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Measurement of the time-integrated $C P$ asymmetry in $D^{0} \to π^{0} π^{0}$ decays at Belle II

I. Adachi , Y. Ahn , N. Akopov , S. Alghamdi , M. Alhakami , A. Aloisio , N. Althubiti , K. Amos , M. Angelsmark et al. (Belle II Collaboration)

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 , J. Baudot , A. Baur , A. Beaubien , F. Becherer , J. Becker , J. V. Bennett , F. U. Bernlochner , V. Bertacchi , M. Bertemes , E. Bertholet , M. Bessner , S. Bettarini , B. Bhuyan , F. Bianchi , T. Bilka , D. Biswas , A. Bobrov , D. Bodrov , A. Bondar , J. Borah , A. Boschetti , A. Bozek , M. Bračko , P. Branchini , R. A. Briere , T. E. Browder , A. Budano , S. Bussino , M. Campajola , L. Cao , G. Casarosa , C. Cecchi , P. Cheema , B. G. Cheon , K. Chilikin , J. Chin , K. Chirapatpimol , H.-E. Cho , K. Cho , S.-J. Cho , S.-K. Choi , S. Choudhury , I. Consigny , L. Corona , J. X. Cui , E. De La Cruz-Burelo , S. A. De La Motte , G. De Pietro , R. de Sangro , M. Destefanis , A. Di Canto , J. Dingfelder , Z. Doležal , I. Domínguez Jiménez , T. V. Dong , M. Dorigo , G. Dujany , P. Ecker , D. Epifanov , J. Eppelt , R. Farkas , P. Feichtinger , T. Ferber , T. Fillinger , C. Finck , G. Finocchiaro , A. Fodor , F. Forti , B. G. Fulsom , A. Gabrielli , A. Gale , E. Ganiev , M. Garcia-Hernandez , R. Garg , G. Gaudino , V. Gaur , V. Gautam , A. Gaz , A. Gellrich , D. Ghosh , H. Ghumaryan , G. Giakoustidis , R. Giordano , A. Giri , P. Gironella Gironell , B. Gobbo , R. Godang , O. Gogota , P. Goldenzweig , W. Gradl , E. Graziani , D. Greenwald , Z. Gruberová , K. Gudkova , I. Haide , Y. Han , H. Hayashii , S. Hazra , C. Hearty , M. T. Hedges , A. Heidelbach , G. Heine , I. Heredia de la Cruz , M. Hernández Villanueva , T. Higuchi , M. Hoek , M. Hohmann , P. Horak , C.-L. Hsu , T. Iijima , K. Inami , G. Inguglia , N. Ipsita , A. Ishikawa , R. Itoh , M. Iwasaki , P. Jackson , D. Jacobi , W. W. Jacobs , D. E. Jaffe , Q. P. Ji , S. Jia , Y. Jin , A. Johnson , J. Kandra , K. H. Kang , G. Karyan , T. Kawasaki , F. Keil , C. Ketter , M. Khan , C. Kiesling , D. Y. Kim , J.-Y. Kim , K.-H. Kim , K. Kinoshita , P. Kodyš , T. Koga , S. Kohani , K. Kojima , A. Korobov , S. Korpar , E. Kovalenko , R. Kowalewski , P. Križan , P. Krokovny , K. Kumara , T. Kunigo , A. Kuzmin , Y.-J. Kwon , K. Lalwani , T. Lam , J. S. Lange , T. S. Lau , M. Laurenza , R. Leboucher , F. R. Le Diberder , M. J. Lee , C. Lemettais , P. Leo , H.-J. Li , L. K. Li , Q. M. Li , W. Z. Li , Y. Li , Y. B. Li , Y. P. Liao , J. Libby , J. Lin , S. Lin , V. Lisovskyi , M. H. Liu , Q. Y. Liu , Y. Liu , Z. Liu , D. Liventsev , S. Longo , C. Lyu , Y. Ma , C. Madaan , M. Maggiora , S. P. Maharana , R. Maiti , G. Mancinelli , R. Manfredi , E. Manoni , M. Mantovano , D. Marcantonio , S. Marcello , C. Marinas , C. Martellini , A. Martens , T. Martinov , L. Massaccesi , M. Masuda , S. K. Maurya , M. Maushart , J. A. McKenna , F. Meier , D. Meleshko , M. Merola , C. Miller , M. Mirra , S. Mitra , K. Miyabayashi , R. Mizuk , G. B. Mohanty , S. Moneta , H.-G. Moser , M. Nakao , H. Nakazawa , Y. Nakazawa , M. Naruki , Z. Natkaniec , A. Natochii , M. Nayak , M. Neu , S. Nishida , S. Ogawa , R. Okubo , H. Ono , E. R. Oxford , G. Pakhlova , S. Pardi , K. Parham , H. Park , J. Park , K. Park , S.-H. Park , A. Passeri , S. Patra , R. Pestotnik , L. E. Piilonen , P. L. M. Podesta-Lerma , T. Podobnik , A. Prakash , C. Praz , S. Prell , E. Prencipe , M. T. Prim , S. Privalov , H. Purwar , P. Rados , G. Raeuber , S. Raiz , V. Raj , K. Ravindran , J. U. Rehman , M. Reif , S. Reiter , M. Remnev , L. Reuter , D. Ricalde Herrmann , I. Ripp-Baudot , G. Rizzo , J. M. Roney , A. Rostomyan , N. Rout , L. Salutari , D. A. Sanders , S. Sandilya , L. Santelj , V. Savinov , B. Scavino , C. Schmitt , J. Schmitz , S. Schneider , M. Schnepf , C. Schwanda , A. J. Schwartz , Y. Seino , A. Selce , K. Senyo , J. Serrano , M. E. Sevior , C. Sfienti , W. Shan , X. D. Shi , T. Shillington , J.-G. Shiu , D. Shtol , B. Shwartz , A. Sibidanov , F. Simon , J. Skorupa , R. J. Sobie , M. Sobotzik , A. Soffer , A. Sokolov , E. Solovieva , S. Spataro , B. Spruck , M. Starič , P. Stavroulakis , S. Stefkova , R. Stroili , Y. Sue , M. Sumihama , N. Suwonjandee , H. Svidras , M. Takizawa , K. Tanida , F. Tenchini , F. Testa , O. Tittel , R. Tiwary , E. Torassa , K. Trabelsi , F. F. Trantou , I. Tsaklidis , M. Uchida , I. Ueda , T. Uglov , K. Unger , Y. Unno , K. Uno , S. Uno , Y. Ushiroda , R. van Tonder , K. E. Varvell , M. Veronesi , A. Vinokurova , V. S. Vismaya , L. Vitale , R. Volpe , A. Vossen , S. Wallner , M.-Z. Wang , A. Warburton , M. Watanabe , S. Watanuki , C. Wessel , E. Won , B. D. Yabsley , S. Yamada , W. Yan , S. B. Yang , J. Yelton , J. H. Yin , K. Yoshihara , J. Yuan , Y. Yusa , L. Zani , M. Zeyrek , B. Zhang , V. Zhilich , J. S. Zhou , Q. D. Zhou , L. Zhu , and R. Žlebčík (Belle II Collaboration)

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Phys. Rev. D 112, 012006 – Published 8 July, 2025

DOI: https://doi.org/10.1103/vg9c-xvdc

Abstract

We measure the time-integrated $C P$ asymmetry, $A_{C P}$ , in $D^{0} \to π^{0} π^{0}$ 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 $428 {fb}^{- 1}$ . 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 samples of $D^{0} \to K^{-} π^{+}$ decays, with or without an associated pion from a $D^{* +}$ decay, are used to correct for detection asymmetries. The result, $A_{C P} (D^{0} \to π^{0} π^{0}) = (0.30 \pm 0.72 \pm 0.20) %$ , where the first uncertainty is statistical and the second systematic, is consistent with $C P$ symmetry.

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References (48)

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Phys. Rev. D 112, 012006– Published 8 July, 2025

Vol. 112, Iss. 1 — 1 July 2025

Received 7 May 2025
Accepted 25 June 2025

DOI: https://doi.org/10.1103/vg9c-xvdc

Published 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.

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Measurement of the time-integrated $C P$ asymmetry in $D^{0} \to π^{0} π^{0}$ decays at Belle II

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Measurement of the time-integrated CP asymmetry in D0→π0π0 decays at Belle II

Abstract

Physics Subject Headings (PhySH)

Article Text

References (48)

Measurement of the time-integrated $C P$ asymmetry in $D^{0} \to π^{0} π^{0}$ decays at Belle II