First Measurement of Time-Dependent C P Violation in the Flavor-Changing Neutral-Current Decay B 0 → K S 0 μ + μ −

Physical Review Letters 2026 Open access

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Authors: R. Aaij, A. S. W. Abdelmotteleb, Carlos Abellán Beteta, C. Abellán Beteta, T. Ackernley, A. A. Adefisoye, B. Adeva, M. Adinolfi, P. Adlarson, C. Agapopoulou, C. Aidala, Z. Ajaltouni
+88 more S. Akar, K. Carvalho Akiba, P. Albicocco, J. Albrecht, R. Aleksiejūnas, F. Alessio, P. Álvarez Cartelle, R. Amalric, S. Amato, S. Amato, Y. Amhis, L. An, L. Anderlini, M. Andersson, P. Andreola, M. Andreotti, Sergio Andres Estrada, Alessia Anelli, D. Ao, C. Arata, F. Archilli, Zaratsyan Areg, Matteo Argenton, S. Arguedas Cuendis, Lisa Arnone, A. Artamonov, M. Artuso, E. Aslanides, R. Ataíde Da Silva, M. Atzeni, B. Audurier, Juliette Authier, D. Bacher, I. Bachiller, S. Bachmann, Marie Bachmayer, John J Back, Z. B. Bai, P. Baladrón Rodríguez, V. Balagura, Alessandra Balboni, W. Baldini, Zachary Baldwin, Luca Balzani, Huirong Bao, J. Baptista de Souza Leite, C. Barbero Pretel, M. Barbetti, I. R. Barbosa, Roger John Barlow, Mikhail Barnyakov, S. Barsuk, W. Barter, W. Barter, B. Batsukh, B. Batsukh, Piera Battista, Ali Bavarchee, A. Bay, A. Beck, M. Becker, F. Bedeschi, I. Bediaga, Noah Albin Behling, S. Belin, Alberto Bellavista, K. Belous, I. Belov, I. Belyaev, G. Benane, G. Bencivenni, E. Ben-Haim, Alexander Berezhnoy, R. Bernet, A. Bertolin, F. Betti, J. Bex, Oleg Bezshyyko, Senjuti Bhattacharya, M. S. Bieker, N. V. Biesuz, Alice Biolchini, M. Birch, F. C. R. Bishop, A. Bitadze, A. Bizzeti, T. Blake, F. Blanc
DOI: 10.1103/nnt3-nyds
Cited by: 1
References: 66

Abstract

A flavor-tagged time-dependent analysis of B^{0}→K_{S}^{0}μ^{+}μ^{-} decays is performed across the full dimuon mass range excluding the J/ψ and ψ(2S) resonance regions. The analysis uses proton-proton collision data collected by the LHCb experiment in 2011-2018 at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb^{-1}. The CP violation parameters are determined to be C=-0.13±0.32±0.04, S=+0.82±0.29±0.05, where the first uncertainties are statistical and the second are systematic. The results are consistent with the standard model prediction. This is the first experimental study of time-dependent CP violation in b→sℓ^{+}ℓ^{-} processes.

Fields of Study & Subjects

Particle physics theoretical and experimental studies Quantum Chromodynamics and Particle Interactions Neutrino Physics Research

Publication details

Journal / source
Physical Review Letters
Publisher
American Physical Society (APS)
Volume
136
Issue
23
Pages
231904–231904
Publication date
14 May 2026
Language
EN