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Model-independent measurement of $D^{0} − {\bar{D}}^{0}$ mixing parameters in $D^{0} \to K_{S}^{0} π^{+} π^{-}$ decays at Belle and Belle II

I. Adachi , L. Aggarwal , H. Ahmed , H. Aihara , N. Akopov , A. Aloisio , N. Althubiti , N. Anh Ky , D. M. Asner et al. (Belle and Belle II Collaborations)

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 , J. V. Bennett , V. Bertacchi , M. Bertemes , E. Bertholet , M. Bessner , S. Bettarini , B. Bhuyan , D. Biswas , D. Bodrov , A. Bolz , A. Bondar , A. Boschetti , A. Bozek , M. Bračko , P. Branchini , R. A. Briere , T. E. Browder , A. Budano , S. Bussino , Q. Campagna , M. Campajola , G. Casarosa , C. Cecchi , P. Chang , R. Cheaib , P. Cheema , B. G. Cheon , K. Chilikin , K. Chirapatpimol , H.-E. Cho , K. Cho , S.-J. Cho , S.-K. Choi , S. Choudhury , J. Cochran , L. Corona , J. X. Cui , S. Das , E. De La Cruz-Burelo , S. A. De La Motte , G. De Pietro , R. de Sangro , M. Destefanis , A. Di Canto , F. Di Capua , J. Dingfelder , Z. Doležal , T. V. Dong , M. Dorigo , D. Dossett , G. Dujany , P. Ecker , D. Epifanov , J. Eppelt , P. Feichtinger , T. Ferber , T. Fillinger , C. Finck , G. Finocchiaro , A. Fodor , F. Forti , B. G. Fulsom , A. Gabrielli , E. Ganiev , M. Garcia-Hernandez , R. Garg , G. Gaudino , V. Gaur , A. Gaz , A. Gellrich , G. Ghevondyan , D. Ghosh , H. Ghumaryan , G. Giakoustidis , R. Giordano , A. Giri , P. Gironella Gironell , A. Glazov , B. Gobbo , R. Godang , P. Goldenzweig , G. Gong , W. Gradl , E. Graziani , D. Greenwald , Z. Gruberová , K. Gudkova , I. Haide , T. Hara , K. Hayasaka , H. Hayashii , S. Hazra , C. Hearty , M. T. Hedges , A. Heidelbach , I. Heredia de la Cruz , T. Higuchi , M. Hoek , M. Hohmann , R. Hoppe , C.-L. Hsu , T. Humair , T. Iijima , K. Inami , N. Ipsita , R. Itoh , M. Iwasaki , W. W. Jacobs , E.-J. Jang , Q. P. Ji , Y. Jin , A. Johnson , H. Junkerkalefeld , A. B. Kaliyar , J. Kandra , G. Karyan , F. Keil , C. Kiesling , C.-H. Kim , D. Y. Kim , J.-Y. Kim , K.-H. Kim , Y.-K. Kim , K. Kinoshita , P. Kodyš , T. Koga , S. Kohani , K. Kojima , A. Korobov , E. Kovalenko , R. Kowalewski , P. Križan , P. Krokovny , T. Kuhr , R. Kumar , K. Kumara , T. Kunigo , A. Kuzmin , Y.-J. Kwon , K. Lalwani , T. Lam , J. S. Lange , T. S. Lau , R. Leboucher , F. R. Le Diberder , M. J. Lee , C. Lemettais , P. Leo , C. Li , L. K. Li , Q. M. Li , W. Z. Li , Y. Li , Y. B. Li , J. Libby , M. H. Liu , Q. Y. Liu , Z. Q. Liu , D. Liventsev , S. Longo , T. Lueck , C. Lyu , C. Madaan , M. Maggiora , R. Maiti , G. Mancinelli , R. Manfredi , E. Manoni , M. Mantovano , S. Marcello , C. Marinas , C. Martellini , A. Martens , A. Martini , T. Martinov , L. Massaccesi , M. Masuda , D. Matvienko , S. K. Maurya , M. Maushart , J. A. McKenna , F. Meier , M. Merola , C. Miller , M. Mirra , S. Mitra , K. Miyabayashi , G. B. Mohanty , S. Mondal , S. Moneta , H.-G. Moser , R. Mussa , I. Nakamura , M. Nakao , H. Nakazawa , Y. Nakazawa , M. Naruki , Z. Natkaniec , A. Natochii , M. Nayak , G. Nazaryan , M. Neu , S. Nishida , S. Ogawa , H. Ono , E. R. Oxford , G. Pakhlova , S. Pardi , K. Parham , H. Park , J. Park , K. Park , S.-H. Park , B. Paschen , A. Passeri , S. Patra , T. K. Pedlar , R. Peschke , L. E. Piilonen , P. L. M. Podesta-Lerma , T. Podobnik , C. Praz , S. Prell , E. Prencipe , M. T. Prim , H. Purwar , S. Raiz , J. U. Rehman , M. Reif , S. Reiter , L. Reuter , D. Ricalde Herrmann , I. Ripp-Baudot , G. Rizzo , M. Roehrken , J. M. Roney , A. Rostomyan , N. Rout , D. A. Sanders , S. Sandilya , L. Santelj , V. Savinov , B. Scavino , C. Schwanda , A. J. Schwartz , Y. Seino , A. Selce , K. Senyo , J. Serrano , M. E. Sevior , C. Sfienti , W. Shan , C. P. Shen , X. D. Shi , T. Shillington , J.-G. Shiu , D. Shtol , 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 , M. Sumihama , K. Sumisawa , H. Svidras , M. Takizawa , K. Tanida , F. Tenchini , O. Tittel , R. Tiwary , E. Torassa , K. Trabelsi , M. Uchida , I. Ueda , T. Uglov , K. Unger , Y. Unno , K. Uno , S. Uno , P. Urquijo , S. E. Vahsen , R. van Tonder , K. E. Varvell , M. Veronesi , A. Vinokurova , V. S. Vismaya , L. Vitale , R. Volpe , M. Wakai , S. Wallner , M.-Z. Wang , A. Warburton , M. Watanabe , S. Watanuki , C. Wessel , B. D. Yabsley , S. Yamada , W. Yan , J. H. Yin , K. Yoshihara , J. Yuan , Z. Zhang , V. Zhilich , J. S. Zhou , Q. D. Zhou , L. Zhu , V. I. Zhukova , and R. Žlebčík (Belle and Belle II Collaborations)

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Phys. Rev. D 111, 112011 – Published 26 June, 2025

DOI: https://doi.org/10.1103/7p5s-f9qp

Abstract

We perform a model-independent measurement of the $D^{0} − {\bar{D}}^{0}$ mixing parameters using samples of $e^{+} e^{-}$ -collision data collected by the Belle and Belle II experiments that have integrated luminosities of $951 {fb}^{- 1}$ and $408 {fb}^{- 1}$ , respectively. Approximately $2.05 \times 10^{6}$ neutral $D$ mesons are reconstructed in the $D^{0} \to K_{S}^{0} π^{+} π^{-}$ channel, with the neutral $D$ flavor tagged by the charge of the pion in the $D^{* +} \to D^{0} π^{+}$ decay. Assuming charge-parity symmetry, the mixing parameters are measured to be $x = (4.0 \pm 1.7 \pm 0.4) \times 10^{- 3}$ and $y = (2.9 \pm 1.4 \pm 0.3) \times 10^{- 3}$ , where the first uncertainties are statistical and the second systematic. The results are consistent with previous determinations.

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Phys. Rev. D 111, 112011– Published 26 June, 2025

Vol. 111, Iss. 11 — 1 June 2025

Received 7 May 2025
Accepted 5 June 2025

DOI: https://doi.org/10.1103/7p5s-f9qp

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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Model-independent measurement of $D^{0} − {\bar{D}}^{0}$ mixing parameters in $D^{0} \to K_{S}^{0} π^{+} π^{-}$ decays at Belle and Belle II

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Model-independent measurement of D0−D¯0 mixing parameters in D0→KS0π+π− decays at Belle and Belle II

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Model-independent measurement of $D^{0} − {\bar{D}}^{0}$ mixing parameters in $D^{0} \to K_{S}^{0} π^{+} π^{-}$ decays at Belle and Belle II