly an excited Λ_{c}^{+} and is tentatively named Λ_{c}(2910)^{+}. Its mass and width are measured to be (2913.8±5.6±3.8) MeV/c^{2} and (51.8±20.0±18.8) MeV, respectively. The products of branching fractions for the Λ_{c}(2910)^{+} are measured to be B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{0}π^{+})=(9.5±3.6±1.6)×10^{-6} and B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{++}π^{-})=(1.24±0.35±0.10)×10^{-5}. Here, the first and second uncertainties are statistical and systematic, respectively.

Search for B 0 meson decays into Λ and missing energy with a hadronic tagging method at Belle

Abstract: We present a search for the decays of B 0 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 × 10 6 B ¯ B pairs and was collected near the ϒ ð 4 S Þ resonance with the Belle detector at the KEKB asymmetric-energy e þ 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.

Search for a Dark Photon and an Invisible Dark Higgs Boson in μ^{+}μ^{-} and Missing Energy Final States with the Belle II Experiment.

Abstract: The dark photon A^{'} and the dark Higgs boson h^{'} are hypothetical particles predicted in many dark sector models. We search for the simultaneous production of A^{'} and h^{'} in the dark Higgsstrahlung process e^{+}e^{-}→A^{'}h^{'} with A^{'}→μ^{+}μ^{-} and h^{'} invisible in electron-positron collisions at a center-of-mass energy of 10.58 GeV in data collected by the Belle II experiment in 2019. With an integrated luminosity of 8.34 fb^{-1}, we observe no evidence for signal. We obtain exclusion limits at 90% Bayesian credibility in the range of 1.7-5.0 fb on the cross section and in the range of 1.7×10^{-8}-200×10^{-8} on the effective coupling ϵ^{2}×α_{D} for the A^{'} mass in the range of 4.0 GeV/c^{2}

First Observation of Υ(3 S ) → τ + τ − and Tests of Lepton Universality in Υ Decays.

Abstract: Using data collected with the CLEOIII detector at the CESR e + e − collider, we report on a first observation of the decay Υ(3 S ) → τ + τ − , and precisely measure the ratio of branching fractions of Υ( nS ) , n = 1 , 2 , 3 , to τ + τ − and µ + µ − final states, finding agreement with expectations from lepton universality. We derive absolute branching fractions for these decays, and also set a limit on the influence of a low mass CP-odd Higgs boson in the decay of the Υ(1 S ).

Search for the decay B 0 s → η ′ K 0 S

Abstract: T. Pang,74 V. Savinov,74 I. Adachi,21, 17 H. Aihara,90 D. M. Asner,3 H. Atmacan,8 V. Aulchenko,4, 70 T. Aushev,23 R. Ayad,84 V. Babu,9 P. Behera,29 K. Belous,33 M. Bessner,20 V. Bhardwaj,26 B. Bhuyan,27 T. Bilka,5 A. Bobrov,4, 70 D. Bodrov,23, 48 G. Bonvicini,94 J. Borah,27 A. Bozek,66 M. Bračko,54, 39 P. Branchini,35 T. E. Browder,20 A. Budano,35 M. Campajola,34, 62 D. Červenkov,5 P. Chang,65 A. Chen,64 B. G. Cheon,19 K. Chilikin,48 H. E. Cho,19 K. Cho,43 S.-J. Cho,96 S.-K. Choi,7 Y. Choi,82 S. Choudhury,37 D. Cinabro,94 S. Cunliffe,9 S. Das,53 G. De Pietro,35 R. Dhamija,28 F. Di Capua,34, 62 J. Dingfelder,2 Z. Doležal,5 T. V. Dong,11 D. Dossett,56 S. Dubey,20 D. Epifanov,4, 70 T. Ferber,9 A. Frey,16 B. G. Fulsom,72 R. Garg,73 V. Gaur,93 N. Gabyshev,4, 70 A. Giri,28 P. Goldenzweig,40 E. Graziani,35 T. Gu,74 K. Gudkova,4, 70 C. Hadjivasiliou,72 S. Halder,85 K. Hayasaka,68 H. Hayashii,63 M. T. Hedges,20 C.-L. Hsu,83 T. Iijima,61, 60 K. Inami,60 G. Inguglia,32 A. Ishikawa,21, 17 R. Itoh,21, 17 M. Iwasaki,71 Y. Iwasaki,21 W. W. Jacobs,30 E.-J. Jang,18 S. Jia,13 Y. Jin,90 K. K. Joo,6 J. Kahn,40 D. Kalita,27 A. B. Kaliyar,85 K. H. Kang,41 G. Karyan,9 T. Kawasaki,42 C. Kiesling,55 C. H. Kim,19 D. Y. Kim,81 K.-H. Kim,96 Y.-K. Kim,96 K. Kinoshita,8 P. Kodyš,5 T. Konno,42 A. Korobov,4, 70 S. Korpar,54, 39 E. Kovalenko,4, 70 P. Križan,50, 39 R. Kroeger,57 P. Krokovny,4, 70 T. Kuhr,51 R. Kumar,75 K. Kumara,94 A. Kuzmin,4, 70, 48 Y.-J. Kwon,96 Y.-T. Lai,41 T. Lam,93 J. S. Lange,14 S. C. Lee,46 C. H. Li,49 J. Li,46 L. K. Li,8 Y. Li,13 L. Li Gioi,55 J. Libby,29 K. Lieret,51 D. Liventsev,94, 21 A. Martini,97 M. Masuda,89, 76 T. Matsuda,58 D. Matvienko,4, 70, 48 F. Meier,10 M. Merola,34, 62 F. Metzner,40 K. Miyabayashi,63 R. Mizuk,48, 23 G. B. Mohanty,85 R. Mussa,36 M. Nakao,21, 17 Z. Natkaniec,66 A. Natochii,20 L. Nayak,28 M. Niiyama,45 N. K. Nisar,3 S. Nishida,21, 17 K. Ogawa,68 S. Ogawa,87 H. Ono,67, 68 P. Oskin,48 P. Pakhlov,48, 59 G. Pakhlova,23, 48 S. Pardi,34 H. Park,46 S.-H. Park,21 A. Passeri,35 S. Patra,26 S. Paul,86, 55 T. K. Pedlar,52 R. Pestotnik,39 L. E. Piilonen,93 T. Podobnik,50, 39 V. Popov,23 E. Prencipe,24 M. T. Prim,2 A. Rostomyan,9 N. Rout,29 G. Russo,62 D. Sahoo,37 S. Sandilya,28 A. Sangal,8 L. Santelj,50, 39 T. Sanuki,88 G. Schnell,1, 25 Y. Seino,68 K. Senyo,95 M. E. Sevior,56 M. Shapkin,33 C. Sharma,53 C. P. Shen,13 J.-G. Shiu,65 F. Simon,55 J. B. Singh,73, ∗ A. Sokolov,33 E. Solovieva,48 S. Stanič,69 M. Starič,39 J. F. Strube,72 M. Sumihama,15, 76 T. Sumiyoshi,92 M. Takizawa,79, 22, 77 U. Tamponi,36 K. Tanida,38 N. Taniguchi,21 F. Tenchini,9 K. Trabelsi,47 M. Uchida,91 K. Uno,68 S. Uno,21, 17 P. Urquijo,56 R. Van Tonder,2 G. Varner,20 A. Vinokurova,4, 70 E. Waheed,21 E. Wang,74 M.-Z. Wang,65 X. L. Wang,13 M. Watanabe,68 S. Watanuki,96 E. Won,44 X. Xu,80 B. D. Yabsley,83 W. Yan,78 H. Ye,9 J. Yelton,12 J. H. Yin,44 C. Z. Yuan,31 Y. Zhai,37 Z. P. Zhang,78 V. Zhilich,4, 70 and V. Zhukova48

Measurement of Two-Particle Correlations of Hadrons in e^{+}e^{-} Collisions at Belle.

Abstract: The measurement of two-particle angular correlation functions in high-multiplicity e^{+}e^{-} collisions at sqrt[s]=10.52 GeV is reported. In this study, the 89.5 fb^{-1} of hadronic e^{+}e^{-} annihilation data collected by the Belle detector at KEKB are used. Two-particle angular correlation functions are measured in the full relative azimuthal angle (Δϕ) and three units of pseudorapidity (Δη), defined by either the electron beam axis or the event-shape thrust axis, and are studied as a function of charged-particle multiplicity. The measurement in the thrust axis analysis, with mostly outgoing quark pairs determining the reference axis, is sensitive to the region of additional soft gluon emissions. No significant anisotropic collective behavior is observed with either coordinate analyses. Near-side jet correlations appear to be absent in the thrust axis analysis. The measurements are compared to predictions from various event generators and are expected to provide new constraints to the phenomenological models in the low-energy regime.

Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II.

Abstract: We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8 fb^{-1}, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} and τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ^{-}→e^{-}α)/B(τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ}) in the range (1.1-9.7)×10^{-3} and on B(τ^{-}→μ^{-}α)/B(τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}) in the range (0.7-12.2)×10^{-3} for α masses between 0 and 1.6 GeV/c^{2}. These results provide the most stringent bounds on invisible boson production from τ decays.

First decay-time-dependent analysis of B 0 → K 0 S π 0 at Belle II

Abstract: We report measurements of the branching fraction ( B ) and direct CP -violating asymmetry 93 ( A CP ) of the charmless decay B 0 → K 0 π 0 at Belle II. A sample of e + e − collisions, corresponding 94 to 189 . 8 fb − 1 of integrated luminosity, recorded at the Υ (4 S ) resonance is used for the first decay- 95 time-dependent analysis of these decays within the experiment. We reconstruct about 135 signal 96 candidates, and measure B ( B 0 → K 0 π 0 ) = [11 . 0 ± 1 . 2(stat) ± 1 . 0(syst)] × 10 − 6 and A CP ( B 0 → 97 K 0 π 0 ) = − 0 . 41 +0 . 30 − 0 . 32 (stat) ± 0 . 09(syst). 98

Measurements of the branching fraction, isospin asymmetry, and lepton-universality ratio in $B \to J/\psi K$ decays at Belle II

Abstract: We report a study of B → J/ψ ( (cid:96) + (cid:96) − ) K decays, where (cid:96) represents an electron or a muon, using e + e − collisions at the Υ(4 S ) resonance. The data were collected by the Belle II experiment at the SuperKEKB asymmetric-energy collider during 2019–2021, corresponding to an integrated luminosity of 189 fb − 1 . The measured quantities are the branching fractions ( B ) of the decay channels B + → J/ψ ( e + e − ) K + , B + → J/ψ ( µ + µ − ) K + , B 0 → J/ψ ( e + e − ) K 0 S , and B 0 → J/ψ ( µ + µ − ) K 0 S ; the lepton-flavor-dependent isospin asymmetries for the electron [ A I ( B → J/ψ ( e + e − ) K )] and muon [ A I ( B → J/ψ ( µ + µ − ) K )] channels; and the ratios of branching fractions between the muon and electron channels for the

Measurement of B(Bs→DsX) with Bs semileptonic tagging

Abstract: We report the first direct measurement of the inclusive branching fraction B(Bs→DsX) via Bs tagging in e+e−→ϒ(5S) events. Tagging is accomplished through a partial reconstruction of semileptonic decays Bs→DsXℓν, where X denotes unreconstructed additional hadrons or photons and ℓ is an electron or muon. With 121.4 fb−1 of data collected at the ϒ(5S) resonance by the Belle detector at the KEKB asymmetric-energy e+e− collider, we obtain B(Bs→DsX)=(60.2±5.8±2.3)%, where the first uncertainty is statistical and the second is systematic.Received 21 June 2021Revised 3 December 2021Accepted 17 December 2021DOI:https://doi.org/10.1103/PhysRevD.105.012004Published by the American Physical Society under the terms of the 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.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasParticle decaysParticle interactionsParticles & Fields

Belle II Executive Summary

Abstract: D.M. Asner1, H. Atmacan2, Sw. Banerjee3, J.V. Bennett4, M. Bertemes1, M. Bessner5, D. Biswas3, G. Bonvicini6, N. Brenny7, R.A. Briere8, T.E. Browder5, C. Chen7, S. Choudhury7, D. Cinabro6, J. Cochran7, L.M. Cremaldi4, A. Di Canto1, S. Dubey5, K. Flood5, B. G. Fulsom9, V. Gaur10, R. Godang11, T. Gu12, Y, Guan2, J. Guilliams4, C. Hadjivasiliou9, O. Hartbrich5, W.W. Jacobs13, D.E. Jaffe1, S. Kang7, L. Kapitánová12, C. Ketter5, A. Khatri7, K. Kinoshita2 , S. Kohani5, H. Korandla5, I. Koseoglu Sari5, R. Kroeger4, J. Kumar8, K.J. Kumara4, T. Lam10, P.J. Laycock1, L. Li2, D. Liventsev6, F. Meier14, S. Mitra7, A. Natochii5, N. Nellikunnummel1, K.A. Nishimura5, E.R. Oxford8, A. Panta4, K. Parham14, T.K. Pedlar15, R. Peschke5, L.E. Piilonen10, S. Pokharel4, S. Prell7, H. Purwar5, D.E. Ricalde Herrmann6, C. Rosenfeld16, D. Sahoo7, D.A. Sanders4, A. Sangal2, V. Savinov12, S. Schneider14, J. Schueler5, A.J. Schwartz2, V. Shebalin5, A. Sibidanov5, Z.S. Stottler10, J. Strube9, S. Tripathi5, S.E. Vahsen5, G.S. Varner5, A. Vossen14, D. Wang17, E. Wang12, L. Wood9, J. Yelton17, Y. Zhai7, and B. Zhang5

Search for Z ′ → μ + μ − in the L μ − L τ gauge-symmetric model at Belle

Abstract: T. Czank, I. Jaegle, 85 A. Ishikawa, 15 I. Adachi, 15 K. Adamczyk, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, J. Bennett, F. Bernlochner, M. Bessner, V. Bhardwaj, B. Bhuyan, T. Bilka, J. Biswal, A. Bobrov, 67 G. Bonvicini, A. Bozek, M. Bračko, T. E. Browder, M. Campajola, 58 L. Cao, D. Červenkov, M.-C. Chang, A. Chen, B. G. Cheon, K. Chilikin, H. E. Cho, K. Cho, Y. Choi, S. Choudhury, D. Cinabro, S. Das, N. Dash, G. De Nardo, 58 R. Dhamija, F. Di Capua, 58 Z. Doležal, T. V. Dong, S. Eidelman, 67, 45 T. Ferber, D. Ferlewicz, B. G. Fulsom, R. Garg, V. Gaur, A. Garmash, 67 A. Giri, P. Goldenzweig, B. Golob, 36 O. Grzymkowska, Y. Guan, K. Gudkova, 67 C. Hadjivasiliou, O. Hartbrich, K. Hayasaka, H. Hayashii, M. T. Hedges, M. Hernandez Villanueva, T. Higuchi, W.-S. Hou, C.-L. Hsu, T. Iijima, 56 K. Inami, G. Inguglia, R. Itoh, 15 M. Iwasaki, Y. Iwasaki, W. W. Jacobs, E.-J. Jang, S. Jia, Y. Jin, C. W. Joo, K. K. Joo, K. H. Kang, G. Karyan, T. Kawasaki, H. Kichimi, C. Kiesling, B. H. Kim, C. H. Kim, D. Y. Kim, K.-H. Kim, S. H. Kim, Y.-K. Kim, P. Kodyš, I. Komarov, T. Konno, A. Korobov, 67 S. Korpar, E. Kovalenko, 67 P. Križan, 36 R. Kroeger, P. Krokovny, 67 T. Kuhr, M. Kumar, K. Kumara, Y.-J. Kwon, Y.-T. Lai, J. S. Lange, I. S. Lee, S. C. Lee, Y. B. Li, L. Li Gioi, J. Libby, K. Lieret, D. Liventsev, 19 T. Luo, C. MacQueen, M. Masuda, 73 T. Matsuda, D. Matvienko, 67, 45 M. Merola, 58 F. Metzner, K. Miyabayashi, R. Mizuk, 21 G. B. Mohanty, S. Mohanty, 91 T. Mori, M. Mrvar, R. Mussa, M. Nakao, 15 Z. Natkaniec, A. Natochii, L. Nayak, M. Niiyama, N. K. Nisar, S. Nishida, 15 H. Ono, 65 Y. Onuki, P. Pakhlov, 55 G. Pakhlova, 45 T. Pang, S. Pardi, H. Park, S.-H. Park, S. Patra, S. Paul, 51 T. K. Pedlar, R. Pestotnik, L. E. Piilonen, T. Podobnik, 36 V. Popov, E. Prencipe, M. T. Prim, M. Röhrken, A. Rostomyan, N. Rout, G. Russo, D. Sahoo, S. Sandilya, A. Sangal, L. Santelj, 36 T. Sanuki, V. Savinov, G. Schnell, 23 J. Schueler, C. Schwanda, Y. Seino, K. Senyo, M. E. Sevior, M. Shapkin, C. Sharma, V. Shebalin, C. P. Shen, J.-G. Shiu, B. Shwartz, 67 A. Sokolov, E. Solovieva, S. Stanič, M. Starič, Z. S. Stottler, M. Sumihama, T. Sumiyoshi, W. Sutcliffe, M. Takizawa, 20, 74 K. Tanida, Y. Tao, F. Tenchini, K. Trabelsi, M. Uchida, S. Uehara, 15 T. Uglov, 21 K. Uno, S. Uno, 15 P. Urquijo, R. Van Tonder, G. Varner, A. Vossen, C. H. Wang, E. Wang, M.-Z. Wang, P. Wang, S. Watanuki, E. Won, X. Xu, B. D. Yabsley, H. Yamamoto, W. Yan, S. B. Yang, H. Ye, J. Yelton, J. H. Yin, Y. Yusa, Z. P. Zhang, V. Zhilich, 67 V. Zhukova, and V. Zhulanov 67

First decay-time-dependent analysis of $B^{0} \to K_{S}^{0} \pi^{0}$ at Belle II

Abstract: We report measurements of the branching fraction ( B ) and direct CP -violating asymmetry ( A CP ) of the charmless decay B 0 → K 0 π 0 at Belle II. A sample of e + e − collisions, corresponding to 189 . 8 fb − 1 of integrated luminosity, recorded at the Υ (4 S ) resonance is used for the first decay-time-dependent analysis of these decays within the experiment. We reconstruct about 135 signal candidates, and measure B ( B 0 → K 0 π 0 ) = [11 . 0 ± 1 . 2(stat) ± 1 . 0(syst)] × 10 − 6 and A CP ( B 0 → K 0 π 0 ) = − 0 . 41 +0 . 30 − 0 . 32 (stat) ± 0 . 09(syst).

Study of B + → pnπ 0

Abstract: K.-N. Chu , Y.-R. Lin , M.-Z. Wang , I. Adachi , K. Adamczyk , H. Aihara , S. Al Said , D. M. Asner , H. Atmacan , V. Aulchenko , T. Aushev , R. Ayad , V. Babu , Sw. Banerjee , P. Behera , K. Belous , J. Bennett , M. Bessner , V. Bhardwaj , B. Bhuyan , T. Bilka , D. Biswas , D. Bodrov , G. Bonvicini , J. Borah , A. Bozek , M. Bračko , P. Branchini , T. E. Browder , A. Budano , M. Campajola , D. Červenkov , M.-C. Chang , P. Chang , A. Chen , B. G. Cheon , K. Chilikin , H. E. Cho , K. Cho , S.-J. Cho , S.-K. Choi , Y. Choi , S. Choudhury , D. Cinabro , G. De Nardo , G. De Pietro , R. Dhamija , F. Di Capua , J. Dingfelder , Z. Doležal , T. V. Dong , D. Epifanov , T. Ferber , D. Ferlewicz , B. G. Fulsom , V. Gaur , A. Garmash , A. Giri , P. Goldenzweig , B. Golob , E. Graziani , T. Gu , K. Gudkova , C. Hadjivasiliou , S. Halder , X. Han , K. Hayasaka , H. Hayashii , W.-S. Hou , C.-L. Hsu , K. Huang , T. Iijima , K. Inami , N. Ipsita , A. Ishikawa , R. Itoh , M. Iwasaki , W. W. Jacobs , E.-J. Jang , Y. Jin , K. K. Joo , D. Kalita , A. B. Kaliyar , T. Kawasaki , C. Kiesling , C. H. Kim , D. Y. Kim , K.-H. Kim , Y.-K. Kim , P. Kodyš , T. Konno , A. Korobov , S. Korpar , E. Kovalenko , P. Križan , P. Krokovny , T. Kuhr , R. Kumar , K. Kumara , A. Kuzmin , Y.-J. Kwon , Y.-T. Lai , T. Lam , J. S. Lange , S. C. Lee , C. H. Li , J. Li , L. K. Li , S. X. Li , Y. Li , Y. B. Li , L. Li Gioi , J. Libby , K. Lieret , D. Liventsev , T. Luo , M. Masuda , T. Matsuda , D. Matvienko , S. K. Maurya , F. Meier , M. Merola , F. Metzner , K. Miyabayashi , R. Mizuk , G. B. Mohanty , I. Nakamura , M. Nakao , Z. Natkaniec , A. Natochii , L. Nayak , N. K. Nisar , S. Nishida , Y. Onuki , P. Oskin , P. Pakhlov , G. Pakhlova , S. Pardi , H. Park , J. Park , A. Passeri , S. Paul , T. K. Pedlar , R. Pestotnik , L. E. Piilonen , T. Podobnik , E. Prencipe , M. T. Prim , A. Rostomyan , N. Rout , G. Russo , S. Sandilya , L. Santelj , V. Savinov , G. Schnell , C. Schwanda , Y. Seino , K. Senyo , M. E. Sevior , W. Shan , M. Shapkin , C. Sharma , C. P. Shen , J.-G. Shiu , B. Shwartz , F. Simon , A. Sokolov , E. Solovieva , M. Starič , Z. S. Stottler , J. F. Strube , M. Sumihama , K. Sumisawa , T. Sumiyoshi , M. Takizawa , U. Tamponi , K. Tanida , F. Tenchini , K. Trabelsi , M. Uchida , T. Uglov , Y. Unno , S. Uno , P. Urquijo , Y. Usov , S. E. Vahsen , R. van Tonder , G. Varner , K. E. Varvell , A. Vinokurova , A. Vossen , S. Watanuki , E. Won , X. Xu , B. D. Yabsley , W. Yan , S. B. Yang , J. Yelton , J. H. Yin , C. Z. Yuan , L. Yuan , Y. Yusa , Z. P. Zhang , V. Zhilich , and V. Zhukova (The Belle Collaboration)

3 2 4 Fe b 20 00 First Observation of the Decay B → J / ψ φK

Abstract: A. Anastassov, J. E. Duboscq, K. K. Gan, C. Gwon, T. Hart, K. Honscheid, D. Hufnagel, H. Kagan, R. Kass, J. Lorenc, T. K. Pedlar, H. Schwarthoff, E. von Toerne, M. M. Zoeller, S. J. Richichi, H. Severini, P. Skubic, A. Undrus, S. Chen, J. Fast, J. W. Hinson, J. Lee, N. Menon, D. H. Miller, E. I. Shibata, I. P. J. Shipsey, V. Pavlunin, D. Cronin-Hennessy, Y. Kwon, A.L. Lyon, E. H. Thorndike, C. P. Jessop, H. Marsiske, M. L. Perl, V. Savinov, D. Ugolini, X. Zhou, T. E. Coan, V. Fadeyev, I. Korolkov, Y. Maravin, I. Narsky, R. Stroynowski, J. Ye, T. Wlodek, M. Artuso, R. Ayad, C. Boulahouache, K. Bukin, E. Dambasuren, S. Karamov, S. Kopp, G. Majumder, G. C. Moneti, R. Mountain, S. Schuh, T. Skwarnicki, S. Stone, G. Viehhauser, J.C. Wang, A. Wolf, J. Wu, S. E. Csorna, I. Danko, K. W. McLean, Sz. Márka, Z. Xu, R. Godang, K. Kinoshita, I. C. Lai, S. Schrenk, G. Bonvicini, D. Cinabro, L. P. Perera, G. J. Zhou, G. Eigen, E. Lipeles, M. Schmidtler, A. Shapiro, W. M. Sun, A. J. Weinstein, F. Würthwein, D. E. Jaffe, G. Masek, H. P. Paar, E. M. Potter, S. Prell, V. Sharma, D. M. Asner, A. Eppich, J. Gronberg, T. S. Hill, D. J. Lange, R. J. Morrison, H. N. Nelson, R. A. Briere, B. H. Behrens, W. T. Ford, A. Gritsan, J. Roy, J. G. Smith, J. P. Alexander, R. Baker, C. Bebek, B. E. Berger, K. Berkelman, F. Blanc, V. Boisvert, D. G. Cassel, M. Dickson, P. S. Drell, K. M. Ecklund, R. Ehrlich, A. D. Foland, P. Gaidarev, L. Gibbons, B. Gittelman, S. W. Gray, D. L. Hartill, B. K. Heltsley, P. I. Hopman, C. D. Jones, D. L. Kreinick, M. Lohner, A. Magerkurth, T. O. Meyer, N. B. Mistry, C. R. Ng, E. Nordberg, J. R. Patterson, D. Peterson, D. Riley, J. G. Thayer, P. G. Thies, B. Valant-Spaight, A. Warburton, P. Avery, C. Prescott, A. I. Rubiera, J. Yelton, J. Zheng, G. Brandenburg, A. Ershov, Y. S. Gao, D. Y.-J. Kim, R. Wilson, T. E. Browder, Y. Li, J. L. Rodriguez, H. Yamamoto, T. Bergfeld, B. I. Eisenstein, J. Ernst, G. E. Gladding, G. D. Gollin, R. M. Hans, E. Johnson, I. Karliner, M. A. Marsh, M. Palmer, C. Plager, C. Sedlack, M. Selen, J. J. Thaler, J. Williams, K. W. Edwards, R. Janicek, P. M. Patel, A. J. Sadoff, R. Ammar, P. Baringer, A. Bean, D. Besson, R. Davis, I. Kravchenko, N. Kwak, X. Zhao, S. Anderson, V. V. Frolov, Y. Kubota, S. J. Lee, R. Mahapatra, J. J. O’Neill, R. Poling, T. Riehle, A. Smith, J. Urheim, S. Ahmed, M. S. Alam, S. B. Athar, L. Jian, L. Ling, A. H. Mahmood, M. Saleem, S. Timm, and F. Wappler

Measurement of the mass and width of the $\Lambda_c(2625)^+$ and the branching ratios of $\Lambda_c(2625)^+ \to \Sigma_c^{0}\pi^{+}$ and $\Lambda_c(2625)^+ \to \Sigma_c^{++}\pi^{-}$

Abstract: Using the entire data sample of $980\,\textrm{fb}^{-1}$ collected with the Belle detector operating at the KEKB asymmetric-energy collider, we report the measurement of the mass, width, and the relative branching ratios of the $\Lambda_c(2625)^+$ charmed baryon. The mass difference between $\Lambda_c(2625)^+$ and $\Lambda_c^+$ is measured to be $M(\Lambda_c(2625)^{+}) - M(\Lambda_c^{+}) = 341.518 \pm 0.006 \pm 0.049\ \mathrm{MeV}/\mathit{c}^2$. The upper limit on the width is measured to be $\Gamma(\Lambda_c(2625)^+)<0.52\,\mathrm{MeV}/\textit{c}^2$ at 90\% credibility level. Based on a full Dalitz plot fit, branching ratios with respect to the mode $\Lambda_c(2625)^+ \to \Lambda_c^+ \pi^+ \pi^-$ are measured to be $\frac{\mathcal{B}(\Lambda_c(2625)^+ \to \Sigma_c^{0} \pi^{+})} {\mathcal{B}(\Lambda_c(2625)^+ \to \Lambda_c^+ \pi^{+} \pi^{-})} = (5.19 \pm 0.23 \pm 0.40) \%$ and $\frac{\mathcal{B}(\Lambda_c(2625)^+ \to \Sigma_c^{++} \pi^{-})} {\mathcal{B}(\Lambda_c(2625)^+ \to \Lambda_c^+ \pi^{+} \pi^{-})} = (5.13 \pm 0.26 \pm 0.32) \%$. These measurements can be used to further constrain the parameters of the underlying theoretical models.

Measurement of the branching fraction for the decay $B \to K^{\ast}(892)\ell^+\ell^-$ at Belle II

Abstract: We report a measurement of the branching fraction of B → K ∗ (892) (cid:96) + (cid:96) − decays, where (cid:96) + (cid:96) − = µ + µ − or e + e − , using electron-positron collisions recorded at an energy at or near the Υ (4 S ) mass and corresponding to an integrated luminosity of 189 fb − 1 . The data was collected during 2019–2021 by the Belle II experiment at the SuperKEKB e + e − asymmetric-energy collider. We reconstruct K ∗ (892) candidates in the K + π − , K 0 S π + , and K + π 0 final states. The signal yields with statistical uncertainties are 22 ± 6, 18 ± 6, and 38 ± 9 for the decays B → K ∗ (892) µ + µ − , B → K ∗ (892) e + e − , and B → K ∗ (892) (cid:96) + (cid:96) − , respectively. We measure the branching fractions of these decays for the entire range of the dilepton mass, excluding the very low mass region to suppress the B → K ∗ (892) γ ( → e + e − ) background and regions compatible with decays of charmonium resonances, to be

Determination of | V ub | from untagged B 0 → π − (cid:96) + ν (cid:96) decays using 2019-2021 Belle II data

Abstract: We present an analysis of the charmless semileptonic decay B 0 → π − (cid:96) + ν (cid:96) , where (cid:96) = e, µ , from 198.0 million pairs of B ¯ B mesons recorded by the Belle II detector at the SuperKEKB electron-positron collider. The decay is reconstructed without identifying the partner B meson. The partial branching fractions are measured independently for B 0 → π − e + ν e and B 0 → π − µ + ν µ as functions of q 2 (momentum transfer squared), using 3896 B 0 → π − e + ν e and 5466 B 0 → π − µ + ν µ decays. The total branching fraction is found to be (1 . 426 ± 0 . 056 ± 0 . 125) × 10 − 4 for B 0 → π − (cid:96) + ν (cid:96) decays, where the uncertainties are statistical and systematic, respectively. By fitting the measured partial branching fractions as functions of q 2 , together with constraints on the nonperturbative hadronic contribution from lattice QCD calculations, the magnitude of the

First Measurement of the B^{+}→π^{+}π^{0}π^{0} Branching Fraction and CP Asymmetry.

Abstract: We study B^{+}→π^{+}π^{0}π^{0} using 711 fb^{-1} of data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We measure an inclusive branching fraction of (19.0±1.5±1.4)×10^{-6} and an inclusive CP asymmetry of (9.2±6.8±0.7)%, where the first uncertainties are statistical and the second are systematic, and a B^{+}→ρ(770)^{+}π^{0} branching fraction of (11.2±1.1±0.9_{-1.6}^{+0.8})×10^{-6}, where the third uncertainty is due to possible interference with B^{+}→ρ(1450)^{+}π^{0}. We present the first observation of a structure around 1 GeV/c^{2} in the π^{0}π^{0} mass spectrum, with a significance of 6.4σ, and measure a branching fraction to be (6.9±0.9±0.6)×10^{-6}. We also report a measurement of local CP asymmetry in this structure.

Determination of $|V_{ub}|$ from untagged $B^0\to\pi^- \ell^+ \nu_{\ell}$ decays using 2019-2021 Belle II data

Abstract: We present an analysis of the charmless semileptonic decay B 0 → π − (cid:96) + ν (cid:96) , where (cid:96) = e, µ , from 198.0 million pairs of B ¯ B mesons recorded by the Belle II detector at the SuperKEKB electron-positron collider. The decay is reconstructed without identifying the partner B meson. The partial branching fractions are measured independently for B 0 → π − e + ν e and B 0 → π − µ + ν µ as functions of q 2 (momentum transfer squared), using 3896 B 0 → π − e + ν e and 5466 B 0 → π − µ + ν µ decays. The total branching fraction is found to be (1 . 426 ± 0 . 056 ± 0 . 125) × 10 − 4 for B 0 → π − (cid:96) + ν (cid:96) decays, where the uncertainties are statistical and systematic, respectively. By fitting the measured partial branching fractions as functions of q 2 , together with constraints on the nonperturbative hadronic contribution from lattice QCD calculations, the magnitude of the

Measurements of branching fractions of $\Lambda_c^+ \to \Sigma^+ \eta$ and $\Lambda_c^+ \to \Sigma^+ \eta'$ and asymmetry parameters of $\Lambda_c^+ \to \Sigma^+ \pi^0$, $\Lambda_c^+ \to \Sigma^+ \eta$, and $\Lambda_c^+ \to \Sigma^+ \eta'$

Abstract: We report a study of $\Lambda_c^+ \to \Sigma^+ \pi^0$, $\Lambda_c^+ \to \Sigma^+ \eta$, and $\Lambda_c^+ \to \Sigma^+ \eta'$ using the data sample corresponding to an integrated luminosity of 980 $\rm fb^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The branching fractions relative to $\Lambda_c^+ \to \Sigma^+ \pi^0$ are measured as: $\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \eta}/\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \pi^0}=0.25 \pm 0.03 \pm 0.01$ and $\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \eta'}/\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \pi^0}=0.33 \pm 0.06 \pm 0.02$. Using $\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \pi^0}=(1.25 \pm 0.10)\%$, we obtain $\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \eta}=(3.14 \pm 0.35 \pm 0.11 \pm 0.25)\times10^{-3}$ and $\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \eta'}=(4.16 \pm 0.75 \pm 0.21 \pm 0.33)\times10^{-3}$. Here the uncertainties are statistical, systematic, and from $\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \pi^0}$, respectively. The ratio of the branching fraction of $\Lambda_c^+ \to \Sigma^+ \eta'$ with respect to that of $\Lambda_c^+ \to \Sigma^+ \eta$ is measured to be $\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \eta'}/\mathcal{B}_{\Lambda_c^+ \to \Sigma^+ \eta}=1.34 \pm 0.28 \pm 0.06$. We update the asymmetry parameter of $\Lambda_c^+ \to \Sigma^+ \pi^0$, $\alpha_{\Sigma^+ \pi^0} = -0.48 \pm 0.02 \pm 0.02$, with a considerably improved precision. The asymmetry parameters of $\Lambda_c^+ \to \Sigma^+ \eta$ and $\Lambda_c^+ \to \Sigma^+ \eta'$ are measured to be $\alpha_{\Sigma^+ \eta} = -0.99 \pm 0.03 \pm 0.05$ and $\alpha_{\Sigma^+ \eta'} = -0.46 \pm 0.06 \pm 0.03$ for the first time.

D ec 2 01 8 Observation of Υ ( 2 S ) → γη b ( 1 S ) decay

Abstract: B. G. Fulsom, T. K. Pedlar, I. Adachi, 15 H. Aihara, S. Al Said, 40 D. M. Asner, H. Atmacan, V. Aulchenko, 69 T. Aushev, R. Ayad, V. Babu, I. Badhrees, 39 A. M. Bakich, V. Bansal, P. Behera, C. Beleño, M. Berger, V. Bhardwaj, B. Bhuyan, T. Bilka, J. Biswal, A. Bondar, 69 G. Bonvicini, A. Bozek, M. Bračko, T. E. Browder, L. Cao, D. Červenkov, V. Chekelian, A. Chen, B. G. Cheon, K. Chilikin, K. Cho, S.-K. Choi, Y. Choi, S. Choudhury, D. Cinabro, S. Cunliffe, N. Dash, S. Di Carlo, J. Dingfelder, Z. Doležal, T. V. Dong, 15 Z. Drásal, S. Eidelman, 69, 47 D. Epifanov, 69 J. E. Fast, T. Ferber, R. Garg, V. Gaur, N. Gabyshev, 69 A. Garmash, 69 M. Gelb, A. Giri, P. Goldenzweig, E. Guido, J. Haba, 15 K. Hayasaka, H. Hayashii, S. Hirose, W.-S. Hou, T. Iijima, 59 K. Inami, G. Inguglia, A. Ishikawa, R. Itoh, 15 M. Iwasaki, Y. Iwasaki, W. W. Jacobs, H. B. Jeon, S. Jia, Y. Jin, D. Joffe, K. K. Joo, T. Julius, T. Kawasaki, H. Kichimi, C. Kiesling, D. Y. Kim, H. J. Kim, J. B. Kim, K. T. Kim, S. H. Kim, K. Kinoshita, P. Kodyš, S. Korpar, 35 D. Kotchetkov, P. Križan, 35 R. Kroeger, P. Krokovny, T. Kuhr, R. Kulasiri, A. Kuzmin, 69 Y.-J. Kwon, J. S. Lange, I. S. Lee, S. C. Lee, L. K. Li, Y. B. Li, L. Li Gioi, J. Libby, D. Liventsev, 19 M. Lubej, T. Luo, M. Masuda, T. Matsuda, D. Matvienko, 69, 47 M. Merola, 61 K. Miyabayashi, H. Miyata, R. Mizuk, 57, 58 G. B. Mohanty, H. K. Moon, T. Mori, R. Mussa, M. Nakao, 15 T. Nanut, K. J. Nath, Z. Natkaniec, M. Nayak, 19 M. Niiyama, N. K. Nisar, S. Nishida, 15 S. Ogawa, S. Okuno, H. Ono, 68 P. Pakhlov, 57 G. Pakhlova, 58 B. Pal, S. Pardi, H. Park, S. Paul, R. Pestotnik, L. E. Piilonen, V. Popov, 58 E. Prencipe, A. Rabusov, M. Ritter, A. Rostomyan, G. Russo, Y. Sakai, 15 M. Salehi, 49 S. Sandilya, L. Santelj, T. Sanuki, V. Savinov, O. Schneider, G. Schnell, 22 C. Schwanda, Y. Seino, K. Senyo, M. E. Sevior, V. Shebalin, 69 C. P. Shen, T.-A. Shibata, J.-G. Shiu, B. Shwartz, 69 F. Simon, 85 J. B. Singh, A. Sokolov, E. Solovieva, 58 M. Starič, J. F. Strube, M. Sumihama, K. Sumisawa, 15 T. Sumiyoshi, W. Sutcliffe, M. Takizawa, 20, 75 U. Tamponi, K. Tanida, F. Tenchini, M. Uchida, T. Uglov, 58 Y. Unno, S. Uno, 15 P. Urquijo, S. E. Vahsen, C. Van Hulse, R. Van Tonder, G. Varner, A. Vinokurova, 69 V. Vorobyev, 69, 47 A. Vossen, B. Wang, C. H. Wang, P. Wang, X. L. Wang, M. Watanabe, S. Watanuki, E. Widmann, E. Won, H. Ye, J. H. Yin, C. Z. Yuan, Z. P. Zhang, V. Zhilich, 69 V. Zhukova, 57 V. Zhulanov, 69 and A. Zupanc 35

Measurement of decay-time dependent CP violation in B 0 → K 0 S K 0 S K 0 S using 2019–2021 Belle II data The Belle II Collaboration

Abstract: We report a measurement of decay-time dependent CP -violating parameters in B 0 → K 0 S K 0 S K 0 S decays. We use (198 . 0 ± 3 . 0) × 10 6 BB pairs collected at the Υ(4 S ) resonance with the Belle II detector at the SuperKEKB asymmetric-energy e + e − collider. The observed mixing-induced and direct CP violation parameters are S = − 1 . 86 +0 . 91 − 0 . 46 (stat) ± 0 . 09 (syst) and A = − 0 . 22 +0 . 30 − 0 . 27 (stat) ± 0 . 04 (syst), respectively.

Study of $e^+e^- \rightarrow \Sigma^0 \overline{\Sigma}{}^0$ and $\Sigma^+\overline{\Sigma}{}^- $ by Initial State Radiation Method at Belle

Abstract: The processes $ e^+e^-\rightarrow \Sigma^0\overline{\Sigma}{}^0 $ and $ e^+e^-\rightarrow\Sigma^+\overline{\Sigma}{}^-$ are studied using initial-state-radiation events in a sample of 980 $\,\mbox{fb}^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $ e^+e^- $ collider. The cross sections from the mass threshold to $ 3{\mathrm{\,Ge\kern -0.1em V\!/}c^2} $ and the effective form factors of $ \Sigma^0 $ and $ \Sigma^+ $ are measured. In the charmonium region, we observe the decays $J/\psi\rightarrow\Sigma^0\overline{\Sigma}{}^0$ and $J/\psi\rightarrow\Sigma^+\overline{\Sigma}{}^-$ and determine the respective branching fractions.

Search for charged lepton flavor violating decays of Υ(1 S ) The Belle Collaboration

Abstract: : We present a search for the charged lepton-flavor-violating decays Υ(1 S ) → (cid:96) ± (cid:96) (cid:48)∓