Measurement of time-dependent CP asymmetries in decays at Belle and Belle II

The Belle and Belle II collaboration

doi:10.1007/JHEP01(2026)134

Measurement of time-dependent CP asymmetries in decays at Belle and Belle II

The Belle and Belle II collaboration

Chair of Physics I

Research output: Contribution to journal › Article › peer-review

Abstract

We present a measurement of the time-dependent CP asymmetry in decays using a data set of 365 fb⁻¹ recorded by the Belle II experiment and the final data set of 711 fb⁻¹ recorded by the Belle experiment at the Υ(4S) resonance. The direct and mixing-induced time-dependent CP violation parameters C and S are determined along with two additional quantities, S⁺ and S⁻, defined in the two halves of the plane. The measured values are C = −0.17 ± 0.09 ± 0.04, S = −0.29 ± 0.11 ± 0.05, S⁺ = −0.57 ± 0.23 ± 0.10 and S⁻ = 0.31 ± 0.24 ± 0.05, where the first uncertainty is statistical and the second systematic.

Original language	English
Article number	134
Journal	Journal of High Energy Physics
Volume	2026
Issue number	1
DOIs	https://doi.org/10.1007/JHEP01(2026)134
State	Published - Jan 2026

Keywords

B Physics
CP Violation
Flavour Changing Neutral Currents
e-e Experiments

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10.1007/JHEP01(2026)134

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@article{7e82f9a4700140178181a4d8c424f947,

title = "Measurement of time-dependent CP asymmetries in decays at Belle and Belle II",

abstract = "We present a measurement of the time-dependent CP asymmetry in decays using a data set of 365 fb−1 recorded by the Belle II experiment and the final data set of 711 fb−1 recorded by the Belle experiment at the Υ(4S) resonance. The direct and mixing-induced time-dependent CP violation parameters C and S are determined along with two additional quantities, S+ and S−, defined in the two halves of the plane. The measured values are C = −0.17 ± 0.09 ± 0.04, S = −0.29 ± 0.11 ± 0.05, S+ = −0.57 ± 0.23 ± 0.10 and S− = 0.31 ± 0.24 ± 0.05, where the first uncertainty is statistical and the second systematic.",

keywords = "B Physics, CP Violation, Flavour Changing Neutral Currents, e-e Experiments",

author = "\{The Belle and Belle II collaboration\} and M. Abumusabh and I. Adachi and L. Aggarwal and H. Ahmed and Y. Ahn and H. Aihara and N. Akopov and S. Alghamdi and M. Alhakami and K. Amos and \{Anh Ky\}, N. and Asner, \{D. M.\} and H. Atmacan and T. Aushev and R. Ayad and V. Babu and S. Bahinipati and P. Bambade and Sw Banerjee and M. Barrett and M. Bartl and J. Baudot and A. Beaubien and F. Becherer and J. Becker and Bennett, \{J. V.\} and V. Bertacchi and E. Bertholet and M. Bessner and S. Bettarini and V. Bhardwaj and B. Bhuyan and F. Bianchi and T. Bilka and D. Biswas and A. Bobrov and D. Bodrov and J. Borah and A. Boschetti and A. Bozek and M. Bra{\v c}ko and P. Branchini and Briere, \{R. A.\} and Browder, \{T. E.\} and A. Budano and S. Bussino and Q. Campagna and M. Campajola and G. Casarosa and S. Paul",

note = "Publisher Copyright: {\textcopyright} The Author(s) 2026.",

year = "2026",

month = jan,

doi = "10.1007/JHEP01(2026)134",

language = "English",

volume = "2026",

journal = "Journal of High Energy Physics",

issn = "1126-6708",

publisher = "Springer Verlag",

number = "1",

}

TY - JOUR

T1 - Measurement of time-dependent CP asymmetries in decays at Belle and Belle II

AU - The Belle and Belle II collaboration

AU - Abumusabh, M.

AU - Adachi, I.

AU - Aggarwal, L.

AU - Ahmed, H.

AU - Ahn, Y.

AU - Aihara, H.

AU - Akopov, N.

AU - Alghamdi, S.

AU - Alhakami, M.

AU - Amos, K.

AU - Anh Ky, N.

AU - Asner, D. M.

AU - Atmacan, H.

AU - Aushev, T.

AU - Ayad, R.

AU - Babu, V.

AU - Bahinipati, S.

AU - Bambade, P.

AU - Banerjee, Sw

AU - Barrett, M.

AU - Bartl, M.

AU - Baudot, J.

AU - Beaubien, A.

AU - Becherer, F.

AU - Becker, J.

AU - Bennett, J. V.

AU - Bertacchi, V.

AU - Bertholet, E.

AU - Bessner, M.

AU - Bettarini, S.

AU - Bhardwaj, V.

AU - Bhuyan, B.

AU - Bianchi, F.

AU - Bilka, T.

AU - Biswas, D.

AU - Bobrov, A.

AU - Bodrov, D.

AU - Borah, J.

AU - Boschetti, A.

AU - Bozek, A.

AU - Bračko, M.

AU - Branchini, P.

AU - Briere, R. A.

AU - Browder, T. E.

AU - Budano, A.

AU - Bussino, S.

AU - Campagna, Q.

AU - Campajola, M.

AU - Casarosa, G.

AU - Paul, S.

PY - 2026/1

Y1 - 2026/1

N2 - We present a measurement of the time-dependent CP asymmetry in decays using a data set of 365 fb−1 recorded by the Belle II experiment and the final data set of 711 fb−1 recorded by the Belle experiment at the Υ(4S) resonance. The direct and mixing-induced time-dependent CP violation parameters C and S are determined along with two additional quantities, S+ and S−, defined in the two halves of the plane. The measured values are C = −0.17 ± 0.09 ± 0.04, S = −0.29 ± 0.11 ± 0.05, S+ = −0.57 ± 0.23 ± 0.10 and S− = 0.31 ± 0.24 ± 0.05, where the first uncertainty is statistical and the second systematic.

AB - We present a measurement of the time-dependent CP asymmetry in decays using a data set of 365 fb−1 recorded by the Belle II experiment and the final data set of 711 fb−1 recorded by the Belle experiment at the Υ(4S) resonance. The direct and mixing-induced time-dependent CP violation parameters C and S are determined along with two additional quantities, S+ and S−, defined in the two halves of the plane. The measured values are C = −0.17 ± 0.09 ± 0.04, S = −0.29 ± 0.11 ± 0.05, S+ = −0.57 ± 0.23 ± 0.10 and S− = 0.31 ± 0.24 ± 0.05, where the first uncertainty is statistical and the second systematic.

KW - B Physics

KW - CP Violation

KW - Flavour Changing Neutral Currents

KW - e-e Experiments

UR - https://www.scopus.com/pages/publications/105030940840

U2 - 10.1007/JHEP01(2026)134

DO - 10.1007/JHEP01(2026)134

M3 - Article

AN - SCOPUS:105030940840

SN - 1126-6708

VL - 2026

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

IS - 1

M1 - 134

ER -

Measurement of time-dependent CP asymmetries in decays at Belle and Belle II

Abstract

Keywords

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